FOREWORD
This manual includes procedures for diagnosis, maintenance and
adjustments, m inor service operations, and removal and installation
for com ponents of Chevrolet Light Duty Trucks. Procedures involv
ing disassembly and assembly of m ajor components for these vehi
cles are contained in the 1977 Chevrolet Passenger Car and Light
Duty Truck Overhaul Manual. W iring diagrams for 1977 trucks are
contained in a separate W iring Diagram Booklet.
The Section Index on the contents page enables the user to
quickly locate any desired section. At the beginning of each section
containing more than one major subject is a Table of Contents,
which gives the page num ber on which each major subject begins.
An Index is placed at the beginning of each m ajor subject w ithin the
section.
S um m aries of Special Tools, w hen required, and specifications
are found at the end of m ajor sections.
This manual should be kept in a handy place fo r ready reference. If
properly used, it w ill enable the technician to better serve the o w n
ers o f Chevrolet built vehicles.
All inform ation, illustrations and specifications contained in this
literature are based on the latest product inform ation available at
the tim e of publication approval. The right is reserved to make
changes at any tim e w ithout notice.
IMPORTANT SAFETY NOTICE
P r o p e r s e r v ic e and re p a ir is im p o rta n t to the safe, re lia b le o p e ra tio n
of
a ll
m otor
v e h ic le s .
The
s e r v ic e
p ro ce d u re s
re c o m m e n d e d
and
d e scrib e d in this s e r v ic e m anual a re e f f e c t iv e m ethods of p e rfo rm in g
s e r v ic e o p e ra tio n s. Som e of these s e r v ic e o p e ra tio n s re q u ire the use of
to o ls s p e c ia lly designed fo r the purpose. T h e s p e c ia l tools should be
used when and as reco m m e n d e d .
It is im p o rta n t to note th a t this m anu al c o n ta in s va rio u s W arn in g s, and
C a u tio n s w h ich should be c a r e f u lly read in o rd er to m in im iz e the risk
of perso n al in ju ry to s e r v ic e person nel or the p o s s ib ility th a t im p ro p e r
s e r v ic e
m eth od s w ill be fo llo w e d
re n d e r
it
W a rn in g s,
u n safe.
and
It
is
C a u tio n s
also
are
w h ich
im p o rta n t
not
m ay d am ag e the v e h ic le or
to
e x h a u s tiv e .
u nd erstan d
We
cou ld
th a t
not
these
possibly
kn ow , e v a lu a te and a d vise the s e r v ic e tra d e of a ll c o n c e iv a b le w ays in
w h ich s e r v ic e m ig h t be done or of the possible h azard ous co n seq u e n ce s
o f each
w a y . C o n se q u e n tly ,
we h ave not u n d e rta k e n an y such broad
e v a lu a tio n . A c c o rd in g ly , anyo ne who uses a s e r v ic e p ro c e d u re or tool
w h ich
is
not
reco m m e n d e d
by
the
m a n u fa c tu r e r
m ust
firs t
s a tis fy
h im s e lf th o ro u g h ly th a t n e ith e r his s a fe ty nor v e h ic le s a fe ty w ill be
je o p a rd iz e d by the s e r v ic e m eth od he s e le c ts .
1977
LIGHT DUTY
TRUCK
(SERIES 10-35)
CHASSIS SERVICE
MANUAL
CA U TIO N
This vehicle contains some parts dimensioned in the metric
system as well as in the customary system. Some fasteners
are metric and are very close in dimension to familiar cus
tomary fasteners in the inch system. It is important to note
that, during any vehicle maintenance procedures, replace
m ent fasteners must have the same measurements and
strength as those removed, whether metric or customary.
(Numbers on the heads of metric bolts and on surfaces of
metric nuts indicate their strength. Customary bolts use ra
dial lines for this purpose, while most customary nuts do not
have strength markings.) Mismatched or incorrect fasteners
can result in vehicle damage or malfunction, or possibly per
sonal injury. Therefore, fasteners removed from the vehicle
should be saved for re-use in the same locations whenever
possible. Where the fasteners are not satisfactory for re-use,
care should be taken to select a replacement that matches
the original. For information and assistance, see your au
thorized dealer.
SECTION
NAME
OA
GENERAL INFORMATION
OB
LUBRICATION
1A
HEATER
1B
MANUAL
AIR CONDITIONING
2A
FRAME
2B
BUMPERS
2C
SHEET METAL
2D
BODY
3A
FRONT ALIGNMENT
3B
STEERING
3C
FRONT SUSPENSION
3D
REAR SUSPENSION
3E
WHEELS AND TIRES
4A
PROPSHAFT
4B
DRIVE AXLE
4C
FOUR WHEEL DRIVE
BRAKES
6A
ENGINE MECHANICAL
6B
ENGINE COOLING
6C
FUEL SYSTEM
6D
ENGINE ELECTRICAL
6E
ENGINE EMISSION
6F
ENGINE EXHAUST
7A
AUTOMATIC
TRANSMISSION
7B
MANUAL TRANSMISSION
7C
CLUTCH
8
CHASSIS ELECTRICAL
ACCESSORIES
© 1976 G eneral M o to rs C o rp o ra tio n
P rinted in U.S.A.
SECTION OA
GENERAL INFORMATION
C O N TE N TS OF TH IS SEC TIO N
Truck Model Identification............................................. OA-1
Vehicle Identification N u m b e r and Rating Plate... OA-1
Engine N u m b e r ...................................................................OA-1
U nit and Serial N u m b e r L ocations............................OA-1
Service Parts Identification P la te ................................ 0A-3
Keys and Locks................................................................. 0A-3
T o w in g .................................................................................. 0A-3
T R U C K M O DEL ID E N T IF IC A T IO N
Axles
All 10-30 series models are identified by the model
system shown in the chart on the following page.
Basically the designation consists o f 7 characters, 2
letters followed by live numbers. The first letter indicates
a model and the second identifies the chassis type. The
first n u m b er designates the G V W range, the second and
third identify the cab-to-axle dimension or model type
and the last two identify the cab or body style.
C h ev ro le t B uilt
VEHICLE ID E N T IF IC A T IO N N U M B ER
A ND R A TIN G PLATE
A com bination vehicle identification num ber and
rating plate used on all models (fig. 0A-1) is located on
the left door lock pillar o f C-K-G models. On Forward
Control models, it is attached to the dash and toe panel.
The vehicle identification num b er stamped on the
plate decodes into the inform ation shown in Figure 0A-
• On 10 Series, the Code is stamped on Front of
Right Rear Axle Tube.
• On 20-30 Series, the Code is stamped on U pper
Surface of the Right Rear Axle Tube.
Dana Built
• On Front Axles, code is stamped on Front
Surface o f Left Axle Tube.
• On R ear Axles, code is stamped on Rear Surface
o f Right Axle Tube.
Transmissions
The engine num b er indicates m anufacturing plant,
m onth and day o f m anufacture, and transmission type.
A typical engine num b er would be F1210TFA, which
would breakdown thus:
F - M anufacturing Plant (F-Flint, T-Tonawanda)
12 - M onth o f M anufacture (December)
10 - Day o f M anufacture (tenth)
T - Truck
FA - Transmission and engine type
• On 3-Speed Transmissions (except Tremec), the
Unit N u m b er is located on Lower Left Side o f Case
Adjacent to Rear o f Cover.
• On Tremec Transmissions, Unit N u m b er is
located on U p p er Forward M ounting Flange o f Case.
• On 70 mm 4-Speed Transmissions, Unit N um ber
is stamped on U pper Center Front o f Case. On Borg
W arn er 4-Speeds, Unit N u m b er is located on Left Side
of Case Rearward o f Side Cover. Muncie 4-Speeds, Unit
N u m b e r is located on R ear Face o f Case below Retainer.
• On Turbo Hydra-Matic 350 Transmission, Unit
N u m b er is Located on Right Rear Vertical Surface of
Oil Pan.
• On the Turbo Hydra-Matic 400 Transmission,
Serial N u m b er is Located on the Light Blue Plate on the
Right Side of the Transmission.
U N IT AND SERIAL N U M B E R LO CATIO NS
Engines
2.
EN G IN E N U M B E R
For the convenience o f service technicians and
engineers when writing up certain business papers such
as W arran ty Reports. Product Inform ation Reports, or
reporting product failures in any way, the location of the
various unit num bers have been indicated. These unit
num bers and their prefix or suffix are necessary on these
papers for various reasons - such as accounting, followup on production, etc.
The prefixes on certain units identify the plant in
which the unit was m anufactured and thereby permits
proper follow-up of the plant involved to get corrections
m ade when necessary.
Always include the prefix in the number.
• 6-Cylinder Engine
at Right Hand Side of
Distributor.
• 8-Cylinder Engine
at Front, Right Hand Side
Unit N u m b er Located on Pad
Cylinder Block at Rear of
Unit N u m b e r Located on Pad
o f Cylinder Block.
Generators
G en erato r Unit Serial N u m b er is located on the
Drive End F ram e Below the Part N um ber.
Batteries
Battery Code N u m b er is Located on Cell Cover Top
o f Battery.
TRUCK MODEL IDENTIFICATION
c c 0703 + E63 + LG9
1. C = C h e vro le t; T = GM C Truck
2. C h assis Type_________________________
3. G V W R a n g e _________________________
4. CA Dimension/Model Type_
5. C a b or Body S ty le ___________
6. Body O rdering C o d e _______
7. Engine O rdering C o d e .
©
©
C A Dimension/Model Type
C hassis Type
C— C o n v e n t i o n a l 4 x 2
G — F o r w a r d C o n t ro l 4 x 2
(B ody-Fram e In te g ra l)
K— C o n v e n t i o n a l 4 x 4
(Four W h e e l Drive)
P—- F o r w a r d C o n tro l 4 x 2
( C o n v e n t i o n a I)
05-
B l a z e r , Jimmy,
S tep-Van, V a lu e Van
07- 4 2 " / P i c k u p , C h as s is -C a b
08- FC or M o t o r Ho m e
Chassis, S t e p - V a n , V a l u e
Van
09— 5 6 "/S u bu rb an,
C h a s s is - C a b , Pickup
6 0 " / F C Chassis, Chevy
V a n , V a n d u r a , S p o r tv a n ,
R a lly W a g o n ,
C h a s s is - C a b , S t e p - V a n ,
V a lu e Van
10
©
Series/GVW Range
1 — 4 8 0 0 to 7 3 0 0
1 1— M o t o r H o m e Chassis
1 3 — Chevy V a n , V a n d u r a ,
S p o r t v a n , Rally
W a g o n , C u ta w a y
Van , H i-C u b e Van
1 4 — 84"/F C or M otor Home
Chassis, C h a s s is -C a b ,
S te p-V a n , V a lu e Van
1 6 — C u ta w a y Van,
H i-C u b e Van
1 8 — M o t o r H o m e Chassis
2 — 6 4 0 0 to 8 4 0 0
3 — 6 4 0 0 to 14,500
©
Body Code
Z W 9 — Base Body
Z 5 8 — B l a z e r , Jimmy w / W h i t e
©
C a b or Body Style
0 3 — C o nventional C a b
( C -K mo dels);
C u ta w a y V an , H i-C ub e
V a n ( G models)
0 5 — C h ev y V a n , V a n d u r a
06 — Suburban/S portvan,
R a lly W a g o n with
P a n e l R e a r Doors
16 — B l a z e r , Jimmy
3 2 — M o t o r H o m e Chassis
4 2 — F o r w a r d Co n tro l
Chassis, S t e p - V a n ,
V a lu e Van
4 3 — Bonus C a b . C r e w C a b
Top
Z 5 9 — B l a z e r , Jim m y w / B la c k
Top
Z 6 4 — RV C u t a w a y V a n
E 3 1 — H i - C u b e V a n (1 O' Steel
96" W id e )
E 3 2 — S te p-V a n , V a lu e Van
( S t e e l)
E 3 3 — S te p -V a n , V a lu e Van
(A lu m in u m )
E 3 4 — H i - C u b e V a n (10 ' Steel
82" W id e)
E 3 6 — H i-C ub e Van ( 96" W id e
10' A lu m in u m )
E 3 8 — H i - C u b e V a n (1 2' Steel
96" W id e )
E 3 9 — H i-C u b e Van (9 6 " W id e
1 2' A lu m in u m )
E 5 5 — S u b u r b a n (w /E nd G a t e )
E 6 2 — S te p s id e ( F e n d e r s i d e )
Pickup
E 6 3 — Fle e ts ide ( W i d e S i d e )
Pickup
E 9 4 — B e a u v i l l e S p o r tv a n ,
R a lly STX
©
Engine Code
LD4— 2 5 0 Six
L25 — 2 9 2 Six
L G 9 —3 0 5 - 2 V 8
LS 9 — 3 5 0 - 4 V 8
LF4 — 4 0 0 - 4 V8
LF8— 4 5 4 -4 V8
MFD. BY GENERAL MOTORS CORPORATION
GVWRI
□
GAWR FRONT
GAWR REAR !
o
o
SERVICE
PARTS
IDENTIFICATION
V I N — VtHIClf IDENTIFICATION NUMBER
THE S P E CI A L EQUIPMENT L IS TED B E L O W HA S
T H I S V E H I C L E . F O R P R O P E R IDE N T I FIC AT IOh
______ P A R T S BE S U R E TO S P E CI FY THE A PP LI CA BLI
573
I
nccroiDT.AM
I OPTION I
NOTE:
VIN
CAMPER LOADING DATA
CWR
DIM A
DIM B
INFLATION DATA FOR TIRES FURNISHED WITH VEHICLE
FRONT I
~1
PRESSURE □
REAR I
1
PRESSURE □
Q
WARRANTY VOIDED IF LOADED IN EXCESS OF RATINGS □
SEE OWNERS MANUAL FOR OTHER LOADING AND INFLATION DATA
INSTALLED OK
REPLACEMEN'
rtON NUMBERS
IM P O R T A N T : R E TA IN THIS PLA T E A S A P E R M A N E N T RE C O R D
o
Fig. 0A-3-Service Parts Id e n tifica tio n Plate
Fig. 0A-1--Vehicle Id e n tifica tio n N um ber and Rating
wheelbase, and all Production options or Special
Equipment on the vehicle when it was shipped from the
factory including p a in t inform ation. A L W A Y S REFER T O
Plate In fo rm a tion
T H IS IN F O R M A T IO N W H E N O R D E R IN G P A R T S .
E N G IN E
D E S IG N A T IO N
KEYS AND LOCKS
- V 8 - 4 5 4 - 4 - ( P M o d e ls )
— V 8 - 4 5 4 - 4 - ( C M o d e ls )
= V 8 -4 0 0 -4
Two separate identifiable keys (with different cross
section) are provided for the lock cylinders o f each
vehicle. The key codes are stamped on the "knock out"
plug in the key head.
• Key with square head (stamped " E ") - or ignition
SERIES
1 44 TO N
2 %
D IV IS IO N
3 1
C = CHEVRO LET
T= GMT \
CHASSIS TYPE
— M O D E L YEAR
7 = 1977 fo r a ll
S e rie s.
S E Q U E N T IA L N U M B E R
C - 2 W HEEL DR IV E
G = L IG H T DUTY
FO RW ARD CO NTRO L
K = 4 W HEEL DR IV E
L = LIG H T UTILITY
P = FO RW ARD CO NTRO L
BO D Y STYLE
2 -F o rw a rd C o n tro l
chassis o n ly
3 - C a b -c h a s s is
- Pickup and Van
4
5- Panel
ASSEM BLY
A -L a k e w o o d
B - B a ltim o r e
F -F lin t
J - J a n e s v ille
PLANT
V -G M
T r u c k -P o n tia c
S-St. Louis
U -L o r d s to w n
Z -F re m o n t
1 -O s h a w a
3 -G M A D D e tr o it
4 -S c a r b o r o u g h
6 - S u b u rb a n
7 - M o to r H o m e
8 - U tility
Fig. 0A-2-Vehicle Id e n tifica tio n N um ber
Starters
Starter Serial N u m b e r and Production Date are
Stam ped on O uter Case, Toward Rear.
SERVICE PARTS IDENTIFICATION PLATE
The Service Parts Identification Plate (fig. OA-3) is
provided on all Truck models. On most series it will be
located on the inside o f the glove box door, or, on
Forward Control series, it will be located on an inner
body panel. The plate lists the vehicle serial number,
switch only.
• Key with oval head (stamped " H " ) - or all other
locks.
TOWING
Proper lifting or towing equipm ent is necessary to
prevent dam age to the vehicle during any towing
operation. State (Provincial in C anada) and local laws
applicable to vehicles in tow must be followed.
All Except Four W h e e l D riv e Tru cks
Norm ally this vehicle may be towed on all four
wheels, at speeds o f less than 35 MPH, for distances up
to 50 miles, provided the driveline, axle and transmis
sion, and steering system are otherwise normally
operable. Use only towing e q u ip m e n t specifically
designed for this purpose, following the instructions of
the equipm ent m anufacturer. A separate safety chain
system must be used. For such towing the steering must
be locked, transmission in neutral and park in g brake
released. A ttachm ents must be m ade to m ain structural
m em bers o f the vehicle. Do not attach to bumpers or
associated brackets. R em em ber that power brake and
power steering assists will not be available when engine
is inoperative.
The rear wheels must be raised off the ground or the
drive shaft disconnected when the transmission is not
operating properly or when a speed o f 35 MPH or
distance of 50 miles will be exceeded.
C A U T IO N : I f a truck is towed on its front
wheels only, the steering wheel must be secured
with the wheels in a straight ahead position.
TIPS FOR T O W I N G F O U R W H E E L D R I V E V E H I C L E S
FRONT WHEELS OFF THE G R O U N D
FULL TIME ( 4 X 4 )
P A R T T I M E (4 X 4)
A U T O M A T I C T R A N S M I S S IO N
M A N U A L T R A N S M IS S IO N
1.
2.
3.
4.
T R A N S F E R C A S E IN N E U T R A L
T R A N S M I S S I O N IN P A R K
M A X I M U M S P E E D 3 5 MPH
M A X IM U M D IS T A N C E 50 M IL E S
N O T E : F o r distances o v e r 5 0 miles, d i s c o n n e c t rear p r o p s h a f t at
rear axle c a r r ie r an d secure in safe p o s i ti o n .
1. T R A N S F E R C A S E IN 2 H
2. T R A N S M I S S I O N IN N E U T R A L
3. M A X I M U M S P E E D 3 5 M PH
4. M A X I M U M D I S T A N C E 5 0 M I L E S
N O T E : F o r dis tances o ver 5 0 miles, d is c o n n e c t the rear p r o p s h a f t
at rear ax le c a r r ie r and secure in safe p o s i ti o n .
REAR WHEELS OFF THE GRO U ND
C A U T IO N :
W h e n t o w i n g a v e h ic le in t h is p o s it io n , th e s te e r in g w h e e l s h o u ld be s e c u re d t o k e e p th e f r o n t w h e e ls in a s t r a ig h t a h e a d p o s it io n .
P A R T T I M E (4 X 4)
F U L L T I M E (4 X 4)
1.
2.
3.
4.
T R A N S F E R C A S E IN N E U T R A L
T R A N S M I S S I O N IN P A R K
M A X I M U M SPEED 35 MPH
M A X IM U M D IS T A N C E 50 M IL E S
N O T E : F o r distances ovei 5 0 miles, d i s c o n n e c t f r o n t p r o p s h a f t at
f r o n t ax le c a rr ie r a nd secuie in safe p o s i t i o n .
1.
2.
3.
4.
T R A N S F E R C A S E IN 2 H
T R A N S M I S S I O N IN N E U T R A L
M A X I M U M S P E E D 3 5 MPH
M A X I M U M D IS T A N C E 50 M IL E S
NOTE:
For distances over 5 0 miles, d is c o n n e c t the f r o n t p r o p s h a f t
at f r o n t axle c a r r ie r and secure in safe p o s i ti o n .
ALL FOUR WHEELS ON G R O U N D
F U L L T I M E ( 4 X 4)
P A R T T I M E (4 X 4)
1. T R A N S F E R C A S E IN N E U T R A L
2. T R A N S M I S S I O N IN P A R K
N O T E : D o n o t exceed speed as per S tat e laws f o r t o w i n g vehicles.
1.
2.
3.
4.
T R A N S F E R C A S E IN 2 H
T R A N S M I S S I O N IN N E U T R A L
M A X I M U M SP E E D 3 5 M PH
M A X IM U M D IS T A N C E 50 M IL E S
N O T E : For speeds or distances greater than above, b o t h p r o p s h a ft s
m u s t be d i s c o n n e c t e d at th e axle c a r r ie r end an d secured in a safe
p o s i ti o n . It is r e c o m m e n d e d t h a t b o t h p r o p s h a ft s be re m o v e d and
st o re d in the ve hicle.
N O T E : Do n o t excee d speeds as per State laws f o r t o w i n g vehicles.
Keyliner Towing Chart OA-2
F our W h e e l D riv e Tru cks
It is recom m ended that the truck be towed with the
fron t wheels off the ground. T he truck can be towed,
however, with the rear wheels off the ground if there is
d a m ag e in the rear wheel area. Refer to Chart on "Tips
for Towing Four Wheel Drive Vehicles".
LOADED— M A X IM U M GVW R: 6200-LBS.
FRONT GAWR: 3250 LBS.
REAR GAWR: 3582 LBS.
STEEL T U B IN G R E P LACEM ENT
In the event that replacem ent o f steel tubing is
required on brake line, fuel line, evaporative emission,
and transmission cooling lines, only the recom m ended
steel replacem ent tubing should be used.
Only special steel tubing should be used to replace
brake lines. T hat is, a double layer and brazed steel
tubing m eeting G.M . Specification 123M. Further, any
oth e r steel tubing should be replaced only with the
released steel tubing or its equivalent. U n der no
co ndition should copper or alum inum tubing be used to
replace steel tubing. Those materials do not have
satisfactory fatigue durability to withstand normal
vehicle vibrations.
All steel tubing should be flared using the upset
(double lap) flare method.
VEH IC LE LO ADING
Vehicle loading must be controlled so weights do not
exceed the numbers shown on the Vehicle Identification
* F ro n t C u rb
2261
lb s .
* R e a r C u rb
Pass. L o a d
1 5 4 9 lb s .
R ear C a rg o &
F ro n t C a r g o &
4 5 0 lb s .
2711
Pass. L o a d
1 9 4 0 lb s .
3 4 8 9 lb s .
lb s .
TOTAL W EIGHT AT GROUND: 6200 lbs.
* C u r b w e ig h t e q u a ls th e w e ig h t o f th e
v e h ic le
w it h o u t d r iv e r ,
p a s s e n g e r o r c a r g o , b u t in c lu d i n g f u e l a n d c o o la n t .
Fig. 0A-4--Typical Vehicle Loaded Condition
N u m b e r and Rating Plate for the vehicle.
A typical example o f a truck in a loaded condition is
shown in Figure OA-4. N ote that the axle or GVW
capabilities are not exceeded.
SECTION OB
LUBRICATION
INDEX
M aintenance S c he d ule......................................................
E n g in e .....................................................................................
Oil and Filter R e c om m end ation s..............................
Drive B e lts.........................................................................
Positive Crankcase Ventilation (P.C.V.)..................
Air Injection Reactor System (A .l.R .)....................
Controlled Combustion System (C.C.S.).................
E vaporation Control System (E.C.S.)......................
Early Fuel Evaporation (E.F.E.) S ystem ................
Air C le a n e r ........................................................................
Fuel F ilt e r ..........................................................................
Accelerator L in k a g e ........................................................
Automatic Transm ission..................................................
M an u al T ra n s m is s io n .......................................................
Transm ission Shift L in k ag e...........................................
Clutch......................................................................................
OB-1
OB-1
OB-l
OB-2
OB-2
OB-3
OB-3
OB-3
OB-3
OB-3
OB-3
OB-3
OB-3
OB-4
OB-4
OB-4
R ear A x le ...................................................................
Propeller Shaft Slip Joints...................................
Universal J o i n t s ........................................................
Wheel B earin g s.........................................................
Brake Master C ylinder..........................................
Brake and Clutch Pedal Springs........................
Parking B rake............................................................
S te e r in g ........................................................................
Hood Latch and Hood H inge.............................
Body L u b ric a tio n .....................................................
Speedometer A d a p t e r .............................................
Complete M aintenance Schedule........................
Recommended Fluids L u b rican ts.......................
Lubrication D i a g r a m s ............................................
Conventional and Forward Control Models
1/2 Ton G M o d e ls...............................................
M A IN T E N A N C E SCHEDULE
ENG INE
A separate m aintenance folder has been provided
with each vehicle which contains a complete schedule
and brie f explanation of the safety, emission control,
lubrication and general m aintenance it requires. The
m aintenance folder inform ation is supplemented by this
section o f this manual, as well as the separate vehicle
and emissions w arranty booklet also furnished with each
vehicle. Read all three publicatio n s for a full
understanding o f vehicle m aintenance requirements.
Oil and Filter Recom m endations
The time or mileage intervals for lubrication and
m aintenance services outlined in this section are
intended as a general guide for establishing regular
m aintenance and lubrication periods for trucks with light
and heavy duty emission control systems (see chart).
Sustained heavy duty and high speed operation or
operation under adverse conditions may require more
frequent servicing.
LIGHT A N D H EA VY DUTY
EM ISSION C LA SS VEHICLES
L ig h t D u ty V ehicle
C lO -P ickup (exc. o v er 6000 lbs. GVW )
H eavy D u ty
C lO -P ickup (o v er 6000 lbs. G VW )
C IO -S uburban
C-10-Utility
C20-30 A ll models
A ll K m odels
A ll P m odels
OB-4
OB-4
OB-4
OB-4
OB-5
OB-5
OB-5
OB-5
OB-5
OB-6
OB-6
OB-6
OB-17
OB-18
OB-18
OB-19
The letter designation "S E " has been established to
correspond with the requirements o f G M 6136-M. "SE"
engine oils will be better quality and p erform better than
those identified with "S A " through " S D " designations
and are recommended for all light-duty gasoline trucks
regardless of model y ear and previous engine oil quality
recommendations.
O il C h an g e Period
•
Use only SE engine oil.
ENGINE OIL PERFORMANCE AND
ENGINE SERVICE CLASSIFICATION SYSTEM
L e tte r
Designation
GM S p e c ific a tio n
A p p lic a b le
M odel Year
SA
N one
None
SB
None
None
SC
G M 4745-M
1967 and
P rio r Years
SD
GM 6041 -M
(1 9 6 8 Release)
1 970 and
P rio r Years
SE
G M 6136-M
1972
1977 and
P rio r Years
•
L ig h t D uty Em ission V eh icles-C h an ge oil each
12 months or 7,500 miles. If more than 7,500 miles are
driven in a 12 month period, change oil each 7,500 miles.
•
H e a v y D uty E m ission V eh icles-C h an ge oil each 4
months or 6,000 miles. If more than 6,000 miles are
driven in a 4-m onth period, change oil each 6,000 miles.
• C hange oil each 3 months or 3,000 miles (2
m onths or 3.000 miles on Heavy Duty Emission
Vehicles), whichever occurs first, u nder the following
conditions:
—Driving in dusty conditions.
—Trailer pulling or c am per use.
—M otor Home use.
—Extensive idling.
—Short-trip operation at freezing temperatures
(engine not thoroughly warmed-up).
• O p eration in dust storms may require an
im m ediate oil change.
• F o r Light D uty Emission Vehicles replace the oil
filter at the first oil change, and every second oil change
thereafter, if mileage (7,500 miles is the determ ining
factor. If time (12 month) is the determ ining factor, then
c hange oil filter with every oil change. For Heavy Duty
Emission Vehicles, replace the oil filter at the first oil
ch an ge and every other oil change th ereafter using 6,000
miles or 12 m onth as the d eterm ining factors. AC oil
filters (or equivalent) provide excellent engine protection.
The above recom m endations apply to the first
c hange as well as subsequent oil changes. The oil change
interval for the engine is based on the use o f SE oils and
quality oil filters. Oil change intervals longer than those
listed above will seriously reduce engine life and may
affect the m a n u fa c tu rer’s obligation under the provisions
o f the New Vehicle W arranty.
A high quality SE oil was installed in the engine at
the factory. It is not necessary to change this factoryinstalled oil prior to the recom m ended normal change
period. However, check the oil level more frequently
d u rin g the break-in period since higher oil consumption
is norm al until the piston rings become seated.
N O T E : Non-detergent and other low quality oils
are specifically not recommended.
O il F ilter T y p e and C a p a c ity
• Throw aw ay type, 1 qu a rt U.S. measure, .75 quart
Imperial measure.
• 250 and 292 cu. in., AC Type PF-25. 305, 350,
400 and 454 cu. in., AC Type PF-35.
____________SOW 2 0 . 2 0 W 4 0
l
I
•
I
°F - 2 0
C -3 0
I
0
20
lo w
I
I
60
40
0
I
4 0 ..........
30. l o w
I
20
-1 0
? 0 w 50
I
10
80
20
100
30
40
Tem peratu re Range A ntic p a te d Before N ext O il C hange
NOTE: SAE 5 W -3 0 oils a re re co m m en d e d fo r all
seasons in vehicles n o rm a lly o p e rate d in C anada.
SAE 5 W -2 0
oils are n o t
re co m m en d e d
fo r
sustained hig h -sp eed d rivin g .
C h ec kin g O il Level
The engine oil should be m aintained at p rop er level.
The best time to check it is before operating the engine
or as the last step in a fuel stop. This will allow the oil
accumulation in the engine to drain back in the
crankcase. To check the level, remove the oil gauge rod
(dipstick), wipe it clean and reinsert it firmly for an
accurate reading. The oil gauge rod is m arked " F U L L "
and " A D D " . The oil level should be m aintained in the
safety margin, neither going above the " F U L L " line nor
below " A D D " line.
NOTE: The oil gauge rod is also m arked "Use SE
Engine Oil" as a rem inder to use only SE oils.
S u p p lem e n ta l E n gin e Oil A dditives
The regular use o f supplemental additives is
specifically not recom mended and will increase operating
costs. However, supplemental additives are available that
can effectively and economically solve certain specific
problems without causing other difficulties. For example,
if higher detergency is required to reduce varnish and
sludge deposits resulting from some unusual operational
difficulty, a thoroughly tested and approved additive "G .M . Super Engine Oil S upplem ent" (or equivalent) - is
available.
C ra n k c a s e C a p a c ity (D o es N o t Inclu d e F ilte r)
Drive Belts
• 292 L6 Engine; 5 quarts U.S. measure, 4.25
quarts Im perial measure.
• All other engines; 4 quarts U.S. measure, 3.25
q uarts Imperial measure.
Drive belts should be checked every 7,500 miles or
12 months (6,000 miles or 4 months Heavy Duty
Emission Vehicles) for proper tension. A loose belt will
affect water pu m p and generator operation.
R e c o m m e n d e d V isc o s ity
Positive Crankcase V entilation Valve (P.C.V.)
To help assure good cold and hot starting, as well as
m axim um engine life, fuel economy, and oil economy,
select the pro p e r oil viscosity for the tem perature range
anticipated from the following chart:
Every 30,000 miles (24,000 miles Heavy Duty
Emission Vehicles) or 24 months the valve should be
replaced. Connecting hoses, fittings and flame arrestor
should be cleaned. At every oil change the system should
be tested for pro per function and serviced, if necessary
(Also see m aintenance schedule at end o f this section.)
Air Injection Reactor System
(A .I.R .)--C ontrolled Combustion
1. On V8 engine, lubricate the ball stud at the
carburetor lever.
2. On L6 engine, lubricate the two ball studs at the
carburetor lever and lubricate the lever m ounting stud.
Do not lubricate the accelerator cable.
System (E.C.S.)
A U T O M A T IC T R A N S M IS S IO N
The Air Injection Reactor system should have the
drive belt inspected for w ear and tension every 24
m onths or 30,000 miles (4 m onths or 6,000 miles Heavy
Duty Emission Vehicles), whichever occurs first. In
addition, complete effectiveness o f either system, as well
as full power an d perform ance, depends upon idle speed,
ignition timing, and idle fuel mixture being set
according to specification. A quality tune-up which
includes these adjustm en ts should be p e rfo rm e d
periodically to assure norm al engine efficiency, operation
and perform ance.
Fluid Recom m endations
Evaporation Control S ystem (E.C.S.)
Every 30,000 miles (24,000 miles Heavy Duty
Emission Vehicles) or 24 months, (more often under
dusty conditions) the filter in the base o f the canister
must be replaced and the canister inspected.
Early Fuel Evaporation (E.F.E.) System
First 7,500 miles or 12 months check valve for
freedom o f operation. A binding condition must be
corrected. Check hoses for cracking, abrasion or
deterioration. Replace parts as necessary.
Air C leaner
CAUTION: Do not remove the engine air
cleaner unless temporary removal is necessary
during repair or maintenance o f the vehicle.
When the air cleaner is removed backfiring can
cause fire in the engine compartment.
N O T E: U n d e r prolonged dusty driving conditions,
it is recom m ended that these operations be
perfo rm e d more often.
Replace the engine air cleaner element under
norm al operatin g conditions every 30,000 miles (12,000
miles Heavy Duty Emission Vehicles except C alifornia
350-400 engines, replace every 24,000 miles).
Use automatic transmission fluids identified with the
mark D E X R O N ® II.
Check the fluid level at each engine oil change
period.
Automatic transmissions are frequently overfilled
because the fluid level is checked when the fluid is cold
and the dipstick indicates fluid should be added.
However, the low reading is norm al since the level will
rise as the fluid tem perature increases. A level change o f
over 3 /4 inch will occur as fluid tem perature rises from
60 F to 180°F.
Overfilling can cause foam ing and loss o f fluid
through the vent. Slippage and transmission failure can
result.
Fluid level too low can cause slipping, particularly,
when the transmission is cold or the vehicle is on a hill.
Check the transmission fluid level with engine
running, the shift lever in PARK and the vehicle level.
NOTE: If the vehicle has recently been operated
for an extended period at high speed o r in city
traffic in hot w eather or the vehicle is being used to
pull a trailer, an accurate fluid level cannot be
determ ined until the fluid has cooled down usually about 30 minutes after the vehicle has been
parked.
Remove the dipstick and touch the transmission end
o f the dipstick cautiously to find out if the fluid is cool,
w arm or hot.
W ipe it clean and re-insert until cap seats. Remove
dipstick and note readings.
• If the fluid feels cool, about room temperature
65 °F to 8 5 °F the level should be 1/8 to 3 /8 inch below
the ADD mark. The dipstick has two dimples below the
"A D D ' mark to show this range (fig. 0B-1).
• If it feels warm , the level should be close to the
ADD m ark (either above or below).
Fuel Filter
L ig h t D u ty Em ission V eh icles-R ep lace filter element
located in c arburetor inlet every 12 months or 15,000
miles whichever occurs first, or, if an in-line filter is also
used, replace both filters every 30,000 miles.
Heavy Duty Em ission Vehicles-R ep lace filter ele
ment in carburetor inlet every 12 months or 12,000 miles,
w hichever comes first, except C alifornia 350-400 engines
should be replaced every 24 months or 24,000 miles.
A c c ele rato r Linkage
Lubricate with engine oil every 15,000 miles (12,000
miles Heavy D uty Emission Vehicles) as follows:
(6 5
85 F .)
COOL
i
- r ^ ADD 1
\
____ I __ S
(1 8
? 9 C .)
HOT
HOT
'
______________
W ARM
NOTE: DO NOT OVERFILL. It takes only one pint to raise
level from ADD to FULL with a hot transmission.
• If it feels hot (cannot be held comfortably), the
level should be between the A D D and FU LL marks.
Drain Intervals
The transmission operating temperature resulting
from the type o f driving conditions under which your
vehicle is used is the m ain consideration in establishing
the proper frequency of transmission fluid changes.
C hange the transmission fluid and filter every
15,000 miles (12,000 miles Heavy Duty Emission
Vehicles), if the vehicle is usually driven under one or
more of the following conditions which are considered
severe transmission service:
• In heavy city traffic.
• W here the outside tem perature regularly reaches
90 °F.
• In very hilly or m ountainous areas.
• Frequent trailer pulling.
• Commercial uses, such as taxi, police car or
delivery service.
If you do not use your vehicle under any o f these
conditions, change the fluid and filter every 60,000 miles,
(24,000 miles Heavy Duty Emission Vehicles).
T o C h a n g e T urbo H y d ra -M a tic 4 0 0 and Turbo
H y d r a -M a tic 3 5 0 fluid , remove fluid from the transm is
sion sump, add approximately 7.5 pints U.S. measure
(6.25 pints Imperial measure) for the T urbo Hydra-M atic
400 and 2-1/2 qts. U.S. measure (2 qts. Imperial
measure) for the Turbo Hydra-M atic 350 o f fresh fluid,
to return level to proper mark on the dipstick.
Every 6 0 ,0 0 0 M ile s ( 2 4 ,0 0 0 m iles H e av y
E m ission V e h ic le s )- the T u rbo H ydra-M atic 400
Duty
linkage idler lever at fitting) every 7,500 miles or 12
months (6,000 miles or 4 months Heavy Duty Emission
Vehicles) with water resistant EP chassis lubricant which
meets G eneral Motors Specification G M 6 0 3 l-M.
REAR AXLES
S tan d ard
Every 12 months or 7,500 miles (4 months or 6,000
miles Heavy Duty Emission Vehicles), whichever occurs
first, check lubricant level and add lubricant, if
necessary, to fill to level o f filler plug hole. Use SAE 80W
or SAE 80W-90 GL-5 G e a r Lubricant. For those vehicles
normally operated in Canada, use SAE 80W GL-5 G ear
Lubricant.
Positive Locking or Positraction
Every 12 months or 7,500 miles (4 months or 6,000
miles Heavy Duty Emission Vehicles), whichever occurs
first, check lubricant level and add SAE 80W or SAE
80W-90 GL5 gear lubricant, if necessary, to fill to level
of filler plug hole.
PROPELLER SHAFT SLIP JO IN T S
Propeller shaft slip joints should be lubricated every 7,500
miles or 12 months (6,000 miles or 4 months Heavy Duty Emis
sion Vehicles) with water resistant EP chassis lubricant which
meets General Motors Specification GM 603l-M.
trans
mission sum p filter should be replaced.
3-A N D 4-SPEED M A N U A L T R A N M IS S IO N
UNIV E R S A L JO IN T S
Lubricant
All universal joints are the needle bearing type.
Lubricate those universal joints (depending on truck
model) equipped with lube fittings every 7,500 miles or
12 months (6,000 miles or 4 months Heavy Duty
Emission Vehicles) with water resistant EP chassis
lubricant which meets G eneral Motors Specification G M
60 3 l-M. More frequent lubes may be required on heavy
duty or "O ff the R o a d " operations.
Every 12 months or 7,500 miles (4 months or 6.000
miles Heavy Duty Emission Vehicles), whichever occurs
first, check lubricant level and add lubricant, if
necessary, to fill to level o f filler plug hole with SAE 80W
or SAE 80W-90 GL-5 G e a r Lubricant. If temperatures
below + 3 2 ' F are expected, use SAE 80W GL-5 G e a r
L ubricant only. For those vehicles normally operated in
C a na da , use SAE 80W GL-5 G e a r Lubricant only.
T R A N S M IS S IO N S H IF T LINKAG E
WHEEL BEARINGS
Fro nt
(M A N U A L AN D A U T O M A T IC )
Every 7,500 miles or 12 months (6,000 miles or 4
months Heavy Duty Emission Vehicles), lubricate shift
linkage and, on M anual transmission floor control, lever
contacting faces with w ater resistant EP chassis lubricant
which meets G eneral Motors Specification GM6031-M.
Clutch
The clutch pedal free travel should be checked at
regular intervals.
Lubricate the clutch cross-shaft at fitting (on Series
10 Forward Control models also lubricate the clutch
NOTE: Use wheel bearing lubricant G M Part No.
1051344 or equivalent which meets all require
ments o f G eneral Motors Specification G M 6031 M.
Due to the weight of the tire and wheel assembly it
is recom m ended that they be removed from hub before
lubricating bearings to prevent dam age to oil seal. Then
remove the front wheel hub to lubricate the bearings.
The bearings should be thoroughly cleaned before
repacking with lubricant.
Front wheels are equipped with tapered roller
bearings on all trucks. Wheel bearings should be
lubricated every 30,000 miles (24.000 miles Heavy Duty
Emission Vehicles) - lubricate every 12,000 miles in four
wheel drive trucks. Do not mix wheel bearing lubricants.
CAUTION: "Lo n g fibre" type greases should
not be used on roller bearing front wheels.
Rear
The rear wheel bearings receive their lubrication
from the rear axle. W hen installing bearings which have
been cleaned, prelube with wheel bearing grease.
BRAKE M A S TE R CYLINDER
Check m aster cylinder fluid level in both reservoirs
every 7,500 miles or 12 months (6,000 miles or 4 months
Heavy Duty Emission Vehicles). If the fluid is low in the
reservoir, it should be filled to a point about 1/4" from
the top rear o f each reservoir with Delco Supreme No.
11 Hydraulic Brake Fluid or equivalent.
BRAKE A N D CLUTCH PEDAL S PR IN G S
Lubricate brake and clutch pedal springs every 7,500
miles or 12 m onths (6,000 miles or 4 months Heavy Duty
Emission Vehicles) with engine oil for all models.
P A R K IN G BRAKE
Every 7,500 miles or 12 months (6,000 miles or 4
m onths Heavy Duty Emission Vehicles) clean and
lubricate all park in g brake pivot points with w ater
resistant EP chassis lubricant which meets G eneral
M otors Specification G M 6 0 3 1-M.
STE ER IN G
M anual S teering Gear
The steering gear is factory-filled with steering gear
lubricant. Seasonal change of this lubricant should not
be perfo rm e d and the housing should not be drained-no
lubrication is required for the life o f the steering gear.
Every 30,000 miles (36.000 miles Heavy Duty
Emission Vehicles), the gear should be inspected for seal
leakage (actual solid grease-not ju st oily film). If a seal is
replaced or the gear is overhauled, the gear housing
should be refilled with No. 1051052 (13 oz. container)
Steering G e a r Lubricant which meets G M Specification
G M 4673-M or its equivalent.
N O TE : Do not use EP Chassis Lube, which meets
G M Specification G M 6 0 3 1-M. to lubricate the
gear. D O N O T O VER-FILL the gear housing.
Pow er S teering System
Check the fluid level in the pum p reservoir at each
oil change period. Add G M Power Steering Fluid (G M
1050017 or equivalent) as necessary to bring level into
pro p e r range on filler cap indicator depending upon fluid
tem perature.
If at op eratin g tem perature (approximately 150 °Fhot to the touch), fluid should be between " H O T " and
" C O L D " marks.
If at room tem perature (approximately 70 F), fluid
should be between " A D D " and " C O L D " marks. Fluid
does not require periodic changing.
Linkage and Suspension
M aintain correct front end alignment to provide
easy steering, longer tire life, and driving stability.
Check control arm bushings and ball joints for wear.
Lubricate tie rods, upper and lower control arms,
and ball joints at fittings with water resistant EP chassis
lubricant which meets G eneral Motors Specification G M
6 0 3 1-M every 7,500 miles or 12 months (6,000 miles or 4
months Heavy Duty Emission Vehicles).
Lubricate every 3,000 miles or 3 months (2 months
Heavy Duty Emission Vehicles), whichever occurs first,
under the following conditions:
• Driving in dusty or muddy conditions.
• Extensive off-road use.
NOTE: Ball joints must be at + 1 0 GF. or more
before lubricating.
Keep spring to axle U bolts and shackle bolts
properly tightened (see Specifications Section for torque
recommendations). Check U bolt nuts after the first
1,000 miles o f operation if the U bolt or U bolt nuts are
changed in service.
HOOD LATCH AN D HOOD H IN G E
Every 7,500 miles or 12 months (6,000 miles or 4
months Heavy Duty Emission Vehicles), whichever
occurs first, lubricate hood latch assembly and hood
hinge assembly as follows:
1. Wipe off any accumulation of dirt or contaimination on latch parts.
2. Apply lubriplate or equivalent to latch pilot bolt
and latch locking plate.
3. Apply light engine oil to all pivot points in
release mechanism, as well as prim ary and secondary
latch mechanisms.
4. Lubricate hood hinges.
5.
M ake hood hinge a n d latch m echanism allowed to remain, these materials can result in
accelerated rusting and deterioration o f underbody
functional check to assure the assembly is working
components such as fuel lines, fram e and floor pan,
correctly.
exhaust system, etc. At least once each year, preferably
after a w in te r’s exposure these corrosive materials should
BODY L U B R IC A T IO N
be removed by flushing the underbody with plain water.
N o rm a l use of a truck causes metal-to-metal
Particular attention should be given to cleaning out those
movem ent at certain points in the cab or body. Noise,
areas where mud and other foreign materials collect.
w e a r and im p ro p er operation at these points will result
w hen a protective film o f lubricant is not provided.
For exposed surfaces, such as door checks, door lock
SPEEDO M ETER ADAPTER
bolts, lock striker plates, dovetail bu m per wedges, etc.
apply a thin film o f light engine oil.
On vehicles so equipped, lubricate ad ap ter at fitting
W h ere oil holes are provided in body parts a
with water resistant E P chassis grease which meets
dripless oil can be safely used, but any lubricant should
G eneral Motors Specification G M 6031-M every 7,500
be used sparingly, and after application all excess should
miles or 12 months (6,000 miles or 4 months Heavy Duty
be carefully wiped off.
Emission Vehicles).
The seat adjusters and seat track, ordinarily
overlooked, should be lubricated with w ater resistant EP
chassis lubricant which meets G eneral Motors Specifica
C O M PLETE VEHICLE M A IN T E N A N C E
tion G M 6 0 3 1-M.
SCHEDULE
T here are other points on bodies which may
occasionally require lubrication and which are difficult to
Three separate M aintenance Schedules are used for
service, window regulators and controls are confined in
the
1977
truck models. Two schedules (L-6 Schedule and
the space between the upholstery and the outside door
V-8
Schedule)
are used on the Light Duty Emission
panel. Easy access to the w orking parts m a y be m ade by
Vehicles
while
a
third schedule applies only to Heavy
removing the trim. Door weatherstrips and rubber hood
D uty Emission Vehicles.
bum pers should be lightly coated with a rubber
Presented on the following pages are the M ainte
lubricant.
nance Schedules, followed immediately by the schedule
explanation. Section " A " (Lubrication and General
U N D ER B O D Y M A IN T E N A N C E
M aintenance) and Section "B " (Safety M aintenance) are
Corrosive materials used for ice and snow removal
the same for both L-6 and V-8 Schedules; however,
and dust control accumulate on the underbody. If
Section " C " (Emission Control M aintenance) differs.
COMPLETE VEHICLE MAINTENANCE SCHEDULE I
Series 10 with V -8 Engine and Light D uty Emission System
T h is M a in te n a n c e S c h e d u le is a p p lic a b le to a ll C h e v r o le t e n g in e s w h ic h do no t c o n ta in th e le tte r “ U ” in th e e n g in e
id e n tific a tio n c o d e (w h ic h b e g in s w ith the n u m e ra l “ 7 ” ) s h o w n in th e u p p e r left c o r n e r o f th e u n d e r h o o d " V e h ic le
E m is s io n C o n tro l In fo r m a t io n " la b e l. (E x a m p le : 712Y2).
When To Perform Services
Months or Miles, Whichever Occurs First)
Item
No.
Services
S E C TIO N A —Lubrication and G eneral M aintenance
Every 12 Months or 7,500 Miles
See Explanation
A-1
Chassis Lubrication
A -2
•*Fluid Levels Check
A-3
‘ Engine Oil Change
A-4
*Oil Filter Change
A -5
Tire Rotation
A -6
Rear Axle Lube Change
Every 12 Months
A-7
Air Conditioning Check
Every 12 Months or 15,000 Miles
A -8
*Cooling System Check
Every 30,000 Miles
A -9
W heel Bearing Repack
A -10
Manual Steering G ear Check
A -1 1
Every 60,000 Miles
A -1 2
Clutch Cross Shaft Lubrication
*Auto. Trans. Fluid & Filter Change
S E C TIO N B —Safety M aintenance
Every 12 Months or 7,500 Miles
B-1
B-2
B -3
B-4
B-5
Every 12 Months or 15,000 Miles
B-6
Owner Safety Checks
Tire, W heel and Disc Brake Check
*Exhaust System Check
Suspension and Steering Check
Brake and Power Steering Check
*Drive Belt Check
B-7
Drum Brake and Parking Brake Check
B-8
Throttle Linkage Check
B-9
Underbody Flush & Check
S E C TIO N C —Emission Control M aintenance
At First 6 Months or 7,500 M ile s C-1
Thermo. Controlled Air Cleaner Check
Then at 18 M onth/22,500 Mile
C -2
Carburetor Choke Check
Intervals as Indicated in Log
C -3
Engine Idle Speed Adjustment
C -4
Every 12 Months or 15,000 Miles
Carburetor Mounting Torque
C -6
Vacuum Advance System, Hoses Check
C -7
Fuel Filter Replacem ent
C -8
C -9
Every 22,500 Miles
Every 24 Months or 30,000 Miles
Every 30,000 Miles
•Also A Safety Service
EFE System Check
C -5
PCV System Check
—PCV Valve & Filter Replacem ent
Spark Plug Wires Check
C -10
Idle S p eed-U p Solenoid Check
C -1 1
Spark Plug Replacem ent
C -1 2
Engine Timing Adjustment & Dist. Check
C -1 3
Carburetor Vacuum Break Adjustment
C -1 4
ECS System Check & Filter Replacem ent
C -1 5
Fuel Cap, T an k and Lines Check
C -1 6
Air Cleaner Element Replacem ent
*Also An Emission Control Service
(1)
(1) Applies to 305 C ID engine only
Your 1977 Chevrolet has been certified to m eet emission standards at either high or low altitude as
designated on the underhood Vehicle Emission Control Information Label. Vehicle driveability will be
optimum at the altitude designated on the Label but will be satisfactory at all altitudes.
T h e exhaust emission control systems used on 1977 model GM vehicles are not designed for conversion
to allow the vehicles to meet emission standards when operated at other than the altitude designated
on the Label. However, for some GM vehicles, conversion to meet emission standards at other th^p
the designated altitude is possible and is permitted by government regulations. Information regarding
conversion of your vehicle, if permitted, can be obtained from: (Customer Services Manager, Chevrolet
Central Office —Detroit, Michigan 48202). Include your Vehicle Identification Number in your request.
COMPLETE VEHICLE MAINTENANCE SCHEDULE
II
Series 10 w ith L-6 Engine and Light D u ty Emission System
This Maintenance Schedule is applicable to all Chevrolet engines which contain the letter “U” in the engine
identification code (which begins with the numeral “7”) shown in the upper left corner of the under hood “Vehicle
Emission Control Information” label. (Example: 712F1U).
When To Perform S e rv ice s
(Months or Miles, Whichever Occurs First)
Item
No.
S e rv ic e s
SECTION A —Lubrication and General Maintenance
Every 12 Months or 7,500 Miles
See Explanation
Every 12 Months
Every 12 Months or 15,000 Miles
Every 30,000 Miles
Every 60,000 Miles
A-1
A-2
A-3
A-4
A-5
A-6
A-7
A-8
A-9
A-10
A-11
A-12
Chassis Lubrication
•*Fluid Levels Check
♦Engine Oil Change
*Oil Filter Change
Tire Rotation
Rear Axle Lube Change
Air Conditioning Check
♦Cooling System Check
Wheel Bearing Repack
Manual Steering Gear Check
Clutch Cross Shaft Lubrication
*Auto. Trans. Fluid & Filter Change
SECTION B -S a fe ty Maintenance
Every 12 Months or 7,500 Miles
Every 12 Months or 15,000 Miles
B-1
B-2
B-3
B-4
B-5
B-6
B-7
B-8
B-9
Owner Safety Checks
Tire, Wheel and Disc Brake Check
♦Exhaust System Check
Suspension and Steering Check
Brake and Power Steering Check
♦Drive Belt Check
Drum Brake and Parking Brake Check
Throttle Linkage Check
Underbody Flush & Check
SECTION C —Emission Control Maintenance
See Explanation
At First 6 Months or 7,500 MilesThen at 24 Month/30,000 Mile
Intervals as Indicated in Log
C-1
C-2
C-3
C-4
C-5
C-6
C-7
Carburetor Choke Check
Thermo. Controlled Air Cleaner Check
Engine Idle Speed Adjustment
EFE System Check
Carburetor Mounting Torque
Vacuum Advance System, Hoses Check
Every 12 Months or 15,000 Miles
Fuel Filter Replacement
PCV System Check
C-8
—PCV Valve & Filter Replacement
Every 15,000 Miles
C-9
Spark Plug Wires Check
Every 30,000 Miles
C-10
Idle Stop Solenoid Check
C-11
Spark Plug Replacement
C-12
Engine Timing Adjustment & Dist. Check
C-13
Air Cleaner Element Replacement
Every 24 Months or 30,000 Miles
C-14
ECS System Check & Filter Replacement
C-15
Fuel Cap, Tank and Lines Check
•Also A Safety Service
*Also An Emission Control Service
Your 1977 Chevrolet has been certified to meet emission standards at either high or low altitude as
designated on the underhood Vehicle Emission Control Information Label. Vehicle driveability will be
optimum at the altitude designated on the Label but will be satisfactory at all altitudes.
The exhaust emission control systems used on 1977 model GM vehicles are not designed for conversion
to allow the vehicles to meet emission standards when operated at other than the altitude designated
on the Label. However, for some GM vehicles, conversion to meet emission standards at other than
the designated altitude is possible and is permitted by government regulations. Information regarding
conversion of your vehicle, if permitted, can be obtained from: (Customer Services Manager, Chevrolet
Central Office —Detroit, Michigan 48202). Include your Vehicle Identification Number in your request.
EXPLANATION OF COMPLETE
1977 VE H ICLE MAINTENANCE SCH EDU LE
SECTION A - L U B E & GENERAL MAINTENANCE
O B -9
ITEM
NO.
SERVICES
A-1 CHASSIS — Lubricate all grease fittings in front
suspension and steering linkage. Also lubricate
transmission shift linkage, hood latch, hood and
door hinges, and parking brake cable guides
and linkage, clutch linkage, propeller shaft slip
joint, universal joints and brake and clutch pedal
springs. Lubricate suspension and steering link
age every 3 months or 3,000 miles when operat
ing under dusty or muddy conditions and in
extensive off-road use.
Also see Item B-8.*
A-2 FLUID LEVELS-Check level of fluid in brake mas
ter cylinder*, power steering pump*, battery,
engine*, axle, transmission* and windshield
washer*. Check test indicator on battery (if so
equipped). Engine coolant should be checked
for proper level and freeze protection to at least
—20°F (—29°C) or to the lowest temperature
expected during the period of vehicle opera
tion.* Proper engine coolant also provides cor
rosion protection.
L U B R IC A T IO N
Presented below is a brief explanation of each of the
services listed in the preceding Complete Vehicle
Maintenance Schedule.
NORMAL VEHICLE USE—The owner’s maintenance
instructions contained in this maintenance schedule
are based on the assumption that your vehicle will
be used as designed:
• to carry passengers and cargo within the limita
tions indicated on the VIN plate affixed to the
edge of t'he driver’s door,
• on reasonable road surfaces within legal operat
ing limits,
• on a daily basis, as a general rule, for at least
several miles, and
• on unleaded fuel.
Unusual operating conditions will require more fre
quent vehicle maintenance as specified in the re
spective sections included below.
After each of the following maintenance services
is performed, it is recommended that you insert the
month, day and mileage in the maintenance sched
ule under the appropriate “Owner Service Log”
column.
Any significant fluid loss in any of these systems A-10 MANUAL STEERING GEAR-Check for seal leakage
around the pitman shaft and housing. If leakage
or units could mean that a malfunction is devel
oping and corrective action should be taken
is evident (solid grease oozing out—not just oily
film), it should be corrected immediately.
immediately. A low fluid level in the brake mas
ter cylinder front reservoir could also be an indi A-11 CLUTCH CROSS SHAFT - Lubricate clutch cross
cator that the disc brake pads need replacing.
shaft lever.
A-3 ENGINE OIL*—Change each 12 months or 7,500 A-12 AUTOMATIC TRANSMISSION FLUID*-Under normal
miles, whichever occurs first under normal driv
driving conditions, change the transmission fluid
ing conditions, or each 3 months or 3,000 miles
and service the sump filter every 60,000 miles.
when the vehicle is operated under the following
Under unusual conditions such as constant
conditions: (a) driving in dusty conditions, (b)
driving in heavy city traffic, trailer pulling, and
trailer pulling, (c) extensive idling or (d) shortcommercial applications, services should be
trip operation at freezing temperatures (with
performed at 15,000-mile intervals. See your
engine not thoroughly warmed-up). See your
Owner's and Driver’s Manual for further details
Owner’s and Driver’s Manual for additional de
on transmission care.
tails on engine oil.
A-4 ENGINE OIL FILTER * - Replace at the first oil
SECTION B - S A F E T Y MAINTENANCE
change and every other oil change thereafter, if
mileage (7,500 miles) is the determining factor.
NOTE: Items B-1 (a) thru (v) can be checked by
If time (12 months) is the determining factor,
the owner or driver, while items B-2 thru B-9
then change oil filter with every oil change.
should only be checked by a qualified mechan
A-5 TIRES—To equalize wear, rotate tires as indi
ic. It is particularly important that any safety
cated in Owner’s and Driver’s Manual and adjust
systems which may have been adversely af
tire pressures. Steel-belted radial tires should
fected in an accident be checked and repaired
be rotated at first 7,500 miles and then at every
as necessary before the vehicle is returned to
15,000 miles thereafter. Bias-belted tires should
use.
be rotated every 7,500 miles.
B-1 SAFETY CHECKS TO BE PERFORMED BY OWNER OR
A-6 REAR AXLE — Change lubricant every 7,500 miles
DRIVER—The following checks should be made
on all type rear axles or final drives when using
regularly during operation at no greater interval
vehicle to pull a trailer.
than 12 months or 7,500 miles, whichever oc
A-7 AIR CONDITIONING—Check condition of air condi
curs first, and more often when the need is in
tioning system hoses and refrigerant charge at
dicated. Any deficiencies should be brought to
sight glass (if so equipped). Replace hoses and/
the attention of your dealer or another service
or refrigerant if need is indicated.
outlet, as soon as possible, so the advice of a
qualified mechanic is available regarding the
A-8 COOLING SYSTEM*-At 12-month or 15,000-mile
need for repairs or replacements.
intervals, wash radiator cap and filler neck with
clean water, pressure test system and radiator
(a)STEERING COLUMN LOCK (EXCEPT VAN) cap for proper pressure holding capacity, tighten
Check for proper operation by attempting to
hose clamps and inspect condition of all cool
turn key to LOCK position in the various
ing and heater hoses. Replace hoses if checked,
transmission gear ranges when the vehicle
swollen or otherwise deteriorated. Clean exte
is stationary. Key should turn to LOCK
rior of radiator core and air conditioning con
position only when transmission control is
denser. Every 24 months or 30,000 miles, drain,
in PARK on automatic transmission mod
flush, and refill the cooling system with a new
els. Key should be removable only in LOCK
coolant solution as described in your Owner’s
position.
and Driver’s Manual.
(b) PARKING BRAKE—Check parking brake hold
A-9 WHEEL BEARINGS—Clean and repack front wheel
ing ability by parking on a fairly steep hill
bearings with a lubricant as specified in the
and restraining the vehicle with the parking
“Recommended Fluids & Lubricants” chart in
brake only.
this folder.
CAUTION: Before making checks (c) or (d) be
low, be sure to have a clear distance ahead and
‘Also a Safety Service
behind the vehicle, set the parking brake and
*Also an Emission Control Service
firmly apply the foot brake. Do not depress ac-
celerator pedal. Be prepared to turn off ignition
switch immediately if engine should start.
(c) STARTER SAFETY SWITCH (AUTOMATIC TRANS
MISSION VEHICLES)-Check starter safety
switch by attempting to start the engine with
the transmission in each of the driving gears.
The starter should operate only in the Park
(“P”) or Neutral (“N”) positions.
(d)STARTER SAFETY SWITCH (MANUAL TRANS
MISSION VEHICLES)—To check, place the shift
lever in neutral, depress the clutch halfway,
and attempt to start. The starter should op
erate only when clutch is fully depressed.
(e) TRANSMISSION SHIFT INDICATOR—Check to be
sure automatic transmission shift indicator
accurately indicates the shift position se
lected.
( f ) STEERING—Be alert to any changes in steer
ing action. The need for inspection or servic
ing may be indicated by increased effort to
turn the steering wheel, excessive free play
or unusual sounds when turning or parking.
(g) WHEEL ALIGNMENT AND BALANCE—In addition
to uneven or abnormal tire wear, the need for
wheel alignment service may be indicated by
a pull to the right or left when driving on a
straight and level road. The need for wheel
balancing is usually indicated by a vibration
of the steering wheel or seat while driving at
normal highway speeds.
(h) BRAKES—Be alert to illumination of the brake
warning light or changes in braking action,
such as repeated pulling to one side, unusual
sounds either when braking or between
brake applications, or increased brake pedal
travel. Any of these could indicate the need
for brake system inspection and/or service.
(i) EXHAUST SYSTEM—Be alert to any change in
the sound of the exhaust system or a smell of
fumes which may indicate a leak or overheat
condition requiring inspection and/or ser
vice. (See also Engine Exhaust Gas Caution
and Catalytic Converter information in Own
er’s and Driver's Manual and Item B-3 in this
folder.)
(j) WINDSHIELD WIPERS AND WASHERS - Check
operation of wipers, as well as condition and
alignment of wiper blades. Check amount
and direction of fluid sprayed by washers
during use.
(k) DEFROSTER—Check performance by moving
controls to “DEF” and noting amount of air
directed against the windshield.
(I) REARVIEW MIRRORS AND SUN VISORS-Check
that friction joints are properly adjusted so
mirrors and sun visors stay in the selected
position.
(m) HORN—Blow the horn occasionally to be sure
that it works. Check all button locations.
(n) LAP AND SHOULDER BELTS - Check belts,
buckles, latch plates, retractors, reminder
systems, guide loops, clips and anchors for
proper operation or damage. Check to make
certain that anchor mounting bolts are tight.
(o) SEAT ADJUSTERS—Check that seat adjusters
(and swivel seat lock, if present) securely en
gage by pushing forward and backward (and
twisting) whenever seat is adjusted.
(p) SEAT BACK LATCHES-Check to see that seat
back latches are holding by pulling forward
on the top of each folding seat back.
(q) LIGHTS AND BUZZERS - Check all instrument
panel illuminating and warning lights, seat
belt reminder light and buzzer (if so
equipped), interior lights, license plate
lights, side marker lights, headlamps, park
ing lamps, tail lamps, brake lights, turn sig
nals, backup lamps, and hazard warning
flashers. Have headlamp aim checked every
12 months or 15,000 miles, or more often if
light beams seem to be aimed improperly.
(r) GLASS—Check for broken, scratched, dirty or
damaged glass on vehicle that could obscure
vision or become an injury hazard.
(s) DOOR LATCHES — Check for positive closing,
latching and locking.
( t ) HOOD LATCHES — Check to make sure hood
closes firmly by lifting on the hood after each
closing. Check also for broken, damaged or
missing parts which might prevent secure
latching.
(u) FLUID LEAKS—Check for fuel, water, oil or
other fluid leaks by observing the ground be
neath the vehicle after it has been parked for
a while. (Water dripping from air condition
ing system after use is normal.) If gasoline
fumes or fluid are noticed at a n y tim e, the
cause should be determined and corrected
without delay because of the possibility of
fire.
(v) SPARE AND JACK—Check that spare tire as
sembly and jack equipment are securely
stowed at all times.
B-2 TIRES, WHEELS AND DISC BRAKES - Check disc.
brake pads for wear and surface condition of
rotors while wheels are removed during tire ro
tation (see Item A-5). Check tires for excessive
wear or damage. Make certain wheels are not
bent or cracked and that wheel nuts have been
tightened to torque value specified in Owner’s
and Driver’s Manual. Check tire inflation pres
sure (including spare tire) when tires are “cold”
at least monthly, or more often if daily visual in
spection indicates the need.
B-3 EXHAUST SYSTEM* — Check complete exhaust
system including catalytic converter and nearby
body areas for broken, damaged, missing or mispositioned parts, open seams, holes, loose con
nections or other deterioration which could per
mit exhaust fumes to seep into the passenger
compartment or cause a heat buildup in floor
pan. Any necessary corrections should be made
immediately. To help continue integrity, exhaust
system pipes and resonators rearward of the
muffler must be replaced whenever a new
muffler is installed. (Also see Item B-1 (i).
B-4 SUSPENSION AND STEERING—Check for damaged,
loose or missing parts, or parts showing visible
signs of excessive wear or lack of lubrication in
front and rear suspension and steering system.
Questionable parts noted should be replaced by
a qualified mechanic without delay.
B-5 BRAKES AND POWER STEERING—Check lines and
hoses for proper attachment, leaks, binding,
cracks, chafing, deterioration, etc. Any question
able parts noted should be replaced or repaired
immediately. When abrasion or wear is evident
on lines or hoses, the cause must be corrected.
B-6 ENGINE DRIVE BELTS*-Check belts driving fan,
AIR pump, generator, power steering pump and
air conditioning compressor for cracks, fraying,
wear and tension. Adjust or replace as neces
sary.
B-7 DRUM BRAKES AND PARKING BRAKE—(See Item B-2
for disc brake check.) Check drum brake linings
for wear or cracks and other internal brake com
ponents at each wheel (drums, wheel cylinders,
etc.). Parking brake adjustment also should
be checked whenever drum brake linings are
checked.
NOTE: More frequent brake checks should be
made if driving conditions and habits result in
frequent brake application.
B-8 THROTTLE LINKAGE — Lubricate as covered in
Owner’s and Driver’s Manual. Check for dam
aged or missing parts, interference or binding.
Any deficiencies should be corrected without
delay by a qualified mechanic.
f-
B-9 UNDERBODY—Corrosive material used for ice and
snow removal and dust control can accumulate
on the underbody. If allowed to remain, these
materials can result in accelerated rusting and
deterioration of underbody components such as
fuel lines, frame and floor pan, exhaust system,
etc. At least once each year, preferably after a
winter’s exposure, these corrosive materials
should be removed by flushing the underbody
with plain water. Particular attention should be
given to cleaning out those areas where mud
and other foreign materials collect.
SECTION C—EMISSION CONTROL MAINTENANCE
L-6 ENGINE
NOTE: Additional recommended maintenance
instructions relating to vehicle use, evidence of
maintenance, and service replacement parts are
included in the New Car Warranty Information
folder.
C-2 THERMOSTATICALLY CONTROLLED AIR CLEANER Inspect installation to make certain that all hoses
and ducts are connected and correctly installed.
Also check valve for proper operation.
C-5 CARBURETOR MOUNTING—At designated intervals
torque carburetor attaching bolts and/or nuts
C-7 FUEL FILTER—Replace filter in carburetor at des
ignated intervals or more frequently if clogged.
C-8 POSITIVE CRANKCASE VENTILATION SYSTEM (PCV)
—Check the PCV system for satisfactory oper
ation at 15,000-mile intervals, and clean filter.
Replace the PCV valve at 30,000-mile intervals
and blow out PCV valve hose with compressed
air. Replace deteriorated hoses.
The PCV filter (located in the air cleaner) should
be replaced whenever the air cleaner element
is replaced.
C-9 SPARK PLUG WIRES—Clean exterior of wires; re
move any evidence of corrosion on end termi
nals. Inspect spark plug wires for evidence of
checking, burning, or cracking of exterior insu
lation and tight fit at distributor cap and spark
plugs or other deterioration. If corrosion cannot
be removed or other conditions above are noted,
replace wire.
C-10 IDLE STOP SOLENOID—Check for proper operation.
An inoperative solenoid must be replaced.
C-11 SPARK PLUGS—Replace plugs at designated in
tervals with type specified in Owner’s and
Driver’s Manual.
C-12 TIMING AND DISTRIBUTOR CAP - Adjust ignition
timing following the specifications shown on
label under the hood. Also, carefully inspect the
interior and exterior of the distributor cap and
rotor for cracks, carbon tracking and terminal
corrosion. Clean or replace as necessary.
C-13 AIR CLEANER ELEMENT— Replace the engine air
cleaner element at designated intervals. The
PCV filter should be replaced at the same inter
val. Operation of vehicle in dusty areas will
necessitate more frequent replacement. Your
dealer can be of assistance in determining the
proper replacement frequency for the condi
tions under which you operate your vehicle.
CAUTION: Do not operate the engine without
the air cleaner unless temporary removal is
necessary during repair or maintenance of the
vehicle. When the air cleaner is removed, back
firing can cause fire in the engine compartment.
SECTION C — EMISSION CONTROL MAINTENANCE
V-8 ENGINE
NOTE: Additional recommended maintenance
instructions relating to vehicle use, evidence of
maintenance, and service replacement parts are
included in the New Vehicle Warranty Informa
tion folder.
C-1 THERMOSTATICALLY CONTROLLED AIR CLEANER Inspect installation to make certain that all
hoses and ducts are connected and correctly in
stalled. Also check valve for proper operation.
C-2 CARBURETOR CHOKE AND HOSES - Check choke
mechanism and vacuum break for proper oper
ation. Any binding condition which may have de
veloped due to petroleum gum formation on
the choke shaft or from damage should be
corrected. Check carburetor choke hoses for
proper connection, cracking, abrasion or deteri
oration and correct or replace as necessary.
C-3 ENGINE IDLE SPEED - Adjust engine idle speed
accurately (following the specifications shown
on the label under the hood). Adjustments must
be made with test equipment known to be accu
rate.
C-4 EARLY FUEL EVAPORATION (EFE) SYSTEM-Check
valve for proper operation. A binding condition
must be corrected. Check thermal vacuum
switch for proper operation. Check hoses for
cracking, abrasion or deterioration. Replace
parts as necessary.
C-5 CARBURETOR MOUNTING—At designated intervals,
0 B -1 1
C-3 ENGINE IDLE SPEED - Adjust engine idle speed
accurately (following the specifications shown
on the label under the hood). Adjustments must
be made with test equipment known to be
accurate.
C-4 EARLY FUEL EVAPORATION (EFE) SYSTEM-Check
valve for proper operation. A binding condition
must be corrected. Check thermal vacuum
switch for proper operation. Check hoses for
cracking, abrasion or deterioration. Replace
parts as necessary.
C-6 VACUUM ADVANCE SYSTEM AND HOSES-Check
system for proper operation and hoses for
proper connection, cracking, abrasion or deteri
oration. Replace parts as necessary.
C-14 EVAPORATOR CONTROL SYSTEM (ECS)-Check all
fuel and vapor lines and hoses for proper con
nections and correct routing as well as condi
tion. Remove canister and check for cracks or
damage. Replace damagedordeteriorated parts
as necessary. Replace filter in lower section of
canister.
C-15 FUEL CAP, FUEL LINES AND FUEL TANK 1. Inspect the fuel tank, cap and lines for dam
age which could cause leaks.
2. Remove fuel cap and inspect gasket for an
even imprint from the filler neck, and any indi
cations of physical damage.
3. Replace any damaged or deteriorated parts.
L U B R IC A T IO N
C-1 CARBURETOR CHOKE AND HOSES-Check choke
mechanism and vacuum break for proper oper
ation. Any binding condition which may have
developed due to petroleum gum formation on
the choke shaft or from damage should be cor
rected. Check carburetor choke hoses for
proper connection, cracking, abrasion or deteri
oration and correct or replace as necessary.
Check operation at 6 months or 7,500 miles, 24
months or 30,000 miles and every 12 months or
15,000 miles thereafter.
to compensate for compression of the gasket.
OB-12
SERVICE
MANUAL
nections and correct routing as well as condi
tion. Remove canister and check for cracks or
damage. Replace damaged or deteriorated parts
as necessary. Replace filter in lower section of
canister.
C-15 FUEL CAP, FUEL LINES AND FUEL TANK—
1. Inspect the fuel tank, cap and lines for dam
age which could cause leaks.
2. Remove fuel cap and inspect gasket for an
even imprint from the filler neck, and any indi
cations of physical damage.
3. Replace any damaged or deteriorated parts.
C-1G AIR CLEANER ELEMENT—Replace the engine air
cleaner element at designated intervals. Oper
ation of vehicle in dusty areas will necessitate
more frequent replacements. Your dealer can be
of assistance in determining the proper replace
ment frequency for the conditions under which
you operate your vehicle.
CAUTION: Do not operate the engine without
the air cleaner unless temporary removal is nec
essary during repair or maintenance of the
vehicle. When the air cleaner is removed, back
firing can cause fire in the engine compartment.
TRUCK
be removed or other conditions above are noted,
replace wire.
C-10 IDLE SPEED-UP SOLENOID—Check for proper oper
ation. An inoperative solenoid must be replaced.
C-11 SPARK PLUGS—Replace plugs at 22,500-mile in
tervals with type specified in Owner’s and
Driver's Manual.
C-12 TIMING AND DISTRIBUTOR CAP - Adjust ignition
timing following the specifications shown on
label under hood. Also, carefully inspect the in
terior and exterior of the distributor cap and
rotor for cracks, carbon tracking and terminal
corrosion. Clean or replace as necessary.
C-13CARBURETOR VACUUM BREAK ADJUSTMENT — In
spect vacuum break linkage for proper oper
ation. A binding condition must be corrected.
Check hoses for proper connection, cracking,
abrasion or deterioration. Replace parts as nececessary. Adjust vacuum break at specified in
tervals following procedure and specifications
found in appropriate service manual.
C-14 EVAPORATION CONTROL SYSTEM (ECS)-Check all
fuel and vapor lines and hoses for proper con
LIGHT
torque carburetor attaching bolts and/or nuts to
compensate for compression of the gasket.
C-6VACUUM ADVANCE SYSTEM AND HOSES - Check
system for proper operation and hoses for
proper connection, cracking, abrasion or deteri
oration. Replace as necessary.
C-7 FUEL FILTER—Replace filter in carburetor at des
ignated intervals or more frequently if clogged.
C-8 POSITIVE CRANKCASE VENTILATION SYSTEM (PCV)
—Check the PCV system for satisfactory oper
ation at 15,000-mile intervals, and clean filter.
Replace the PCV valve at 30,000-mile intervals
and blow out PCV valve hose with compressed
air. Replace deteriorated hoses.
The PCV filter (located in the air cleaner) should
be replaced whenever the air cleaner element
is replaced.
C-9 SPARK PLUG WIRES—Clean exterior of wires; re
move any evidence of corrosion on end termi
nals. Inspect spark plug wires for evidence of
checking, burning, or cracking of exterior insu
lation and tight fit at distributor cap and spark
plugs or other deterioration. If corrosion cannot
COMPLETE VEHICLE MAINTENAHCE SCHEDULE
Heavy Duty Emission System
When To P erfo rm S e r v ic e s
(Months or Miles, Whichever Occurs First)
Every 4 months or 6,000 miles
Every 6,000 miles
At 1st oil change-then every 2nd
Every 12,000 miles
Every 12 months or 12,000 miles
Every 24,000 miles
Every 36,000 miles
Every 4 months or 6,000 miles
Every 6,000 miles
Every 12 months or 12,000 miles
At 1st 4 months or 6,000 miles —
then at 12 month/12,000 mile
intervals
Every 12 months or 12,000 miles
Every 12,000 miles
Every 12 months or 12,000 miles
Every 24 months or
24,000 miles
Every 12,000 miles
Every 12 months or 12,000 miles
Item
No.
(For Details, See Numbered Paragraghs)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
Chassis Lubrication
•Fluid Levels
*Engine Oil
Air Conditioning System
Tire Rotation
*Engine Oil Filter
Rear Axle
Cooling System
Wheel Bearings**
Automatic Transmission
Manual Steering Gear
Owner Safety Checks
Tires and Wheels
Exhaust System
*Engine Drive Belts
Suspension and Steering
Brakes and Power Steering
Disc Brakes
Drum Brakes and Parking Brake
Throttle Linkage
Underbody
Carburetor Choke and Hoses (1)
Engine Idle Speed Adjustment (1)
Carburetor Mounting (1)
Thermostatically Controlled Air Cleaner (1)
Manifold Heat Valve (1)
Spark Plugs (2)
Engine Timing Adjust. & Distributor Check (2)
EGR System
Carburetor Fuel Inlet Filter (1)
Engine Idle Mixture (1)
Throttle Return Control (1)
Idle Stop Solenoid
PCV System
ECS System
Fuel Cap, Tank and Lines
Air Cleaner Element (2)
Spark Plug and Ignition Coil Wires (1)
S e r v ic e s
*Also an Emission Control Service
*Also a Safety Service
**On 4-Wheel Drive Vehicles, lubricate wheel bearings every 12,000 miles.
(1) All except California 350 CID & 400 CID engines which receive this service at 24 months
or 24,000 miles.
(2) All except California 350 CID & 400 CID engines which receive this service at 24,000 miles.
EXPLANATION OF COMPLETE
1977 VEH ICLE MAINTENANCE SCHEDULE
Presented below is a brief explanation of each of the
services listed in the preceding Complete Vehicle
Maintenance Schedule.
NORMAL VEHICLE USE—The owner’s maintenance
instructions contained in this maintenance schedule
are based on the assumption that your vehicle will
be used as designed:
• to carry passengers and cargo within the limita
tions indicated on the VIN plate,
• on reasonable road surfaces within legal operat
ing limits, and
• on a daily basis, as a general rule, for at least
several miles.
Unusual operating conditions will require more fre
quent vehicle maintenance as specified in the re
spective sections included below.
After each of the following maintenance services
is performed, it is recommended that you insert the
month, day and mileage in the maintenance sched
ule under the appropriate “Owner Service Log”
column.
LUBE & G ENERAL MAINTENANCE
ITEM
NO.
SERVICES
1 CHASSIS — Lubricate all grease fittings in front
suspension, steering linkage, and constant ve
locity universal joint. Also lubricate transmission
and transfer case shift linkage, hood latch, hood
and doorhinges, parking brake cable guides and
linkage, clutch linkage, propeller shaft slip joint,
universal joints, and brake and clutch pedal
springs. Lubricate suspension and steering link
age every 2 months or 3,000 miles when oper
ating under dusty or muddy conditions and in
extensive off-road use. See your Owner’s and
Driver’s Manual for additional services required
on four wheel drive models. Also see Item 20/
2 FLUID LEVELS—Check level of fluid in brake mas
ter cylinder*, power steering pump*, battery, en
gine, axles, transmission, transfer case and
windshield washer*. Check test indicator on bat
tery (if so equipped). Check coolant for proper
level regularly (daily if necessary, depending on
severity of service), and every 4 months or 6000
miles for freeze protection to at least —20°F
(—29°C) or to the lowest temperature expected
during the period of vehicle operation. Proper
‘ Also a Safety Service
‘ Also an Emission Control Service
engine coolant also provides corrosion protec
tion.
Any significant fluid loss in any of these systems
or units could mean that a malfunction is devel
oping and corrective action should be taken
immediately. On vehicles with disc brakes, a low
fluid level in the brake master cylinder front res
ervoir could also be an indicator that the disc
brake pads need replacing.
3 ENGINE OIL* — Change each 4 months or 6,000
miles, whichever occurs first, or each 2 months
or 3,000 miles when the vehicle is operated un
der the following conditions: (a) driving in dusty
conditions, (b) trailer pulling, (c) extensive idling
or (d) short-trip operation at freezing temper
atures (with engine not thoroughly warmed-up).
See Owner’s and Driver’s Manual for additional
details.
4 AIR CONDITIONING—Check condition of air condi
tioning system hoses and refrigerant charge at
sight glass (if so equipped). Replace hoses and/
or refrigerant if need is indicated.
5 TIRES—To equalize wear, rotate tires and adjust
tire pressures as indicated in Owner’s and
Driver’s Manual.
6 ENGINE OIL FILTER* —Replace at the first oil
change and every other oil change thereafter,
if mileage (6,000 miles) is the determining factor.
If time (4 months) is the determining factor, then
change oil filter with every oil change.
7 REAR AXLE—On 20 and 30 Series trucks, change
lubricant every 24,000 miles. Change lubricant
every 12,000 miles on all type rear axles under
severe operating conditions.
FRONT AXLE AND TRANSFER CASE-Check every
6,000 miles. See Owner’s and Driver’s Manual
for further information.
8 COOLING SYSTEM - At 12-month or 12,000-mile
intervals, wash radiator cap and filler neck with
clean water, pressure test system and radia
tor cap for proper pressure holding capacity,
tighten hose clamps and inspect condition of
all cooling and heater hoses. Replace hoses if
checked, swollen or otherwise deteriorated.
Clean exterior of radiator core and air condi
tioning condenser. Every 24 months or 24,000
miles, drain, flush, and refill the cooling system
with a new coolant solution as described in your
Owner’s and Driver's Manual.
9 WHEEL BEARINGS—Clean and repack front wheel
bearings with a lubricant as specified in the
“Recommended Fluids & Lubricants” chart in
this folder.
10 AUTOMATIC TRANSMISSION FLUID-Under normal
driving conditions, change the transmission
fluid and service the sump filter every 24,000
miles. Under unusual conditions such as con
stant driving in heavy city traffic during hot
weather, trailer pulling, etc., these services
should be performed at 12,000-mile intervals.
See your Owner's and Driver’s Manual for fur
ther details on transmission care.
11 MANUAL STEERING GEAR-Check for seal leakage
around the pitman shaft and housing. If leakage
is evident (solid grease oozing out—not just oily
film), it should be corrected immediately.
SA F E T Y MAINTENANCE
NOTE: Items 12(a) thru (v) can be checked by the
owner or driver while Items 13 thru 22 should
only be checked by a qualified mechanic. It is
particularly important that any safety systems
which may have been adversely affected in an
accident be checked and repaired as necessary
before the vehicle is returned to use.
12 SAFETY CHECKS TO BE PERFORMED BY OWNER OR
DRIVER—The following checks should be made
regularly during operation at no greater interval
than 4 months or 6,000 miles, whichever occurs
first, and more often when the need is indicated.
Any deficiencies should be brought to the atten
tion of your dealer or another service outlet, as
soon as possible, so the advice of a qualified
mechanic is available regarding the need for
repairs or replacements.
(a) STEERING COLUMN LOCK (IF SO EQUIPPED) Check for proper operation by attempting to
turn key to LOCK position in the various
transmission gear ranges when the vehicle
is stationary. Key should turn to LOCK posi
tion only when transmission control is in
PARK on automatic transmission models or
in reverse on manual transmission models.
Key should be removable only in LOCK posi
tion.
(b) PARKING BRAKE—Check parking brake hold
ing ability by parking on a fairly steep hill
and restraining the vehicle with the parking
brake only.
CAUTION: Before making the checks (c) or (d)
below, be sure to have a clear distance ahead
and behind the vehicle, set the parking brake
and firmly apply the foot brake. Do not depress
accelerator pedal. Be prepared to turn off igni
tion switch immediately if engine should start.
bent or cracked and that wheel nuts have been
tightened to torque value specified in Owner’s
and Driver’s Manual. Check tire inflation pres
sure (including spare tire) when tires are “cold”
at least monthly, or more often if daily visual
inspection indicates the need.
EXHAUST SYSTEM—Check complete exhaust sys
tem and nearby body areas for broken, dam
aged, missing or mispositioned parts, open
seams, holes, loose connections or other dete
rioration which could permit exhaust fumes to
seep into the passenger compartment. Any nec
essary corrections should be made immediately.
To help continue integrity, exhaust system pipes
and resonators rearward of the muffler must be
replaced whenever a new muffler is installed.
Also see Item 12(i).
15 ENGINE DRIVE BELTS*—Check belts driving fan,
AIR pump, generator, power steering pump and
air conditioning compressor for cracks, fraying,
wear and tension. Adjust or replace as neces
sary.
16 SUSPENSION AND STEERING—Check for damaged,
loose or missing parts, or parts showing visible
signs of excessive wear or lack of lubrication in
front and rear suspension and steering system.
Questionable parts noted should be replaced by
a qualified mechanic without delay.
17 BRAKES AND POWER STEERING - Check lines and
hoses for proper attachment, binding, leaks,
cracks, chafing, deterioration, etc. Any ques
tionable parts noted should be replaced or re
paired immediately. When abrasion or wear is
evident on lines or hoses, the cause must be
corrected.
18 DISC BRAKES — Check brake pads for wear and
surface condition of rotors while wheels are re
moved during tire rotation. (See Item 5.)
NOTE: More frequent brake checks should be
made if driving conditions and habits result in
frequent brake application.
19 DRUM BRAKES AND PARKING BRAKE-Check drum
brake linings for wear or cracks and other in
ternal brake components at each wheel (drums,
wheel cylinders, etc.). Parking brake adjustment
also should be checked whenever drum brake
linings are checked.
14
NOTE: More frequent brake checks should be
made if driving conditions and habits result in
frequent brake application.
O B -1 5
(m) HORN—Blow the horn occasionally to be sure
that it works. Check all button locations.
(n) LAP AND SHOULDER BELTS - Check belts,
buckles, latch plates, retractors, reminder
systems, guide loops, clips and anchors for
proper operation or damage. Check to make
certain that anchor mounting bolts are tight.
(o) SEAT ADJUSTERS—Check that seat adjusters
(and swivel seat lock, if so equipped) se
curely engage by pushing forward and back
ward (and twisting) whenever seat is ad
justed.
(p) SEAT BACK LATCHES (IF SO EQUIPPED)-Check
to see that seat back latches are holding by
pulling forward on the top of each folding
seat back.
(q) LIGHTS AND BUZZERS - Check all instrument
panel illuminating and warning lights, seat
belt reminder light and buzzer (if so
equipped), interior lights, license plate
lights, side marker lights, headlamps, park
ing lamps, identification or clearance lights,
tail lamps, brake lights, turn signals, backup
lamps, and hazard warning flashers. Have
headlamp aim checked every 12 months or
15,000 miles, or more often if light beams
seem to be aimed improperly.
(r) GLASS—Check for broken, scratched, dirty or
damaged glass on vehicle that could ob
scure vision or become an injury hazard.
(s) DOOR LATCHES — Check for positive closing,
latching and locking.
( t ) HOOD LATCHES — Check to make sure hood
closes firmly by lifting on the hood after each
closing. Check also for broken, damaged or
missing parts which might prevent secure
latching.
(u) FLUID LEAKS — Check for fuel, water, oil or
other fluid leaks by observing the ground be
neath the vehicle after it has been parked
for a while. (Water dripping from air condi
tioning system after use is normal.) If gaso
line fumes or fluid are noticed a t a n y tim e,
the cause should be determined and cor
rected without delay because of the possi
bility of fire.
(v) SPARE AND JACK—Check that spare tire as
sembly and jack equipment are securely
stowed at all times.
13 TIRES AND WHEELS — Check tires for excessive
wear or damage. Make certain wheels are not
L U B R IC A T IO N
(c) STARTER SAFETY SWITCH (AUTOMATIC TRANS
MISSION) — Check starter safety switch by
attempting to start the engine with the trans
mission in each of the driving gears. The
starter should operate only in the Park (“P”)
or Neutral (“N") positions.
(d) STARTER SAFETY SWITCH (MANUAL TRANSMIS
SION)—To check, place the shift lever in neu
tral, depress the clutch halfway, and attempt
to start. The starter should operate only
when clutch is fully depressed.
(e) TRANSMISSION SHIFT INDICATOR—Check to be
sure automatic transmission shift indicator
accurately indicates the shift position se
lected.
( f ) STEERING—Be alert to any changes in steer
ing action. The need for inspection or servic
ing may be indicated by increased effort to
turn the steering wheel, excessive free play
or unusual sounds when turning or parking.
(g) WHEEL ALIGNMENT AND BALANCE—In addition
to uneven or abnormal tire wear, the need
for wheel alignment service may be indi
cated by a pull to the right or left when driv
ing on a straight and level road. The need
for wheel balancing is usually indicated by a
vibration of the steering wheel or seat while
driving at normal highway speeds.
(h) BRAKES—Be alert to illumination of the brake
warning light or changes in braking action,
such as repeated pulling to one side, un
usual sounds when braking or increased
brake pedal travel. Any of these could indi
cate the need for brake system inspection
and/or service.
(i) EXHAUST SYSTEM—Be alert to any change in
the sound of the exhaust system or a smell of
fumes which may indicate a leak requiring
inspection and/or service. (See also Engine
Exhaust Gas Caution in Owner’s and Driver’s
Manual and Item 14 in this folder.)
(j) WINDSHIELD WIPER AND WASHER-Check op
eration of wipers, as well as condition and
alignment of wiper blades. Check amount
and direction of fluid sprayed by washers
during use.
(k) DEFROSTER—Check performance by moving
controls to “DEF” and noting amount of air
directed against the windshield.
(I) REARVIEW MIRRORS AND SUN VISORS-Check
that friction joints are properly adjusted so
mirrors and sun visors stay in the selected
position.
L I N K A G E — Lubricate as covered in
Owner’s and Driver’s Manual. Check for dam
aged or missing parts, interference or binding.
Any deficiencies should be corrected without
delay by a qualified mechanic.
UN DE R B OD Y — Corrosive material used for ice and
snow removal and dust control can accumulate
on the underbody. If allowed to remain, these
materials can result in accelerated rusting and
deterioration of underbody components such as
fuel lines, frame and floor pan, exhaust system,
etc. At least once each year, preferably after a
winter’s exposure, these corrosive materials
should be removed by flushing the underbody
with plain water. Particular attention should be
given to cleaning out those areas where mud
and other foreign materials collect.
20 T H R O T T L E
21
27
28 ENGINE TIMING A DJ U S T ME N T & D I S T RI BU T O R C H E C K
—Adjust ignition timing following the specifica
tions shown on label under the hood. Also, care
fully inspect the interior and exterior of the dis
tributor cap and rotorforcracks, carbon tracking
and terminal corrosion. Clean or replace as
necessary.
25 T H E R M O S T A T I C A L L Y C O N T R O L L E D AI R C L E A N E R -
Inspect installaticntomake certain that all hoses
and ducts are connected and correctly installed.
Also, check valve for proper operation.
- At
12 month/12,000 mile intervals, inspect and if
deposits exist, clean the EGR valve. Inspect the
EGR passages in the inlet manifold and clean as
required. A damaged EGR valve must be re
paired or replaced. Check thermal switch for
proper operation. A malfunctioning switch must
be replaced. Check hoses for proper connection,
cracking, abrasions, or deterioration and re
place as required.
C A R B U R E T O R F U E L I NL E T F I L T E R - Replace filter
at designated intervals or if clogged.
30
31 ENGINE I DLE MI X T U R E — At
designated intervals or
in case of a major carburetor overhaul, or when
poor idle quality exists, adjust mixture by a me
chanical method (lean drop), following the speci
fications shown on the label under the hood.
32 T H R O T T L E R E T U R N C O N T R O L ( T R C ) S Y S T E M -
Check hoses for proper connections, cracking,
abrasion, or deterioration and replace as neces
sary. Check for proper operation of system.
- Check for proper oper
ation. An inoperative solenoid must be replaced.
33 I DLE S TOP SOLENOID
34 POS I TI VE C R A N K C A S E VENTI LAT I ON S YS TEM ( P C V )
— Check the PCV system for satisfactory oper
ation at 12-month or 12,000-mile intervals. Re
place the PCV valve at 24-month or 24,000-mile
intervals, blow out PCV valve hose with com
(ECS)-Check all
fuel and vapor lines and hoses for proper con
nections and correct routing as well as condi
tion. Remove canisters and check for cracks or
damage. Replace damaged or deteriorated parts
as necessary. Replace filter in lower section of
canister. If vehicle is equipped with two canis
ters, filter is located in lower canister only.
F U E L CAP, F U E L LI NES AND F U E L T A N K -Inspect
the fuel tank, cap and lines for damage which
could cause leakage. Inspect fuel cap for correct
sealing ability and indications of physical dam
age. Replace any damaged or malfunctioning
parts.
AI R C L E A N E R E L E ME N T - Replace the engine air
cleaner element at designated intervals. Oper
ation of vehicle in dusty areas will necessitate
more frequent element replacement. Your dealer
can be of assistance in determining the proper
replacement frequency for the conditions under
which you operate your vehicle.
CAUTION: Do not operate the engine without the
air cleaner unless temporary removal is neces
sary during repair or maintenance of the vehicle.
When the air cleaner is removed, backfiring can
cause fire in the engine compartment.
35 EVAPORATI ON CO N T RO L S Y S T E M
29 E X H A U S T GAS R E C I R C U L A T I O N S Y S T E M ( E G R )
EMISSION CONTROL MAINTENANCE
NOTE: Additional recommended maintenance
instructions relating to vehicle use, evidence of
maintenance, and service replacement parts are
included in the New Vehicle Warranty Informa
tion Folder.
22 C A R B U R E T O R C HOKE AND HOSES - Check choke
mechanism for proper operation. Any binding
condition which may have developed due to
petroleum gum formation on the choke shaft or
from damage should be corrected. Check carbu
retor choke hoses for proper connection, crack
ing, abrasion or deterioration and correct or
replace as necessary.
23 ENGINE I DLE S P E E D A DJ US T ME N T - Adjust engine
idle speed accurately (following the specifica
tions shown on the label under the hood). Adjust
ments must be made with test equipment known
to be accurate.
24 CARBURETOR MOUNTING-At designated intervals,
torque carburetor attaching bolts and/or nuts to
compensate for compression of gasket.
pressed air and replace the filter. The PCV valve
should be replaced at 12-month or 12,000-mile
intervals when the vehicle is used in operations
involving heavy dust, extensive idling, trailer
pulling, and short trip use at freezing tempera
tures where engine does not become thoroughly
warmed up. The PCV filter should be replaced at
12-month / 12,000-mile intervals under dusty
driving conditions.
H E A T V A L V E -S o m e engines are
equipped with a manifold heat valve which
should be inspected and repaired as necessary
to insure free operation.
S P A R K PLUGS — Replace at designated intervals
with type specified in Owner's and Driver’s
Manual.
26 M A N I F O L D
36
37
- Clean
exterior of wires; remove any evidence of corro
sion on end terminals. Inspect spark plug and
ignition coil wires for evidence of checking,
burning, or cracking of exterior insulation and
tight fit at distributor cap and spark plugs, or
other deterioration. If corrosion cannot be re
moved, or other conditions above are noted,
replace wire.
38 S P A R K PLUG AND IGNITION COI L WI RE S
RECOMMENDED FLUIDS & LUBRICANTS
USAGE
FLU ID /LU BRICAN T
Power steering system and
pump reservoir
GM power steering fluid Part No.
1050017 or equivalent
D iff e r e n tia l- s t a n d a r d & p o s itr a c t io n f r o n t a x le & p a rt
tim e T ra n s fe r case
SAE-80W or SA E-80W -90 G L-5
gear lubricant(S A E -80W in Canady)
F u ll T im e
tr a n s fe r case
E n g in e o il
M anual steering gear
L u b ric a n t G M Part No. 1051052
o r e q u iva le n t.
Manual transmission
SAE-80W or SAE-80W -90 G L-5
gear lubricant (SAE-80W in Canada)
Brake system and master cylinder
Delco Supreme 11 flu id or D O T-3
C lutch linkage (Man. trans. only)
a. Pivot points
b. Push rod to clu tch fork jo in t,
and cross shaft pressure fittin g
Engine oil
Chassis grease m eeting require
ments of GM 6031-M
Manual transm ission shift linkage,
colum n shift
Engine oil
Shift linkage, floor shift
Engine oil
Hood Latch assembly
a. Pivots and spring anchor
Engine oil
b. Release pawl
Chassis grease
Hood and Door hinges
Engine oil
A utom atic transm ission shift
linkage
Engine oil
Chassis lubrication
Chassis grease m eeting require
ments of GM 6031-M
Constant V e lo city Universal Jo in t
GM Lubricant Part No. 1050679 or
grease m eeting requirem ents of
GM 6040-M
A u to m atic transm ission
DEXRON® II autom atic
transm ission fluid
Parking brake cables
Chassis grease
Front wheel bearings
W heel b e a rin g lu b ric a n t GM Part
No. 1051344 o r e q u iva le n t.
Body door hinge pins, ta ilg a te hinge
and linkage, folding seat, fuel door
hinge, rear com partm ent lid hinges
Engine oil
W indshield washer solvent
GM O ptikleen washer solvent Part
No. 1051515 or equivalent
Battery
Colorless, odorless, drinking w ater
Engine coolant
M ixture of water and a high quality
Ethylene G lycol base type
an ti-fre e ze conform ing to GM
Spec. 1899-M
C O N V E N T IO N A L AND FORWARD CONTROL MODELS
L U B R IC A T IO N P O IN T S
1
2
3
4
5
Low er C o n tro l Arm s
Upper C o n tro l Arm s
Upper and Low er C o n tro l
A rm Ball Jo in ts
Interm e dia te Steering
Shaft (PA10)
Tie Rod Ends
Wheel Bearings
Steering Gear
A ir Cleaner — Elem ent
Master C ylin d e r
Transm ission - Manual
— A u to m a tic
6
7
8
9
10
11
12
13
14
15
T h ro ttle Bell C rank - L-6
C a rbu re tor Linkage - V-8
Brake and C lutch Pedal
Springs
Universal Joints
Rear A xle
FOUR WHEEL DRIVE MODELS
L U B R IC A T IO N P O IN T S
1
2
3
4
5
A ir Cleaner
C o ntrol Linkage Points
Tie Rod Ends
Wheel Bearings
Steering Gear
6
7
8
9
10
Master C ylin d e r
Transm ission - Manual
— A u to m a tic
C a rbu re tor Linkage — V-8
Universal Joints
Propeller Shaft Slip Jo in ts
Fig. 0B-3--Lubrication Points Conventional
11
12
13
14
15
Four Wheel Drive
F ro n t and Rear A xle
Drag L in k
Brake and Clutch
Pedal Springs
Transfer Case
T h ro ttle Bell C rank -
L-6
1 / 2 TON " G " MODELS
L U B R IC A T IO N P O IN T S
1
2
3
4
C o n tro l A rm Bushings and
Ball Jo in ts
Tie Rod Ends
Wheel Bearings
Steering Gear
C lutch Cross-Shaft
5
6
7
Trans. C o n tro l S ha ft
A ir Cleaner - Elem ent
T ransm ission - Manual
- A u to m a tic
Fig. 0B-4--Lubrication Points 1 /2 Ton G-Van
8
9
10
11
Rear A x le
O il F ilte r
Brake Master C ylin d e r
Parking Brake Linkage
SECTION 1A
HEATER
C O N T E N T S OF T H IS SEC TIO N
Stan dard H e a t e r ............................................................................... 1A-1
Auxiliary H e a te r............................................................................... 1A-14
Specifications...................................................................................... 1A-18
STANDARD HEATER
INDEX
G e n e ra l D e s c rip tio n .............................................................
1A-1
System C om ponents........................................................ 1A - 1
System C ontrols............................................................... 1A-3
D ia g n o sis............................................................................... 1A-4
O n Vehicle Service
Blower M o t o r .................................................................... 1A-9
H eater Distributer and Core A ssem b ly ................. 1A-9
H e a te r H o s e s .......................................................................... 1A-10
Center Distributor Duct - G M o d els.....................
Left Distributor Duct - G M o d e ls ..........................
Defroster D u c t .................................................................
Control A ssem bly............................................................
C
on , rol C
Control
C aa bb le
le s.................................................................
s .................................................................
Blower Switch....................................................................
Resistor U n it.....................................................................
1A-10
1A-10
1A-10
1A - 10
1A-11
1A-11
1A-12
1A-13
GENERAL DESCRIPTION
Heating components are attached to the dash panel
on the right side of the vehicle. The blower and air inlet
assembly and water hoses are located on the forward
side o f the dash panel while the heater core and
distributor duct are on the passenger side.
which outside air is heated and then mixed in varying
amounts with cooler outside air to attain the desired air
temperature. The system consists basically o f three parts:
(1) the blower and air inlet assembly, (2) the heater
distributor assembly and (3) the heater control assembly.
The heater system is an air mix type system in
Fig. 1A 1-H eater A ir Flow Schematic- G Models
1 A-2
HEATER & DEFROSTER A S M
HEATER A
DEFROSTER A S M
(HEATER IN OFF P O S I T I O N )
AIR OUTLET
LIGHT
TRUCK
SERVICE
MANUAL
V IE W
A
A IR F L O W L E G E N D
Q]
TEMPERATURE V A L V E [
(jj
DEFROSTER V A L V E
GO
PURGE V A L V E
HEATER A S M
D A S H PA N E L -
C-K MODELS
Fig. 1A-2- Heater A ir Flow Schem atic-C-K Models
O U T S ID E AIR
M I X E D AIR
HEATED AIR
BLOWER AN D AIR INLET ASSEMBLY
T he blower and air inlet assembly draws outside air
through the outside air inlet grille located forward o f the
windshield reveal m olding and channels the air into the
heater distributor assembly. The operation of the blower
motor is controlled by the FA N switch on the heater
control. The motor is connected in series with the FA N
switch and also the blower resistor assembly. Located in
the fuse block, in series between the blower motor and
the battery, is a 25 amp. fuse C-K models - a 20 am p
fuse on G models.
radio o f heated to unheated
temperature door).
air (controlled
by the
CO NTRO LS
C-K Models (Fig. 1A-3)
These controls are mounted in the center o f the
dash, above the radio assembly. The control incorporates
two levers which m ake use o f bowden cables to control
positioning o f the purge, tem perature and defroster
doors.
HEA TER D IS T R IB U T O R ASSEMBLY
Tem perature Lever
T he heater distributor assembly houses the heater
core an d the doors necessary to control mixing and
c hanneling o f the air. Since the unit has no w ater valve,
water circulation keeps the core hot at all times. That
portion of the air passing through the core receives
m ax im um heat from the core. Air entering the
distributor assembly is channeled as follows:
This lever control the positioning o f the T E M P E R A
T U R E door in the heater distributor assembly. All
incoming "outside" air is directed around the heater core
in the CO LD position or through the core in the HO T
position. The desired outlet tem perature is obtained by
blending the heated and unheated air according to the
setting o f the tem perature lever.
C-K Models
Heater-Def Lever
A ir entering the distributor can be directed out the
purge door opening, on the right end o f the distributor
assembly, by the purge door. If the purge door is closed,
then air is directed through a n d / o r around the heater
core by the tem perature door. Air is then directed into
the passenger com partm en t through the heater (floor)
outlets a n d / o r the defroster (dash) outlets by the
defroster door. The tem perature o f the outlet air is
de p e n d e n t on the ratio o f heated to unheated air
(controlled by the tem perature door).
G Models
A ir flow is controlled by three doors in the
distributor assembly. The air door can be adjusted to
vary airflow. If air is allowed to enter the distributor
assembly, it is then directed through a n d / o r around the
heater core by the tem perature door. Air is directed into
the passenger co m p artm en t through the heater (floor)
a n d / o r defroster (dash) outlets by the defroster door.
The tem peratu re o f the outlet air is dependent o f the
The H E A T E R -D E F lever controls the position of
the D E FR O ST E R door and the P U R G E door. In the
O F F position, the blower is " o n " and incoming air is
directed up under the dash through the purge door
opening. As the lever is moved to the right o f the O F F
position, the door closes, directing airflow on into the
distributor assembly. With the lever at HEATER, the
D E FR O STE R door directs almost all airflow to the
heater (floor) outlets - a small am ount of air is directed
to the defroster (dash) outlets. In the D E F position, most
airflow is diverted to the defroster outlets. Moving the
lever part way, as desired, will split airflow between the
floor and defroster outlets.
Fan Control
The blower fan lever is located at the left hand side
o f the control assembly. The blower motor will operate
as soon as the ignition switch is turned to the R U N
position. The control has three' positions only; LO, MED,
HI. There is no O F F position.
G Models (Fig. 1A-4)
The controls are located in the instrum ent panel,
just to the right o f the instrument cluster. In opeation,
two levers control all heating operations.
Fig. lA -3~ H eater Control -C-K Models
Fig. 1A-4- Heater C ontrol-G Models
Tem perature Lever
This lever controls the positioning o f the TEM PER ATURF. door in the heater distributor assembly. All
incoming "outside" air is directed around the heater core
in the C O L D position or through the core in the HOT
position. The desired outlet tem perature is obtained by
blending heated an d unheated air according to the
setting o f the tem perature lever.
H eater-D ef Lever
T he H E A T E R -D E F lever controls positioning o f the
A IR and D E F R O S T E R doors in the heater distributor
assembly. In the O F F position, no air is allowed to enter
the system. Moving the lever to the right (toward
HEATER) opens the air door with the AIR door being
fully open at the H EATER position. Incoming air is
directed to the heater outlets (with slight air bleed to the
defroster outlets). Moving the lever between HEATER
and DKF, directs increasing amounts of air to the
defroster outlets until all air is directed to the defroster
outlets in the D EF position.
Fan Control
The blower fan lever is located on the left h an d side
o f the control assembly. W hen the lever is fully down,
the blower motor is inoperative. M oving the lever
upward actuates the three speed blower motor (LOWMED-HI).
DIAGNOSIS
TROUBLE
Temperature of heater a ir a t outlets too low to heat up pas
senger compartment.
Temperature of heater a ir a t outlets adequate but the v e h i c l e
w ill not build up s u ffic ie n t heat.
Inadequate defrosting action.
Inadequate c irc u la tio n of heated a i r through v e h i c l e .
E rra tic heater operation.
Hard operating or broken controls.
CAUSE AND CORRECTION
1.
See "In s u ffic ie n t Heat Diagnostic Chart".
1.
Check fo r body leaks such as:
Floor side kick pad ven tilato rs p a r tia lly open.
2.
Leaking grommets in dash.
3.
Leaking welded seams along rocker panel and windshield.
4.
Leaks through access holes and screw holes.
5.
Leaking rubber molding around door and windows.
6.
Leaks between sealing edge of blower and a ir in le t assembly
and dash, and between sealing edge of heater d istrib u to r
assembly and dash.
1.
Check that DEFROST lever completely opens defroster door
in DEF position - Adjust i f necessary.
2.
Insure that temperature and a ir doors open f u l ly - Adjust.
3.
Look fo r obstructions in defroster ducts - Remove any
obstructions.
4.
Check for a ir leak in ducting between defroster o u tle t on
heater assembly and defroster duct under instrument panel Seal area as necessary.
5.
Check position of bottom of nozzle to heater locating tab Adjust.
6.
Check position of defroster nozzle openings re la tiv e to in stru
ment panel openings. Mounting tabs provide positive position
i f properly in s ta lle d .
1.
Check heater a ir o u tlet for correct in s ta lla tio n - R e in s ta ll.
2.
Inspect flo o r carpet to insure that carpet lie s f l a t under
fro nt seat and does not obstruct a ir flow under seat, and
also inspect around o u tlet ducts to insure that carpet is
well fastened to flo o r to prevent cupping of a ir flow - Correct
as necessary.
1.
Check coolant level - F i l l
2.
Check for kinked heater hoses - re lie v e kinks or replace hoses.
3.
Check operation of a ll bowden cables and doors - Adjust as
necessary.
4.
Sediment in heater lin es and radiator causing engine thermo
s ta t to stick open - flush system and clean or replace thermo
sta t as necessary.
5.
P a r t ia lly plugged heater core - backflush core as necessary.
1.
Check fo r loose bowden cable tab screws or mis-adjusted bowden
cables - Correct as required.
2.
Check fo r sticking heater system door(s) - Lubricate as required
using a silico n e spray.
to proper le v e l.
INSUFFICIENT HEAT DIAGNOSIS
P osition th e c o n tro ls so th a t the:
Tem perature lever is o n fu ll heat.
Selector o r heater lever is o n Heater.
Fan sw itch is o n H i.
| *C H E C K DUM P DO O R O U T L E T FOR A IR FLO W ~|
NO A IR FLO W
A d ju st d um p d o o r fo r no air flo w .
CHECK D E F R O S T E R O U T L E T S FO R A IR FLOW
( I f in d o u b t as to High o r L o w air flo w
set selector o n D E F w h ich is High and
com pare. Reset selector on Heater)
H IG H A IR FLOW
NO OR LOW A IR FLOW
J
CHECK H E A T E R O U T L E T A IR FLOW
A d ju st d efro ster d o o r fo r lo w a ir flo w .
( If in d o u b t, sw itch fan
sw itch fro m Hi to Lo)
C H A N G E IN A IR FLOW
L IT T L E OR NO C H A N G E IN A IR FLOW
......... ...... T ..............
N O R M A L A IR FLOW
LOW OR NO A IR FLOW
Check heater o u tle t tem perature
w ith 2 20 ° F range the rm om ete r.
**C h e c k s h u to ff d o o r p o s itio n fo r fu ll
system a ir flo w . A d ju st if necessary.
(a p p ro xim a te o u tle t a ir tem peratures)
O u tle t A ir
A m b ie n t A ir
145
0
150
25
165
75
155
40
LOW A IR FLOW
NO A IR FLOW
Check heater o u tle t fo r o b s tru c tio n - re
move.
CHECK FUSE
NORM AL TEM PER ATURE
Remove a ll o b stru ctio n s under fro n t seat.
Check m o to r voltage at closest m o to r line
co nn ectio n w ith a v o ltm e te r.
Car does n o t b u ild up heat - operate vent
c o n tro ls and see th a t th e air vent doors
close c o m p le te ly, if n o t, adjust.
FUSE BLO W N - replace fuse.
A IR FLOW - system okay.
LOW T E M P E R A T U R E
U N D E R 10 V O L T S
HZ
(Check th e system tem pe ra ture a fte r re
p airin g th e item checked to co m p lete the
diagnosis.)
X
Check c o o la n t level; if low , f ill. L o o k fo r
or feel a ll ra d ia to r and heater hoses and
conn ectio n s fo r leaks. Repair o r replace.
Check th e ra d ia to r cap fo r damage and re
place if required.
BLOWS FUSE
O V E R 10 V O L T S
Check b a tte ry vo lts - under 10 volts,
recharge then recheck m o to r voltage.
Check w irin g and co nnections fo r
under 10 v o lts fro m m o to r to fan
sw itch. Repair or replace last p o in t
o f u nder 10 v o lt reading.
Remove p ositive lead fro m m o to r and
replace fuse.
FUSE R E M A IN S O K - rem ove m o to r
and check fo r o b s tru c tio n in system
opening, if none, R E PLACE M O TO R .
If o b s tru c tio n , remove m aterial and
re -in sta ll m o to r.
X
Check heater a nd ra d iato r hoses fo r kin ks
straighten and replace as necessary.
Check tem pe ra ture d o o r fo r m ax heat po
sitio n. A d ju s t if necessary.
[
BLOWS FUSE - check fo r shorted
w ire in b low er electric c irc u it See Heater C irc u it Diagnostic Chart.
A p p ly external ground, (jum p e r w ire) to
m o to r case. IN C R E A S E D A lR FLOW re p air ground.
H E A T E R CORE
r
FUSE OK
| Feel tem peratures o f heater in le t and o u tle t hoses,
j
SAM E A l R FLO W - rem ove m o to r and
check fo r o b s tru c tio n in system open
ing. I f none, R EPLACE M O T O R . If
o b stru ctio n , rem ove m aterial and re
install m o tor.
W A R M IN L E T A N D O U T L E T HOSES
X
i Check engine the rm osta t.
H O T IN L E T A N D W A R M O U T L E T HOSES
......:.....................— ~
Check p u lle ys, belt tension, etc., fo r p ro
per o p e ra tio n . Replace o r service as neces
sary.
.................. i .
~xz
Remove hoses fro m heater core. Reverse
flush w ith tap water. I f plugged, repair or
replace.
‘ C H E C K F OR C-K M O D E L S
ONLY
" C H E C K F O R G M OD E L S
ONLY
FUSE O K - See Heater C irc u it
Diagnostic Chart.
HEATER C IRC U IT DIA GN O SIS*
BLO W E R M O T O R
(A N Y
IN O P E R A T IV E
SP E E D)
X
Check fuse
in fuse pane!.
I_ J L _
FU S E B L O W N
“
FU S E O K
I___ I
T h e fo llo w in g te sts s h o u ld be m ade w it h
W ith I g n itio n s w itc h in
th e ig n itio n s w itc h in " R U N " p o s itio n
" R U N " p o s itio n and b lo w e r
th e b lo w e r speed s w itc h " O N " a n d th e
speed s w itc h " O N " use
lever on h e a t p o s itio n .
m e te r to lo ca te s h o rt in one
X
o f th e fo llo w in g w ire s :
Check b lo w e r m o to r g ro u n d
speed s w itc h .
x
X
P O O R O R NO G R O U N D
G R O U N D OK
R e p a ir g ro u n d
Check m o to r c o n n e c to r
2. F ro m b lo w e r speed s w itc h
to h eater re sisto r.
3. F ro m h e a ter re sisto r to
x
b lo w e r.
N o te :
w it h
S h o rt c ir c u it m a y be
Circuit
HEATER
Fig. lA-5-H eater
1. F ro m fuse p an el to b lo w e r
12 v o lt te s t lig h t.
in t e r m it t e n t . I f m e te r does
n o t in d ic a te a s h o rt c ir c u it,
X
m o ve harness a ro u n d as
| L A M P L IG H T S
Diagnosis
m u c h as p o s sib le to re-create
L A M P D O E S N O T L IG H T
X
s h o rt c ir c u it . W a tch and
Replace Motor
lis te n f o r a rcin g .
L A M P D O E S N O T L IG H T
Use 12 v o lt te s t lig h t a nd c h e c k feed
te r m in a l (b ro w n ) o n b lo w e r speed s w itc h .
Check blower feed wire in connector
on resistor with 12 volt test light
| L A M P L IG hT T )
Repair open in feed wire
from resistor to blower motor.
L A M P D O E S N O T L IG H T
L A M P L IG H T S
R e p a ir o p e n in b ro w n w ire
Replace switch
"See heater circuit diagrams
f r o m b lo w e r speed s w itc h
to fuse pan el.
1 A-7
BLOWER MOTOR
a
RESISTOR
• DASH
r T tp p i—
S
| 721
■1 4B LBL STR-1 4
BRN
14B ORN STR
-------- 14B LBL STR —
□3
■14B ORN STR---------14 BRN
14B ORN STR----------
BLOWER SWITCH
Z
QO
£
C
i i
_ P
TO
FU SE
PANEL
C-K MODELS
I fV W W —t l
OFF
LO
MED
HI
,
HEATER O P E R A T I O N
CIRCUIT
B A T -O N L Y
B A T -B L O SW-RES Rl R 2 BLO M T R - G R D
LO
B A T -L O
MED
B A T -M E D
B A T-H I
HI
HI
R I
|
i j r
B A T -B L O SW-RES RlBLO M T R - G R D
S
BL OWER
RESISTOR
It
|B L O MED|
B A T -B L O S W BLO M T R - G R D
- 1 6 LBLMED
0
< CQ
CSCN C T T o r n "
LO
1 6 YEL 16 O R N '
[52B |
50
BAT
J
BL OWER
S W IT C H
, DASH
i 52 I
L-1
14 ORN
1 J j /
INST. PA NEL H A R N
C IR C U IT #4 (ACC)
2 5 A M P IN FUSE PANEL
I : rn
FUSE
PANEL I
LJ
1 !52
i
r* i
on
eng
h a r n
)
15 2 *
\
BUL KHEAD C O N N
J U N C T I O N BLOCK
BLOWER
MOTOR
eo
□
:o
i
ON VEHICLE SERVICE
BLOWER M O TO R
Removal (Fig. 1A-7)
1. Disconnect battery ground cable.
G Models - Remove the battery.
2. Disconnect the blower m otor lead wire.
3. Remove the five blower motor m ounting screws
and remove the motor and wheel assembly. Pry gently
on the blower flange if the sealer acts as an adhesive.
4. Remove the blower wheel to motor shaft nut
a n d separate the wheel and motor assemblies.
5. To install a new motor, reverse Steps 1-4 above.
b. If the motor m ounting flange sealer has
hardened, or is not intact, remove the old sealer and
apply a new bead o f sealer to the entire circumference o f
the mounting flange.
c. Check blower operations: blower wheel should
rotate freely with no interference.
HEATER D IS T R IB U T O R A N D CORE
ASSEMBLY
C-K Models
Replacement (Fig. 1A-8)
N O T E : The following precautions should be taken
to assure proper installation:
1. Disconnect the battery ground cable.
a.
Assemble the blower wheel to the motor with
2. Disconnect the heater hoses at the core tubes
the open end o f the wheel away from the blower motor.
and drain engine coolant into a clean pan. Plug the core
tubes to prevent coolant spillage at removal.
3. Remove the nuts from the distributor duct studs
projecting into the engine compartment.
4.
Remove the glove box and door assembly.
5. Disconnect the Air-Defrost and Tem perature
door cables.
6. Remove the floor outlet and remove
defroster duct to heater distributor duct screw.
the
7. Remove the heater distributor to dash panel
screws. Pull the assembly rearward to gain access to
w iring harness and disconnect all harnesses attached to
the unit.
8.
Remove the heater-distributor from the vehicle.
9. Remove the core retaining straps and remove
the core.
Fig. lA -7- Blower M otor Assembly
Fig. lA-8--Heater D istrib u to r Assem bly-C K Models
N O TE : Be sure core to case and case to dash pane!
sealer is intact before assembling unit.
G Models
Replacem ent (Fig. 1A-9)
1. Disconnect the battery ground cable.
2. Place a clean p a n under the vehicle and then
disconnect the heater core inlet and outlet hoses at the
core connections (see " H e a te r Hoses-Replacem ent" later
in this section). Quickly plug the heater hoses and
support them in a raised position. Allow the coolant in
the heater core to drain into the p a n on the floor.
3. Disconnect the right h an d air distributor hose
fro m the heater case and rotate it up out o f the way.
4. Pry off the tem perature door cable eyelet clip
and then remove the bowden cable attaching screw.
5. Remove the distributor duct to heater case
screws and pull the duct rearw ard out o f the heater case
retainer.
6. Remove the four heater case to dash screws and
then remove the heater case an d core as an assembly.
Tilt the case assembly rearw ard at the top while lifting
up until the core tubes clear the dash openings.
7. Remove the core retaining strap screws and
remove the core.
8. To install a new core, reverse Steps 1-7 above.
N O T E : Be sure core to case and case to dash panel
sealer is intact before assembling unit.
HEATER HOSES
H eater hoses are routed from the tnermostat
housing or inlet m anifold and w ater p u m p (radiator on
some automatic transmission vehicles) to the core inlet
and outlet pipes as shown in Figure 1A - 10. Hoses are
attached at each end with screw type clamps.
Replacem ent
The heater core can be easily dam aged in the area
o f the core tube attachm ent seams whenever undue force
is exerted on them. W henever the heater core hoses do
not readily come off the tubes, the hoses should be cut
just forward o f the core tubes. The portion o f the hose
rem aining on the core tube should then be split
longitudinally. Once the hoses have been split, they can
be removed from the tubes without d am age to the core.
CENTER D IS T R IB U T O R D U C T - G Models
Replacement (Fig. 1A -11)
1. Disconnect the battery ground cable.
2. U nsnap the engine cover front latches. Remove
the two cover to floorpan screws and remove the cover.
3. Remove the heater core case and core as an
assem bly
(see
" H e a te r
D is trib u to r
and
CoreReplacement").
4. Disconnect the right h a n d heater outlet hose
and the two defroster hoses from the distributor duct.
5. Disconnect the air and defroster door cables by
prying off the eyelet clips and removing the cable
attaching screws.
6. Pull the center distributor duct to the right and
remove it from the vehicle.
7. To install, reverse Steps 1-6 above.
NOTE: Check cable and door opeation; cables
should be free from kinks or binding and doors
should close properly. If cable adjustm ent is
necessary, see "Bowden Cable-Adjustment."
LEFT D IS T R IB U T O R DUC T - G Models
Replacement (Fig. 1A -11)
1.
2.
the two
3.
duct.
4.
Disconnct the battery ground cable.
U n snap the engine cover front latches. Remove
cover to floorpan screws and remove the cover.
Remove the duct bracket screw and remove the
To install, reverse Steps 1-3.
N OTE: All
the duct. It
down as the
duct is fully
three bowden cables are routed under
m ay be necessary to hold the cables
duct is being installed. Be sure the left
installed over the center duct.
DEFROSTER DUCT
The defroster hose and
illustrated in Figure 1A -12.
outlet
assemblies
are
CO N TR O L ASSEMBLY
C-K M odels
Replacement (Fig. 1A -13)
1. Disconnect the battery ground cable.
2. Remove the instrum ent panel bezel.
3. Disconnect the bowden cables and the blower
switch wiring harness.
A U T O M A TIC TRANSMISSION MODELS
EXCEPT C -K IO 3 5 0 V 8 W / O V O I OR C 6 0
C -K M O D EL S
G M O D EL S
Fig. lA -1 0 -Heater Hose Routings
C A U T IO N : Be careful not to kin k the bowden
cables.
4. Remove the control through the opening above
the control.
5. If a new unit is being installed, transfer the
blower switch to the new unit.
6. To reinstall, reverse Steps l -4 above.
4. Disconnect the three bowden cables, the control
illumination bulb, the blower switch connector and
remove the control from the vehicle.
5. Remove the blower switch screws an d remove
the blower switch.
6. To install, reverse Steps 1-5 above.
C O NTRO L CABLES
G Models
Replacem ent (Fig. 1A -14)
C-K Models
Replacement
1. Disconnect the battery ground cable.
2. Remove the ignition switch from the instrument
panel (see Section 3B o f this manual).
3. R em o ve the control to in stru m e n t p a n e l
m oun ting screws and carefully lower the control far
enough to gain access to the bowden cable attachments.
C A U T IO N : Care should be taken to prevent
kin kin g the bowden cables while lowering the
control.
1. Disconnect the battery ground cable.
2. Remove the instrument panel bezel.
3. Remove the control to instrument panel screws.
4. Raise or lower control as necessary to remove
cable push nuts and tab attaching screws.
5. Remove glove box and door as an assembly.
6. Remove cable push nut an d tab attaching screw
at door end o f cable.
7. Remove cable from retaining clip and remove
cable assembly.
LEFT
DISTRIBUTOR
DUCT
CENTER
DISTRIBUTOR
DUCT
HEATER
CORE
CASE
Fig. 1A-11 -D istrib u to r Ducts--G Models
8.
To install, reverse Steps 1-7 above.
NOTE: If cable adjustment is required, see below.
C A U TIO N : Be careful not to kink the cable
Adjustm ent
during installation. Be sure to route the cable
as when removed. Check cable adjustment.
1.
2.
U nsnap
cover to
G Models
Replacem ent (Fig. 1A -15)
1.
Disconnect the battery ground cable.
2. U nsn a p the engine cover front latches. Remove
the two cover to floorpan screws an d remove the cover.
3. Remove the left distributor duct attaching screw
and remove the duct.
4. Pry off the cable eyelet clip at both the door and
control lever. Remove the cable attaching screw at both
doo r and control locations.
5. Attach a 4 ’ piece o f wire to the door end o f the
cable. Place protective tape around the cable m ounting
tab and attached wire and carefully pull the cable from
the vehicle. Remove the tape and disconnect the 4 ’ piece
o f wire.
6.
To install, attach the new cable to the 4 ’ piece of
wire. Tape the m ounting tab and attached wire.
Carefully pull the new cable into position.
7.
Reverse Steps 1-4.
Disconnect the battery ground cable.
G
Model
Air
and
Defroster
Door
Cables -
the engine cover front latches. Remove the two
floorpan screws and remove the engine cover.
C-K Models - Remove glove box and door as an
assembly.
3. Pry off the appropriate cable eyelet clip and
disconnect the cable from the door.
4. Remove the cable retaining screw.
5. While holding the cable with pliers, rotate the
m ounting tab on the cable to lengthen or shorten the
cable, whichever is required.
NOTE: Do not pinch the cable too tightly or
dam age to the cable could result.
6. Install the cable, reversing Steps 1-4 above.
BLOWER S W ITC H
C-K Models
Replacement (Fig. 1A-13)
1. Disconnect the battery ground cable.
2. Remove the instrument panel bezel.
3. Remove the control to instrum ent panel screws
and lower the control onto the radio.
Fig. 1A-14-C ontrol Assembly G Models
C-K M O D EL S
DEFROSTER HOSES
G MODELS
Fig. 1A 1 2 -D e fro ster Outlets
4. Disconnect the switch electrical harness.
5. Remove the swith attaching screws and remove
the switch.
6. To install, reverse Steps 1-5 above.
G Models
Replacement (Fig. 1A -14)
1. Disconnect the battery ground cable.
2. Disconnect the blower switch wiring harness
connector at the switch.
3. Remove the two switch attaching screws and
remove the switch assembly.
4. To install a new switch, reverse Steps 1-3 above.
RESISTOR
Replacement (Figs. 1A-7 and 1A-9)
1.
connector.
Disconnect the wiring harness at the resistor
2. Remove the two resistor m ounting screws and
remove the resistor.
3.
above.
To install a new resistor, reverse Steps 1 and 2
AUXILIARY HEATER
INDEX
G eneral D e s c r ip tio n ........................................................................
C o n tr o l...............................................................................................
D ia g n o sis .............................................................................................
On Vehicle Se rv ice ..........................................................................
S pecifications......................................................................................
1A-14
1A-15
1A - 15
1A-15
1A - 18
GENERAL DESCRIPTION
A n auxiliary heater is available as a dealer installed
accessory to provide additional heating capacity for the
rearmost extremities o f the C-K (06) and G (05 and 06)
models.
This unit operates entirely independent o f the
standard heater and is regulated through its own controls
at the instrum ent panel.
Heater hoses extend from the unit to the front of
the vehicle w here they are connected to the standard
heater hoses with "tees". An "on-off" w ater valve is
installed in the heater core inlet line in the engine
compartm ent. This valve must be operated manually-"o n " for cold weather, "off" in warm weather. The
purpose o f the valve is to cut off coolant flow to the
This system consists o f a separate core and fan unit
mounted as shown in Figures 1A-16 and 1A-17.
CONTROL SWITCH
EXISTING HEATER
AUXILIARY HEATER
WATER VALVE
Fig. 1A-16--Auxiliary Heater Installations (C-K Models)
auxiliary core during w arm weather an d eliminate the
r a d ia n t heat tha t would result.
in the core inlet line). D uring the sum m er months, this
valve should be placed in the "off" position.
CO N TR O LS
Two methods of control are employed with this
system:
Fan Sw itch (Fig. 1A -19)
W a te r Valve (Fig. 1A -18)
T he three speed fan switch (LO W -M ED-HI) is
located in the instrument panel, to the right of the
steering column. Full down, the blower is inoperative;
fully up the blower is on HI.
W hen heat is desired, the w ater valve must be in the
" o n " position (valve located in the engine com partm ent
DIAGNOSIS
Refer to the "S tan d a rd H ea te r” section o f this
m a n u a l for diagno stic in fo rm a tio n ; see Electrical
D iag ram Figure 1A-20.
NOTE: If the heater blower motor is inoperative
on C-K models (equipped with Overhead Air
Conditioning), check that the connectors have not
been interchanged with one another.
EXISTING HEATER
HEATER
(ALL 1 2 5 "
WATER VALVE
Fig. 1A -17-A uxiliary Heater In sta lla tion s (G M odels)
110"
W.B. MODELS)
INSTALL V A L V E W IT H A R R O W
P O I N T I N G A W A Y F R O M TEE.
O RIENT V A L V E S O " O N " " O F F ”
IS VISIBLE
Fig. 1A -18-W ater Valve In sta lla tion - G Model Shown
Fig. 1A 19--A uxiliary Heater Control
as Typical
OFF
LO
MED
HI
CIRCUIT
B AT -O NL Y
BAT-LO
BAT-MED
BAT-H I
HEATER OPERATION
BAT-BLO SW-RES Rl R2LO
BLO M TR-G RD
BAT-BLO SW-RES R2MED BLO M TR-G RD
BAT-BLO SW HI
BLO M TR-G RD
v/\ZV\Arf
Rl
vW i
blclL
Imed
lo
Hi------------ 1
n
MEDl
U
-14 ORN-
BLOWER
SWITCH
-1 4 YEL-
-1 4 LBL-
12 BRN
50C
n
" I
51
5 2A
5 2B
i|BAT_____
D LO
50A
,500 ^ ,2BI,N
16
BLOWER
RESISTOR
R2
I
14 ORN
|52B|
[5 2 ]
15 AM P
INLINE FUSE
14
B
BRN{ s OB]
■
j
"CK" I G N # 3 - 3 0 0 UNFUSED
" G " IG N A C C # 4 FUSED
MH1
FUSE
PANEL
GRD (o
BLOWER
M O TO R
Fig. 1A-20-E lectrical Diagram - All Models
ON VEHICLE SERVICE
Since a detailed list o f installation instructions is
included with the auxiliary he a te r unit, replacement
procedures will not be repeated in this section.
CAUTION: G M odels--W hen replacing heater
hoses, m aintain a 1 /2 " m inim um clearance
between hose clip and upper control arm, a
1 -1/2" m inim um clearance between hoses and
propshaft and a 1 -1 /4 " m inim um clearance
between the auxiliary heater core lines an d the
exhaust pipe as shown in Figure 1A-22. A ll
M odels-D raw hoses tight to prevent sag or rub
against other components. Be sure to route
hoses through all clamps as originally installed.
SPECIFICATIONS
SECTION 1A
HEATER
V o lts
A m p s.
(Cold)
RPM
(Cold)
Blower Motor
C-K Models............. 13.5
G M o d e ls................13.5
6.25 Max.
7.1 Max.
2550
2950
2850
3250
Min.
Max.
Min.
Max.
Fuses
C-K Models........................................................................20 Amp.
G M o d e ls.......................................................................... 20 Amp.
A U X IL IA R Y
Blower Motor . . . .
HEATER
Volts
Amps.
(Cold)
13.5
9.6 Max.
RPM
(Cold)
2700 Min.
SECTION IB
AIR CONDITIONING
CONTENTS
G e n e ra l D e sc rip tio n ..........................................................
Four-Season System (C-K M odels)...........................
C60 System (G M odels)...............................................
Overhead Systems (C-K-G M o d e ls).........................
M otor Home Chassis S y stem ......................................
Basic Air C o n d itio n e r ...................................................
M ain Units o f the S y s te m ..........................................
System C o n tro l...............................................................
D ia g n o s is ............................................................................
R efrig eran t S y s te m .......................................................
Compressor D ia g n o sis.................................................
Vacuum System D ia g n o sis.........................................
Insufficient C o o lin g .......................................................
Electrical System D ia g n o sis.......................................
Air C onditioning System C a p a c ity .........................
Perform ance T e s t ..........................................................
Perform ance D a t a .........................................................
Checking O il....................................................................
R efrig eran t Quick-Check P ro ced u re.......................
On Vehicle Service..........................................................
Thermostatic Switch......................................................
Potentiometer (G M o d e ls ).........................................
Expansion V a lv e ............................................................
Engine Idle C om p en sato r...........................................
C o m p resso r.......................................................................
Four Season S y stem -C -K M o d e ls..........................
C o n d e n s e r.........................................................................
A c c u m u la to r.....................................................................
Blower Assembly............................................................
E vaporator C o r e ............................................................
Expansion T u b e .............................................................
Selector Duct and Heater C o re ...............................
Kick Panel Air Valve...................................................
Plenum Air V a l v e .........................................................
Control A sse m b ly ..........................................................
T em p eratu re D oor Cable A d ju s tm e n t................
M aster Switch a n d / o r Blower S w itch...................
V acuum T a n k ..................................................................
Blower Resistor U n i t ....................................................
T herm ostatic Switch......................................................
D ischarge Pressure S w itc h .........................................
F u s e .....................................................................................
O verhead System--C-K M odels................................
R e a r D u c t.........................................................................
Blower M otor R esistor................................................
Blower M otor A sse m b ly .............................................
Expansion V a lv e ............................................................
IB-2
IB-2
IB-2
IB-2
IB-2
IB-2
IB-5
I B-12
IB-16
IB -16
IB -16
IB-17
IB -19
IB-21
IB -17
IB-17
IB-30
IB-30
IB-32
IB-33
IB-33
IB-33
IB-34
IB-34
IB-35
IB-36
IB-36
IB-37
IB-37
IB-37
IB-38
IB-38
IB-39
IB-39
1B-39
IB-40
IB-40
IB-40
IB-41
IB-41
IB-41
IB-42
IB-42
IB-42
IB-42
IB-42
IB-44
Evaporator C o r e ............................................................ 1B-44
Blower Motor Switch................................................... IB-45
Fuse..................................................................................... IB-45
C60 S y s te m - G M o d els............................................... IB-45
C o n d e n se r......................................................................... IB-45
R eceiv er-D eh y d rato r.................................................... 1B-45
Sight Glass Replacem ent............................................ IB-46
A /C Air Distributor D u c t ......................................... IB-46
A /C Center and Right Dash O utlets................... IB-47
Heater, A ir D istributor and Extension Ducts.. IB-48
Heater Core Case and C o r e .................................... IB-48
Expansion V a lv e ............................................................ IB-48
Blower M o to r.................................................................. IB-48
Evaporator C o r e ............................................................ IB-49
Air Inlet V alve............................................................... IB-49
Temperature D oor C a b l e ........................................... 1B-49
C o n tr o l.............................................................................. 1B-49
Blower Switch................................................................. IB-50
Amplifier Circuit B o a rd .............................................. IB-50
Resistors............................................................................ IB-50
Blower Motor R e la y .................................................... IB-50
Resistors............................................................................ IB-50
Blower Motor R e la y .... ................................................ IB-50
Discharge Pressure S w itc h ......................................... IB-50
Vacuum T a n k ................................................................. IB-51
Circuit Breaker............................................................... IB-51
Overhead S y s te m - G Models.................................... IB-51
Blower-Evaporator S h r o u d ........................................ 1B-51
Blower M otor A ssem blies........................................... 1B-51
Expansion Valves........................................................... IB-52
Evaporator C o r e ............................................................ 1B-53
Resistor.............................................................................. IB-54
Blower Sw itch................................................................. IB-54
Rear Blower Relay........................................................ IB-54
Tie Relay.......................................................................... IB-54
Dash M ounted S y ste m -M o to r Home U n i t s ...... IB-54
C o n d e n s e r......................................................................... IB-54
R e c e iv e r-D eh y d ra to r.................................................... IB-55
Sight G la ss....................................................................... IB-55
Blower-Evaporator A ssem bly.................................... IB-55
Blower Assembly............................................................ IB-56
Expansion Valve, Evaporator Case or C o r e ...... 1B-56
Thermostatic a n d / o r Blower S w itches.................. IB-57
Resistor.............................................................................. IB-57
Fuse..................................................................................... IB-57
Specifications......................................................................1B-57
Special Tools........................................................................IB-58
GENERAL DESCRIPTION
FOUR-SEASON SYSTEM (C-K MODELS)
Both the h e a tin g a n d cooling functions are
perform ed by this system. Air e ntering the vehicle must
pass through the cooling unit (evaporator) and through
(or around) the heating unit, in that order, and the
system is thus referred to as a " r e h e a t" system.
The evap orator provides m aximum cooling o f the
air passing through the core when the air conditioning
system is calling for cooling. A thermostatic switch,
located on the blow er-evaporator case, acts to control
compressor op eration by sensing the evaporator inlet
line temperature.
System operation is as follows" Air, either outside
air or recirculated air, enters the system and is forced
through the system by the blower. As the air passes
through the evaporator core, it receives m axim um
cooling if the air conditioning controls are calling for
cooling. A fter leaving the evaporator, the air enters the
H eater and Air C onditioner Selector Duct Assembly
where, by m eans o f diverter doors, it is caused to pass
through or to bypass the heater core in the proportions
necessary to provide the desired outlet temperature.
Conditioned air then enters the vehicle through either
the floor distributor duct or the dash outlets. W hen,
during cooling operations, the air is cooled by the
evapo rator to below com fort level, it is then warm ed by
the heater to the desired tem perature. D uring "h eating
only" operations, the evaporator will not be in operation
and am bien t air will be w a rm e d to the desired level in
the same m anner.
The dash outlets are rectangular in design. The
outlets can be rotated horizontally or vertically to direct
air as desired. U n de r the left distributor duct is located a
floor cooler which can be rotated to provide cooling air
or shut off completely.
C 6 0 SYSTEM (G M O DELS)
This system perform s both the heating and cooling
functions: however, the h eating and cooling systems
operate independently o f one another — the system
provides e ith er heating or cooling and thus is referred to
as a "p arallel system".
In the air conditioning modes, air (either a mixture
o f inside an d outside at N O R M or inside air only at
MAX) enters the system and passes through the
evaporator core (receiving m axim um cooling) an d is
then directed into the passenger c om partm ent through
the dash outlets and foot coolers.
A therm ister clipped to the evaporator core is used
to control com pressor o p e r a tio n by sensing air
tem perature as it leaves the evaporato r core. As the core
tem peratu re increases the resistance o f the therm ister to
400 ohms, the amplifier (on the control) furnishes
current to energize the compressor clutch coil. As the
eva p o ra to r cools down, the tem perature o f the thermister
decreases which biases the amplifier off and compressor
clutch coil is de-energized.
The dash outlets are rectangular in design and can
be rotated horizontally or vertically to direct air as
desired. Foot coolers are provided on both driver and
passenger side.
In the heater-defrost modes, the air conditioning
outside air door is closed. The heater air door is open
and outside air is allowed to pass through the heater core
(receiving m aximum heating) and is then directed into
the passenger co m p artm en t through the heater a n d /o r
defroster outlets.
OVERHEAD SYSTEMS (C-K-G MODELS)
These systems (C69 on C-K -G Models) operate in
conjunction with the Four-Season System (C-K Models)
or C60 System (G M o d e ls)-th e y do not operate
independently.
N OTE: O verhead system kits are available for
non-factory installation on C-K Models, providing
the vehicle is equipped with the front system.
These units are self contained, operating on inside
(recirculated) air only. Air is drawn into the unit, passed
through the evaporator core and then directed into the
passenger com partm ent through the air distributor duct.
System control is through the front system. The only
control on the overhead system is a three speed blower
switch.
M O TO R H O M E CHASSIS SYSTEM
This system perform s the cooling functions only.
W hen heating (above am bient temperatures) is desired,
the vehicle heater must be used. W hen air conditioning
is desired, the heater should be completely shut off.
This self-contained unit is bracket m ounted to the
dash by the body m anufacturer. It operates on inside
(recirculated) air only. Air is drawn into the unit, passed
throu gh the e v a p o ra to r core (receiving m axim um
cooling) and then directed into the vehicle through
adjustable outlets.
A thermostatic switch, located on the face plate is
used to control compressor operation by sensing air
tem perature as it leaves the evaporator core.
BASIC A IR C O N D IT IO N E R
W hen we look at an air conditioning unit, we will
always find a set o f coils or a finned rad iato r core
through which the air to be cooled passes. This is known
as the "evaporator". The refrigerant boils in the
evaporator. In boiling, or course, the refrigerant absorbs
heat and changes into a vapor. By piping this vapor
outside the car we can bodily carry out the heat that
caused its creation.
Once we get vapor out o f the evaporator, all we
have to do is remove the heat it contains. Since heat is
EVAPORATOR CORE
BLOWER &
EVAPORATOR ASM
CONTROL ASM
A /C
SHROUD
R.H. OUTLET
VIEW A
/
CENTER OUTLET
R.H. OUTLET
L.H. OUTLET
AIR C O N D IT IO N IN G
OVERHEAD SYSTEM
EVAPORATOR
CORE
3
FLOOR
OUTLET R.H
CENTER OUTLET
A /C
DASH PANEL
DUCT ASM
AIR INLET \ \
DUCT ASM. \
AIR VACUUM
CONTROL
BLOWER &
EVAPORATOR
ASM
A IR J L O W
H______
FLOOR
OUTLET L.H
LEGEND
RECIRCULATED
H i g B i COOLED AIR
f e r S e - l HEATED AIR
(G) MODELS
Fig. lB - l- A ir flo w Chart G-Models
L.H. OUTLET
1 B-4
EVAPORATOR CORE
BLOWER &
EVAPORATOR A S M
SHROUD
R.H. OUTLET
CONTROL
R.H. OUTLET
AIR CONDITIONING
OVERHEAD SYSTEM
TRUCK
Fig. lB-2-Airflow
R.H. CENTER
OUTLET
INLET VALVE
DISTRIBUTOR
M DUCT
HEATER CORE
Models
^TEM P
MANUAL
Chart - CK
PLENUM
VALVE
SERVICE
AIR
^
VALVE [ 3]
BLOWER &
EVAPORATOR ASM
L.H. CENTER
OUTLET ^
DEFROSTER
VALVE Q ]
^
\
DIVERTER VALVE
OR HEATER [ 2]
7 ^ A /C
DASH PANEL
^
■EVAPORATOR CORE
(CK) MODELS
L.H. OUTLET
LIGHT
CENTER
OUTLET
VIEW A
SELECTOR
DUCT ASM
FOOT
DEFLECTOR
3 . Liquid re frig e ra n t
flo w rate is re g u la te d
2 . U p o n re m o v a l o f h e a t,
h e re. H igh pressure
v a p o r b e c om es High
liquid becom es low
pressure liq u id .
pressure liquid.
4. H e a t rem oved from
a ir e n te rin g veh icle
v a p o riz e s lo w pressure
liquid.
1. R e frig e ra n t
leaves com pressor
as a high pressure
high te m p e ra tu re
v a p o r.
16 .
R e frig e ra n t returns
to com pressor as
low pressure v a p o r.
5 - Liquid re frig e ra n t
a n d v a p o r a re
s e p a ra te d here.
C-K FOUR-SEASON SYSTEM
COMPRESSOR
EXPANSION VALVE
H P. VAPOR
H.P. LIQUID
L.P. LIQUID
L.P. VAPOR
CONDENSER
EXCEPT C-K FOUR-SEASON SYSTEM
£ ^ 3
the only thing that expanded the refrigerant from a
liquid to a v apor in the first place, removal of that same
h e a t will let the vapor condense into a liquid again. Then
we can return the liquid refrig erant to the evaporator to
be used over again.
Actually, the vapor com ing out of the evaporator is
very cold. We know the liquid refrigerant boils at
tem peratures considerably below freezing and that the
vapors arising from it are only a shade w arm er even
though they do contain quantities o f heat. Consequently,
we c a n ’t expect to remove heat from sub-freezing vapors
by "cooling" them in air tem peratures that usually range
between 15 C and 38 C (60 °F and 100 °F)...heat refuses
to flow from a cold object toward a w arm er object.
But with a pump, we can squeeze the heat-laden
v apor into a smaller space. And, when we compress the
vapor, we also concentrate the heat it contains. In this
way, we can make the vap or hotter without adding any
heat. T hen we can cool it in comparatively w arm air.
T h a t is the only responsibility o f a compressor in an
air conditioning system. It is not intended to be a pump
just for circulating the referigerant. Rather, its jo b is to
exert pressure for two reasons. Pressure makes the vapor
hot enough to cool off in w arm air. At the same time, the
compressor raises the re f rig e r a n t’s pressure above the
condensing point at the tem perature o f the surrounding
air so it will condense.
As the refrigeran t leaves the compressor, it is still a
v a p o r although it is not quite hot and ready to give up
the heat that it absorbed in the evaporator. One o f the
easiest ways to help refrigerant vapor discharge its heat
is to send it through a readiator-like com ponent known
as a condenser.
The condenser really is a very simple device having
no moving parts. It does exactly the same jo b as the
fam iliar radiator in a typical home steam -heating
system. There, the steam is nothing more than water
vapor. In passing through the radiator, the steam gives
up its heat and condenses back into water.
The purpose o f the condenser, as the nam e implies,
is to condense the high pressure, high temperature
refrigeran t vapor discharged by the compressor into a
high pressure liquid refrigerant. This occurs when the
high pressure, high tem perature refrigerant is subjected
to the considerably cooler metal surfaces o f the
condenser. This is due to the fu ndam ental laws, which
state that " h e a t travels from the w arm er to the cooler
surface," an d that "when heat is removed from vapor,
liquid is produced."
W hen the refrigerant condenses into a liquid, it
again is ready for boiling in the evaporator. So, we run a
pipe from the condenser back to the evaporator.
MAIN UNITS OF THE SYSTEM
T hese three units then; the e v a pora tor, the
compressor, and the condenser...are the main working
parts in any typical air conditioning system. We have the
evapo rator w here the refrigerant boils and changes into
a vapor, ab sorbing heat as it does so. We have the pum p
or compressor to put pressure on the refrig erant so it can
get rid o f its heat. And we have a condenser outside the
car body to help discharge the heat into the surrounding
air.
Now let’s look at the compressor in detail, and some
o f the components that work with these m ain units to
complete the air conditioning system.
AXIAL SIX-CYLINDER CO M PRESSO R
The prim e purpose o f the compressor (fig. IB-4) is
to take the low pressure refrigerant vapor produced by
the evaporator and compress it into a high pressure, high
tem perature vapor which will be sent on to the
condenser.
It utilizes the principle that "when a vapor is
compressed, both its pressure and tem perature are
raised" which we have already discussed. The axial six
cylinder compressor is mounted above the engine in a
special ru b b e r mounted bracket and is belt driven from
the engine through an electromagnetic clutch pulley on
the compressor.
The compressor has three double-acting pistons,
making it a six cylinder compressor. The compressor has
a l .5 inch bore and 1.1875 inch stroke, giving it a total
displacement of 12.6 cu. in. Identification o f the
compressor is by model and serial n um b e r stamped on a
plate on top of the compressor.
Clutch-Pulley
The movable part o f the clutch drive plate is in
front of the pulley and bearing assembly. The arm ature
plate, the movable m ember, is attached to the drive hub
through driver springs and is riveted to both members.
The hub o f the drive plate is pressed over a square drive
key located in the compressor shaft. A spacer and
retainer ring are assembled to the shaft and the
assembly is held in place with a self-locking nut. The
pulley rim, power element ring and pulley hub are
formed into a final assembly by molding a frictional
material between the rim and the hub with the power
element ring im bedded in the forward face of the
assembly.
A two-row ball bearing is pressed into the pulley
hub and held in place by a retainer ring. The entire
pulley and bearing assembly is then pressed over the
front head o f the compressor and secured by a retainer
ring.
Clutch coil
The coil is molded into the coil housing with a filled
epoxy resin and must be replaced as a complete
assembly. Three protrusions on the rear o f the housing
fit into alignm ent holes in the compressor front head. A
retainer ring secures the coil and housing in place. The
coil has 3.85 ohms resistance at 26.7X1 (80 °F) am bient
tem perature and will require no more than 3.2 amperes
at 12 vols D.C. Since the clutch coil is not grounded
internally, a ground lead is required as well as a "h o t"
lead.
Compressor Connector
Compressor connectors, are attached to the compres
sor rear head by means o f a single bolt and lock washer.
FRONT
DISCHARGE V A L VE PLATE
SHAFT SEAL ASM.
PULLEY
PULLEY BEARING
CLUTCH PLATE
AND
HUB ASSEMBLY
REAR HEAD
OIL PUMP
GEARS
SEAL SEAT
RETAINER RING
SEAL SLEEVE
PRESSURE RELIEF
VALVE
CLUTCH COIL
AND HOUSING
OIL PICK-UP TUBE
OIL SUMP
THRUST
RACE
REAR CYL INDER
HALF
FRONT CYLINDER
HALF
RETAINER RING (CO NVEX .
SIDE FACING SPACER)
SHAFT NUT
Fig. IB -4 -A x ia l Six Cylinder Compressor -Cross Sectional View
All have inlet and outlet connections connected by a
strap to form an integral unit.
G Models have gauge fittings located on the muffler
a n d com pressor inlet line. M otor Home Chassis unit
fittings are located on the inlet and outlet lines. C-K
model gauge fittings are located on the accumulator and
ev ap orator inlet line. All fittings are equipped with a
valve core.
Pressure Relief Valve
The pressure relief valve, located on the compressor
rear head, is simply a safety valve designed to open
automatically if the system pressure should reach a p re
determined level high enough to cause system damage.
A fter the pressure drops to a safe level the valve will
close. A fter such an occurence, the system should be
throughly checked to discover and correct the cause of
the abnorm al pressure increase, and then should be
purged, evacuated and charged.
RAD IA L FOUR CYLINDER CO M PRESSO R
A Radial four cylinder compressor (Fig. IB-5) is
used on a vehicle with a six cylinder engine.
T he compressor is m ounted to the engine by
m ounting brackets (Fig. IB-6) an d is belt driven by the
engine w hen the electromagnetic clutch assembly on the
compressor is energized by the air conditioning controls.
The purpose o f the compressor is to pum p low
pressure, low tem perature refrigerant vapor produced by
the evapo rator and compress it into a high pressure, high
tem perature vapor which can then be readily condensed
back to a liquid state by the condenser.
The compressor has a displacement o f 10.0 cu. in.
The compressor has variations in the pulley rim
d iam eter specified for the respective vehicle applications.
The basic compressor m echanism is a modified
scotch yoke with four cylinders located radially in the
same plane. Opposed pistons are pressed into a yoke
which rides upon a slider block located on the shaft
eccentric. Rotation o f the shaft provides reciprocating
piston motion with no "connecting rods". The m echa
nism is completely balanced with counterweights. Needle
bearings are used for the shaft journals and the shaft
eccentric. Pistons and yokes, along with the m ain
cylinder housing an d fro nt cover, are m ade from
alum in um to provide light weight. Teflon piston rings
are used to provide both a gas compression seal and
piston-to-bore bearing surface. The outer shell is a
simple steel band which encloses a large annu lar
discharge muffler space.
Two O-rings provide a seal between the compressor
shell and the compressor cylinder. A ru b b er seal ring
seals the front head to the cylinder assembly and the
sh aft seal assembly provides a front head to shaft seal.
R efrigerant flows into the crankcase from the
connector block at the rear, is draw n through the reeds
attached to the piston top during the suction stroke, and
is discharged outward through the discharge valve plate
which is held in place at the top o f the cylinder by a
snap ring. D ischarge gas flows out of the compressor
muffler cavity through the connector block at the rear.
Clutch Coil
The clutch coil is molded into the steel coil housing
an d must be replaced as a complete assembly. Three
protrusions on the rear o f the housing fit into alignment
holes in the compressor front head. The coil is secured to
the front h e a d by a pressed fit between the coil housing
and neck portion of the fron t head. The coil has 3.65
ohm s resistance at 26.1X1 (80 °F) am b ient and will
require no m ore than 3.2 am peres at 12 volts D.C. The
clutch coil has two terminals for the power and ground
leads.
shaft and is tightened against the shaft. The rotor and
hub is a welded assembly and contains six threaded holes
for mounting the pulley rim. The pulley rim is secured to
the rear portion o f the rotor by six screws and six special
lock washers.
A two-row ball bearing is pressed into the rotor hub
and held in place by three punch stakes, 1200 apart, into
the rotor hub near the hub bore. The entire clutch coil,
pulley rim, rotor and bearing assembly is pressed on the
front head o f the compressor and secured by a retainer
ring.
W hen power is supplied to the clutch coil the
arm ature plate o f the drive plate and hub assembly
electromagnetically engages the slotted portion o f the
rotor face which then drives the crankshaft through the
drive plate leaf springs and hub.
Refrigerant Lines
Special refrigerant hose lines are required to carry
the refrigerant liquid and vapor between the various
system components. The hose line with the smallest
diam eter is called the high pressure liquid line. It is
routed from the condenser or receiver-dehydrator to the
evaporator or thermostatic expansion valve. The large
diam eter hose line connecting the compressor and
evaporator (or accumulator) is the low pressure vapor
line. The large diam eter hose between the compressor
and condenser is the high pressure vapor discharge line.
These hoses are constructed with a synthetic
material core covered by a woven fabric and coated for
extra protection. This hose is so constructed to withstand
the extreme pressures and temperatures found in the
m odern refrigeration system. None but special refriger
ant type hoses should be used.
All systems make use o f swaged type connections
(hose to metal fittings) with metal to metai fittings being
m ade using " O " rings. Care must be taken when making
these connections that they not be turned down too
tightly or dam age to the " O " rings m ay result.
Flexible refrigerant hoses should not be permitted
to contact the hot engine manifold nor should they be
bent into a radius o f less than 4 times their diameter.
M uffler
A muffler, located in the high pressure line from the
compressor to the condenser, serves as a surge cham ber
for high pressure gas to reduce the noise level o f the
system while in operation. The muffler is actually a
welded portion of the compressor connector assembly. It
is found on all truck air contiioning systems.
C lutch-Pulley
The m ovable part o f the clutch drive plate is in
f ro n t of an d adjacent to the rotor and bearing assembly.
T he arm a tu re plate, the movable m ember, is attached to
the drive hub through driver springs riveted to both
m em bers. The hub of the drive plate is pressed on the
com pressor sh a ft and keyed to the shaft by a square
drive key. A self-locking nut threads on the end o f the
Fan Slip Clutch
A special engine fan is used on most systems. It is a
19.5 inch six or seven bladed fan, limited by means o f a
viscous clutch to a m axim um speed o f 3400-3700 rpm,
regardless of the speed o f the engine. The silicone fluid
in the clutch transmits only enough torque to drive the
fan at this limited speed, thus avoiding excessive noise
1.
Screw
20.
B e lle v ille W a s h e r
2.
Locking W a s h e r
21.
O -R in g
S h e l l Assy.
3.
P u l l e y Rim
11 • P r e s s u r e R e l i e f V a l v e
22.
4.
C o il a n d
12.
O -R in g
23.
Ring S e a l
5.
R o tor B e a r i n g
13.
Screw
24.
M a in
6.
R o t o r a n d B e a r i n g As s y .
S h ip p in g P late
25.
F r o n t H e a d Assy.
H o u s i n g A ssy .
B e a rin g
7.
R e ta in in g Ring
15.
O -R in g
26.
S c r e w a n d W a s h e r Assy .
8.
C l u t c h D r i v e As s y .
16.
R e t a i n in g Ring
27.
O -R in g
9.
C lutch H u b Key
17 . V a l v e P l a t e Assy .
28.
S h a ft Seal
18.
C y l i n d e r a n d S h a f t Assy.
29.
Seal Seat
19 .
Thrust W a s h e r
30.
R e t a i n in g Ring
10 . S h a f t N u t
Fig. lB-5--Radial Four Cylinder Compressor-Exploded View
and power consum ption by the fan at higher engine
speeds.
Condenser
In a properly charged system, the condenser delivers
sub-cooled liquid. This is because all the vapor condenses
before the end o f the condenser and the rem aining
portion o f the condenser subcools the liquid.
Receiver-D ehydrator (G and M o to r Hom e
Chassis M odels)
The receiver-dehydrator, serving as a reservoir for
storage o f high pressure liquid produced in the
condenser, incorporates a screen sack filled with the
dehydrating agent.
OUTLET
Fig. IB 6- Compressor M ou n tin g - L6 Engine
T he receiver-dehydrator, used prim arily as a liquid
storage tank, also functions to trap minute quantities of
moisture and foreign material which may have rem ained
in the system after installation or service operations. A
re frig e ran t sight glass is bult into the receiverd e h y d ra to r to be used as a quick check o f the state and
condition o f charge o f the entire system. The receiverd eh y d ra to r is mounted near the condenser.
S ig h t Glass (G and M o to r Hom e Chassis Models)
W hile having no real function to perform in the
system, the sight glass is a valuable aid in determ ining
w heth er or not the refrigerant charge is sufficient and for
elim inating some guess work in diagnosing difficulties.
The sight glass, is built into the receiver-dehydrator
outlet connection and is designed and located so that a
shortage of refrigerant at this point will be indicated by
the appearance o f bubbles beneath the glass. The dust
cap provided should be kept in place when the sight
glass is not in use.
T h erm o static Expansion Valve (Fig. IB -7 )
C-K Overhead, G C60 and O verhead and Motor
Home Chassis systems use a thermostatic expansion
valve in place o f a float system.
The valve consists prim arily o f the power element,
body, actuating pins, seat an d orifice. At the high
pressure liquid inlet, is a fine mesh screen which prevents
dirt, filings or other foreign m atter from entering the
valve orifice.
W hen the valve is connected in the system, high
pressure liquid refrigeran t enters the valve through the
screen from the receiver-dehydrator or condenser and
passes on to the seat an d orifice. Upon passing through
the orifice the high pressure liquid becomes low pressure
liquid. T he low pressure liquid leaves the valve and flows
into the e vaporator core where it absorbs heat from the
e vapo rato r core and changes to a low pressure vapor.
Fig. lB-7--Expansion Valve
and leaves the evaporator core as such. The power
element bulb is clamped to the low pressure vapor line
just beyond the outlet o f the evaporator (fig. IB-7).
The operation o f the valve is quite simple. It is a
matter o f controlling opposing forces produced by a
spring and the refrigerant pressures. For example: The
pressure in the power element is trying to push the seat
away from the orifice, while the adjusting spring is
trying to force the seat toward the orifice. These
opposing pressures are established in the design of the
valve so that during idle periods the adjusting spring
tension and the referigerant pressure in the cooling coil
are always greater than the opposing pressure in the
power element. Therefore, the valve rem ains closed.
W hen the compressor is started, it will reduce the
pressure and tem perature of the refrigerant in the
cooling coil to a point where the vapor pressure in the
power element becomes the stronger. The seat then
moves off the orifice and liquid starts to flow through the
valve orifice into the cooling coil.
The purpose o f the power element is to help
determ ine the quantity o f liquid that is being metered
into the cooling coil. As the tem perature of the low
pressure line changes at the blub, the pressure o f the
vapor in the power element changes, resulting in a
change o f the position o f the seat. For example if the
cooling coil gets more liquid than is required, the
tem perature o f the low pressure line is reduced and the
resultant lowering o f the bulb tem perature reduces the
pressure o f the vapor in the power element, allowing the
seat to move closer to the orifice. This immediately
reduces the am ount of liquid leaving the valve. Under
norm al operation, the power element provides accurate
control o f the quantity o f refrigerant to the cooling coil.
To employ our tire pu m p analogy once more for
clarity, it is the same situation that would exist if you
were inflating a tire with a very slow leak. Providing you
pu m p ed the air into the tire as fast as it leaked out. you
would be able to m aintain pressure even though the air
would merely be circulating through the tire and leaking
out through the puncture.
A ccum u lato r-C -K M odels (Fig. IB -8 )
T he accumulator is located at the evaporator outlet.
Its most im p ortant function is not to "accum ulate"
although this too is im portant. Its prim ary function is to
separate liquid retained from vapor, retain the liquid
and release the vapor to the compressor.
Thus, in and ideal accumulator with no oil bleed
hole, an d in a correctly designed system, no liquid can
get to the compressor.
In an actual accumulator, there is some entrained
liquid in the vapor stream to the compressor. The
measure o f a good accumulator is how well it separates
vapor from liquid and how little entrained liquid is
released to the com pressor. Also, in an actual
accumulator, an oil bleed hole is required to prevent
trap ping o f oil in the bottom o f the accumulator; this oil
bleed hole bleeds some liquid refrigerant as well.
Therefore, flow out o f the accumulator to the
compressor consists mostly of vapor with the addition of
entrained liquid and liquid flow through the oil bleed
hole.
A bag o f desiccant (dehydrating agent) is located in
the base of the accumulator as a moisture collecting
device.
N OTE: There is no sight glass in the accumulatorclutch cycle system.
Expansion T ube-C -K Models
Expansion tube flow rate depends on pressure
difference and on subcooling; however, the flow rate is
more sensitive to subcooling.
The expansion tube is located in the evaporator inlet
line (fig. IB-9).
Therm ostatic Switch
System tem perature is controlled by running the
compressor intermittently, automatically turning it on
and off as necessary to m aintain proper temperatures.
The compressor is started and stopped through the use o f
an electro-magnetic clutch and a thermostat affected by
variations in temperature.
The thermostatic switch incorporates a metallic tube
which contains a highly expansive gas. This tube is
inserted into the evaporator inlet line (C-K Four-Season
System) or is located in the air stream as it leaves the
evaporator (Motor Home Chassis Unit). The tube leads
to a bellows operated switch. As air tempeature rises, the
gas inside the tube expands, travels through the tube to
the bellows and closes the electrical switch which engages
the compressor clutch.
As soon as the compressor starts running, the
tem perature begins to go down. As the air being cooled
gets colder, the gas in the thermostatic tube begins to
reduce the pressure on the switch bellows. This allows the
X T *
switch contact
disengages.
to
open
and
the
compressor
clutch
Low R efrigerant Charge P rotection System
C-K-G Models
The compressor discharge pressure switch perform s
the function o f shutting off the compressor when it
senses low refrig erant pressure. The switch is located in
the evaporator inlet line (high pressure). The switch
electrically is wired in series between the compressor
clutch and the master switch on the control. W hen the
switch senses low pressure it breaks contact and opens
the circuit to the compressor clutch, thus shutting off the
A / C system an d preventing compressor failure or
seizure.
The compressor discharge pressure switch also
perform s the function o f the am bient switch as the
pressure at the switch varies directly with am bient
tempeatures. The compressor should not run below
-3 .91 (25 °F) am bient or 37 psi at the switch. The
compressor should run in A / C modes above 7.2 C (45 F)
a m b ien t or 42 psi at the switch.
T he switch interacts with other switches so that in an
A / C system where the compressor will not operate above
12 °C (45 °F) am bient the following components should
be checked for continuity:
1. Compressor discharge pressure switch.
2. Master switch (on control head).
If both switches show proper continuity, check the
harness for shorts or im proper ground conditions.
SYSTEM CONTROLS
FOUR-SEASON SYSTEM (C-K M O DELS) FIG. IB -1 0
The system selector lever (air control lever)
determ ines the mode o f operation: OFF, MAX, N O R M ,
BI-LEVEL, VENT, HEATER, DEF. W hen the system
selector lever is placed in the MAX, N O R M , BI-LEVEL
or DEF. positions, electical circuit connection is made to
the compressor clutch through the control panel switch
and the discharge pressure switch. If the compressor
discharge pressure switch is closed (am bient tem perature
above approxim ately 5 . 5 ^ (42 T ) , the compressor will
run. In the O FF, or EC O N O M Y , (VENT or HEATER)
positions, the compressor is not energized.
The system selector lever also determ ines the
direction o f outlet air flow. Moving the lever from mode
to mode varies the position o f a sliding-type vacuum
valve on the control. The position o f the vacuum valve
will supply vacuum to, or vent, vacuum diaphragm s
which position the upper and lower mode and defroster
air doors in the selector duct assembly. The position of
these air doors determines if output air flow is from
heater outlet (OFF), the heater outlet with slight air flow
from defroster nozzles (HEATER), heater and A /C
outlets (VENT), A / C outlets only at MAX and N O R M ,
heater. A /C and defroster outlets (BI-LEVEL) or the
defroster nozzles with slight air flow from the heater
outlet (DEF).
W hen the system is in M AX A /C mode and the
tem perature lever is at full CO LD the air inlet door is
positioned to reduce the supply o f outside air from
a p p ro x im a tely 100% to a p p rox im ately 20%. The
re m ain der of the air input 80% to the A /C system is then
taken from the interior o f the passenger compartment.
This recirculation o f interior air (recirc operation)
provides a source of fast cool down of interior
temperatures.
A switch connected to the selector lever overrides
the blower (F A N ) switch (in MAX A /C ) and
automatically provides high blower speed.
Tem perature Control
The tem perature lever determines the temperature
of outlet airflow by positioning the tem peature door in
the slector duct assembly, through the motion of a
bowden cable linking the control panel lever to the
tem perature door.
NOTE: An engine thermal switch prevents LO
blower operation until the tem perature at the
switch reaches 3 5 1 (95 °F). This blower delay can
be by-passed by placing the fan switch in any of
the other three positions.
Fan Switch
The blower (FA N ) switch provides a means of
selecting! th e 'a m o u n t o f airflow from the system by
regulating the speed o f the blower motor. There are,
however, limitations to the control of blower speed. To
provide constant ventilation, the blower m otor electrical
circuitry prevents the blower motor from being shut off
w hen the ignition switch is on. Therefore, the blower
speeds available are HI, LO and two m edium speeds.
The control m aster switch incorporates a n "over
ride " function which overrides the blower speed switch
and automatically provides HI blower speed when the
system selector lever is in MAX and the temperature
lever is set to full COLD.
System Operation - CK Truck
System operation is as illustrated in Fig. IB-11.
Vacuum Schem atic - CK Truck
Fig. lB-10-Four-Season System Controls (C-K
Models)
The CK Truck air conditioning vacuum schematic is
illustrated in Figure IB-12.
S Y S T E M O P E R A T IO N - C K T R U C K
SELECTOR
LEVER
POSITION
COMPRESSOR
BLOWER
SPEEDS
A V A IL
AIR
SOURCE
AIR
ENTERS
VEHICLE
HEATER A/C
DOOROPEN TO:
HEATER
DEFROSTER
DOOR-OPEN TO:
OFF
OFF
LOW
OUTSIDE
FLOOR OUTLETS
HEATER
HEATER
M A X A/C
ON
HI
INSI DE%
DASH OUTLETS
A/C
HEATER
NORM A/C
ON
ALL
OUTSIDE
DASH O UTLETS
A/C
HEATER
OUTSIDE
FLOOR AND
DASH OUTLETS
A /C &
HEATER
HEATER
B I-LE VEL
ON
ALL
VE NT
OFF
ALL
OUTSIDE
DASH OUTLETS
A/C
HEATER
HTR
OFF
ALL
OUTSIDE
FLOOR OUTLETS
HEATER
HEATER
HEATER
DEFROST
DEF
OUTSIDE
DEFROST OUTLETS
ON
ALL
NOTE % 100% Inside air is not availab e, some bleed through o f outside air is allowed.
Fig. 1 B 1 1 -S yste m Operation - CK Truck
Fig. 1B- 12 -Air C o n d itioning Vacuum Schematic - CK Truck
O VERHEAD SYSTEM (C-K MODELS)
This system operates in conjunction with the FourSeason System. Since refrig eran t flow is controlled by the
front system, the only control provided for on the
overhead system is a three-speed fan switch (LOW,
MED, HI). T he fan switch is mounted in the instrum ent
panel, to the right o f the steering coloumn (fig. IB-13.
In the O F F position, the blower is inoperative;
however, refrigerant is circulating in the system if the
Four-Season System is ON. In any o f the three blower
positions (LOW, MED, HI), the blower will be operative
regardless if the Four-Season System is ON.
N OTE: To o btain m axim um cooling, the FourSeason System should be on A /C , temperature
amplifier on the control and th e rm iste r
evaporator) to control compressor operation.
on
the
(Heater-Defrost Modes)
The tempeature lever determ ines the tem perature of
outlet air flow by positioning the tem perature door in the
heater distributor assembly, through the motion o f a
bowden cable linking the control panel lever to the
tem perature door.
Fan Switch
Fig. IB -13-O verhead U n it Control (C-K Models)
lever on COLD, blower switch on HI and the
overhead unit blower switch should be on HI.
C 6 0 SYSTEM (G M O DELS)~FIG . IB -1 4
The system selector lever (air control lever)
determ ines the mode o f operation: OFF, MAX, N O R M ,
HEAT, D E F O G or D EF. W hen the system selector lever
is placed in the A /C , positions, electrical circuit
connection is m ade to the compressor clutch through the
control panel switch and the discharge pressure switch. If
the switch is closed (am bient tem perature above 4 .4 XI.),
the compressor will run. In the O FF, HEAT, D E F O G or
D E F positions, the compressor is not energized.
The system selector lever also determines the
direction o f outlet air flow. M oving the lever from mode
to mode varies the position o f a rotary vacuum valve on
the control. The position o f the vacuum valve will supply
vacuum to, or vent, vacuum diaph rag m s which position
the air and defroster doors in the heater distributor duct
and the outside air door in the right side o f the cowl
plenum. The position o f these doors determines if ouput
air flow is from the A / C outlets using recirc air (MAX),
or recirc and outside air (N O R M ), the heater outlet
(HEAT), heater and defroster outlets (D E FO G ), or the
defroster nozzles with slight air flow from the heater
outlet (DEF).
The blower (FAN ) switch provides a means of
selecting the am ount o f air flow from the system by
regulating the speed of the heater or A /C blower motor.
There is no O F F position on the fa n switch; however the
blower is inoperative if the selector lever is placed in the
O F F position. If the selector lever is placed in any of the
heater or A /C modes, the appropriate blower is
operative. The blower speeds available are LO, M l, M2
and HI.
O VERHEAD SYSTEM (G MODELS)
This system opeates in conjunction with the C60
system. Since refrigerant is controlled by the C60 system,
the only control provided on the rear overhead system is
a three speed blower switch (fig. 1B -15).
In the O F F position, the blower is inopertive;
however, refrigerant is circulating in the system if the
front system is ON. To operate the rear overhead system,
simply select the desired blower speed (LOW, MED, HI).
W hen air circulation only is desired, the rear A /C
Tem perature Control
(A /C Modes)
T he tem perature lever activates a potentiom eter on
the control assembly (connected in series with the
Fig. IB-15-O verhead U nit Control (G Models)
Fig. 1B-14--C60 System Controls (G Models)
Fig. lB -1 6 -M o to r Home U n it Control
M e t a l T u b e O .D .
1 /4
3/8
1/2
5/8
3/4
T h r e a d and
F ittin g Size
A lu m . T ubing
T orque*
7 /16
5/8
3/4
7/8
1 -1 /1 6
6
12
18
24
30
*Foot Pounds
blower m otor m ay be operated in d ep end en t o f the front
A / C blower m otor and without the cooling function.
DASH M O U N T E D U N IT (M O T O R HO M E
CH A SS IS U N IT S )
This system is self contained and is mounted below
the dash by the body m anufacturer. System controls
consist o f an AIR knob and T E M P knob located in the
center o f the unit face plate (fig. IB-16).
Air Knob
T u rning the AIR knob clockwise operates a three
speed (L O W -M E D -H I) blower motor.
Temp Knob
This knob is used to control the degree o f cooling
desired. Fully clockwise at CITY provides maximum
cooling, while turning the knob to H IW AY provided
adequate cooling for highway operation.
N O T E: Reduced cooling could be encountered
w hen operating at highway speeds with the controls
at the CITY setting. The heater must be fully off to
ob tain m axim um cooling.
R E FR IG E R A N T LINE C O N N E C T IO N S
"
0
"
Rings
Always replace the " O " ring when a connection has
been broken. W hen replacing the " O " ring, first dip it in
clean re frigeration oil. Always use a backing wrench on
" O " ring fittings to prevent the pipe from twisting and
d a m a g in g the " O " ring. D o not overtighten. Correct
torque specifications are as follows:
CAUTION: Where steel to alum inum connec
tions are being made, use torque fo r alum inum
tubing.
Hose Clam ps
W h e n hose clamp connections are encountered,
special procedures are necessary for both removal and
installation.
Removal
Fig. IB-17- Hose Clamp Connections
1. Carefully, with a sharp knife, make an angle cut
in the hose as shown in Figure IB -17. This should loosen
the hose so that it may be worked off the fittings.
2.
Cut off slit end of hose.
CAUTION: Use only approved refrigeration
hose. Never use heater hose. Use extereme care
not to nick or score the sealing beads when
cutting o ff the hose. Cutting the hose lengthwise
m ay result in this problem.
Installation
1.
Coat tube and hose with clean refrigeration oil.
2. Carefully insert hose over the three beads on the
fitting and down as fa r as the fourth, or locating bead.
Hose must butt against this fourth bead.
CAUTION: Use no sealer o f any kind.
3. Install clamps on hose, hooking the locating
arms over the cut end o f the hose.
4. Tighten the hose clamp screw to 35-42 in. lbs.
torque. DO N O T R E T O R Q U E . The clamp screw torque
will normally decrease as the hose conform s to the force
o f the clamp. The screw should be retorqued only if its
torque falls below 10 in. lbs. In this case, retorque to 2025 in. lbs. F urther tightening may dam age the hose.
DIAGNOSSS
REFRIGERANT SYSTEM
The following is a description o f the type o f
sym ptom each refrig eran t com ponent will evidence if a
defect occurs:
CO M PRESSO R
A compressor defect will ap p e a r in one o f four
ways: Noise, seizure, leakage, or low discharge pressure.
N O T E : R esonant com pressor noises are not cause
for alarm ; however, irregular noise or rattles m ay
indicate broken parts or excessive clearances due to
wear. To check seizure, de-energize the magnetic
clutch and check to see if drive plate can be
rotated. If rotation is impossible, compressor is
seized (See "False C om pressor Seizure"). To check
for a leak, refer to leak testing in the service
m anual. Low discharge pressure m ay be due to a
faulty internal seal o f the compressor, or a
restriction in the compressor.
Low discharge pressure m ay also be due to an
insufficient refrigerant charge or a restriction
elsewhere in the system. These possibilities should
be checked prior to servicing the compressor. If the
compressor is inoperative, but is not seized, check
to see if current is being supplied to the magnetic
clutch coil terminals.
CO NDENSER
A condenser may be defective in two ways: it may
leak, or it may be restricted. A condenser restriction will
result in excessive compressor discharge pressure. If a
partial restriction is present, sometimes ice or frost will
form im m ediately after the restriction as the refrigerant
expands after passing through the restriction. If air flow
through the condenser or rad ia to r is blocked, high
discharge pressures will result. D uring norm al condenser
operation, the outlet pipe will be slightly cooler than the
inlet pipe.
RECEIVER-DEHYD RATO R
A defective receiver-dehydrator may be due to a
restriction inside the body o f the unit. A restriction at
the inlet to the receiver-dehydrator will cause high head
pressures. Outlet tube restrictions will be indicated by
low head pressures and little or no cooling. An
excessively cold receiver-dehydrator outlet may be
indicative o f a restriction.
E X P A N S IO N VALVE
A m alfunction o f the expansion valve will be caused
by one o f the following conditions: valve stuck open,
valve stuck closed, broken power element, a restricted
screen o r an im properly located or installed power
elem ent bult. The first three conditions require valve
replacement. The last two may be corrected by replacing
the valve inlet screen and by properly installing the
power element bulb.
Attachment o f the expansion valve bulb to the
evaporator outlet line is very critical. The bulb must be
attached tightly to the line and must make good contact
with the line along the entire length of the bulb. A loose
bulb will result in high low side pressures and poor
cooling.
Indications o f expansion valve trouble are provided
by Perform ance Tests; consult Diagnostic Charts.
VALVE STU CK OPEN
NOISY COM PRESSOR.
N o Cooling - Freeze Up.
VALVE STUCK CLOSED, BROKEN POW ER
E L E M E N T OR P L U G G E D SCREEN
Very Low Suction Pressure.
N o Cooling.
PO ORLY LOCA TED POW ER E L E M E N T BULB
N orm al Pressure.
Poor Cooling.
Diagnosis for Defective Valve
The following procedure must be followed to
determine if a malfunction is due to a defective
expansion valve.
1. Check to determ ine if the system will meet the
perform ance test as outlined previously. If the expansion
valve is defective, the low pressure readings (evaporator
pressure) will be above specifications.
2. The loss o f system perform ance is not as evident
when the compressor head pressure is below 200 psi.
Therefore, it m ay be necessary to increase the system
head pressure by partially blocking the condenser.
Disconnect the blower lead wire and repeat the
"perform ance check" to determ ine if the evaporator
pressure can be obtained.
3. The system will also indicate a low refrigerant
charge by bubbles occurring in the sight glass.
EVAPO RATOR
W hen the evaporator is defective, the trouble will
show up as an inadequate supply o f cool air. A partially
plugged core due to dirt, a cracked case, or a leaking seal
will generally be the cause.
REFR IG ER A N T LINE R E S TR IC TIO N S
Restrictions in the refrigerant lines will be indicated
as follows:
1. Suction Line - A restricted suction line will
cause low suction pressure at the compressor, low
discharge pressure and iittle or no cooling.
2. Discharge Line - A restriction in the discharge
line generally will cause the pressure relief valve to open.
3. Liquid Line - A liquid line restriction will be
evidenced by low discharge and suction pressure, and
insufficient cooling.
S ight Glass Diagnosis (G and M o to r Hom e
Chassis U nits)
At tem peratures higher than 21 XT (70 degrees F),
the sight glass may indicate w heter the refrigerant
charge is sufficient. A shortage o f liquid refrigerant is
indicated after above five minutes o f compressor
operation by the appearance o f slow-moving bubbles
(vapor) or a broken column o f refrigerant under the
glass. Continuous bubbles m ay app ea r in a properly
ch arged system on a cool day. This is a no rm al situation.
If the sight glass is generally clear and perform ance is
satisfactory, occasional bubbles do not indicate refriger
an t shortage.
If the sight glass consistently shows foam ing or a
broken liquid column, it should be observed after
partially blocking the air to the condenser. If under this
condition the sight glass clears and the perform ance is
otherwise satisfactory, the charge shall be considered
adequate.
In all instances w here the indications o f refrigeran t
shortage continues, additional refrigerant should be
added in 1/4 lb. increments until the sight glass is clear.
A n additional charge o f 1/2 lb. should be added as a
reserve after the glass clears. In no case should the
system be overcharged.
VACUUM SYSTEM DIAGNOSIS
(C-K-G FOUR-SEASON SYSTEM )
Start the engine and allow it to idle - move the
selector lever to each position and refer to the vacuum
d iagram s and operational charts for proper airflow, air
door functioning and vacuum circuits. If air flow is not
out of the proper outlets at each selector lever position,
then proceed as follows:
1. Check for good hose co nn ectio ns-at the
vacuum actuators, control head valve, reservoir, tees, etc.
2. Check the vacuum source circuit as follows:
Install vacuum tee and gauge (with restrictor) at the
vacuum tank outlet (see V acuum D iagram ). Idle the
engine and read the vacuum (a norm al vacuum is
equivalent to manifold vacuum) at all selector lever
positions.
a. Vacuum Less Than N orm al At All PositionsRemove the tee and connect the vacuum gauge
line directly to the tank - read the vacuum. If
still low, then the problem lies in the feed circuit,
the feed circuit to the tank or in the tank itself.
If vacuum is now normal, then the problem lies
downstream.
b. Vacuum Less T han N orm al at Some Posi
tio n s -
If vacuum was low at one or several o f the
selector lever positions, a leak is indicated in
these circuits.
c. Vacuum N orm al at Alt P osition sIf vacuum was norm al and even at all positions,
then the m alfunction is probably caused by
improperly connected or plugged
defective vacuum valve or valves.
lines or a
3. Specific Vacuum Circuit Check
Place the selector lever in the m alfunctioning
position and check for vacuum at the pertinent
vacuum actuators. If vacuum exists at the actuator
but the door does not move, then the actuator is
defective or the door is mechanically bound. If low
or no vacuum exists at the actuator, then the next
step is to determ ine w hether the cause is the vacuum
harness or the vacuum valve. Check the vacuum
harness first.
Vacuum Harness Circuit Check
4.
a.
Disconnect the vacuum harness at the control
head.
b. The black line ( # 1 ) should show engine
vacuum - if not, trace back through connector to vacuum
tank.
c. To check any individual circuit place the
selector lever at the involved circuit position and check
for vacuum presence.
CHECK IN G SYSTEM O P ER A TIO N
1. O perate system for a maxim um o f five minutes
at maximum cooling, high blower speed and with engine
operating at 2000 R P M (exhaust should be vented if
inside).
2. W hen system is stabilized, the pressure gauges
on the charging station should read pressures corre
sponding to values listed under P E R F O R M A N C E
DATA.
3. W hen correct system pressures are observed,
check system charge as described under "R efrig era n t
Quick Check Procedure".
4. Feel outlet air distribution to ensure that cold
air is being distributed.
5. Disconnect gauge lines and cap fittings.
C A U TIO N : When removing gauge lines fr o m
fittings, be sure to remove the adapters fro m the
fittings rather than the gauge lines fr o m the
adapters.
PER FO R M A N C E TEST
U n d e r norm al circumstances, it will not be necessary
to Perform ance Test a sytem as outlined below; however,
in certain instances, the following procedure may be
advantageous in diagnosing system malfunction.
The following fixed conditions must be adhered to
in order to make it possible to compare the perform ance
o f the system being tested with the standards below:
1. Doors and window closed. (Vehicle inside or in
shade.)
2. Hood up and engine exhaust suitably ventilated.
3. Vehicle in N E U T R A L with engine running at
2000 rpm.
4. Air C onditioning controls set for • M axim um cooling.
• High blower speed
1B-18
CO M PR ESSO R DIAGNOSIS
Retrace electrical circuit back to source of power loss.
NO V O L T A G E A T
C O M PRESSO R
C O IL.
(See wiring diagrams).
C-K-G MODELS:
Check for defective discharge Pressure Switch by jumping switch connector terminals.
operates, check for low refrigerant charge.
If compressor
If charge is satisfactory, switch is defective-replace.
COMPRESSOR N O T E N G A G E D .
PRO PER
VO LTAG E
TO
C O M P R E S S O R C O IL.
C LU T C H S L IP P IN G .
C h eck f o r p ro p e r g ro u n d and
g o o d cle an e le c tric a l c o n ta c t
C h eck f o r p ro p e r a ir gap.
I f p re v io u s ste p does n o t
C o rre c t if necessary.
c o rre c t c lu t c h slip p ag e ,
(.0 2 2 .0 5 7 )
re p a ir c o m p re s s o r.
ENGAGED
LIGHT
COM PRESSO R
I f c o il is s t ill in o p e ra tiv e ,
re p la ce c o m p re s s o r c o il.
at te rm in a ls .
B U T N O T O P E R A T IO N A L .
B E L T S L IP P IN G .
C h eck a n d c o rre c t
b e lt te n s io n .
TRUCK
Fig. IB-18
A d d one p o u n d
R E F R IG E R A T IO N
H IG H T O R Q U E
C O M PRESSO R.
CHARG E
re frig e ra n t.
IS D E P L E T E D .
(S E IZ E D )
H A S SO M E
R E F R IG E R A N T .
T H R O W S O IL .
rl LEAKS
REFRIGERANT.
R e p a ir c o m p re s s o r.
O p e ra te a n d leak
re m o v in g c o m p re s s o r.
te s t s y s te m .
MANUAL
Diagnosis
8 lo w o u t seal c a v ity
COM PRESSO R
L e a k te s t c o m p le te
syste m b e fo re
R e p a ir c o m p re s s o r.
w it h a ir hose and
le ak test.
DO ES
NOT
LEAK
W ip e o ff o il - O .K .
N O IS Y O N L Y W H E N
C LU T C H
IS E N G A G E D .
CO MPRESSOR
lin e s to u c h in g m e tal
p a rts . Is o la te and
C h eck a n d a d iu s t
b e lt te n s io n .
R e p a ir c o m p re s s o r
if noise is
o b je c tio n a b le .
re -e va lu a te noise.
N O IS Y .
N O TE:
Check f o r re frig e ra n t
A/C system noise is to
be evaluated in the
vehicle with doors and
windows closed and low
blower on.
N O IS Y W H E N
C LU T C H
IS NO T E N G A G E D .
SERVICE
-Compressor
SYSTEM
R e m o ve c o m p re s s o r b e lt
C h eck f o r in te r fe re n c e
I f in te rfe re n c e
to d e te rm in e if noise
b e tw e e n c o il h o u s in g
e x is ts , re p a ir
s till persists.
a nd p u lle y h u b .
c o m p re s s o r.
INSUFFICENT COOLING-FOUR SEASON SYSTEM(C-K MODELS)
I
M o v e te m p e ra tu re le v e r ra p id ly b a ck a nd fo rth fro m m ax
h ea t to m a x c o ld Listen fo r te m p e ra tu re d o o r hitting a t e a c h end.
|
H ittin g
] -------------------------------------------------------------------1------------------------------------------------------------------1 N o t H ittin g |
Adjust D o or
1. Set T e m p eratu re Leve r a t D e ten t to the Right o f C o ld
2 Set S e le cto r L e ve r a t A / C
3. Set B lo w e r S w itch on High
4. O p e n D o ors a n d H o o d
5. W a rm Engine
6. Run Engine at ld le ( E x c e p t 0 6 M o d e ls)
1 0 0 0 R P M . ( C -K 0 6 M o d e ls )
Feel For A ir Flow A t H e a te r A n d A / C
O utle ts
Som e o r A ll A ir Flow From H e ate r O utle t
C h eck M o d e D oor O p e ra tio n -R e p a ir
O f f A ll the Tim e
A ir Flow From
A / C O u tle ts O n ly
------ 1-------C h eck C o m p re ssor Hot Lead W ire W ith Test
C h eck V isually For C om p re ssor Clutch O p e ra tio n
Light o r P lace a Jum per W ire From The
| E ng a ge d o r C y c lin g j"~
NOTE :
THIS SYSTEM DOES NOT HAVE A SIGHT GLASS. UNDER NO
CIRCUMSTANCES SHOULD A SIGHT GLASS BE INSTALLED
I
Feel Liquid Line B efo re Expansion Tube
------------------------------------------------------------------ 1
_______________________________
|-----------------------------------
I C o ld
o
o
Visually Look For Frost Spot to
L ocate Restriction R epair, E vacuate ,
Z3
O
( O .K.)
~T
to o c o ld - See P e rfo rm a n ce D ata
High -
_r
System
(OK.)
W a rm as
~T~
( O.K.)
Frost
~T~
D e fe c tiv e Therm ostatic
S w itch
I
R eplace
I
System
(O K .)
Therm ostatic
S w itch
High To N o rm a l
System
a n d E va cu a te , C h a rg e a n d
C h eck System .
( O .K.)
at High Side Fitting
( A t Pressure S w itch )
System
o r R e place a n d E va cu a te , C h argi
System
A bove
R e place E xpansion Tube
P lugged E xpansion Tube. Repair
N o Frost
D ischarge
Pressure S w itch
Pipes Sam e T e m p e ra tu re ( C old)
o r O u tle t C o ld e r Than Inlet
Check R e frig e ra n t Pressure
Lo*
E va p o ra to r Pipes For Frost.
a t the F o llo w in g :
|
For P lugged Filter E vacu a te a n d C h a rg e
Pipes Still C o ld a nd
See P e rfo rm a n ce D ata
( See P e rfo rm a n ce D a ta)
i
To L ow ,
I
C h eck For O p e n Circuit
System C h eck Inlet & O u tle t Pipe Tem p eratu res.
C h eck A ccu m u la to r Pressure
a n d O b s e rv e A ccu m u la to r a nd
if Clutch is Still n ot E n g a ge d , R eplace
C om p re sor Clutch - See the
_L
O u tle t T e m p eratu re
E ng a ge d
A p p ly E xternal G ro u n d to C o m p re sso r,
Leak C h eck S ystem -R epair Leak If N o
Leak is Found, C h eck E xpansion Tube
_L_
O u tle t Tem p eratu re S a tisfa cto ry o r
|
C h eck For B low n M a in Fuse
O v e ra u l M a n ua l
O
C h a n g e B lo w e r S pe e d
p
Inlet Pipe C o ld e r
Than O u tle t Pipe
Install the T h e rm o m e te r in A / C O u tle t and
C h eck P e rfo rm a n c e -S e e P e rfo rm a n ce Test
a nd P e rfo rm a n ce D a ta O u tlin e d E arler in
This Section.
I
System
| N o t E ng a ge d
W a rm
Pipes same Tem p eratu re o r
O u tle t C o ld e r Than Inlet
C h arge a nd C h eck The System
I
The B attery.
Feel E va p o ra to r Inlet a n d A ccu m u la to r O u tle t Pipes
-------------------------------- L -
Restriction in High Side o f System.
(TO
C o m p re ssor to The P ositive ( +) Term inal o f
a n d C h eck System.
I
System
(OK.)
( O .K .) -
I A b o v e 5 0 PSIG
C h eck C o m p re ssor C y c lin g
~r
Jump S w itch
O n C ontinuously f
C y c le s on a n d O f f
|
~r
C h eck For M issing E xpansion Tube
M issing
_L
D e fe c tiv e Therm o sta tic S w itch
~T
Install E xpansion Tube, E vacu a te ,
C h a rg e a n d Check System ,
Inlet S creen
i
__________
System
P lugged
C h a rg e a n d Check S ystem ,
i
i
Replace S witch, Evacuate,
System
Charge a nd C h eck System.
(O .K .)
I
System
C le a n
System O v e r-C h a rg e d .P u rg e ,
E vacu a te , C h a rg e a n d C h eck System.
I
System
System
( O.K.I
( O K .)
i
( O .K.)
~r~
R epair o r R e place S creen, E v a c u a te ,
C h a rg e a nd C h eck System
System
i
(OK.)
T“
Leak Check System,
R e place
In P lace
I
C h eck C om p re ssor
i
Com pressor Runs
i
D e fe ctive Switch
I
' 5 0 PSIG
Lost C h a rg e Leak Test a nd
R epair Evacuate,
( O K.)
D e fe c tiv e
S w itch
I
R e place
I
System
( O .K.)
INSUFFICIENT COOLING D IA GNO SIS CHART (EXCEPT C-K FOUR-SEASON SYSTEM)
The following procedures should be applied before performance testing an A/C System.
1. Check for proper belt installation and tension w ith J-23600.
2. Check for proper clutch coil terminal connector installation.
3. Check for clutch air Gap (.022 - .057).
4. Check for broken, burst, or cut hoses. Also check for loose fittings on all components.
I NORMAL AIR FLOW
\
5.
6.
7.
8.
9.
Check
Check
Check
Check
Install
1
JORMAL BLOWER OPERATION |
_______
CHECK FOR BLOWN FUSE, DEFECTIVE BLOWER SWITCH,
BROKEN WIRE, LOOSE CONNECTIONS, LOOSE BLOWER MOTOR
GROUND WIRE OR INOPERATIVE BLOWER MOTOR.
ICE BLOCKING
EVAPORATOR
NO FOAMING
CHECK FOR LOW EVAPORATOR PRESSURE
1. ALLOW SYSTEM TO WARM UP.
2. S10P ANU RESTART ENGINE.
3. CHECK EVAPORATOR PRESSURE
IM M EDIATELY AFTER RESTART AND
PULL DOWN OF EVAPORATOR PRESSURE.
, SYSTEM MAY BE EITHER FU LLY CHARGED OR FMPTY.
FEEL HIGH AND LOW PRESSURE PIPES AT COMPRESSOR.
HIGH PRESSURE PIPE SHOULD BE WARM. LOW PRESSURE
PIPES SHOULD BE COLD.
. IF PIPES ARE NOT INDICATING PROPER TEMPERATURES,
RECHARGE SYSTEM AS RECOMMENDED. IF NOZZLE AIR
TEMPERATURE IS STILL HIGH. CHECK EVAPORATOR
PRESSURE.
~T~
SYSTEM IS PROBABLY LOW ON REFRIGERANT.
CHECK FOR LEAKS, REPAIR, AND ADD
REFRIGERANT. IF FOAMING S TILL OCCURS,
CHECK FOR RESTRICTION IN REFRIGERANT
SYSTEM BETWEEN CONDENSER AND SIGHT
GLASS.
o
‘ CHECK EVAPORATOR PRESSURE!
NORMAL EVAPORATOR
PRESSURE
LOW EVAPORATOR
*
PRESSURE
33
C
o
t:
SYSTEM HAS EXCESS MOISTURE. REPLACE RECEIVER
UEHYDRATOR AND EVACUATE THOROUGHLY. RECHARGE
SYSTEM.
Check fo r malfunctioning
expansion valve-See
Component Diagnosis.
HIGH EVAPORATOR
*
PRESSURE
CHECK EVAPORATOR OUTLET LINE
EVAPORATOR OUTLET
LINE WARM
Check fo r loose or disconnected air distribution ducts,
restricted or leaking air ducts, partially closed air out
let valve or clogged evaporator core, if above check is
OK, check for ice blocking evaporator.
CHECK SIGHT GLASS
( f o a m in g ! "
LOW EVAPORATOR
•PRESSURE
:___
OWER NOT OPERATING
1
CHECK FOR AIR LEAKS THROUGH DASH PANEL.
DOORS, WINDOWS, OR FROM HEATER.
i
CHECK BLOWER OPERATION
CHECK DISCHARGE AIR TEMPERATURE (SEE PERFORMANCE DATA) 1
HIGH OUTLET AIR
TEMPERATURE
ro
o
- IN O OR LOW AIR FLOW I
CHECK AIR FLOW
I
DISCHARGE TEMPERATURE
AT OUTLET COLD
CD
fo r condenser air blockage due to foreign material.
fo r proper air ducting hose connections.
heater temperature dour adjustment, adjust if incorrect.
evaporator sealing fo r air leak, repair if leaking.
pressure gages and thermometer and make performance test.
NORMAL
EVAPORATOR PRESSURE
CHECK COMPRESSOR DISCHARGE PRESSURE
c/j
m
33
<
O
m
| Check Compressor Discharge Pressure. I
1. CHECK FOR LIQ UID LINE RESTRICTION
(FROST SPOT ON LINE). IF NOT,
2. CHECK FOR PLUGGED INLET SCREEN IN
EXPANSION VALVE. IF NOT,
3. CHECK FOR DEFECTIVE EXPANSION VALV E
BY REMOVING VALVE AND BLOWING THROUGH
V ALV E. IF U N A B IF TO RLOW THROUGH V ALV E.
BULB IS DISCHARGED. REPLACE EXPANSION
V ALVE.
LOW DISCHARGE
*
PRESSURE
Check fo r malfunctioning
expansion valve-See
Component Diagnosis.
* | HIGH DISCHARGE PRESSURE |
- I NORMAL DISCHARGE PRESSURE I
i
1. Check engine cooling system, fan clutch and check
for restricted air flow thru condenser.
2. Check expansion valve bulb contact. Correct if
necessary.
3. Check tor refrigerant restriction in condenser.
Return bends at equal elevation should be
approximately same temperature. If temperature
of bends is appreciably different, the cooler
bend indicates a restricted circuit, replace con
denser if restriction is found, If condenser is OK,
check for air in system. To check observe outlet
air temperature and compressor discharge
pressure while slowly discharging system at
receiver inlet connection.
OUTLET AIR TEMPERATURE
DROPS AS COMPRESSOR
DISCHARGE PRESSURE DROPS
•REFER TO PERFORMANCE
CHART FOR CORRECT PRESSURES
| LOW DISCHARGE PRESSURE \
Check for restriction in liquid line,
partially plugged inlet screen at
expansion valve, or defective
expansion valve, replace valve if
defective.
OUTLET AIR TEMPERATURE
INCREASES AS COMPRESSOR
DISCHARGE PRESSURE DROPS
i ...............
LEAK TEST SYSTEM, REPAIR
AS NECESSARY, DISCHARGE,
EVACUATE, AND RECHARGE.
REPLACE EXPANSION VALVE
' —r _ _ .
Refrigeration System is ok
1. Check for proper function of heater TEMPERATURE door.
L Check fo r proper sealing of evaporator case.
3. Check fo r proper operation and seal around temperature door.
4. Non-Foaming sight glass does not always indicate a fully
charged system. Add 1/2 lb. refrigerant and observe
performance.
5. Check for excess oil in system. A symptom of excess oil is a
slipping clutch or belt or broken belt. To remove excess oil
in system see "CHECKING COMPRESSOR OIL CHARGE".
NOTE: G-MODELS, Insufficient cooling, or too much cooling may
be the result of a potentiometer out of calibration; see "A m p lifier
Board Potentiometer Adjustm ent" in the Maintenance and Adjust
ment portion of this section.
c
>
ELECTRICAL SYSTEM DIAGNOSTIC CHART
BLOWER
MOTOR
B L O W E R M OTOR IN O P E R A T IV E
(C E R T A IN S P E E D S - E X C E P T H IGH
ON C-K F O U R - SE A SO N )
IN O PER ATIVE
( A N Y SPE E D)
Check for proper
fuse
|FUSE
(
BLOW N!
fuse
o k
)
Disconnect resistor connectors, connect one lead
of a self powered test light to any one terminal
and use the other lead to probe each of the
other terminals.
Th e f o l l o w i n g tests sh ou ld be made
With ign. switch in " R u n " position
and heater or A/C on, locate short in
one of the following wires: (see note)
w i t h the ig n iti o n s w it c h in " R u n "
p o s it io n , heater or A / C on and
b lo w e r s w it c h on high.
C-K Four-Season System
Check b lo w e r m o t o r g ro un d
X
X
| P O O R O R NO G R 0 U N D |
| Re pai r g r o u n d ]
I
g
ROUND
T E S T L I G H T DO E S NO T
OkI
L IG H T ON A L L
TEST L IG H T
T ER M IN ALS
I
Check m o t o r c o n n e c t o r w it h
JL
X
Check w ir e c o n n e c t o r on
Replace m o t o r
1. From fuse panel to blower switch.
2. From blower switch to resistor.
3. From resistor to blower motor.
b lo w e r relay w i t h 12 v o l t
test ligh t.
[L A M P
| LAM P DOES NOT L IG H T )
I L A M P L IG H T S
Diagnois
N O TE: Short circuit may be inter
mittent. If tester does not indicate
a short circuit, move heater harness
around as much as possible to re
create short circuit. Watch and listen
for arcing.
m o t o r to b lo w e r
IN A L L
Check w ir e c o n n e c t o r on b lo w e r
f r o m resistor t o b lo w e r relay).
relay w i t h 12 v o lt test light.
1
I LAM P LIG H T S l
Chart
| L A M P DOES NO T L I G H T j
Use 12 v o l t test lig h t a nd c hec k
I
lam p
lig h t s
Replace relay
!
1
LAMP DOES NOT L IG H T
IN A L L
POSITIONS
Co nne ct 12 v o lt test light at wire
relay.
X
Replace b lo w e r relay.
|L A M P
DOES N O T L I G H T |
X
Turn ignition key off and put Heater or A/C
Control in off position. With blower resistor wire
connector disconnected, connect a jumper lead
from battery positive terminal to the wire terminal
in connector. Use 12 volt test light to check for
voltage at wire at blower speed switch connector.
Repeat same test on the other wires.
Re pair open in wire
X
f r o m resistor to
b lo w e r relay.
LA M P L IG H T S ON
A L L W IR E S
w ir e t er m in al s at resistor.
X
LAMPOFF
POSITIO NS|
t e r m in a l on b lo w e r relay (wire
Repair open in
w ir e f r o m b lo w e r
LIG H TS
C O N D ITIO N IN G
With ignition switch in " R u n " position and heater
or A/C on, use 12 volt test lamp to check for
voltage at resistor connector with blower speed
switch in each position.
LA M P DOES N O T L IG H T l
| LAMP L IG H T s l
Except C-K Four-Season
ON
X
Replace resistor
12 v o lt test light.
L IG H TS
A L L T E R M IN A LS
AIR
Fig. IB -2 1 -E le ctrica l System
1. From fuse panel to master
switch on control.
2. From master switch to compressor
clutch.
3. Master switch to blower switch.
4. From blower speed switch to
resistor.
6. From resistor to blower motor.
LA M P L IG H T S
L A M P D O ES NO T L IG H T
ON A L L W IR E S
Replace b lo w e r speed
Repair open in
switch.
a ff e c te d wir e.
T
Replace resistor
Check F E E D wi re f r o m
resistor t o b lo w e r
speed s w it c h .
|
la m p
q n
|
'L A M P OFF I
_
speed s w it c h .
I
Re pair open in wi re
f r o m b lo w e r speed s w it c h .
1B -21
Replace b lo w e r
1B-22
E L E C T R IC A L S Y S T E M D IA G N O S T IC CHART
BLOWER M OTOR IN O P E R A T IV E
COMPRESSOR CLUTCH IN O P E R A T IV E *
A T HIG H SPEED O N LY
(C-K FOUR-SEASON SYSTEM)
^^hed^use^
Check
| FUSE BLOWN |
in-line fuse
FUSE OK |
I
Check Compressor S olenoid Ground
W ith ig n itio n switch in " R u n ” position, and A /C "O n ", connect
tester and locate short in one o f the fo llo w in g wires or com po
FUSE B L O W N !
Connect Tester. Use to check
w ire fro m ju n c tio n to blow er
relay to locate short. Repair
short c irc u it as required.*
nents. Replace a shorted w ire o r defective switch.
C-K M O D E L SYSTEMS
heater or A /C on, move the
blow er speed sw itch to Hi.
1. Wire fro m fuse panel to master switch (on control).
2. Master sw itch.
3. Wire fro m master sw itch to therm ostatic switch.
4. Therm ostatic sw itch.
5. Wire fro m therm ostatic switch to discharge pressure switch.
6. Discharge pressure switch.
Relay "c lic k ” should be
heard when sw itch is moved.
| C LIC K H E A R D I
—
1
I
NO C LIC K H E A R D !
-*
Check relay coil connector
w ith 12 v o lt test lig h t.
w ith 12 v o lt test lamp.
I LAM P DOES NOT L IG H T ! I LAM P L IG H TS I
Repair open in w ire
Replace blow er
relay.
fro m ju n c tio n block
to relay.
ok
|bad
ground
12 v o lt test light.
|
lam p
l ig h t s
Chart
I
1
Replace relay
Repair ground
Repair open
in w ire fro m
blow er speed
switch to relay.
* S h o rt c irc u it may be in te rm itte n t.
If tester does n o t indicate a short circ u it,
move harness around as much as possible
to re-create short c irc u it. Watch and
listen fo r arcing.
* * R e fe r to W iring Diagrams w h ile perform ing
the fo llo w in g checks.
6. Discharge pressure sw itch.
7. Wire fro m discharge pressure switch to compressor clutch
solenoid.
MOTOR HOME U N IT
1. Wire fro m fuse panel to blow er switch.
2. Blower switch.
3. Wire fro m blow er switch to therm ostatic switch.
4. Therm ostatic switch.
5. Wire fro m therm ostatic switch to compressor clu tch solenoid.
|
)
LAM P DOES
NOT L IG H T
1
Replace
Blower speed
switch.
I NO C L IC K H E A R D !
CLICK H E A R D
Replace solenoid
W ith ig n itio n sw itch in " R u n ” p ositio n and A /C ” 0 n ” , check
fo r defective sw itch at the fo llo w in g locations. Using an external
jum per w ire, disconnect the electrical lead at the switch and
ju m p the sw itch term inals (see "W irin g Diagrams” ).
C-K M O D E L SYSTEM
1. Master S witch.
2.
3.
G
1.
2.
3.
Therm ostatic S w itch.
Discharge Pressure Switch.
M O D E L SYSTEM
A m p lifie r.
Therm ister.
Discharge pressure sw itch.
MO TO R HOME U N IT
1. B lower sw itch.
2. Therm ostatic sw itch.
NO TE:
If the compressor is s till inoperative a fte r the above
checks, check fo r power feed at each com ponent since
tw o or m ore com ponents are defective or there is an
open in the wires connecting the components.
MANUAL
Diagnosis
|G R O U N D
Check w ire term inal on blower
speed switch connector w ith
Check ground
on relay
r ..... “
I
I LAM P DOES NOT L IG H T !
and apply 12 volts to solenoid.
7. Wire fro m discharge pressure switch to compressor clutch
solenoid.
G M O D E L SYSTEMS
1. Wire fro m fuse panel to a m plifier.
2. A m p lifie r.
3. Wires fro m a m p lifie r to therm ister.
4. Therm ister.
5. Wire fro m a m p lifie r to discharge pressure switch.
| GROUND O k I
Disconnect connector on
compressor clu tch solenoid
SERVICE
LAM P L IG H TS
Repair ground
TRUCK
Check w ire term inal on relay
th a t goes to ju n ctio n block
| POOR OR NO G R 0 U N D |
LIGHT
Fig. IB 22- Electrical System
W ith ig n itio n sw itch in the
" R u n " positio n and the
JU N C T IO N
BLOCK
/ oN
J (^ 4 '
COM PRESSOR
DISCHARGE
R E S IS T O R
B L O W E R M O TO R
C U T-O U T
SW ITCH
10 R E D z
0J
o
I
INL INE
FUSE
30 A M P
I
I"
16 BLK
Wiring
Diagram
POS
OFF
MED 1
MED 2
HIGH
DK GRN
ORN
YEL
DK G R N / D B L W HT ST R
ORN
L T GRN
L T BLU
C IR C U IT
BATT. TO
B A TT. TO
B A TT. TO
B A TT. TO
NONE
Ml
M2
BLOWER
C O N D ITIO N IN G
System
-16
-10
-16
-16
-18
-16
-16
AIR
Fig. lB-23-Four-Season
;
40
(C-K
Models)
SELECTOR
SWIT CH
.
1
R ECIRC
|------ 1-----O V E R R ID E (T50B159AK
50A
SWITCH
51
7V
1 B -2 3
1B-24
LIGHT
TRUCK
Fig. IB 24- Four-Season
Vacuum
SERVICE
System
MANUAL
Diagram
(C-K
Models)
AIR
Fig. lB-25-Overhead
Wiring
Diagram
C O N D ITIO N IN G
System
(C-K
Models)
1 B -2 5
Fig. IB -2 6 -C60 System W iring Diagram (G Models)
V A C U U M R E S E R V O IR
(IN E N G I N E C O M P A R T M E N T )
T O V A CUUM S O R C E
:g
r a y
:
DASH P A N E L
H E A T E R C O RE CASE
ra y
:
____
H EA TER TEM PERATURE
DOOR C A B L E
AIR
Fig. IB-27 -C60
:g
= p in k :
Vacuum
Diagram
C O N D ITIO N IN G
System
HEATER
D IS T R I B U T O R
DUCT
H E A T E R AIR
DEFROST
(G Models)
: ORANGE
S E L E C T VALV E O PEItA T IN G CHA RT
P O R T NO.
9
2
4
1
8
HEAT
DEF
A / C - O . S. A IR
H T R AIR
SOURCE
OFF
VAC
VAC
VENT
VAC
VAC
MAX NO RM H T R
VAC
VAC
VAC
VENT VENT VENT
VENT
V E N T VA C
VAC
VENT
VAC
VAC
VAC
VA C
DEFOG DEF
VENT VENT
VENT
VAC
VENT VENT
VENT VENT
VA C
VAC
1 B -2 7
AIR
Home
Chassis
C O N D ITIO N IN G
Fig. lB-29--Motor
Wiring
Diagram
THERMOSTATIC
SWITCH
IB - 2 9
5. T E M P control set at " C O L D " and all air
c on ditioning outlets open.
6. G a u g e set installed.
7. System settled out (run-in approxim ately 10
minutes).
8. A therm om eter placed in front o f vehicle grille
and ano th er in the right h a nd diffuser outlet.
N OTE: On O verhead Systems, place a third
therm o m eter in the rear unit center outlet.
9. An 18" fan placed in front of the vehicle and
blowing into the condenser.
N O TE : H igher tem peratures and pressures will
occur at higher am bien t temperatures. In areas o f
high humidity it is possible to have therm om eter
and gauge readings approach but not reach the
figures listed in the perform ance tables and still
have a satisfactory op eratin g unit. However, it is
im po rtan t to rem e m be r that low pressure has a
direct relationship to nozzle outlet temperature. If
pressure is too low, ice will gradually form on the
evaporato r fins, restricting air flow into the
passenger area and resulting in insufficient or no
cooling.
Overhead System (C -K Models)
(R efrig e ra n t C harge - 5 lbs.-4 o z .)
T e m p e ra tu re of
A ir E n tering
C o n d en ser
70°
90°
80°
E ngine rp m
100°
110°
2000
C om pressor
H ead
P ressure *
135185
160210
195245
230280
270320
A c c u m u la to r
P ressure *
2228
2230
3038
3341
3747
D ischarge A ir
T em p , a t R ig h t
H and O u tle t *
4248
4248
5058
5462
5767
R ear C en ter
O u tle t *
4349
4753
5058
5563
5868
P E R F O R M A N C E DATA
The following Perform ance D ata define normal
operation o f the system un der the above conditions.
Relative hum idity does not a p p e a r in the tables because
after ru n n in g the prescribed length o f time on
recirculated air and m axim um cooling, the relative
hum idity o f the air passing over the evaporator core will
re m ain at approximately 35% to 40% regardless o f the
a m b ien t tem perature or humidity.
C 6 0 System (G Models)
(R efrig eran t Charge — 3 lb s .)
T e m p eratu re of
Air E ntering
C ondenser
80°
Engine rp m
C H E C K IN G OIL
C om pressor
H ead Pressure*
In the six cylinder compressor it is not recom
m ended that the oil be checked as a matter o f course.
S u ctio n
Pressure*
D ischarge Air
T em p, a t R ight
U pper O utlet*
Four-Season A ir Conditioning (C-K Models)
70°
90°
100°
110°
120°
2 0 0 0 RPM
10
60
39
42
48
20
70
140190
160210
190240
210260
39
39
410
714
1018
4248
4349
4557
4956
5360
(R efrigerant Charge - 3 Lbs. - 1 2 o z . )
T em perature of
Air E ntering
C ondenser
70°
80°
Engine rpm
Com pressor Head
Pressure *
90°
100°
110°
2000
150205
170220
190240
220270
240290
A ccum ulator
Pressure *
2026
2028
2129
2230
2332
Discharge Air
Tem p, at Right
Hand O utlet *
4147
4147
4250
4351
4351
Generally, compressor oil level should be checked only
where there is evidence o f a m ajor loss of system oil such
as might be caused by:
• A broken refrigerant hose
• A severe hose fitting leak
• A very badly leaking compressor seal
• Collision dam ag e to the system components
As a quick check on compressor oil charge, operate
the engine at idle on maximum cold for approximately
10 minutes, turn off the engine and momentarily crack
open the oil drain plug on bottom of the compressor
letting a slight am ount o f oil d rain out. Retighten plug.
Again slightly crack open the plug. If oil comes out, the
compressor has the required am ount of oil.
Overhead System (G Models)
Dash M ounted U n it (M o to r Hom e Chassis)
(R efrigerant Charge — 5 lbs.-4 o z.)
(R efrig eran t Charge — 3 lb s.-4 oz.)
T em p eratu re o f
Air E ntering
C ondenser
70°
80°
90°
100°
110°
120°
T em p eratu re o f
Air E nterin g
C ondenser
70°
80°
90°
Engine rpm
S uction
Pressure*
D ischarge A ir
T em p, at R ight
F ro n t U pper
O utlet*
110°
120°
19 0 200
220230
260270
2000
Engine rpm
C om pressor
Head Pressure*
100°
502 00
160210
200250
225275
250300
280320
13
19
1 321
1624
1927
23
31
2634
38
38394544
44
47
53
R ear systejn tem p e ra tu re s a t
ru n 5 - 1 0 higher th a n fro n t
505458
62
ce n ter o u tle t
system .
2000
C om pressor
Head Pressure*
110120
13 5 145
1 60170
S u ctio n
Pressure psi*
6
7
9
10
10
13
D ischarge A ir
T em p eratu re*
4 045
41 46
4146
4247
4449
4 449
* Ju st p rio r to com pressor clu tch disengagem ent.
N O T E: The oil may app e a r foamy. This is
considered normal.
To further check the compressor oil charge, should
the above test show insufficient oil, it is necessary to
remove the compressor from the vehicle, drain and
m easure the oil as outlined under "C hecking Compressor
Oil C h arg e."
4.
In the event that it is not possible to idle the
compressor as outlined in Step 1 to effect oil return to it,
proceed as follows:
a.
Remove the compressor, drain, measure and
discard the oil.
b.
If the am ount drained is more than 1-1/2
C hecking Com pressor Oil Charge
fluid oz. and the system shows no signs of a m ajor leak,
1. Run the system for 10 minutes at 500-600
engine rpm with controls set for m axim um cooling and
high blower speed.
2. T urn off engine, discharge the system, remove
compressor from vehicle, place it in a horizontal position
with the drain plug downward. Remove the drain plug
and, tipping the compressor back and forth and rotating
the compressor shaft, d rain the oil into a clean container,
m easure and discard the oil.
3. Add new refrigeration oil to the compressor as
follows.
a. If the quantity drained was 4 fluid oz. or
more, add the same am ou nt of new refrigeration oil to
the replacem ent compressor.
b. If the quantity drained was less than 4 fluid
oz., add 6 fluid oz. of new refrigeration oil to the
replacem ent compressor.
c. If a new service compressor is being installed,
drain all oil from it an d replace only the am ount
specified in Steps 3a and 3b above.
d. If a field repaired compressor is being
installed, add one additional fluid oz. to the compressor.
add the same am ount to the replacement compressor.
c.
If the am ount drained is less than 1-1/2 fluid
oz. and the system appears to have lost an excessive
am ount o f oil, add 6 fluid oz. of clean refrigeration oil to
replacement
compressor,
7 fluid
oz.
to
a
repaired
compressor.
If
the
oil
contains
chips
or
other
foreign
material, replace the receiver-dehydrator (expan
sion tube on C-K models) and flush or replace all
com ponent
parts
as necessary. A dd
the
full
specified volume o f new refrigeraton oil to the
replacement compressor.
5.
Add additional oil in the following amounts for
any system components being replaced.
Evaporator C o r e ................................... 3 fluid oz.
C o n d e n s e r.... :......................................... 1 fluid oz.
R eceiv er-D eh y d rato r........................... 1 fluid oz.
A ccu m u la to r........................................... 1 fluid oz.
C A U TIO N : When adding oil to the compressor,
it will be necessary to tilt the rear end o f the
compressor up so that the oil will not run out o f
the suction and discharge prots. Do not set the
compressor on the shaft end.
REFRIGERANT Q U IC K -C H EC K PROCEDURE
The following procedure can be used to quickly determ ine w hether or not an air conditioning system has a proper charge
o f refrigerant. This check can be m ade in a m anner of m inutes thus facilitating system diagnosis by pinpointing the problem
to the am ount of charge in the system or by elim inating this possibility from the overall checkout.
C-K Models
G M odels and Motor H om e Chassis Units
1.
2.
3.
4.
Start engine and place on fast idle. Set controls for
maximum cold with blower on high.
Engine m ust be warm (therm ostat open).
Hood and body doors open.
Selector lever set at A/C.
T em perature lever at first detent to the right of COLD (set
for outside air).
5. Blower on HI.
6. Engine idling at 1000 RPM.
7. Feel tem perature of evaporator inlet and accum ulator o u t
let pipes with com pressor engaged (fig. 52).
a. If both are cold this is a proper condition.
b. If inlet pipe is cooler than outlet pipe, system is low on
charge.
• A dd a slight am ount of refrigerant until bo th pipes
feel the same (system stabilized —3-5 m inutes).
• Then add 15 oz. (1 can) additional refrigerant.
Bubbles present in sight
glass.
No bubbles.
clear.
Sight glass
System low on charge.
Check with leak detector.
Correct leak, if any, and
fill s y s te m to proper
charge.
S y s te m is either fully
charged or em pty. Feel
high a n d low p r e s s u r e
pipes at com pressor. High
pressure pipe should be
warm; low pressure pipe
should be cold.
I""
No appreciable tem pera
ture differential noted at
com pressor. |
T e m p e ra tu re differential
noted at com pressor.
System em pty or nearly
em pty. Turn off engine
a n d c o n n e c t Charging
Station. Induce 1/ 2 # of
refrigerant in system (if
system will n o t accept
charge, start engine and
draw 1 /2 # in through low
p r e s s u r e s id e ) . Check
system with leak detector.
Even though a differential
is noted, there exists a
possibility o f overcharge.
An overfilled system will
result in poor cooling dur
ing low speed operation
(as a result of excessive
head pressure). An overfill
is easily checked by dis
connecting the com pressor
c l u tc h connector while
observing the sight glass.
I
I
If refrigerant in sight glass
remains clear for more
than 45 seconds (before
foaming and then settling
away from sight glass) an
overcharge is indicated.
Verify with a perform ance
check.
If refrigerant foams and
then settles away from
sight glass in less than 45
seconds, it can be assumed
that there is a proper
charge of refrigerant in
system . C ontinue checking
out system using perfor
m a n c e checks outlined
previously.
Fig. IB -3 0 Checking Evaporator Inlet and
A cu um ulator O utlet Tem peratures
ON VEHICLE SERVICE
T H E R M O S T A T IC S W ITCH
C-K Systems and Motor Home Chassis Units make
use o f a therm ostatic switch with either an air or
evapo rator inlet line sensing capillary. This capillary
controls the switch by sensing the tem perature o f the air
leaving the evaporator core (M otor Home Units) or
tem perature o f the core fins (C-K models).
Checking for Proper Operation
M o to r Hom e Chassis Units
1. Install the gauge set and set up the vehicle as
described un der "P erfo rm an ce Test."
2. M ovem ent o f the tem perature control knob
should result in a definite change in suction pressure and
cycling o f the compressor clutch.
• If compressor continued to operate regardless
o f the knob adjustment, it indicates that the switch
points are fused which will lead to evaporator freeze-up.
Replace the switch.
• If the compressor does not operate, regardless
o f the position o f the knob, a loss o f the power element
charge is indicated (provided that it has been established
that power is supplied to the switch). This, o f course,
results in no cooling. Replace the switch.
C-K Models
1. Install the gauge set and set up the vehicle as
described under "P erfo rm an ce Test".
2. Set the control at A /C , HI blower, max C O LD
and run the engine at 2000 rpm.
• The thermostatic switch should cycle the
compressor off when the low limit o f the outlet air
tem perature is reached (see Peformance Data). If it does
not, the switch points are fused which will lead to
evaporator freeze up. Replace the switch.
•
If the compressor does not operate, a loss of
power element charge is indicated (provided that it has
been established that power is supplied to the switch).
This, of course, results in no cooling. Replace the switch.
N OTE: Do not attem pt to run a Performance
Check with the system disassembled since inaccu
rate readings would be the result. ALWAYS
reinstall switch and capillary and any duct work
before run ning a perform ance check.
A M P LIFIE R BOARD P O TE N TIO M E TE R (Fig.
IB -3 1 )
To cure a "too cold" or "not cold e n o ug h" capacity
complaint, the sensor should be simulated by a 400
± 1%, 1/2 W att resistor. By connecting the resistor as
shown in Figure IB-31, the control pot can be rotated
until the compressor clutch energizes. The procedure is
as follows:
1. Remove the headlam p switch knob and then
remove the instrum ent panel bezel.
2. Remove the control to instrum ent panel screws.
3. Rem ove the left foot cooler bracket to
instrument panel reinforcement screws and remove the
foot cooler and duct.
4. With the system in the vehicle and the engine
running, disconnect the terminals F and J from the
connector at the control wiring harness connector.
5. Connect a 400 ohm ± 1% , 1/2 W att resistor
across terminals F and J.
6. Set the control tem perature lever at C O LD and
then adjust by rotating the pot until the compressor
clutch engages.
7. Reverse the adjustm ent by carefully rotating the
pot until the compressor clutch just disengages.
8. Reverse Steps l -4 above and check system
operation.
C A P I L L A R Y BULB
E XP A N SIO N VALVE (Fig. IB -3 2 )
An expansion valve is used on C-K Model Overhead
Systems, all G Model systems and Motor Home Chassis
Units.
A malfunction o f the expansion valve will be caused
by one o f the following conditions; valve stuck open,
valve stuck closed, broken power element, a restricted
screen or an im properly located or installed power
elem ent bulb.
A ttachm ent of the expansion valve bulb to the
e v ap orator outlet pipe is very critical. The bulb must be
attached tightly to the pipe and must make good contact
with the pipe along the entire length of the bulb. A loose
bulb will result in high " h ig h side" pressures and poor
cooling.
Indications o f expansion valve trouble provided by
the P erform ance Test are as follows"
VALVE S T U C K OPEN
Noisy Compressor.
N o Cooling - Freeze Up.
VALVE
STUCK
C LO SED ,
PLUGGED
SC R E E N OR BRO K EN POW ER ELE M EN TS
Very Low Suction Pressure.
N o Cooling.
1. Connect 400 ±
1%
Vi
W att
re sistor across te rm in a ls F and J
2. W ith e n g in e ru n n in g , syste m on
A/C, te m p le v e r a t COLD, rota te
sh a ft un til com p re sso r clutch
engages. Then reverse a d ju stm e n t
un til the com p re sso r just
OUTLET
Fig. lB-32--Expansion Valve
PO O R L Y
BULB
LOCATED
POWER
ELEMENT
N orm al Pressure.
Poor Cooling.
Check for Defective Valve
The following procedure must be followed to
determine if a malfunction is due to a defective
expansion valve.
1. Check to determ ine if the system will meet the
perform ance test as outlined previously. If the expansion
valve is defective, the low pressure readings will be
above specification.
2. The loss o f system performance is not as evident
when the high side pressure is below 200 PSI. Therefore,
it m ay be necessary to increase the system high side
pressure by partially blocking the condenser. Disconnect
the blower lead wire and repeat the "P erform ance
Check" to determ ine if the low side pressure can be
obtained.
3. The system will also indicate a low refrigerant
charge by bubbles occurring in the sight glass.
E N G IN E IDLE C O M P E N S A TO R
Fig. IB -3 1 -A m p lifie r Board Potentiom eter
A d ju stm e nt
This additional aid to prevent stalling during
prolonged hot weather periods is included with all air
conditioned vehicles. The idle c o m p e n sato r is a
thermostatically controlled air bleed which supplies
additional air to the idle mixture. On V-8 engines, with
factory installed air conditioning systems, the com pensa
tor is located w ithin the carbureto r and is accessible
w hen the engine air cleaner is removed.
2. Remove connector attaching bolt and connector.
Cap or plug open connections at once.
3.
C O M PRESSO R
Removal (Fig. IB -3 3 )
C-K Models
1.
Disconnect electrical lead to clutch actuating
coil.
Purge the refrig eran t from the system.
3 0 5 - 3 5 0 V -8
3 0 5 - 3 5 0 V -8
4 5 4 V - 8 C-
G
4.
Loosen brace and pivot bolts and detach belt.
5.
Remove
the
nuts
and
bolts
attaching
C
MODELS AN D MOTOR HOME CHASSIS
MODELS
4 5 4 V-8
MOTOR HOME CHASSIS
the
compressor brackets to the m ounting bracket. Remove
2. Position compressor on the mounting bracket
the compressor.
and install all nuts, bolts, lock washers, and ground wire.
3. Install the connector assembly to the compressor
6.
Before beginning any compressor disassembly,
d ra in and measure oil in the compressor. Check for
rear head, using new " O " ring coated with clean
evidence of c ontam ination to determ ine if rem aind er of
refrigeration oil.
system requires servicing. Compressor servicing in fo rm a
4. Connect the electrical lead to the coil and install
tion is located in the Overhaul Manual.
and adjust compressor belt, using idler pulley. See
"C om pressor Belt Tension Adjustment."
Installation
5. Evacuate, charge and check the system.
1. If oil previously d rained from the compressor
6. Replace air cleaner. On G models, replace the
upon removal shows no evidence o f contamination,
engine cover.
replace a like am o unt o f fresh refrigeration oil into the
7. Connect the battery ground cable.
compressor before reinstallation. If it was necessary to
Com pressor B elt Tension Adjustm ent
service the entire system because of excessive con ta m in a
tion in the oil removed, install a full charge o f fresh
Adjust the compressor belt to the specifications
re frigeration oil into the compressor.
shown in the T une-U p chart in the Engine section o f the
2. Position compressor on the mounting bracket
Service Manual.
an d install all nuts, bolts and lock washers.
NOTE: On some G and Motor Home Chassis
3. Install the connector assembly to the compressor
models it may be necessary to increase idler pulley
rear head, using new " O " rings coated with clean
slack adjustment. This may be accomplished by (l)
re frigeration oil.
Remove and discard the idler adjustment bolt. (2)
4. Connect the electrical lead to the coil and install
Remove the idler backing plate and elongate all 3
and adjust compressor belt.
adjusting
slots 1/2 inch inboard or outboard as
5. Evacuate, charge and check the system.
required. (3) Reinstall the idler assembly and
G and M o to r Hom e Chassis Models
adjust belt tension using a lever (screwdriver, etc.)
to move the pulley outboard until proper belt
Removal (Fig. IB -3 3 )
tension is reached. If the belt is being replaced it
1. Disconnect battery ground cable.
may be necessary to remove and replace the
2. Disconnect compressor clutch connector.
throttle cable during the belt replacement. If so
3. Purge the system o f refrigerant.
check throttle cable adjustm ent upon completion. It
4. Release the belt tension at the idler pulley and
may also be necessary to remove the crankshaft
remove the bit from the compressor pulley. On some
pulley to install a new compressor belt.
vehicles it may be necessry to remove the crankshaft
FOUR-SEASON SYSTEM-C-K
pulley in order to remove the belt.
MODELS
5. G M o dels-R em ove the two bolts and two
clamps that hold the engine cover and remove the cover.
CO NDENSER
6. Remove the air cleaner to aid access to the
compressor.
Replacement (Fig. IB -34 )
7. Remove fitting and muffler assembly and cap or
l. Disconnect battery ground cable.
plug all open connections.
8. Remove the nuts and bolts attaching the
compressor to the bracket.
9. Remove the engine oil tube support bracket bolt
and nut from the compressor, also compressor clutch
ground lead.
Before beginning any compressor disassembly,
d ra in and measure oil in the compressor. Check for
evidence o f contaim ination to determ ine if rem ain der o f
system requires servicing. Compressor Servicing in fo r
mation is located in the O verhaul Manual.
Installation
l.
If the oil drained from the compressor showed
no evidence of contam ination replace a like am ount of
fresh re frigeration oil into the compressor before
reinstallation. If it was necessary to service the entire
system because o f excessive contam ination in the oil
removed, install a full charge o f fresh refrigeration oil in
the compressor. (See Checking Compressor Oil C harge
in the Diagnosis Section o f this Service M anual.)
2. Purge the system o f refrigerant.
3. Remove the grille assembly.
4. Remove the ra d ia to r grille center support.
5. Remove the left grille support to upper fender
support (2) screws.
6. Disconnect the condenser inlet an d outlet lines
and the outlet tube line at the right end o f the condenser.
C ap or plug all open connections at once.
7. Remove the condenser to radiator support
screws.
8. Bend the left grille support outboard to gain
clearance for condenser removal.
9. Remove the condenser assembly by pulling it
forw ard and then lowering it from the vehicle.
10. To install a new condenser, reverse Steps l -9
above. Add one fluid ounce o f clean refrigeration oil to a
new condenser.
N O T E : Use new " O " rings, coated with clean
refrigeration oil, w hen connecting all refrigerant
lines.
11. Evacuate, charge an d check the system.
A C C U M U L A TO R
Replacem ent (Fig. IB -3 5 )
1. Disconnect the battery ground cable and the
compressor clutch connector.
2. Purge the system o f refrigerant.
W A R N IN G : Be sure system is completely
purged of refrig eran t before completely
d isco n nectin g re frig e ra n t lines. Visually
check th e accum ulator fo r fro s t. The
presence of frost indicates th a t the system is
not fully discharged. To complete purging,
connect the vacuum line to th e vacuum
pump, turn on the vacuum pump and open
vacuum control valve. An alternate method
would be to place warm w ater soaked cloths
(n o t exceeding 51 C (125 F) around the
accum ulator to boil off any rem aining
refrigerant.
3. Disconnect the accumulator inlet and outlet
lines and cap or plug the open connections at once.
4. Remove the accumulator bracket screws and
remove the accumulator from the vehicle.
5. Drain any excess refrigerant oil from the
accumulator into a clean container. M easure and discard
the oil.
6. If a new accumulator is being installed, add one
ounce o f clean refrigeration oil to the new accumulator
PLUS an am ount equal to that drained in Step 5 above.
7. To install the new accumulator, reverse Steps 1-4
above. Connect all lines using new "O " rings, coated
with clean regrigeration oil.
C A U TIO N : Do not uncap the new unit until
readv to fasten the inlet and outlet line to the
unit.
8.
Evacuate charge and check the system.
BLOWER ASSEMBLY
Replacement
1. Disconnect the battery ground cable.
2. Disconnect the blower motor lead and ground
wires.
3. Disconnect the blower motor cooling tube.
4. Remove the blower to case attaching screws and
remove the blower assembly. Pry the blower flange away
from the case carefully if the sealer acts as an adhesive.
5. Remove the nut attaching the blower wheel to
the motor shaft and separate the assemblies.
6. To install, reverse Steps 1-5 above; replace
sealer as necessary.
EVA PO RA TOR CORE
Replacement (Fig. IB -3 6 )
1. Disconnect the battery ground cable.
2. Purge the system o f refrigerant.
3. Remove the nuts from the selector duct studs
projecting through the dash panel.
4. Remove the cover to dash and cover to case
screws and remove the evaporator case cover.
5. Disconnect the evaporator core inlet and outlet
lines and cap or plug all open connectins at once.
6. Rem ove the therm ostatic switch and the
expansion tube assemblies.
7. Remove the evaporator core assembly.
8. To install, reverse Steps 1-7 above. Add three
ounces o f clean refrigeration oil to a new evaporator
core.
Fig. IB -3 5 -A ccu m u la to r In sta lla tion (C-K Models)
C A U TIO N : Be sure to install the thermostatic
switch capillary in the sam e position as when
removed. See Thermostatic switch replacement.
2. Disconnect the condenser to evaporator line at
the evaporator inlet. Cap the open line at once.
3. Using needle-nose pliers, remove the expansion
tube from the evaporator core inlet line (fig. IB-37).
4. Remove the expansion tube " O " ring from the
core inlet line.
5. To install, reverse Steps 1-4 above.
NOTE: Install the expansion tube using a new " 0 "
ring coated with clean refrigeration
oil, by
inserting the short screen end o f the tube into the
evaporator inlet line.
6.
Evacuate, charge and check the system.
SELECTOR D U C T AND HEATER CORE
ASSEMBLY
Replacement (Figs. IB -3 8 and IB -3 9 )
Fig. IB -3 6 -Blower Evaporator (C-K Models)
N O T E: Use new " O " rings, coated with clean
regrigeration oil, when connecting refrigerant
lines.
Be sure cover to case and dash panel sealer is intact
before reinstalling cover.
9.
Evacuate, charge and check the system.
E X P A N S IO N TU B E
The expansion tube is located in the evaporator core
inlet line.
Replacem ent (Fig. IB -3 7 )
l.
Purge the system o f refrigerant.
1.
2.
Disconnect the battery ground cable.
D rain the radiator and remove the heater hoses
from the core tubes. Plug the core tubes to prevent
coolant spillage during removal.
3. Remove the glove box and door as an assembly.
4. Remove the center duct to selector duct and
instrument panel screws and remove the center lower
and center upper ducts.
5. Disconnect the bowden cable at the temperature
door.
6. Remove the nuts from the three selector duct
studs projecting through the dash panel.
7. Remove the selector duct to dash panel screw
(inside vehicle).
8. Pull the selector duct assembly rearw ard until
the core tubes clear the dash panel. Lower the selector
assembly fa r enough to gain access to all vacuum and
electrical harnesses.
Fig. 1 B-37-Expansion Tube - Typical
Fig. IB-38- Heater Hose Routings (C-K Models)
UPPER CENTER DISTRIBUTO R DUCT
R IG H T H A N D OUTLETS
LEFT DISTRIB UTO R DUCT A N D
F O O T COOLER
LOW ER CENTER DISTRIBUTO R DUCT
Fig. IB -39 -Air Selector and Ducts (C-K Models)
9. Disconnect the vacuum and electrical harness
an d remove the selector duct assembly.
10. Remove the core mounting strap screws and
remove the core.
11. To install, reverse Steps 1-10 above.
12. Refill coolant system and connect the battery
ground strap. Check tem perature door cable adjustment.
KICK PAD VALVE
Replacem ent (Fig. IB -4 0 )
1.
2.
Disconnect the vacuum hose at the actuator.
U nhook the valve return spring at the actuator
end.
3.
4.
separate
5.
separate
6.
To install reverse Steps 1-5 above.
PLENUM VALVE
Replacement (Fig. IB -4 0 )
1. Raise the hood.
2. Remove the cowl plastic grille.
3. Remove the three cowl to valve assembly screws
and remove the valve assembly from the vehicle.
4. Remove the actuator arm push nut.
5. Remove the actuator to valve nuts and separate
the valve and actuator.
6. To install, reverse Steps 1-5 above.
CO N TR O L ASSEMBLY
Removal (Fig. IB -4 1 )
Remove the actuator bracket mounting screws.
Remove the cam to actuator arm screw and
the actuator and bracket from the cam.
Remove the actuator to bracket nuts and
the actuator and bracket.
1. Disconnect the battery ground cable.
2. Remove the radio as outlined in Section 9 of
this manual.
3. Remove the instrument panel bezel.
6.
7.
master
8.
control
Remove the control.
If a new unit is being installed, transfer the
blower switches to the new control.
To reinstall, reverse Steps l -6 above. Check
operation.
T E M P E R A T U R E DOOR CABLE
ADJUSTM ENT
1. Remove glove box and door assembly.
2. Loosen the cable attaching screw at the selector
duct assembly.
3. M ake sure the cable is installed in the bracket
on the selector duct assembly.
4. Place temperature lever in full CO LD position
and hold while tightening cable attaching screw.
M A STER S W ITC H A N D /O R BLOWER
S W ITCH
The master switch is located on rear o f the control
assembly.
Replacement
Fig. lB -4 0 -A ir In le t Valves (C-K M odels)
4. Remove the control to instrum ent panel screws
and lower the control far enough to gain access to the
control assembly.
C A U TIO N : Be careful not to kink the bowden
cable.
5. Disconnect the bowden cable, vacuum harness
and electrical harness at the control.
Fig. IB 41--Control Assembly (C-K Four-Season
System)
1. Disconnect the battery ground cable.
2. Remove the instrument panel bezel.
3. Remove the control to instrum ent panel screws
and allow control to rest on top o f the radio.
4. Remove the switch to control screws, disconnect
the electrical harness (and vacuum harness on master
switch) at the switch and remove the switch assembly.
5. To install a new switch, reverse Steps 1-4 above.
V A C U U M TA N K
The vacuum tank is mounted to the engine side of
the dash panel above the blower assembly (fig. IB-42).
Replacement
1. Disconnect the vacuum lines at the tank.
2. Remove the tank to dash panel screws and
remove the tank.
3.
To install, reverse Steps 1 and 2 above.
BLOWER M O T O R RESISTO R
1.
2.
Remove electrical connectors to the switch.
Remove screws to loosen body from evaporator
case.
1. Disconnect the wiring harness at the resistor.
2. Remove the resistor to case attaching screws and
remove the resistor.
3. Place the new resistor in position and install the
attaching screws.
4. Connect the resistor wiring harness.
3. A capillary line (small tube) extends from the
swtich with the other end attached to the evaporator inlet
pipe ( 1 /2 " O.D.) with two clamps. This end is covered
with an insulation material. Carefully remove the
insulation and loosen clamps enough to pull the formed
end o f the capillary tube out from under the clamps.
Solvent clean pipe area to remove rem aining insulation
material and dirt.
4. Identify area by m arking the capillary tube
location on the inlet pipe from where it was removed.
BLOW ER M O TO R RELAY
The replacement switch’s tube should be installed at this
location.
The blower motor resistor is located in the blower
side of the blower-evaporator case (fig. IB-43).
Replacement
T he blower motor relay is located on the blower side
o f the blower-evaporator case.
Replacement
1. Disconnect the wiring harness at the relay.
2. Remove the relay to case attaching screws and
remove the relay.
3. Place the new relay in position and drive the
m o unting screws.
4. Connect the relay wiring harness.
T H E R M O S T A T IC S W ITC H
The thermostatic switch is mounted on the bracket
which supports the inlet tube in position at the
e v ap orator case. The switch sensing capillary is attached
by means o f a clamp to the evap orato r inlet tube.
Removal
Installation
1. M ount switch body to previous location. Do not
over-torque screws. The recom mended reassembly torque
is 15-20 in. lbs. Do not dam age or distort the switch
body, as this m ay affect switch calibration.
2. M ount form ed end o f capillary tube to the inlet
pipe in SAME POSITION AS THE O R IG IN A L tube.
D O N O T INSTALL N E W TUBE M O R E T H A N 1/2" in
either direction o f previously marked location.
3. Adjust each clamp before tightening so that
width of the clamp covers the capillary tub e’s formed
end. Tighten to 1.69 to 2.25 N m (15 to 20 in. lbs.) of
torque. Do not overtorque.
4. Re-cover tube and pipe with insulation material.
If original insulation is damaged, replace with same type
material. (G M P D Part No. 3014431 or equivalent).
5. Reconnect electrical terminals.
DISCHARGE PRESSURE S W ITCH
The discharge pressure switch is located in the
condenser to evaporator line (fig. IB-44).
Replacement
1.
Fig. IB -4 3 -R e sisto r, Relay and T herm ostatic Switch
(C-K Models)
Disconnect the battery ground cable.
2.
3.
4.
5.
Purge the system o f refrigerant.
Disconnect the w iring harness at the switch.
Remove the switch from the refrigerant line.
To replace, reverse Steps 1-4 above.
N OTE: Be sure to use new " O " rings, coated with
clean regrigeration oil, w hen installing the switch.
6. Evacuate charge and check system operation.
FUSE
A 25 am p fuse, located in the junction block protects
the entire air conditioning system except for the blower
circuit, the fuse for the blower circuit is located in the
electrical wiring between the junction block and the
blower relay (fig. IB-45).
OVERHEAD SYSTEM--C-K
MODELS
the rear o f the vehicle, and incorporates four adjustable
air outlets (fig. IB-46).
Replacement
1. Disconnect the battery ground cable.
2. Disconnect the drain tube from the rear duct.
3. Remove the screws securing the duct to the roof
panel and rear header brackets.
4. Remove the duct.
5. To install, reverse Steps 1-4 above.
BLOWER M O TO R RESISTOR
The blower m otor resistor is located on the cover
side of the Four-Season System blower-evaporator as
shown in Figure IB-47.
Replacement
T he Overhead System is used in conjunction with
the Four-Season System. Since replacement o f FourSeason System components has been covered previously,
only those components peculiar to the O verhead System
will be covered in this section.
1.
2.
3.
remove
4.
above.
Disconnect battery ground cable.
Disconnect the electrical harness at the resistor.
Remove the resistor attaching screws and
the resistor.
To install a new resistor, reverse Steps 1-3
REAR D U C T
BLOWER M O TO R ASSEMBLY
This duct covers the blower-evaporator assembly, at
Removal (Fig. IB -4 8 )
J U N C T IO N B L O C K
COMPRESSOR
B L O W E R R E S IS T O R
y
L IN E
D IS C H A R G E PR ESSURE
S W IT C H
BLOW ER M O T O R
C A U TIO N : Before removing the case screws,
support the lower case to prevent damage to the
case or motor assemblies.
6.
Remove the motor retaining strap and remove
the motor and wheels. Remove the wheels from the
motor shaft.
Installation
1. Place the blower wheels onto the m otor shaft
making sure the wheel tension springs are installed on
hub o f wheels.
Fig. lB -4 6 -R e a r Duct (C-K Overhead System)
1. Disconnect the battery ground cable.
2. Remove the rear duct as outlined previously.
3. Disconnect the blower m otor ground strap.
4. Disconnect the blower motor lead wire.
5. Remove the lower to u pper blower-evaporator
case screws and lower the lower case and motor
assembly.
C A U TIO N : Be sure that the blower wheels are
installed as shown in Figure IB-49.
2. Install the blower motor retaining strap and
foam.
3. Place the blower motor and wheel assembly into
the lower case. Align the blower wheels so that they do
not contact the case.
4. Place the lower case and blower motor assembly
in position in the vehicle and install the lower to upper
case screws.
NOTE: Rotate the blower wheels to make sure that
they do not rub on the case.
5. Install the center ground wire and connect the
blower lead wire.
6. Install the rear duct assembly as described
previously.
6. Remove the expansion valve sensing bulb
clamps.
7. Disconnect the valve inlet and outlet lines and
remove the expansion valve assembly. Cap or plug the
open connections at once.
Installation
1. Remove caps or plugs from system connections
and install the new valve assembly using new " O " rings
coated with clean refrigeration oil.
2. Install the sensing bulb, making sure that the
bulb makes good contact with the core outlet line.
3. Install the lower case and blower motor
assemblies. Connect the blower motor lead and ground
wires.
4. Install the rear duct as outlined previously.
5. Connect the battery ground cable.
6. Evacuate, charge and check the system.
Fig. lB -48-B low er-E vaporator (C-K Overhead System)
EVA PO RA TOR CORE(Fig. IB -5 0 )
Removal
M OTOR
CLAM P
FO AM
STRIP
LO W ER
EVAPORATOR CASc
BLADE
ANG LE
Fig. lB-49--Blow er M otor (C-K Overhead System)
7.
Connect the battery ground cable.
E X P A N S IO N VALVE
This sytem incorporates and expansion valve which
does not utilize and external equalizer line (fig. IB-50).
1. Disconnect the battery ground cable.
2. Purge the system or refrigerant.
3. Remove the rear duct as outlined previously.
4. Disconnect the blower motor lead and ground
wire connections.
5. Disconnect the refrigerant lines at the rear of
the blower-evaporator assembly. Cap or plug the open
connections at once.
6. Remove the blower-evaporator support to roof
rail screws, lower the blower-evaporator assembly and
place it on a work bench upside down.
7. Remove the lower to upper case screws and
remove the lower case assembly. Remove the support to
upper case screws and remove the upper case from the
evaporator core.
8. Remove the expansion valve inlet and outlet
lines and cap or plug the open connections at once.
Remove the expansion valve capillary bulb from the
evaporator outlet line and remove the valve.
9. Remove the plastic pins holding the screen to
the core and remove the screen.
Installation
EVAPO RATO R
B L O W E R -E V A P O R A T O R
SCREEN
UPPER C A S E
Removal
1. Disconnect battery ground cable.
2. Purge the system o f refrigerant.
3. Remove the rear duct as outlined previously.
4. Disconnect the blower motor lead and ground
wires.
5. Remove the lower to upper blower-evaporator
case screws and lower the lower case and motor
assembly.
C A U T IO N : Before removing the case screws,
support the lower case and motor assemblies.
E X P A N S IO N
EVAPO RATO R
VALVE
CORE
S E N S IN G
BU LB
1. Install the wire screen to the front o f the core
and insert the plastic pins.
2. Install the expansion valve inlet and outlet lines
using new " O " rings coated with clean refrigeration oil.
Install the sensing bulb to the evapo rator outlet line as
shown in Figure IB-50; make sure the bulb has good
contact with the line.
N O T E: Add 3 oz. clean refrigeration oil when
installing a new core.
3. Install the upper case an d supports to the core.
4. Install the lower core case and blower assembly.
5. Install the blower-evaporator assembly to the
ro o f and install the support to ro o f rail screws.
6. Connect the refrigerant lines to the blowere v ap orator unit using new " O " rings coated with clean
refrigeratio n oil.
7. Connect the blower lead and ground wires.
8. Install the rear duct as outlined previously.
9. Connect the battery ground cable.
10. Evacuate, charge and check the system.
BLOWER M O T O R S W ITC H
T he three-speed (LO -M ED -H I) blower motor switch
is located in the instrument panel, just to the left of the
ash tray (fig. IB-50).
Replacem ent
1.
2.
3.
remove
4.
Disconnect the battery ground cable.
Remove the switch retaining screws.
Disconnect the wiring harness at the switch and
the switch.
To install, reverse Steps 1-3 above.
FUSE
T he F our Season portion of this system is protected
by a 25 am p fuse in the junction block.
The rear blower high speed circuit is protected by a
20 am p in-line fuse, located between the junction block
and the rear blower motor switch.
C60 SYSTEM -G MODELS
CO NDENSER
Replacement (Fig. IB -5 2 )
1. Remove the batery ground cable and com pres
sor clutch connector.
2. Purge the system o f refrigerant.
3. Remove the left and right hand h eadlam p
bezels and parking lamp lens. Place a piece o f protective
tape over upper surface o f the front bum per. Remove
the grille to rad iato r support screws and remove the
grille.
4. Remove the screws from rad iato r center brace
and remove the bracke.
5. Remove the upper ratiato r supports. Move the
upper edge o f the rad iato r rearw ard to gain access to
condenser attachment.
6. Remove the condenser to radiato r support nuts
and bolts.
7. Disconnect the condenser inlet and outlet lines
and remove the condenser. Cap or plug the open
connections at once.
8. Remove the condenser mounting brackets from
the condenser.
9. To install, reverse Steps 1-8 above. Add 1 fluid
ounce o f clean refrigeration oil to a new condenser.
C A U TIO N : Use new "O " rings, coated with
clean regrigeration oil, when connecting all
refrigerant lines.
10. Evacuate, charge and check the system.
RECEIVER-DEHYDRATO R
Replacement (Fig. IB -5 2 )
1. Disconnect the battery ground cable, and the
compressor clutch connector.
2. Purge the system o f refrigerant.
3. Remove left and right hand headlam p bezel and
parking lam p lens. Place a piece o f protective tape over
the upper surface o f the front bum per. Remove the grille
to radiator support screws and remove the grille.
4. Disconnect the receiver-dehydrator inlet and
outlet lines and cap or plug the connections at once.
5. Remove the receiver-dehydrator bracket attach
ing screws.
6. R em ove the re c e iv e r-d e h y d ra to r from the
vehicle.
7. If a new receiver-dehydrator is being installed,
add 1 fluid ounce o f clean refrigeration oil to the new
unit.
8. Connect the inlet and outlet lines using new " O "
rings coated with clean refrigeration oil.
10.
Evacuate, charge and check the system.
S IG H T GLASS R E P LACEM ENT
If dam age to the sight glass should occur, a new
sight glass kit should be intalled. The kit contains the
sight glass, seal and retainer. (See Figure IB-53).
1. Purge system.
2. Remove the sight glass retainer nut using a
screwdriver and remove old glass and " O " ring seal.
3. Install the new glass and seal and retainer nut,
being careful not to turn the nut past the face o f the
housing. To do so may dam age the " O " ring seal.
4. Evacuate, charge and check the system.
A /C AIR D IS T R IB U T O R DUC T
Replacement (Fig. IB -5 4 )
C A U TIO N : Do not uncap the new unit until
ready to fasten the inlet a n d outlet lines to the
unit.
9. Install receiver-dehydrator by reversing Steps
1-6 above.
1. Disconnect the battery ground cable.
2. Remove screws securing the blower-evaporator
shield; remove the shield. Remove the shield bracket to
instrum ent panel reinforcem ent screws and remove the
bracket.
3. Remove the heater intermediate duct to A /C
distributor duct screw and remove the duct.
RH
DASH
O U TLE T
Fig. lB-54--A ir D istrib u to r Ducts (C60 System - G MOdels)
4. U nsn a p the engine cover latches, remove the
lower tab m ounting bolts and remove the engine cover.
5. Loosen both steering column instrum ent panel
re inforcem ent screws; remove one screw.
6. R em ove the left foot cooler bracket to
instru m ent panel reinforcem ent screws, disconnect the
outlet fro m the duct and remove the outlet and bracket
assembly.
7.
Disconnect the speedom eter cable.
8. Remove the instrum ent panel to lower rein
forcem ent attaching screws. Rotate the instrum ent panel
up to gain access to the air distribution duct.
9.
Disconnect the blower resistor electrical harness.
10. Remove the duct to instrum ent panel attaching
screws and remove the duct assembly.
11. If a new duct is being installed, transfer the
blower resistor to the new duct. Reverse Steps 1-10
above.
NOTE: Make sure all ducts and seals are installed
properly.
A /C CENTER A N D R IG H T DASH OUTLETS
Replacement (Fig. IB -54 )
1. Follow Steps
Duct-Replacement".
1-10 o f " A / C
Air Distributor
2. Remove the outlet to instrument panel screws
and remove the outlet.
3.
To install, reverse Steps 1-2 above.
A /C LEFT DASH O UTLET
Replacement (Fig. IB -54 )
1. Follow Steps 1-8 o f " A / C Air D istributor DuctReplacement".
2. Remove the outlet to instrument panel screws
and remove the outlet.
3.
To install, reverse Steps l -2 above.
HEATER AIR D IS T R IB U T O R
Make sure expansion valve sensing bulb makes
good physical contact with the evaporator core
connector block.
6. Evacuate, charge and check system operation.
AN D EXTEN S IO N D U C T - G M O DEL
Replacement (Fig. IB -54 )
A /C BLOWER M O TO R
1. Disconnect battery ground cable.
2. Remove engine cover.
3. Remove evaporator-blower shield.
4. Remove shield bracket.
5. Remove left floor outlet deflector and bracket.
6. Loosen steering column to instrum ent panel
reinforcem ent screws. Remove one screw. Torque both
screws on installation.
7. Disconnect speedometer cable at meter.
8. Remove instrum ent panel to lower reinforce
ment attaching screws.
9. Move instrum ent panel assembly rearward.
Disconnect radio a n te n n a and electrical connector.
Support instrum ent panel at right visor.
Disconnect electrical connector at brake switch.
10. Remove blower-evaporator support bracket to
do or pillar and forward engine housing attaching screws.
Move rearw ard to gain access.
11. Disconnect vacuum lines and electrical connec
tors. R emove heater distributor duct assembly.
12. T ran sfe r duct and relays.
13. To reassemble. Reverse Steps 1-12.
Replacement (Fig. IB -5 5 )
HEA TER CORE CASE AN D CORE-G MODEL
Replacement (Fig. IB -54 )
Follow Steps 1-10 o f "H e a te r Air Distributor and
Extension Duct Replacem ent" procedure.
11. Remove battery.
12. Disconnect heater hoses at heater core (drain
pan below hoses) refill ra d ia to r upon completion.
13. Remove air inlet valve assembly.
14. Remove tem perature door control cable at
heater case.
15. Remove heater assembly.
16. Remove heater core. Reseal heater case.
17. To reassemble. Reverse Steps 1-16.
E X P A N S IO N VALVE
Replacement (Fig. IB -55 )
1. Purge the system o f refrigerant.
2. Follow Steps 1-8 o f
D istrib u to r DuctReplacement.
3. Loosen the expansion valve sensing bulb clamps
and remove the bulb from the evaporator core.
4. Disconnect the expansion valve inlet and outlet
lines and remove the expansion valve assembly. Cap or
plug all open connections at once.
5. To install a new expansion valve, reverse Steps
1-4 above.
1. Purge the system o f refrigerant.
2. Follow Steps 1-8 o f " A / C Air D istributor DuctReplacement".
3. Disconnect evaporator inlet and outlet lines.
C ap or plug open connections at once.
4. Remove the blower-evaporator support bracket
to door pillar and forward engine housing screws and
lower the blow er-evap orater assembly. D isconnect
electrical connections, pull drain hose m through the dash
panel and remove the blower-evaporator as an assembly.
5. Separate the front and rear case halves.
6. Remove the blower motor retaining strap and
insulator strip and remove the m otor and blower wheels
as an assembly.
7. M ark the blower wheel locations (L and R) and
then remove the blower wheels from the motor shaft.
8. To reinstall, reverse Steps 1-7 above.
NOTE: Install blower wheels in pro per position (L
and R) as marked at removal (blade angle as
shown in Figure IB-55). Be sure to install
insulation around motor before installing motor
clamp. Check blower operation that wheels do not
rub on case.
CORE SCREEN
THERMISTER
SENSING LINE
EXPANSION
VALVE
CORRECT
BLADE ANGLE
Fig. IB -55 Blower and Evaporator (C60 System - G
N O T E : Use new " O " rings, coated with clean
refrig eration oil when connecting all lines.
Models)
W hen m aking evaporator core connections, use
new " O " rings coated with clean refrigeration oil.
9. Evacuate, charge and check system operation.
E VA PO R A TO R CORE
Replacem ent (Fig. IB -5 5 )
1. Purge the system o f refrigerant.
2. Follow Steps l -8 o f " A / C Air D istributor DuctR eplacem ent".
3. Disconnect evaporator inlet and outlet connec
tions. C ap or plug open connections at once.
4. Remove the blower-evaporator support bracket
to door pillar and forward engine housing screws and
lower the blower-evaporator assembly. Disconnect the
electrical connections, pull drain hose through the dash
panel and remove the blower-evaporator as an assembly.
5. Remove the expansion valve sensing bulb
clamps and disconnect the line from the evaporator core.
Disconnect the expansion valve inlet and outlet lines and
remove the expansion valve. C ap or plug all open
connections at once.
6. Remove the evaporator core line clamp screws.
Remove the core to case attaching screws and remove the
evap orato r core assembly.
7. To install a new core, reverse Steps 1-6 above.
T ra n sfer the core screen to the new core. NOTE: Add
three ounces o f new refrigeration oil to a new core. Use
new " O " rings, coated with clean refrigeration oil, when
connecting all refrigerant lines. T ransfer thermister to
the new evaporator.
NO TE: Make sure the expansion valve sensing
bulb makes good contact with the core connector
block.
8. Evacuate, charge and check system operation.
Follow Steps 1-10 o f "Fleater Air Distributor and
Extension Duct Extension Duct Replacem ent" procedure.
11. Remove duct assembly. Disconnect vacuum
hose.
12. Remove vacuum valve.
13. To reassemble. Reverse Steps 1-12.
TE M P E R A TU R E DOOR CABLE - G MODEL
Replacement
Follow Steps 1-10 o f "H e a te r Air D istributor and
Extension Duct Replacem ent" procedure.
11. Disconnect tem perature door control cable at
heater case.
12. Disconnect temperature door control cable at
control.
13. Make up new cable.
14. To reassemble. Reverse Steps 1-13.
CO NTRO L
Replacement (Fig. IB -5 7 )
1. Disconnect the battery ground cable.
2. Remove the headlam p switch control knob.
3. Remove the instrum ent panel bezel.
4. Remove the control to in stru m e n t panel
attaching screws.
5. Remove the temperature cable eyelet clip and
mounting tab screw.
6. Pull the control through the instrum ent panel
opening as follows: First pull the lower right mountin
tab through the opening, then the upper tab and finally
the lower right tab.
7. Disconnect electrical and vacuum connections
and remove the control assembly.
AIR IN LE T VALVE ■ G MODEL
Replacem ent (Fig. IB -5 6 )
Fig. 1B-56 -Air Inlet Valve (G Model C60 System)
Fig. IB -5 7 -C o n tro l (G Model C60 System)
8.
To install, reverse Steps l -7 above.
tem perature door operation; adjust if necessary.
Check
4.
To install, reverse Steps 1-3 above.
BLOWER M O TO R RELAY
BLOWER S W ITC H
Replacem ent (Fig. IB -5 7 )
1. Disconnect the battery ground cable.
2. Remove the left foot cooler outlet assembly at
the instrum ent panel attachm ent.
3. Disconnect the switch electrical harness.
4. Remove the switch m ounting screws and remove
the switch.
5. To install, reverse Steps 1-4 above.
A M P LIFIE R C IR C U IT BOARD
R EPLAC EM ENT (Fig. IB -5 7 )
1. Remove the control assembly as outlined under
"C ontrol-R eplacem ent".
2. Remove the potention meter gear from the pot
shaft.
3. Remove amplifier board cover retainers and lay
the cover back.
4. Remove the circuit board attaching screws and
remove the circuit board and pot assembly.
5. To install, reverse Steps 1 and 4 above.
The blower motor relay is attached to the left end of
the heater air distributor duct (fig. IB-59).
Replacement
1. Follow Steps 1-8 o f " A /C Air D istributor DuctReplacement".
2. Disconnect electrical harness at the relay.
3. Remove the relay mounting screw and remove
the relay.
4. To install, reverse Steps 1-3 above.
D ISCHARGE PRESSURE S W ITCH
Replacement (Fig. IB -6 0 )
1.
2.
Raise the hood.
Purge the system o f refrigerant.
RESISTO RS
The heater blower motor resistor is mounted in the
right h a n d plenum (in the same position as without air
conditioning). The A /C blower motor resistor is mounted
in the forward face of the A /C air distribution duct (fig.
IB-57).
Replacem ent
1. Follow Steps 1-8 o f " A / C Air Distributor DuctR eplacem ent".
2. Disconnect electrical harness at the resistor.
3. Remove the resistor m ounting screws and
remove the resistor.
Fig. IB -5 8 Resistors (G Model C60 System)
Fig. IB 59 Relays (C60 and Tie Relay w ith C69)
Fig. IB-60- Discharge Pressure Switch (G Models)
3.
4.
5.
Disconnect the electrical harness at the switch.
Remove the switch from the refrigerant line.
To install, reverse Steps 1-4 above.
N O T E: Use a new " O " ring coated with clean
regrigeration oil, when installing switch.
6. Evacuate, charge and check system opeation.
V A C U U M TA N K
Replacement (Fig. IB -61 )
1. Raise the hood.
2. Disconnect the vacuum harness at the tank.
3. Remove the tank attaching screws and remove
the tank.
4. To install, reverse Steps 1-3 above.
C IR C U IT BREAKER
T he entire air conditioning system is protected by a
45 am p circuit breaker located on the left side of the
dash, in the engine com partm ent.
Fig. IB -6 2 -C irc u it Breaker
OVERHEAD SYSTEM -G MODELS
This system is used in conjunction with the C60
system. Since replacement o f the C60 System C om po
nents has been covered previously, only those com po
nents peculiar to the Overhead system will be covered in
this section.
BLO W ER-EVAPO RATO R SHRO UD
This shroud covers the blower-evaporator at the rear
o f the vehicle, and incorporates four air outlets.
Replacement (Fig. IB -63 )
1. Disconnect the battery ground cable.
2. Disconnect the d rain tubes at the rear corners of
the shroud.
3. Remove the screws securing the shroud to the
unit and roof panel.
Fig. IB-63-B low er-E vaporator Shroud (G Overhead System)
4. Remove the shroud from the side and rear
retaining flanges and remove the shroud.
5. To install, reverse Steps 1-4 above.
BLOWER M O T O R ASSEMBLIES
Removal (Fig. IB -6 4 )
1. D isconnect the battery gro und cable and
compressor clutch connector.
2. Rem ove the blow er-ev ap orato r shroud as
outlined previously.
3. Remove the blower motor ground straps at the
center connector between the motors.
4. Disconnect the blower motor lead wires.
W ARNING: Before removing the case
screws, support the lower case to prevent
damage to the case or motor assemblies.
CORRECT
BLADE
ANGLE
V A LV E SE N SIN G
BULBS
LOWER
CASE HALF
VALVES
Fig. lB-64--Blow er M otors (G Overhead System)
5. Remove the lower to upper
case screws and lower the lower
assemblies.
6. Remove the motor retaining
the motor and wheels. Remove the
motor shaft.
blower-evaporator
case and motor
strap and remove
wheels from the
Installation
1.
Place the blower wheels onto the motor shaft.
C A U TIO N : Be sure that the blower wheels are
installed as shown in Figure IB-64.
2. Install the blower m otor retaining strap and
foam strip.
3. Place the two blower m otor and wheel
assemblies into the lower case. Aligtt the blower wheels
so that they do not contact the case.
4. Place the lower case and blower motor assemblies
in position in the vehicle and install the blower to upper
case screws.
N O T E: Rotate the blower wheels to make sure that
they do not rub on the case.
5. Install the center ground wires and connect the
blower lead wires.
6. Install the blower-evaporator shroud assembly
as described previously.
7. Connect the b attery ground cable and compres
sor clutch connector.
E X P A N S IO N VALVES
This system incorporates two expansion valves.
These valve do not use and external equalizer line (fig.
IB-65).
Removal (In n er Valve)
Fig. IB -65-E xpansion Valves (G Overhead System)
1. D isconnect the battery gro un d
compressor clutch connector.
2. Purge the system of refrigerant.
3. Remove the blo w er-ev apo rator
outlined previously.
cable
shroud
and
as
W A R N IN G : Before rem oving the lower case
screws, support the case to prevent damage
to the case or m otor assemblies.
4. Disconnect the center ground wire and the
blower motor lead wires. Remove the lower to upper case
screws and lower the lower case and blower motor
assemblies.
5. Disconnect the valve sensing bulb from the core
outlet line.
6. Disconnect the core inlet and outlet lines and
remove the valve assembly. C ap or plug the open
connections at once.
Installation (In n e r Valve)
1. Remove caps or plugs from system connections
and install the new valve assembly using new " O " rings
coated with clean refrigeration oil.
2. Install the sensing bulb, m aing sure that the
bulb makes good contact with the core outlet line.
3. Install the lower case and blower motor
assemblies.
4. Install the blower-evaporator shroud as outlined
previously.
5. Connect the battery ground cable and compres
sor clutch connector.
6. Evacuate, charge and check the system.
Removal (O uter Valve)
1. D isconnect the battery g ro u n d
compressor clutch connector.
2. Purge the system of refrigerant.
cable
and
3. R em ov e the b lo w e r-ev a p o rato r shroud as
outlined previously.
4. Disconnect the blower m otor ground straps and
leads.
5. Disconnect the refrig eran t lines at the rear o f
the blower-evaporator assembly. Cap or plug all open
connections at once.
6. Remove the blower-evaporator to ro o f panel
attachm ents and lower the blower-evaporator assembly.
Remove the assembly and place on a work bench upside
down.
7. Remove the lower to upper case screws and
remove the lower case assembly. Remove the upper
shroud from the upp er case and then remove the upper
case from the core.
8. Remove the expansion valve bulb from the
e vapo rato r outlet line. Remove the expansion valve inlet
an d outlet lines and cap or plug the open connections at
once. Remove the valve.
BOW
SUPPORT
EVAP &
BLOWER ASM
SUPPORT
BLOWER
GRD WIRES
BRACKET
Fig. IB-66-B low er-E vaporator (G Overhead System)
Installation (Outer Valve)
1. Remove the caps or plugs from the refrigerant
connections and install the new valve using new " O "
rings coated with clean refrigeration oil. Install the
sensing bulb, m aking sure that the bulb makes good
contact with the core outlet line.
2. Install the u pper case to the core making sure
the sealing strips are positioned correctly. Install the
upper shroud on the upper case.
3. Install the lower case and blower assemblies.
4. Install the blower-evaporator to the roof panel.
5. Connect the refrigerant lines at the rear o f the
blow er-evaporator unit using new " O " rings coated with
clean refrigeration oil.
6. Connect the blower lead wires and ground
straps.
7. Install the blower-evaporator shroud as d e
scribed previously.
8. Connect the battery ground cable and the
com pressor clutch connector.
9. Evacuate, charge an d check the system.
E VA PO R A TO R CORE
6. Remove the blower-evaporator to ro o f panel
attachments an d lower the blower-evaporator assembly.
Remove the assembly and place it on a work bench
upside down.
7. Remove the lower to upper case screws and
remove the lower case assembly. Remove the upper
shroud and u pper case from the evaporator care.
8. Remove the expansion valve inlet and outlet
lines and cap or plug the open connections at once.
Remove the expansion valve capillary bulbs from the
evaporator outlet line and remove the valves.
9. Remove the plastic pins holding the screen to
the core and remove the screen.
Installation
1. Install the wire screen to the fro nt o f the new
core and insert the plastic pins.
2. Install the expansion valve inlet and outlet lines
using new ”0 " rings coated with clean refrigeration oil.
Install the sensing bulbs to the evaporator outlet line.
Make sure the bulbs have good contact with the line.
Removal (Fig. IB -6 6 )
1. D isconnect the b a tte ry g ro u n d
com pressor clutch connector.
2. Purge the system o f refrigerant.
3. R em ove the blo w e r-e v a p o rato r
outlined previously.
4. Disconnect the blower m otor leads
wire.
5. Disconnect the refrigerant lines at
the blower-evaporator assembly. Cap or
connections at once.
cable
N OTE: Add 3 oz. clean refreigeration oil when
installing a new core.
3. Install the upper case and upper shroud to the
and
core.
shroud
as
and ground
the rear o f
plug open
W A R N IN G : Before rem oving th e blowerevaporator unit, support the case to prevent
dam age to components.
4. Install the lower core case and blower
assemblies.
5. Install the blower-evaporator to the roof panel.
6. Connect the refrigerant lines to the blowerevaporator unit using new " O " rings coated with clean
regrigeration oil.
7. Connect the blower lead wires and ground
straps.
8. Install the blower-evaporator shroud as outlined
previously.
9. Connect the battery ground cable and the
compressor clutch connector.
Fig. lES-67~Rear Blower M otor Switch
Fig. IB -6 8 -R e a r Blower M otor Relay
10.
Evacuate, charge and check the system.
R ESISTO R
See "R esistor" in the G Model C60 System Section
o f this m a n ual (fig. IB-58).
4.
operation.
To install, reverse Steps 1-3 above. Check system
T IE RELAY
Replacement (Fig. IB -59 )
BLOWER S W ITCH
Replacement (Fig. IB -67 )
1. Disconnect the battery ground cable.
2. Remove the h e a d la m p and blower switch
control knobs.
3. Remove the instrum ent panel bezel.
4. Disconnect the wiring harness at the switch.
5. Remove the switch locknut and remove the
switch.
6. To install, reverse Steps 1-5 above.
REAR BLOWER RELAY
The rear blower relay is attached to the instrument
panel reinforcem ent, just left o f the steering column (fig.
IB-68).
Replacement
1. Disconnect battery ground cable.
2. Disconnect relay wiring harness at the relay.
3. Remove the relay attaching screw and remove
the relay.
1. Disconnect the battery ground cable.
2. Remove screws securing the blower-evaporator
shield; remove the shield. Remove the shield bracket to
instrument panel reinforcem ent screws and remove the
bracket.
3. Remove the heater interm ediate duct to A /C
distributor duct screw and remove the duct.
4. U n snap the engine cover latches, remove the
lower tab m ounting bolts and remove the engine cover.
5. Loosen both steering column instrument panel
reinforcem ent screws; remove one screw.
6. Remove the left foot cooler bracket to
instrument panel reinforcement screws, disconnect the
outlet from the duct and remove the outlet and bracket
assembly.
7. Disconnect the speedometer cable.
8. Remove the instrument panel to lower rein
forcement attaching screws. Rotate the instrum ent panel
up to gain access to the relay.
9. Disconnect electrical harness at the relay.
10. Remove the relay m ounting screw and remove
the relay.
11. To install, reverse Steps 1-10 above.
DASH MOUNTED SYSTEM-MOTOR HOME CHASSIS
This system is installed on the vehicle and checked
at assembly. The blower-evaporator is then disconnected
and shipped with the chassis unit to the body supplier.
F or this reason, it will only be possible to give basic
replacement procedures on some components.
CO NDENSER
Replacement (Fig. IB -69)
1.
Disconnect the battery ground cable.
Fig. lB-69~C ondenser (M o to r Flome Chasis U n it)
2. Purge the system o f ref rigerant.
3. Disconnect the condenser inlet and outlet lines
and cap or plug all open connections at once.
4. Remove the condenser to radiator support
screws and remove the condenser.
5. To install a new condenser, reverse Steps 1-4
above. Add one fouid ounce of clean refrigeration oil to
a new condenser.
N O T E : Use new " O " rings, coated with clean
refrigeratio n oil. w hen connecting all refrigerant
lines.
Fig. IB -70-R eceiver-D ehydrator (M o to r Flome Chassis U nit)
6.
Evacuate, charge and check the system.
S IG H T GLASS R E P LACEM ENT
Refer to "Sight Glass Replacem ent" in the G Model
C60 System Section o f this manual.
BLO W ER-EVAPO RATO R ASSEMBLY (Fig. 1B71)
Removal
6.
Evacuate, charge and check the system.
RECEIVER-DEHYD RATO R
Replacement (Fig. IB -7 0 )
1. Disconnect the battery ground cable.
2. Purge the system o f refrigerant.
3. Disconnect the inlet and outlet lines at the
receiver-dehydrator and cap or plug the open lines at
once. „
4. Remove the receiver-dehydrator bracket attach
ing screws and remove the bracket and receiverdehydrator.
5. To install a new receiver-dehydrator, reverse
Steps 1-4 above. Add one fluid ounce o f clean
refrigeration oil to a new receiver-dehydrator.
N O T E : Use new ”0 " rings, coated with clean
refrigeration oil, when connecting all refrigerant
lines.
1. Disconnect battery ground cable.
2. Purge system of refrigerant.
3. Disconnect inlet and outlet refrigerant lines
from the back o f unit. Cap or plug all open connections
at once.
4. Disconnect d rain tubes from evaporator case.
5. Disconnect electrical connector from com pres
sor. Remove the term inal (See Figure IB-72) and allow
connector to h ang on ground wire.
6. Remove screws securing grom m et retainer to
dash panel. Remove wire from grom m et through slit.
7. Disconnect electrical lead at connector.
8. Remove unit m ounting bolts. Remove unit from
vehicle, carefully pulling compressor electrical lead
through dash panel.
Once the unit has been removed from the vehicle,
continue with com ponent replacem ent as follows:
BLOW ER ASSEMBLY
CORRECT
BLOWER
BLADE
A N G LE
Fig. lB-73--ESIower Assem bly (M o to r Home Chassis
U n it)
Removal (Fig. IB -73 )
1. Remove the cover plate an d separate the upper
an d lower case halves. Remove blower motor mounting
strap screw and remove strap.
2. Remove blower assembly. Remove the wheels
from the motor shaft.
Installation
4. Reverse Steps 1-8 on the "Blower-Evaporator
Assembly" removal procedure.
5. Evacuate, charge and check the system.
E XP A N SIO N VALVE, EVA PO RA TO R A N D /O R
EVA PO RA TO R CASE
Removal (Fig. IB -74 )
1. Install the blower wheels on the motor so that
the lower blades curve toward the dash panel side o f the
unit w hen the m otor is placed in the case as illustrated in
Figure IB-73.
2. Place the motor in the bracket with the electrical
connector side o f the m otor to the right side o f the
bracket. Attach the m ounting strap. Align blower wheels
so that they do not contact case.
3. Assemble the case halves and attach the cover
plate.
1. Remove the cover plate and separate up per and
lower case halves.
2. R em ove inlet and outlet lines from the
expansion valve. Remove sensing bulb from the
evaporator outlet manifold. Remove expansion valve.
Cap or plug open connections at once.
3. Remove evaporator core retaining screws and
remove core.
TERMINAL
THERMOSTATIC SWITCH
CAPILLARY TUBE
SCREW DRIVER
(NAR RO W BLADE)
SCREEN
MESH
CO NNECTO R
TANG
G RO O VE
A. Insert screw driver in groove & press
tang toward terminal to release.
EXPANSIO N VALVE
BUMPER
B. Pry tang back out to insure locking
when reinstalled into connector.
Fig. lB-74--Expansion Valve (M o to r Home Chassis
U nit)
2. Reverse steps 1-8 o f the "Blower Evaporator
A ssembly" removal procedure.
3. Evacuate, charge and check the system.
T H E R M O S T A T IC A N D /O R BLOWER
SW ITCHES
Replacement
1. Remove the cover plate assembly from the
evaporator case.
2. Remove two screws securing either switch to the
cover plate and remove appropriate switch (fig. IB-75).
3. Install replacement switch, reinstall cover plate
and reverse steps 1-8 o f the "Blower-EVaporator
Assembly" removal precedure.
Fig. IB -7 5 -Therm ostatic and Blower Switches
4.
from case.
Remove blower motor and harness assembly
RESISTOR
Installation
1.
procedure.
NOTE: W hen installing thermostatic switch, be
sure to position sensing capillary as when unit was
removed.
Reverse
applicab le
steps
in
the
removal
CAUTION: Use new "O " rings coated with
clean refrigeration oil when connecting lines.
A d d 3 oz. o f new refrigeration oil to a new
core.
The blower motor resistor is located on the top of
the unit. The entire unit must be removed to replace the
resistor.
FUSE
This U nit does not incorporate an in-line fuse. The
lead wire is connected to the H eater W iring Harness and
operates off the 20 am p Heater Fuse.
SPECIFICATIONS
A IR
C O N D I T I O N IN G
Compressor
M ak e............................................................................. Frigidaire
T y p e .................................................................. 6 Cylinder Axial
D isplacem ent.......................................................... 12.6 Cu. In.
Rotation........................................................................ Clockwise
Volts
Amps.
(Cold)
RPM
(Cold)
Blower Motor
C-K Four Season . . 12.0
C-K-G Overhead,
G Floor and
Motor Home1
U n its.................. 12.0
12.8 Max.
3400 Min.
13.7 Max.
3400 Min.
C-K Four-Season System ................................ 3 lbs.
C-K-G Overhead S y s t e m s ........................5 lbs. 4 oz.
G Floor S ystem ...........................................3 lbs. 4 oz.
Motor Home Chassis U n i t ........................3 lbs. 4 oz.
Torque Specifications
Compressor Suction and Discharge
Connector B o l t ............................................. 25 ft. lbs.
Rear Hend to Shell Stud N u ts.......................... 23 ft. lbs.
Shaft Mounting N u t .......................................... 20 ft. lbs.
Compressor Mounting Bracket Bolts.............. 25 ft. lbs.
Front Bracket to Compressor B o lts ................20 ft. lbs.
Belt T ensio n........................................See Tune Up Chart
Fuses
Compressor Clutch Coil
Ohms (at 8 0 ° F ) ........................................................ 3.70
Amps, (at 8 0 ° F ) ..................................... 3.33 @ 12 volts
Fuse Block—
C-K S y s t e m s .................................................. 25 Amp.
Motor Home Chassis Unit............................. 20 Amp.
In-Line—
System Capacities
Refrigerant 12
C-K S y s t e m s .................................................. 25 Amp.
Motor Home Chassis U n i t .................................. None
Circuit Breaker
G Model Systems.............................................45 Amp.
SPECIAL TOOLS
1 . J - 2 5 0 3 0 C l u t c h H u b H o l d i n g To ol
2.
J - 2 5 0 2 9 Rotor B e a r in g Remover a n d
3.
R o t o r Assy. I n s t a l l e r
J - 2 4 8 9 5 M a i n B e a r in g In staller
4.
J - 2 4 8 9 6 M a i n B e a r in g Remover
5.
J - 2 5 0 3 1 - 2 R ot or a n d B e a r i n g P u l l e r
6.
J - 2 5 0 3 1 -1 R ot or a n d B e a r i n g P u l l e r G u i d e
7.
J-25008-1
8.
J - 2 5 0 0 8 - 2 S h e ll In s ta llin g Fixture
C o m p r e s s o r H o l d i n g F i x t u re
%■
4
5
11
22
25
18
19
20
21
23
26
27
28
24
30
32
1. J - 8 3 9 3
C h a r g in g S t a tio n
11. J - 5 4 2 1 - 0 2
P o c k e t T h e rm o m e te rs (2 )
22. J -9 3 9 8
P u lle y B e a r in g R e m o v e r
2. J - 2 4 0 9 5
O il I n d u c e r
12. J - 5 4 0 3
N o . 21 S n a p R in g P lie rs
2 3 . J -9 4 8 1
P u lle y a n d B e a r in g I n s t a lle r
3. J -5 4 5 3
G o g g le s
13. J - 6 4 3 5
N o . 2 6 S n a p R in g P lie rs
24. J -8 0 9 2
H a n d le
4. J -9 4 5 9
7 / 1 6 " - 2 0 9 0 u G a u g e L in e
14. J - 9 3 9 6
C o m p re s s o r H o ld in g
25. J -2 1 3 5 2
J -2 5 4 9 9
3 /8 "-2 4 A d a p te r
F ix tu r e
I n t e r n a l A s s e m b ly
S u p p o r t B lo c k
7 / 1 6 " - 2 0 S t r a ig h t G a u g e L in e
15. J - 2 5 0 3 0
C o m p r e s s in g F ix tu r e
26. J -5 1 3 9
3 /8 " A d a p te r
16. J - 9 4 0 3
C lu tc h H u b H o ld in g T o o l
27. J -9 4 3 2
N e e d le B e a r in g I n s ta lle r
6 . J -6 0 8 4
L e a k D e te c to r
17. J - 9 3 9 9
9 / 1 6 " T h in W a l l S o c k e t
28. J -9 5 5 3 -0 1
S e a l S e a t " O " R in g
7. J -8 4 3 3
P u lle r
18. J -9 4 0 1
8. J -9 3 9 5
P u lle r P ilo t
29. J -2 1 5 0 8
Seal Seat
9. J -2 3 5 9 5
R e f r ig e r a n t C a n V a lv e
5 . J -5 4 2 0
J -2 5 4 9 8
19. J -9 4 8 0 - 0 1
R em over
H u b a n d D r iv e P la te
" O "
R in g
I n s ta lle r
A s s e m b ly in s t a lle r
30. J -2 2 9 7 4
S h a ft S e a l P r o te c to r
R e f r ig e r a n t C a n V a lv e
2 0 . J -9 3 9 2
S e a l R em over
31. J -9 6 2 5
P re s s u re Test C o n n e c to r
(T o p - T a p )
2 1 . J -2 3 1 2 8
S e a l S e a t R em over
3 2 . J -9 4 0 2
P a rts T r a y
( S id e - T a p )
1 0 . J -6 2 7 1 -01
H u b a n d D r iv e P la te
A s s e m b ly R e m o v e r
O il P ic k u p T u b e R e m o v e r
SECTION 2A
FRAME
CO NTENTS
G eneral D e s c rip tio n ........................................................................2A-1
On-Vehicle Service........................................................................... 2A-1
M aintenance and In spectio n......................................................2A-1
U nd erb ody Inspection................................................................ 2A-1
F ram e In sp e c tio n ......................................................................... ■2A-1
Fram e A lig n m en t........................................................................... 2A-1
U n d erb o d y A lig n m e n t................................................................. 2A-3
Excessive Body D a m a g e .............................................................. 2A-3
GENERAL DESCRIPTION
Light duty 10-30 Series fram es are of the ladder
channel section riveted type.
Figure 2A-1 thru 2A-4 illustrates typical light duty
truck fram es with crossmembers, body mounts and
suspension attaching brackets. This section also includes
general instructions for checking fram e alignment and
recom m endations on frame repair.
The G-Van fram e side rails, cross sills and
outriggers are part o f the underbody assembly which is a
welded unit.
M isalignment o f the underbody can affect door
opening fits and also influence the suspension system,
causing suspension m isalignm ent. It is essential,
therefore, that underbody alignment be exact to within
1/16" o f the specified dimensions.
ON-VEHICLE SERVICE
MAINTENANCE AND
INSPECTION
UN D ER B O D Y IN S PE C TIO N
Raise the vehicle on a hoist (preferably a twin-post
type).
Check for obvious floor pan deterioration.
Check for loose dirt and rust around the inside of
the floor pan reinforcem ent m em b er access holes. This is
the first indication that corrosion may exist in hidden
areas, and that repairs might be required before the final
cleaning and protective treatm ent is performed.
U sing a chisel, ensure that the drain provisions in
the floor pan reinforcem ent m em bers are open.
T here are drain holes in the body side panels also.
These holes can be opened by using a punch or drift.
The side panel drain holes are in the rear section o f the
rocker panels, and in the lower rear quarter panels.
FRAM E IN S PE C TIO N
Raise the vehicle on a hoist (preferably a twin-post
type).
Check for obvious floor p an deterioration.
Check for loose dirt and rust around the inside of
the fram e rails, on top and at the ends where corrosion
may exist in hidden areas. Check especially in the frame
box sections for accumulation of debris.
FRAME A L IG N M E N T
Horizontal fram e checking can be m ade with
tram m ing gauges applied directly to the fram e or by
transferring selected points of measurem ent from the
frame to the floor by means o f a plum bob and using the
floor layout for measuring. Figure 2A-2 or 2A-4 may be
used as a general guide in the selection o f checking
points; however, selection o f these points is arbitrary
d ep e n d in g on accessibility and convenience. An
im portant point to rem em ber is that for each point
selected on one side o f the frame, a corresponding point
on the opposite side of the fram e must be used for
vertical checks, opposite and alternate sides for
horizontal checks.
Vehicle Preparation
Points to rem em ber when preparing vehicle for
frame checking:
1.
Place vehicle on a level surface.
2. Inspect dam ag ed areas for obvious frame
misalignment to eliminate unnecessary measuring.
3.
Support vehicle so that fram e sidemem bers are length. Opposite side m easurem ent should correspond
parallel to the ground.
within 3/16".
3. Measure diagonals marked A, B and C. If the
Tram m ing Sequence (Fig. 2A -1)
lengths o f intersecting diagonals are equal and these
diagonals intersect the centerline, frame area included
1. D im ensions to bolts a n d / o r holes in fram e
between these points o f m easurem ent may be considered
extend to dead center of the hole or bolt.
in alignment.
2. D imensions must be w ithin 3/16".
4. If front or rear end of fram e is dam ag ed and
3. If a tram b a r is used, for horizontal alignment
width is no longer within limits, fram e centerline may be
" X " - check from opposite and alternate reference points
drawn through the intersection o f any two previously
AA. BB and CC. as illustrated by the lines in Figure 2A1. Error will result if a tram bar is not level and centered
drawn pairs o f equal, intersecting diagonals.
at the reference points.
Vertical Check
4. O b tain vertical dim ensions and com pare the
differences between these dimensions with the d im e n
Vertical dimensions are checked with a tram m ing
sions as shown in figure 2A-3 or 2A-4.
bar from indicated points on the fram e (figs. 2A-2 and
H orizontal Check
1. M easure fram e width at front and rear. If
widths correspond to specifications, draw centerline full
length o f vehicle halfway between lines indicating front
and rear widths. If fram e widths are not correct, layout
centerline as shown in Step 4.
2. M easure distance from centerline to correspond
ing points on each side o f fram e layout over entire
2A-4). For example, if the tram bar is set at point B with
a vertical pointer length o f 8-1/4 inches, and at point E
with a vertical pointer length of 5-1/4 inches (a height
difference o f 3 inches), the tram bar should be parallel
with the frame. If the area is twisted or misaligned in
any way, tram bar will not be parallel. Placing the tram
bar vertical pointers on opposite sides o f the fram e side
rail is preferable in that fram e twist will show up during
this vertical check. Figures 2A-2 and 2A-4 show typical
Fig. 2A-1--Frame H orizontal Checking -Typical
DIMENSIONS TO HOLES OR SLOTS ARE MEASURED TO THE CENTER OF HOLE OR SLOT
GAUGE HOLES ARE 5/8" DIAMETER
©
INDICATES THAT THE DIMENSION IS TO THE UNDERSIDE OF THE FRAME TOP
SURFACE OR INSIDE OF THE FRAME OUTER SURFACE
NOTE:
FRAME ILLUSTRATED IS TYPICAL. FRAME DESIGN
VARIES ACCORDING TO TRUCK MODEL
Fig. 2A-2--C-K-P Series Truck Frame
checking points, with dimensions for various frames
shown in figure 2A-3.
Fram e Repair
Welding
Before welding up a crack in frame, a hole should
be drilled at the starting point o f the crack to prevent
spreading. W id en V groove crack to allow complete weld
penetration.
N O T E: Do not weld into corners o f fram e or along
edges o f side rail flanges. W elding at these points
will tend to weaken the fram e and encourage new
cracks.
Bolting
W herever rivets or failed bolts are replaced, bolt
hole must be as n e ar the O.D. o f the bolt as possible to
prevent bolt from w orking and wearing. Drill out and
line ream hole (or holes) to the bolt O.D.
U N D ER B O D Y A L IG N M E N T
O ne m ethod o f d eterm ining the alignm ent of the
u n derbo dy is with a tram gauge which should be
sufficiently felxible to o btain all necessary measurements
up to three quarters the length o f the vehicle. A good
tra m m in g tool is essential for analyzing and determ ining
the extent o f collision m isa lig n m e n t p resent in
underbo dy construction.
M E A S U R IN G
To measure the distance accurately between any two
reference points on the underbody, two specifications are
required.
1. The horizontal dimension between the two
points to be trammed.
2. The vertical dim ension from the datu m line to
the points to be trammed.
The tram bar should be on a parallel to that o f the
body plane. The exception to this would be when one o f
the reference locations is included in the misaligned
area; then the parallel plane between the body and the
tram bar may not prevail. A fter completion of the
repairs, the tram gauge should be set at the specified
dimension to check the accuracy o f the repair operation.
EXCESSIVE BODY DAM AG E
If dam age is so extensive that key locations are not
suitable as reference points, rep air operations should
always begin with the underbody area. All other
components should be aligned progressively from this
area. Unlike the conventional type of fram e design, the
unitized type o f body construction seldom develops the
two conditions o f "twist" and " d ia m o n d " in the
underbody area as a result o f front or rear end collisions,
therefore, there usually is an u n dam ag ed area suitable as
a beginning reference point.
M odel
A
B
C
D
E
F
G
H
1
J
K
L
M
N
P
S
R
T
U
V
CA107
13-3/8
15-1/4
16
19-7/8
12
13
10
14-7/8
17-3/4
17 3/4
19-7/8
16 3/4
15-5/8
17-3/4
69 5/8
76-1/2
110
16-7/8
16-7/8
14
CA109
13-3/8
15-1/4
16
19-7/8
12
13
10
14-7/8
17-3,4
17-3/4
19-7/8
16-3/4
15-5/8
17-3/4
69-5/8
86-1/2
120
16-7/8
16-7/8
14
CA209
13-3/8
15-1/4
17
19-7/8
12
13
10
14 7/8
17-3/4
17 3/4
19-7/8
16-3/4
15-5/8
17 3/4
69-5/8
86-1/2
120
16-7/8
16 7/8
14
C A 210
310
13-3/4
15-1/4
16
18-1/2
10
13
10
14-1/4
17-3/4
17-3/4
19-7/8
15-5/8
17-3/4
69 7/8
105
131
16-7/8
16-7/8
14
CA314
13-3/8
14-7/8
16
18-1/2
10
13
10
14-1/4
17-3/4
17-3/4
19-7/8
15-5/8
17-3/4
69-7/8
129
155-1/2
16-7/8
16 7/8
14
KA107
13-3/8
15-1/4
17
19-7/8
12-1/2
13
10
14 7/8
17-3/4
17-3/4
19-7/8
16-3/4
15-5/8
17-3/4
69-5/8
76-1/2
no
16-7/8
16-7/8
14
13-3/8
15 1/4
17
19-7/8
12-1/2
13
10
14-7/8
17-3/4
17 3/4
19-7/8
16-3/4
15-5/8
17-3/4
69 5/8
86-1/2
120
16-7/8
16-7/8
14
7-5/8
9-3/8
11
14-5/8
9-1/2
13
10
7-5/8
9-3/8
115/8
14-5/8
9-1/2
13
10
9-1/2
7-5/8
9-3/8
11-5/8
14-5/8
9-1/2
13
10
9-1/2
K A 109
209
PA 100
p A 208
308
PA 210
310
9 1/2
13
10-7/8
13
717/8
36
89
16-7/8
16-7/8
14
13
9-1/2
13
10-7/8
13
72-1/4
59
131
16-7/8
16-7/8
14
9-1/2
13
9-1/2
13
10-7/8
10-7/8
13
71-7/8
67
153
16-7/8
16-7/8
14
9-1/2
13
PA314
7 5/8
9-3/8
11-5/8
14-5/8
13
10
9-1/2
13
10 7/8
10-7/8
13
71-7/8
91
177
16-7/8
16-7/8
14
CA105
13-3/8
15-1/4
17
19-7/8
12
13
10
14-1/4
20
17-3/4
15-5/8
17-3/4
69-5/8
46
88
16-7/8
16 7/8
14
KA105
13-3/8
15-1/4
17
19-7/8
12-1/2
13
10
14-1/4
20
17 3/4
15-5/8
17 3/4
69-5/8
46
88
16-7/8
16-7/8
14
9-1/8
11-1/2
10-7/8
9-1/2
13
10
9-1/2
13
9-1/2
13
10-7/8
10-7/8
13
68-1/2
71
157
16-7/8
16-7/8
14
9-1/8
11-1/2
10-7/8
9-1/2
13
10
9-1/2
13
9-1/2
13
9-7/8
10-7/8
13
68-1/2
92-1/2
178-1/2
16-7/8
16-7/8
14
9-1/8
11-1/2
10-7/8
9-1/2
13
10
9-1/2
13
9 1/2
13
10-7/8
10-7/8
13
68-1/2
112
240 3/16
16-7/8
16-7/8
14
PE
31132
(137)
PE
31432
(157)
PE
31832
Fig. 2A-3--C-K-P Series Frame Reference Dim ensions
Fig. 2A-4 G Van Truck Reference Dim ensions
SECTION 2B
BUMPERS
C O N TE N TS
G e n e ra l D escrip tion ..........................................................
Service Procedures - 10 thru 30 Series....................
Fron t Bumper - C, K and P M o dels.....................
R ear Bum per - C and K M odels.............................
2B-1
2B-1
2B-1
2B-1
Rear Step Bumper - C and K M odels..................
Front Bumper G Series................................................
Rear Bumper G S e rie s.................................................
Specifications........................................................................
2B-2
2B-2
2B-2
2B-3
GENERAL DESCRIPTION
All 1977 truck front and rear bumpers are o f a
single piece design. Bumper attachments are the
sta n d a rd bracket and brace to fram e mountings. This
section contains procedures for the removal and
installation o f face b a r , brackets, brackes and license
plate brackets.
SERVICE PROCEDURES—10 THRU 30 SERIES
F R O N T BUM PER-C, K AN D P MODELS
Installation
Removal Fig. 2B-1, 2B-2
Assemble and install front bum per following the
removal procedure in reverse order.
1.
frame.
Remove bolts securing two bum per brackets to
2. Remove bolts securing bum per face bar to
frame, and left and right bu m per brackes and remove
bu m p e r from vehicle.
3. If necessary, disassemble bu m p er by removing
bolts attaching brackets and brackes to bum per face bar.
4. If equipped with b um p e r guards (Fig. 2B-2)
remove re m a in in g nuts and bolts.
REAR BUM PER-C AND K MODELS (FIG 2B3)
Removal
1. Remove bolts attaching bum per to each bum per
brace. Disconnect license lamp wiring on sub urb an and
panels and pickup.
2.
Remove bolts attaching bum per to frame.
3.
Remove b um p e r from vehicle.
4.
If necessary, replace body splash shield.
Installation
Install rear bum p er following removal procedure in
Fig. 2 B -l~ F ro n t Bumper-C, K and P Models
Fig. 2B-2--C, K Model Front Bum per Guards
I
1. Remove nuts securing bumpers to brackets and
braces from left and right side. Remove bumper.
2. Remove the license plate support nut and bolts.
3. If necessary to remove the braces and brackets,
remove screws securing brackets and braces to sheet
metal.
NOTE: The bum per may be removed with the
brackets and braces attached.
4. If equiped with bumper guards (Fig. 2B-6) they
may be removed from the face bar at this time.
installation
Reverse removal steps to install bumpers.
REAR BUM PER-G MODELS
Removal Fig. 2B-7, 2B-8
1. Remove nuts securing bum per to brackets and
braces and remove bumper.
2. Remove brackets and braces from vehicle.
Fig. 2B-3--Rear Bum per • C, K Models
reverse order. Connect license lam p wiring on suburban
panel, and pickup models.
REAR S TE P B U M PE R C AN D K MODELS
Removal (Fig. 2B-4)
1.
2.
3.
Disconnect license lam p wiring.
Remove bolts connecting bum per to brackes.
Remove bum per assembly.
4. Remove bolts securing bu m p er brace to fram e
and remove brace.
Installation
Install rear step bu m p e r by reversing
procedure. Connect license lam p wiring.
F R O N T B U M P E R - G MODELS
removal
Fig. 2B 5 -F ro n t Bum per - G Models
Removal Fig. 2B-5, 2B-6
Fig. 2B-4-R ear Step Bum per C and K Models
Fig. 2B-6-G-Models Front Bum per Guards
Fig. 2B-8--G-Model Rear Step Bum per
Fig. 2B-7 -Rear Bumper-G Models
N OTE: The bum per may be removed with brackets
and braces attached if necessary.
Installation
Instal1 in reverse order o f removal.
SPECIFICATIONS
TO R Q U E S P E C IF IC A TIO N S C , P A N D K
Front Bum per ......................................................................... 35
Front Bum per Bracket a n d B race ............................... 70
Rear Bum per to O u te r Bracket .....................................35
Rear Bum per O u te r B racket a n d Brace .................. 5 0
License P la te B r a c k e t ..........................................................18
G ra v e l D e fle c to r ................................................................. 85
Rear Step Bum per to Bracket or Fram e .................. 4 0
ft.-lb s .
ft.-lb s .
ft.-lb s .
ft.-lb s .
ft.-lb s .
in .-lb s .
ft.-lb s .
TO R Q U E S P E C IF IC A TIO N S G
Front Face B a r to B racket ............................................... 24
Bracket to Cross S i l l ............................................................ 24
License P late Bracket to Face B ar .......................... 100
Rear Face Bar to B r a c k e ts ............................................... 55
B ra c k e t to F lo o r
ft.-lb s .
ft.-lb s .
in .-lb s .
ft.-lb s .
.............................................................................. 5 5 f t . - l b s .
SECTION 2C
CHASSIS SHEET METAL
CONTENTS
G e n e ra l D escription..........................................................
O n Vehicle S e rv ic e ...........................................................
Hood Assembly - CK Series.......................................
Hood Hinge Spring R e p lacem ent...........................
Hood H i n g e .....................................................................
Hood Lock A sse m b ly ...................................................
Hood A ssem bly..............................................................
Hood Assembly - G S e r ie s .........................................
Hood H in g e .....................................................................
Hood Lock A sse m b ly ..................................................
Hood B u m p e r..................................................................
2C-1
2C-1
2C-1
2C-1
2C-1
2C-2
2C-2
2C-3
2C-3
2C-3
2C-4
Hood Assem bly.............................................................. ..2C-4
Front Sheet Metal - CK S e rie s................................ ..2C-6
Radiator Su p p o rt............................................................2C-8
Front F e n d e r .................................................................. .2C-8
Front Fender and S k i r t ............................................. .2C-8
Front F ender S k i r t ........................................................2C-9
R unning B o a r d .............................................................. .2C-9
Front Sheet Metal - G Series................................... .2C-9
Sheet Metal C h ecking................................................. .2C-10
Fender Skirt - P Series................................................ .2C-K)
Wood G ra in Applique Installation P ro c e d u re .... .2C-10
Specifications.........................................................................2C-12
GENERAL DESCRIPTION
not provide
assembly.
CK Series
The chassis sheet metal assembly is attached to the
fram e and body at adjustment points. The front of the
assembly is supported by two mounts located at the
fram e side rails. Fore and aft and side adjustment is
allowed by oversize holes at the fender rear attaching
point an d chassis sheet metal mounts. Special shims at
the rear locations allow adjustm ent of the rear of the
assembly. The lower rear edge of the assembly is
attached to the body at the rocker panel by bolts on each
side. Shims are used at this location to provide in and
out adjustm ent at the rear o f the fender. The bolts that
retain the sheet metal braces must be torqued to the
required torques. If these bolts are loose, the braces will
additional support for the sheet metal
G Series
The front end sheet metal design does not include
the radiator support and fenders as loose items inasmuch
that these items are welded together as an integral part
of the body.
Front end sheet metal includes the hood assembly,
hood hinges, hood lock catch and support, a hood rod
assembly which supports the hood, a bolted radiatorupper tie bar, and series designation plates and hoods
emblems. Refer to figure 13 for sheet metal checking.
Refer to Section 6B for R adiator and Grille service
procedures. Section 2B for Bumpers, and Section 1A for
Heater.
ON VEHICLE SERVICE
HO O D ASSEMBLY - CK SERIES
Hood Hinge (Fig. 2C-2)
Hood Hinge Spring R eplacem ent
Removal
For Hinge Spring Replacement, a tool can be made
to dimensions as shown in Figure 2C-1.
1. Raise and safely support the hood in full open
position.
2. As shown in Figure 2C-2, engage hooked end of
tool to spring, then carefully pull forward to engage or
disengage spring from hinge assembly.
1. Prop the hood in the extreme open position and
place protective covering over the cowl and fenders.
2. Scribe position o f hinge attachment on hood
rear reinforcem ent and remove two bolts.
3. Remove hood hinge spring as described above.
4. Scribe position of hinge attachm ent on fender
assembly and remove bolts.
5. Remove hinge.
Installation
1.
Install hinge assembly
within scribe marks. Install bolts.
to fender
and
align
HOOD
.110
REF
SUPPORT
NUT
L O C K IN G
PLATE
LOCK
NUT
G U ID E
IN
LOCK
BOLT
HOOD
ASSY.
NUBBLE
VIE W
VIE W
LOCK
N U B B L E T O BE
CENTERED IN G U ID E
HOOD
BUMPER
Fig. 2C-2-Hood Hinge and Spring—CK Series
2. Install hood hinge spring.
3. Install bolts a n d align
A lignm ent in this section.
hood.
See
Hood
Hood Lock Assem bly
A bolt-type hood lock is used as shown in Figure
2C-3. The lock bolt, located on the hood dovetails with
the m ounted striker plate, preventing upward or
downward m ovem ent of the hood while the vehicle is in
Fig. 2C-4-Hood Lock Bolt and Bum per—CK Series
motion. Integral with the striker plate is the combination
lock release lever and safety catch.
Replacement
1.
Open hood and remove the four bolts holding
the com bination lock support and lock bolt.
N OTE: If original hood lock assembly is to be
replaced, scribe a line around lock for alignment
on installation.
2. Place hood lock assembly in position.
3. Adjust as outlined under Adjustments.
Adjustment (Fig. 2C-4)
1. Loosen lock nut on lock bolt and adjust lock bolt
approxim ately 2 7/16 inches from bottom o f lock bolt to
bottom o f support.
2. Adjust tightness o f support screws so they are
just snug enough to hold support in position.
3. Adjust support fore and aft until nubble enters
center o f elongated guide. Bending nubble to accomplish
this adjustm ent may seriously effect lock operation and
safety latch e n g a g e m e n t and is. therefore, not
recom m ended.
4. Tighten screws to 14(1 pound inches.
5. Adjust lock bolt to o btain a secure hood closure
and reasonable lock release effort.
Hood Bum per Adjustm ent
Hood Bumpers must be adjusted until hood and
fender line up flush at front corner. Adjust hood lock
bolt to o btain a m inim um load o f 45 pounds to a
m axim um load o f 55 pounds on each bum per after hood
is firmly slammed.
Hood Assembly
Removal
1.
Open hood and prop in full open position.
N O T E: If hood is to be reinstalled and present
a lignm ent is satisfactory, mark each hinge in
relation to hood, to assure original alignment.
2. Remove two (2) cap screws which attach each
hinge to hood; then with a helper remove hood from
vehicle.
Installation
1. If original hood is to be installed, position hood
to hinges and install four cap screws snug which attach
hinges to hood.
N O TE: If a new hood is to be installed, perform
procedures as outlined under Alignment, directly
below.
2. Shift hood on hinges to location marks made
before removal o f hood, then tighten attaching cap
screws at hinges firmly. Close hood and check fit. If
necessary to align hood perform procedure as outlined
u nder "A lig n m e n t” which follows.
Alignment (Fig. 2C-2)
1. Loosen hood hinge bolts. Note that rear most
bolt hole in hinge is slotted to allow hood trailing edge to
move up and down.
2. Adjust hood rear bu m p e r bolt so that bu m p er is
flush with fender. N ut must be threaded completely onto
bolt before torquing to m a intain design height.
3.
Perform hood lock adjustment as outlined in
this section if necessary.
Hood Assembly - G Series
The alignment o f the hood is controlled by the
position o f the hood hinges and the height o f the two
bumpers located one at each side o f the rad iato r support.
The adjustm ent at the hood lock must be m ade after the
hinges and bum pers are properly adjusted (refer to Hood
Lock A djustment fig. 2C-6). To align the hood and lock
proceed as follows:
Hood Hinge (Fig. 2C-5)
The body mounted portion o f the hood hinges are
slotted to provide up and down movement. The hood
mounted end is slotted to provide forward and rearward
movement.
Hood support rod assembly must operate freely
without binding in assembled position.
Hood Lock Assembly
A bolt-type hood lock is used as shown in Figure
2C-6. The lock bolt, located on the hood, dovetails with
the mounted striker plate, preventing upward or
downward movement o f the hood while the vehicle is in
motion. Integral with the striker plate is the combination
lock release lever and safety catch.
1. Scribe a line around the entire hinge plate to be
repositioned.
2. Loosen the appropriate screws and shift the
position o f the hood into correct alignment using the
scribe marks to check am ount o f movement. Check
alignment by tightening screws and closing the hood.
Replacement
1. O pen hood and remove the four bolts holding
the com bination lock catch and lock bolt.
N O T E: If original hood lock assembly is to be
replaced, scribe a line aro un d lock for alignment
on installation.
2. Place hood lock assembly in position.
3. Adjust as outlined u nder Adjustments.
Adjustment
CAUTION: H ood lock assembly to be adjusted
fo r e a nd a ft until hood lock bolt enters center
o f elongated guide. Bending bolt to accomplish
this adjustm ent m ay seriously effect lock
operation a n d safety catch engagement and is,
therefore not recommended.
1. Adjust lock bolt as shown in Figure 2C-7.
2. O pen hood and adjust tightness o f catch
assembly so that it is just "sn u g " enough to hold lock
bolt in position.
3. Close hood in a normal m anner.
4. Raise hood again; lock bolt assembly will have
shifted to operating position. Tighten bolts fully. Further
adjustm ent may be made at lock bolt support, if
necessary.
5. Adjust lock bolt to obtain a secure hood closure
and reasonable lock release effort.
HO O D LATCH CABLE RELEASE - CK
MODELS (FIG. 2C-8)
Replacement
1. Release the hood from below, using a suitable
rod, by pressing on the hood release tab at the right side
o f the lock assembly.
2. Remove the cable at the lock assembly.
3. Rem ove hood release hand le to kickpad
attaching screws.
4. Remove hood release cable.
5. To install, reverse steps 2 through 4 above.
HOOD EMBLEM - CK MODELS (FIG . 2C -9)
Hood Bumper (Fig. 2C-7)
Adjust hood bumpers so that hood top surface is
flush with the fender and grille top surfaces. Refer to
Figure 13 for correct sheet metal adjustm ent dimensions.
Hood Assembly (Fig. 2C-7)
Removal
1. Lay a fender cover along cowl top to prevent
hood from scratching painted surfaces.
2. O pen hood and prop in full open position.
NOTE: If hood is to be reinstalled and present
alignment is satisfactory, mark each hinge in
relation to hood, to assure original alignment.
3. Remove rod assembly (see fig. 2C-5).
4. Remove two cap screws which attach each hinge
to hood; then with a helper remove hood from vehicle.
Installation
1. If original hood is to be installed, position hood
to hinges with helper and install four cap screws snug
which attach hinges to hood.
2. Install rod assembly.
N OTE: If a new hood is to be installed, perform
procedures as outlined under Alignment, directly
below.
3. Shift hood on hinges to location marks made
before removal o f hood, then tighten attaching cap
screws at hinges firmly. Close hood and check fit. If
Fig. 2C-8- Hood Release Cable ■ CK Models
necessary to align hood perform procedure as outlined
under "A lignm ent” which follows.
Alignment
1. Loosen hood hinge bolts. Note that rear bolt
holes in hinge is slotted to allow hood trailing edge to
move up and down.
2. Adjust hood bumpers so that hood and adjacent
surfaces are flush.
3. Perform hood lock adjustment as outlined in
this section if necessary.
NOTE: Hood Lock Assembly to be adjusted fore
and aft until nubble (part o f Hood Lock Bolt
Support Assembly) enters center o f elongated
guide (Socket). Bending nubble to accomplish this
adjustment may seriously effect lock operation and
R A D IA TO R GRILLE M O LD IN G - CK MODELS
(FIG. 2C -12)
FRO NT SHEET M ETA L ASSEMBLY-CK
SERIES
Removal o f entire front sheet metal assembly
including radiator involves disassembly o f mounts,
disconnecting rad iato r hoses and removal of front
bumper. Vehicles equipped with air conditioning a n d / o r
power steering will require special handling.
Refer to appropriate sections o f this m anual for
instructions.
Shims which are found at various locations should
be recorded to ease installation of sheet metal assembly.
Refer to Figure 2C-13 for sheet metal clearance.
Removal
safety catch engagem ent and is, therefore, N O T
RECOMMENDED.
Hood Rod Support - G-Series
Refer to Fig. 2C-10 for removal and installation of
hood rod support.
C A R B U R E TO R O U TS ID E AIR INLET
SNO RKELS (Fig. 2 C -1 1)
Removal
1. Raise hood and remove carburetor air duct
from air snorkel by sliding duct rearward.
2. Remove two (2) screws attaching air snorkel to
ra d ia to r support and remove from vehicle.
SNORKEL L O C A T IO N
L6 SNORKEL
Fig. 2C -11-C arburetor Outside A ir Inlet Snorkels—CK
Series
1. D ra in radiator and remove radiato r hoses.
Disconnect oil cooler lines if so equipped.
2. Disconnect wire connectors at the dash and toe
panel and wire connector to horn and voltage regulator.
3. Disconnect battery and generator wires.
4. R em ove front b um p e r bolts and remove
bumper.
5. Remove bolts attaching fender upper edge to
cowl door frame.
6. Remove fan shroud.
7. W orking from underneath rear o f fender,
remove attachm ent from each fender at the hinge pillar.
HOOD ASS’
HOOD
ASSY
FLUSH
HOOD
ASSY
•FENDER
ASSY
FLUSH
/-F E N D E R
/ ASSY
-FENDER
ASSY
FENDER
ASSY
DOOR ASSY
•FLUSH
SECTION E -E
SECTION B -B
SE CTION C-C
] Hood su rfa c e . 06 below
a t Section C -C to flush a t Section
B -B an d S ection D -D .
SECTION D -D
N OTE
I
\
I
' —DOOR
SECTION F - F ^ l - 0 0
ASSY
I NOTE 1 Shim fro n t fen d er to obtain
su rfa c e flu sh n e ss s ta r tin g a t a
point approx 1.00 fro m leading edge
of d o o r. (T ypical e n tire length of
fe n d e r to door).
HOOD ASSY
FENDER
ASSY
RADIATOR GRILLE
U PPER PANEL
ROCKER
PANEL
FLUSH
r____?EgTioii tt-fi
SECTION A-A
1 NOTE [Shim fro n t fe n d e r to
obtain su rfa c e flu sh n e ss to
r o c k e r p a n el.
Fig. 2C-13--Sheet M etal Clearance—CK Series
8. R em ove bolt from each ra d ia to r sup po rt
mounting.
9. Remove bolts at each fender skirt to cab
underbody (tig. 2C-14).
10. With a helper, remove front sheet metal
assembly, with radiator, battery, horn and voltage
regulator attached.
Installation
1. With a helper place sheet metal assembly in
position.
N O T E : Install all bolts loosely to facilitate aligning
after complete installation.
2. Install fender bolts at cowl.
3. Install c o m b in a tio n bolt an d flat w asher
assembly into each fender reinforcem ent while inserting
shims required between fender reinforcem ent and body
(See Figure 2C-15).
4. Install two bolts and shims required at each
fen der rear lower edge to hinge pillar.
5. Install bolt in each fend er skirt to underbody.
6. Install bolts at steering column skirt reinforce
ment, final torque 25 ft. lbs.
7. Tighten each radiator support mounting bolt 33
ft. lbs.
8. Torque bolts at fender to cowl 25 ft. lbs.
9. Install front bumper.
10. Connect wire connectors at dash and toe panel.
Attach g enerator and regulator wires.
Fig. 2C-14--Fender S kirt Assembly—CK Series
11. Connect upper and lower rad iato r hoses.
Connect oil cooler lines to the rad iator on models so
equipped.
3. Connect hood latch plate.
4. Connect ra d iato r support brackets to fenders.
5. Connect support to fenders.
6. Connect screws from underside o f fender skirts
to support bottom.
7. Attach grille upper panel to fenders loosely.
8. Attach grille lower panel to fenders.
9. Tighten radiator support bolts.
10. Place battery tray in position and fasten to
radiator support.
11. Install radiator coolant recovery tank hoses and
shroud.
12. Connect removed wiring to radiator support.
13. Install both head lamp assemblies.
14. Tighten all previously installed bolts and
screws.
15. Install battery and connect leads and wires.
16. Install grille assembly.
17. Fill rad iato r with coolant as specified in
Section 13.
18. Install hood on previously m arked outline.
FRO NT FENDER (FIG. 2C -15)
Removal
Fig. 2C-15--Front Fender Assem bly—CK Series
1. Remove hood and hinge assembly.
2. Remove head lamp bezel, wiring and attach
12.
Connect battery and fill radiator. Start engine
ments from fender.
and check for leaks.
3. Remove screws attaching upper and lower
radiator grille panels.
Radiator Support
4. Remove screws attaching fender wheel opening
Removal
flange to skirt.
1. Remove hood as described in this section.
5. Remove skirt to fender bolts, located inboard on
2. D ra in radiator, saving coolant, loosen attach
underside o f skirt.
ments an d remove radiator and coolant recovery tank.
6. Remove two (2) screws attaching support
3. Disconnect and remove battery.
bracket to fender.
4. Remove battery tray with battery hanger.
7. Remove five (5) screws attaching radiator
5. Remove wiring from ra d iato r support.
support to front fender.
6. Disconnect fan shroud and lay back on engine.
8. Remove bolt and shim attaching trailing edge
7. Remove both head lam p assemblies.
of fender to hinge pillar.
8. Remove grille assembly.
9. Remove two bolts and shims at top rear of
9. Remove upper and lower radiator grille panels.
fender attaching to cowl.
(Fig. 2C-16).
Installation
10. Remove screws securing front fenders to
To install, reverse the removal procedure using
ra d ia to r support.
sealing tape between filler panel and fender. Check sheet
11. Remove screws securing fender skirts to
metal alignment.
ra d iato r support bottom. (Fig. 2C-14).
12. Remove bolt securing center grille support to
FRONT FENDER AND S K IR T (FIGS. 2C -14
ra d ia to r support.
AMD 2C -15)
13. Remove bolts securing hood catch assembly to
ra d ia to r support.
Removal
14. Remove rad iato r support bolts secured to
1. Remove hood and hood hinge assembly.
frame.
2.
Disconnect and remove battery (right side or
15. Tilt radiator support rearw ard and lift up and
auxiliary
left side).
off.
3. Remove head lamp bezel, wiring and attach
Installation
ments from fender.
4. Remove screws attaching upper and lower
1. Rotate radiator support into position and loosely
radiator grille panels.
install attachments to fram e.
5. Remove screws attaching skirt to radiator
2. C onnect center grille sup po rt to ra d ia to r
support.
support.
UPPER
R A D IA T O R
PANEL
SUPPORT
R A D IA T O R
M O U N T IN G
PANEL
BRACKET
LOWER
PANEL
Fig. 2C-16--Radiator Upper and Lower Grille Panels—CK Series
6. Remove two (2) top re ar fender bolts and shims.
7. Remove bolt and shims at bottom o f fender.
8. Remove bolt and shim(s) attaching skirt to
underbody.
9. Remove two (2) screw attaching support bracket
to fender.
10. Remove five (5) screws attaching radiator
support to front fender.
11. Lift fender and skirt from truck.
Installation
Install front fender and skirt assembly in reverse
order o f removal.
FR O N T FENDER SK IR T
Refer to figure 2C-14 for removal and installation
of Front F en der Skirt.
R U N N IN G BOARDS
Refer to figure 2C-17 for removal and installation
of running boards.
Front Sheet M e ta l Assembly - G Series
The fro nt end sheet metal components not covered
in this section are covered in the Body Section IB.
COWL TO HOOD
± 1 /3 2
3 /1 6
NOTE H o o d s u r f a c e flu sh to
b e lo w
from
cowl
(£_ to
vent
hood
g rille
rear
and
1/16
constant
c o r n e rs .
FENDER TO COWL
1 /1 6 GAP (Ref)
NOTE
Cowl
vent
grille
FENDER TO HOOD
3 /1 6
1 /3 2
GAP
NOTE
Hood
corner
and
becom e
NOTE
Full
range
any
Fig. 2C-17--Running Boards—CK Series
±
the
surface
one
gap.
range
of
dictate
that
f lu sh
f lu sh
of
gap
C learances
good
gap
to
at
1 /1 6
front
b e lo w
of
tolerances
to
be
a ssem b ly
c le a ra n c e s
do
h e ld
at
be
not a p p ly
u n ifo rm ly
practices.
shou ld
fender
rear
hood.
to
w ith in
A p p earances
p a ralle l.
SHEET M E TA L C H EC K IN G
Refer to the sheet metal checking illustration figure
2C-18 for pro per gaps an d hood adjustments.
Fender Skirt - P Series
Refer to figure 2C-19 for removal and installation
o f fend er skirt, brackets, rear supports and hangers.
W O O D G R A IN A PPLIQ U E
IN S T A L L A T IO N PRO CEDURE
Genera!
The wood grain applique (transfer film) is a vinyl
m aterial with a pressure sensitive adhesive backing. The
transfers are serviced in pre-cut panels. The transfers are
designed with an appealing wood grain pattern and a 50
degree or semi-gloss finish.
P reparation o f the surface to which the transfer will
be applied is very im portant. In cases where body metal
rep air has been m ade it is necessary to prime and color
coat these areas to blend with the undam aged surface.
Fig. 2C-18 Front End Sheet M etal Checking—G
Series
Apply the transfer film to color coated panels only, never
to bare metal or primer.
The surface must be free o f any im perfections that
might high-light through the film. Remove dirt nibs and
other foreign material in the paint by light sanding with
600 grit sandpaper.
The tem perature of the body must be m aintained at
a moderate level between approximately 70 and 90
degrees. Too warm a body will cause the wood grain film
to stick prem aturely while too cool a body will reduce the
adhesion o f the wood grain film. Cool the body panel
with cool water when too warm and heat the body panel
with a heat gun or a heat lamp w hen too cold.
Transfers should not be replaced in temperatures
below 65 degrees Fahrenheit. The transfer should not be
subjected to temperature greater than 175 °F and should
not be left at or near this tem perature for extended
periods of time.
Fig. 2C 19 Fender S kirt, Dash and Toe Pan—P Series
S h elf life of the transfer material is 90 days at a
tem perature not to exceed 105 F.
Removal
Remove the moldings from the affected panel. The
transfer film may then be removed by lifting an edge
and peeling the material from the painted surface.
Exercise care so as not to da m a ge the paint. Application
o f heat to the transfer and the panel by means o f a heat
gun or heat lam p will aid in the removal.
Installation
1. With a solvent d a m p e n e d sponge, clean entire
surface to be covered with applique.
2.
W ipe area dry with a clean cloth.
3. Prior to application of transfer, wet down the
complete transfer surface o f the fender with a solution
o f 1/4 oz. of neutral detergent cleaner (must not contain
oils, perfumes, or bleaches) per gallon o f clear water. It
is essential that no substitute for this solution be used
and tha t the specified proportions be maintained.
4.
While entire area is still wet with solution.
remove pap er backing from transfer and align upper
edge with pierced holes in fender and press on lightly.
5. Start at center o f transfer and squeeze outboard
from middle to edges removing all air bubbles and
wetting solution to assure a satisfactory bond. Use teflonbacked plastic squeegee only.
6. Notch applique at fender rear contour bend
areas with scissors. Also notch out front m ark er lamp.
7. Fold ends o f applique over fender flanges using
squeegee. Heat the wrap-around area o f applique with a
heat lamp or gun to approximately 90 T and press with
squeegee to secure entire edge surface.
8. If the w rap-around of the transfer has trouble
sticking to fender edges, brush vinyl adhesive onto the
fender or transfer area. Allow the adhesive to set for one
minute then press transfer to fender for adhesion.
9. Inspect transfer installation from critical angle
using adequate light reflection to detect any irregularities
that may have developed during installation. Remove all
air or moisture bubbles by piercing each at an acute
angle with a fine pin or needle and by pressing the
bubble down.
10. Install previously removed parts and clean up
vehicle as required.
SPECIFICATIONS
SHEET METAL
S E C T IO N 2 C
TORQUE SPECIFICATIONS
CK
Lock Support to Hood
Lock Bolt Nut
Bumper Bolt Nut
Hood Hinge
Hood Lock Catch
Lock Support to Rad. Support
Rad. Support to Frame
Rad. Support to Fender
Fender Skirt to Fender
Fender to Cowl
Rad. Grille Panel
150
30
85
35
150
18
35
150
150
35
150
in. lbs.
ft. lbs.
in. lbs.
ft. lbs.
in. lbs.
ft. lbs.
ft. lbs.
in. lbs.
in. lbs.
ft. lbs.
in. lbs.
P
G
150
40
150
18
18
18
in.
ft.
in.
ft.
ft.
ft.
lbs.
lbs.
lbs.
lbs.
lbs.
lbs.
30 ft. lbs.
150 in. lbs.
SECTION 2D
BODY
The following caution applies to one or more steps in the assembly
procedure o f components in this portion o f the m anual as indicated at
a p propriate locations by the terminology "See Caution on page 1 o f this
Section".
CAUTION: T H I S F A S T E N E R I S A N I M P O R T A N T A T T A C H I N G
P A R T I N T H A T I T CO U LD A F F E C T T H E P E R F O R M A N C E OF
V I T A L C O M P O N E N T S A N D S Y S T E M S , A N D / O R C O U LD R E S U L T
IN M A JO R R E P A IR E X PEN SE. I T M U S T BE R E P L A C E D W ITH
O N E OF T H E S A M E P A R T N U M B E R OR W IT H A N E Q U I V A L E N T
P A R T I F R E P LA C E M E N T B E C O M E S N E C E S S A R Y. DO N O T U SE A
R E P L A C E M E N T P A R T OF L E S S E R Q U A L I T Y OR O F S U B S T I
T U T E D E S IG N . T O R Q U E V A L U E S M U S T B E U S E D A S S P E C I
F IE D D U R I N G R E A S S E M B L Y TO A S S U R E P R O P E R R E T E N T I O N
OF T H I S P AR T.
C O N TE N TS OF TH IS SECTION
G eneral D escrip tion ........................................................................ 2D-1
C-K M odels...................................................................................... 2D-1
G M o d e ls.......................................................................................... 2 D - 1
On Vehicle Service.......................................................................... 2D-4
Specifications.............................................................................. 2D-61,62
Special To ols.................................................................................... 2D-63
GENERAL DESCRIPTION
On the following pages, service procedures will be
given for com ponents on all 10-20-30 series trucks in C.
K and G models. Reference will be made, both in text
and illustrations, to vehicle model lines and to individual
model num bers within these model lines.
As an aid to identification o f specific models, the
following general descriptions are given.
Chassis/Cabs
All chassis cabs use "03 " as the
See figure 2D-1. Two-wheel drive
C-20 an d C-30 series. Four-wheel
either K-10 or K-20. O ptional
available.
model identification.
units come in CIO,
drive units may be
pickup boxes are
Crew C ab/Chassis
Model n u m b e r " 6 3 " designates the crew cab/chassis
models. See figure 2D-2. Optional pickup boxes are
available.
Coach
The four-door coach model num ber is "06". See
figure 2D-3. Base models have rear cargo doors. An
optional endgate with moveable window is available.
U tility
Utility models are designated with the n u m b e r "16".
See figure 2D-4. An optional removable roof is also
available.
Vans
G-Series Vans are available in three model nu m b er
designations. See figures 2D-5 and 2D-6. Vans without
body windows use nu m b e r "05"; vans with body
windows are " 0 6 " models; "03 " vans have an open cargo
area, as shown in figure 2D-6.
Fig. 2 D -5-T ypical ” 0 5 " and " 0 6 " Vans
Fig. 2D-6--Typical ” 0 3 '' Van
ON VEHICLE SERVICE
C-K M O D ELS
INDEX
Front End
W indshield W ip ers....................................................... 2D-5
Glove Box........................................................................ 2D-5
R ear View M irro rs ....................................................... 2D-6
Body Glass
W indshield G la s s .......................................................... 2D-7
Stationary Body G la ss................................................ 2D-9
Side Doors
A d ju stm e n ts................................................................... 2D-11
Fro nt Side D o o r ......................................................... 2D-12
R e p la ce m e n t............................................................. 2D-12
Hinges......................................................................... 2D-12
V e n tila to r................................................................... 2D-12
Window and R e g u la to r ....................................... 2D-14
Locks, Handles, R o d s ........................................... 2D-16
W eath erstrip ............................................................. 2D-17
Rear Side D o o rs.........................................................
R ep lacem ent.............................................................
Hinges.........................................................................
Stationary G la ss.....................................................
Window and R e g u la to r......................................
Locks, Handles, R o d s ...........................................
W eatherstrip .............................................................
R ear Doors
A djustm ents..................................................................
Locks, Handles, R o d s ...............................................
H inges..........................!..................................................
Gates
E n d g ates.........................................................................
T ailg ates.........................................................................
Removable Top - Folding Top (Utility)...............
S e a ts ....................................................................................
Body M o u n tin g ...............................................................
2D-17
2D-17
2D-17
2D-18
2D-19
2D-19
2D-20
2D-20
2D-20
2D-20
2D-24
2D-28
2D-29
2D-30
2D-34
FRONT END
pivot shaft assembly to windshield frame. Remove wiper
linkage and transmission from plenum.
W IN D S H IE LD W IPERS
W indshield wiper units on all models are o f the twospeed electric type. A single wiper motor unit, mounted
to the left side o f the dash panel inside the engine
c om partm ent, powers both wiper blades. The wiper blade
op eratin g link rods and pivot mountings on these models
are located in the outside air inlet plenum chamber.
Installation
1. Place wiper linkage and transmission into
position. Secure assembly with two screws at each
transmission.
2. Attach end o f cross rod to drive arm o f motor
assembly. Secure rod.
3. Before installing wiper arms, operate wiper
motor m omentarily which should rotate pivot shafts to
park position. Install arms and shafts.
Arm Adjustm ent
To adjust sweep of blades, turn on wipers and note
sweep o f arms. If necessary, remove one or both arms as
follows: Pull outer end o f arm away from glass which
will trip lock spring at base o f arm and release spring
from undercut o f pivot shaft. W hile holding arm in this
position, pull outward on cap section at base o f arm to
remove arm. A rm can be reinstalled in any one o f
several positions due to serrations on pivot shaft and in
arm cap. See figure 2D-7.
IN S T R U M E N T PANEL C O M P A R T M E N T AND
LOCK
Replacement
Removal o f the entire assembly including door may
be accomplished by removing four screws which attach
hinge just below box. See figure 2D-8. The outer door
panel may be removed, leaving the com partm ent intact,
by removal o f four screws. Access to the door stop
W iper Arm Pivot Shafts and Linkage
Removal
1.
Remove windshield w iper arms from pivot
shafts. Procedure for removing arms is explained
previously u nd e r A rm A djustemnt".
" 2. Remove two nut and lock washer assemblies
frfom the connector link to m otor drive arm via the
plenum access hole.
3.
Remove
two screws
from
each
transmission
N OTE: C am p er mirror installation is similar to the
Fig. 2D-10--Rear View M irrors
below eyeline mirror installation.
bu m p e r is gained by reaching into c om partm ent opening
with door partially open.
IN S ID E REAR VIEW M IR R O R - FIG URE 2D-
A d ju stm ent
11
E ngagem ent of lock in striker may be adjusted by
loosening striker retaining screws and moving the striker
to desired position.
Replacement
1.
Remove screw retaining m irror to its glass-
mounted bracket and remove mirror.
2.
O U T S ID E REAR V IE W M IR R O R S
Rear view mirror installations are shown in figure
2D-9, 2D-10 and 2D-11.
Occasional tightening o f
Install m irror into its mounting bracket. Torque
screw to specifications.
COWL V E N T VALVE - FIGURE 2D-12
mounting and assembly bolts and screws will sharply
Two styles are shown in Figure 2D-12. Removing
decrease occurrence of failure due to door slamming or
the attaching screws allows removal of the valve from
road shock.
the side panels.
Fig. 2D-12 Cowl Vent Valves
BODY GLASS
W A R N IN G : Always w ear gloves when
handling glass.
W IN D S H IE L D GLASS
T he windshield is a one-piece type and is retained
in the windshield opening by a molded rub ber
weatherstrip. See figure 2D-13.
W hen replacing a cracked windshield glass, it is
very im p o rta n t that the cause o f the glass breakage be
determ ined and the condition corrected before a new
glass is installed. Otherwise, it is highly possible that a
small obstruction or high spot somewhere around the
windshield o pening will continue to crack or break the
newly installed windshield especially w hen the strain on
the glass caused by this obstruction is increased by such
conditions as wind pressures, extremes of temperature,
motion o f the vehicle, etc.
NOTE:
T he
p rocedu re
for
rem oval
of
the
VIEW A
w in dsh ie ld applies to o th e r sta tio n a ry glass
applications, such as in figures 2D-20 and 2D-21.
Removal
1. Before removing the windshield, mark the
location o f the break on the windshield rubb er channel
and the body. Protect the pain t finish inside o f the cab.
Mask around the windshield opening and outside, lay a
suitable covering across the hood and fenders.
N O T E : The windshield glass ru bb er w eatherstrip is
one piece. The glass is held in a channel within the
weatherstrip.
2. On vehicles w ithout reveal moldings, "u n z ip "
the locking strip shown in figure 2D-18.
3. On vehicles with reveal moldings, remove
reveal molding with tools show in figure 2D-19.
4. To free windshield r u b b e r channel of w eather
strip loosen the lip of the windshield weatherstrip from
the pinchweld flange along the top and at the sides by
Fig. 2D-14--Applying Pressure to W indshield
applying firm, controlled pressure to the edge o f the
glass. At the same time assist the lip o f the rubber
weatherstrip channel over the pinchweld flange with a
flat bladed tool. See figures 2D-14 and 2D-15.
5.
With the aid o f an assistant outside the cab,
remove the windshield from the opening. See figure 2D16.
Checking W indshield Opening
Due to the expanse and contour of the windshield it
is im perative in the event of a stress crack that the
windshield opening be thoroughly checked before
installing a replacement windshield. The replacement
glass is used as a template.
1. Check for the following conditions at the
previously marked point o f fracture.
a. Chipped edges on glass.
b. Irregularities in bodyopening.
c. Irregularities in ru bb er channel weatherstrip.
2. Check flange area for solder, weld high spots, or
hardened spot-weld sealer. Remove all high spots.
3. Check windshield glass to opening, by support
ing glass with six spacers contained in packet J-22577.
See figure 2D-17.
C A U TIO N : Do not strike glass against body
metal. Chipped edges on (he glass can lead to
future breaks.
4. With the windshield supported and centered in
its opening, check the relationship of the glass to the
body opening flange around the entire perim eter of the
glass.
5. Check the relationship o f glass to opening as
follows:
a. Inside edge o f glass to body flange.
b. Outer edge of glass to parallel body metal.
6.
M ark areas of body metal or flange to be
reform ed remove glass and correct as necessary.
2ZBS
Fig. 2D -17-C hecking W indshield Opening
7.
Recheck windshield
satisfactory proceed as follows:
in
its
opening
and
if
Installation
1. Place a protective covering over front fenders
and hood, then apply soapy w ater to all grooves of the
w eatherstrip.
2. Install w e a th e rstrip centrally to the body
opening, with the pinchweld flange in the inner
w eatherstrip groove. See figure 2D-18.
N OTE: Because o f the configuration of the
w eatherstrip and o f the im portance o f centrally
locating the w eatherstrip in the body opening, it is
not recomm ended to use the "cord-type" installa
tion technique.
3. Position the lower edge o f the windsheild glas
into the outer weatherstrip groove.
Gently push the
glass " in to " the weatherstrip, assisting rub ber over edge
o f glass.
4. W hen glass is in position, lock the weatherstrip
to the glass as follows:
a. Base W eatherstrip - Bend the "locking strip"
over and use a thin bladed tool to lock w eatherstrip
tightly against windshield. See figure 2D-18 for detail.
b. O ptional W eatherstrip - Use J - 2 189-24 and
J - 2 189-23 in Handle J -2 189 to install flexible reveal
m olding into locking slot o f weatherstrip, as shown in
figure 2D-19. This will expand the w eatherstrip to a tight
Fig. 2D 18 -Locking the W eatherstrip to the Glass
fit against the windshield. Install reveal molding so that
joint is at center o f lower edge of windshield. Cover the
joint with the molding cap.
S TA TIO N A R Y BODY GLASS
Replacement
The method used to remove the windshield glass
may be applied to other stationary glass, such as shown
in figures 2D-20 and 2D-21. R em em ber to check for
cause o f breakage, and to always w ear gloves when
handling glass. Installation procedures are similar to
G-Van windshield. Refer to figures 2D-94 and 2D-95,
later in this section.
Fig. 2D-21--Body Side W indow
(14 and 06)
BODY SIDE DOORS
DOOR A D JU S T M E N T S
Doors can be adjusted for alignm ent o f clearance in
the cab door opening, and for proper latching. D oor
alignm ent adjustments are made at the striker bolt, and
at door hinges. The door, w hen properly located in door
opening, will have .19 inch clearance at the top and side
edges, and .25 inch clearance at the bottom. The door
should be adjusted in the o pening so the edge of the
door across the top and also at the lock side is parallel
with the body opening as nearly as possible.
Hinge Adjustm ent
D o o r hinge bolt holes are oversized to make
adjustm ent possible. A lignm ent adjustments can be
m ade by loosening the proper hinge bolts, aligning door
to pro p e r position, and tightening bolts securely. See
figure 2D-22, for typical adjustments.
Striker Bolt Adjustm ent
With the use o f J-23457, shown in figure 2D-23. the
striker bolt can be adjusted in any o f three ways. See
figure 2D-24.
1.
Up and down - To adjust striker up or down,
loosen bolt, adjust to desired height, and tighten bolt
securely.
NOTE: This adjustm ent is im portant to assure that
the right proportion o f d o o r’s weight will rest on
striker bolt when door is closed. If bolt is
positioned too high on pillar, rapid w ear will occur
to the lock cam; if too low, an extra load will be
placed on door hinges as well as pull door
downward and out o f alignment.
2. In and Out - To adjust striker in and out, loosen
bolt, adjust horizontally to desired position and tighten
bolt securely.
Fig. 2D-22 -Door Hinge
Fig. 2D-24--Typical Striker Bolt A djustm ent
3.
Foreward and R e a rw a rd -T o make this adjust front door check-hinge assembly is replaced
ment, loosen striker bolt, shim to desired position, and
complete unit as follows. See figure 2D-22.
tighten bolt securely.
as
a
Removal
FR O N T DOOR ASSEMBLY
R eplacem ent
Remove the door assembly from
rem oving the hinges from the door.
the
body
by
DO O R H IN G E
The door check is p art o f the front door upper
hinge. The front door torque rod check holds the door in
either of two positions between full open and closed. The
1. Loosen front fender rear bolts.
2. With special Tool J-22585 remove 3 bolts
securing front door upper hinge to cowl pillar.
a. Remove the door to upper hinge retaining
bolts.
b. With aid o f an assistant to support weight of
door, remove the door to lower hinge retaining bolts and
remove door.
Installation
1. Install hinge snugly
hinge removed.
2. With the aid of an
the hinge.
3. Adjustment o f the
should be made after the
opening.
on pillar in same location as
assistant fasten the door to
door lock and striker plate
door is positioned in the
DOOR T R IM PANELS - CK MODELS
Door trim panel installation is illustrated in Fig.
2D-25.
DOOR V E N TILA TO R ASSEM BLY-Fig. 2D -26
Removal
NOTE: The channel between the door window
glass and door vent is removed as p art o f the vent
assembly.
1. Regulate the door window glass to the full down
position.
2. Remove clip from the window regulator handle,
and knob from lock rod.
3. Remove arm rest screws and rim panel. See
figure 2D-27.
Fig. 2D-27--Door Trim Pad
Fig. 2D-2b--Door T rim Panel
Fig. 2D-28--Removing V entilator Assembly
Fig. 2D -26-D oor V e n tila to r Assembly
4. R em ove screws a tta c h in g v en tila to r lower
assembly to door panel.
5. Loosen inner to outer panel attaching screw
through access hole just rearward o f the lower vent pivot.
6. Slide door window glass rearw ard away from
ventilator.
7. Remove three screws at the upper front of the
door frame.
8. T urn vent assembly 90" and carefully remove by
guiding up and out. See figure 2D-28.
V en tilato r Glass Replacement
2. Thoroughly clean the inside of the glass channel
with sandpaper, removing all rust, etc.
3. Using new glass channel filler, cut the piece to
be installed two inches longer than necessary for the
channel. Place this piece o f filler (soapstoned side of
filler away from glass) evenly over the edge o f the glass
which will fit in the channel. The extra filler extending
beyond the rear edge of the glass should be pinched
together to hold it in place during glass installation.
NOTE: One side o f this filler (the outside o f the
roll) is soapstoned. This is the side which goes into
the metal channel.
4. Brush the inside o f the metal glass channel
freely with ordinary engine oil. This will enable the glass
1.
Using an oil can or similar means, squirtand filler to slide freely into the channel. Push the glass
prepsol or equivalent on the glass filler all around the
with the filler around it into the channel until it is firmly
glass channel or fram e to soften the old seal. W hen the
seated. A fter the glass is firmly in place, the oil softens
seal has softened, remove the glass from the channel.
the filler, causing it to swell, thereby making a watertight
seal. Trim off the excess filler material around
channel and at the ends o f the channel.
the
N O T E : Glass should be installed so that rear edge
is parallel to the division post. Allow full cure
before w ater testing.
Installation
N OTE: Replace the door window glass and
regulate to the full down position before installing
the door ventilator assembly.
1. Lower the ventilator assembly into the door
frame.
2. Make certain the ru b b e r lip is positioned inside
the inn er and outer panel before tightening screws.
3. Slide door glass forward engaging glass in vent
channel.
4. Reinstall all screws and tighten.
5. Install and tighten the three screws at the upper
front o f the door.
Adjustment
1. Adjust the ventilator by placing wrench on
adjusting nut thru access hole and turning vent window
to the desired tension. See figure 2D-29.
2. A fter m aking adjustment bend tabs over the hex
nut on base o f assembly. See figure 2D-30.
3. Install arm rest screws and trim panel.
4. Install window regulator handle.
DOOR W IN D O W ASSEM BLY-FIG . 2D-31
Replacement
1. Completely lower glass to bottom o f door.
2. Remove window regulator handles using tool
J-7797. and remove remote control push button knob.
3. Remove door arm rest and trim pad.
4. Mask or cover upper portion o f door window
fram e. Remove ventilator assembly as previously
outlined.
5. Slide glass forward until front roller is in line
with notch in sash channel. Disengage roller from
channel.
6. Push window forward and tilt front portion of
window up until rear roller is disengaged. See figure 2D32.
7. Put window assembly in norm al position (level)
and raise straight up and out.
8. Reverse above procedure for installation.
W IN D O W R E G U LA TO R -M A N U A L-FIG . 2D-31
Replacement
Fig. 2D-29--Adjusting Tension
BEND TAB O VER
HEX NU T
1. Remove ventilator assembly and door window
as outlined previously.
2. Remove screws attaching regulator to door inner
panel.
3. Remove regu lato r assembly through door
opening.
NOTCH
ROLLER
Fig. 2D 32 Removing Door Glass
4.
Install regulator by reversing above
Lubricate regulator gear with lubriplate or equivalent.
steps.
W IN D O W REG ULATO R - POW ER - CK
MODELS
Fig. 2D-34--Power W indw Regulator, M otor and
Connector
In the case that window will not operate, check
electrical connections first. Figure 2D-33 illustrates
location o f junctions, switch, relay and circuit breaker.
Replacem ent
C A U T IO N : Electrical connectors m ust be
rem oved fr o m window lift m otor before
perform ing any operation on the regulator.
Figure 2D -34 illustrates location o f regulator
on door a n d wiring.
1. Disconnect battery ground cable.
2. Remove door upper trim panel.
3. Remove arm rest bracket and pull assist handle
bracket.
4. Remove remote control bolts and lay control
assembly aside for access.
5. Remove glass outer seal.
6. Remove rear glass run channel.
7. Remove regulator to door panel attaching nuts
and screws, and pull rear of glass up as far as possible
and rotate clockwise approximately 90° to remove glass
from door.
8. Disconnect harness from regulator.
9. Rotate motor regulator approxim ately 90° to
access hole in door.
W A R N IN G : Step 10 must be performed when
reg u lato r is rem oved from door. The
regulator lift arms are under tension from
the counterbalance spring and can cause
serious injury if the m otor is removed
without locking the sector gear in position.
Fig. 2D-33--Power W indow Switch, Relay and Breaker
Assembly
10. Drill a hole through the regulator sector gear
and back plate. DO N O T drill hole closer than 1/2" to
edge o f sector gear or back plate. Install a pan head
sheet metal tapping screw (No. 10 - 12 x 3/4 ) in drilled
hole to lock sector g ear in position.
11. Remove m otor to regulator attaching screws.
12. Remove m otor from regulator.
13. Prior to installation, lubricate the motor drive
gear and regulator sector teeth.
N O T E : The lubrication used must be cold w eather
approved to a m inim u m of minus 20° fahrenheit.
14. Install regulator m otor to regulator. Make sure
the motor pinion gear teeth mesh properly with the
sector gear teeth before installing the three motor
attaching screws.
15. Remove screw locking sector gear in a fixed
position.
16. Insert regulator into door in such a position
that motor connector can be installed onto motor.
17. Reinstall regulator into door.
LOCKS, HANDLES A N D RODS
T he d oo r lock, handles and control rods are shown
in figure 2D-32 as they would be installed in the vehicle.
N ote the clips which attach the three control rods to the
lock assembly.
N O T E: All clips which attach control rods to lock
assembly must be replaced whenever removed.
Door Lock Assembly
Replacem ent
1. Raise window to gain access to lock.
2. Remove regulator handle.
3. Remove remote control push botton knob.
4. Remove trim panel.
5. Remove clip from inside handle rod-to-lock.
6. Remove clip from outside handle rod-to-lock.
This is best accomplished by inserting a long screwdriver
through the daylight opening, as shown in figure 2D-35.
7. Remove screws which attach lock assembly to
door panel.
8. Remove lock and rem ote control rod as an
assembly.
9.
To install lock assembly, reverse above steps. Be
sure to replace all clips removed earlier.
Door Outside Handle--Fig. 2D -36
Replacement
1.
2.
3.
Raise window to gain access to lock.
Remove window regulator handle.
Remove remote control rod.
4.
Remove trim panel.
5. Remove clip from outside handle rod-to-lock.
This is best accomplished by inserting a long screwdriver
through the daylight opening, as shown in figure 2D-35.
6. Remove screws which retain outside handle to
door panel.
7. Remove handle and control rod.
8. Reverse above procedures to install outside
handle.
Door Lock Cylinder
Fig 2D -36 -
Replacement
1. Raise door window.
2. Remove window reg ulator handle, rem ote
control knob and trim panel.
3. Use a screwdriver or other suitable tool to slide
the lock cylinder retaining clip out o f engagem ent with
the lock cylinder.
4.
Remove lock cylinder.
5. To install, reverse the above steps.
Door Inside Handle
Replacement
1. Rem ove window re g ula to r handle, rem ote
control push button knob and trim panel.
2. Disconnect control rod from inside handle, as
shown in figure 2D-37.
3. Remove screws retaining inside handle to door.
4.
Remove inside handle.
5. Reverse above steps to install.
' ACCESS FOR REA* CLIP REMOVAL
(WITH GLASS IN FULL DOWN POSITION)
REMOTE
CONTRO L
KNO B
HANDLE
INSIDE HANDLE
DOOR
LOCK
Fig. 2D-35~Lock, Handles and Rods
.. .
mmmm
6.
To install, reverse steps 1 through 5 above.
DOOR TO BODY O P EN IN G W E A TH ER S TR IP -FIGS. 2D -39, 2D -40
Side door sealing incorporates an inner seal. The
inner seal is mounted on the body opening welding
flange and goes completely around the periphery of the
opening. The molded weatherstrip material is snapped in
place.
Success o f w eatherstrip replacem ent depends e n
tirely upon the quality of the cement used and the care
with which it is applied. All rust, road dirt and grease or
oil must be completely removed as should all old cement
and bits of old weatherstrip. A fter removing all foreign
material from door opening surface proceed as follows:
Fig. 2D 3 7 -Inside Handle
,
Q p e n d o o r a n d b |o c k Q pen
2. Remove sill plate retaining screws and remove
sill plate.
3.
Remove side door inner weatherstrip seal.
4. Install molded corner o f inner weatherstrip,
starting at the bottom o f the door opening.
5. Trim inner w eatherstrip with a notch and butt
ends together.
VIEW
B
POWER DO O R L O C K
HARN
6.
screws.
Reinstall
sill
plate
and
sill
plate
retaining
REAR SIDE DOOR (0 6 AND 63 ONLY)
Adjustments and Hinge Replacement
VIEW
A
The procedures for hinge replacement, and for
hinge and striker bolt adjustment are sim ilar to those
detailed in the front door adjustment procedure. Access
to the hinges o f the rear door is shown in figure 2D-41.
Fig. 2D -38-Pow er Door Lock Assembly
POW ER DOOR LOCKS - CK MODELS (Fig.
2D -38)
Replacem ent
1.
Disconnect battery ground cable.
2. Remove door trim panel (fig. 2D-25) to gain
access to power door lock motor. If equipped with
optional trim, remove pull handle assist bracket.
3.
4.
panel.
Disconnect electrical connector from motor.
Remove screws attaching motor to door inner
5. Remove door lock lever from ru bb er mount at
top of motor actuator and remove motor through access
F jg
2 D .3 9 . . D o o r
Weath e rstrip (03-63-06)
S T A T IO N A R Y G LA S S -R E A R DOOR
alignment o f the glass to the rear glass run channel for
full up and down travel.
Replacem ent
1. Lower window to full down position.
2. Remove remote control knob and window
regulator handle.
3. Remove screws retaining door rim pad, and
remove trim pad. See figure 2D-42.
4. Remove glass ru n channel by removing screws
retaining channel to door. See figure 2D-43.
5. Remove stationary glass.
6. Replace glass by reversing above procedure.
Glas Run C hannel Adjustm ent s
Figure 2D-44 illustrates the front ru n channel. At
the lower end, a slotted bracket provides for in-and-out
adjustment. The screw and locknut at that bracket allow
fore -a n d-aft adjustment. Together, this allows proper
W IN D O W G LA SS-FIG . 2D 4 5
Replacement
1. Lower glass to full down position.
2. Remove remote control push botton knob,
window regulator handle and trim pad.
3. Remove stationary glass as previously outlined.
Remove screws from rear division channel, and slide
channel rearw ard in the opening.
4. Raise glass as fa r as possible, then slide glass
until the roller is in line with the notch in the sash
channel. See figure 2D-45. Disengage roller from
channel.
5. Tilt window outboard and move until other
roller can be removed from channel.
6. Raise window up and out.
4.
Install regulator by reversing above procedure.
Lubricate regulator gear with lubriplate or equivalent.
LOCKS HANDLES AND RODS
Lock Assem bly-Fig. 2D-46
Replacement
1.
control
2.
3.
to lock
Remove window regulator handle and remote
push button knob.
Remove trim pad.
Disengage three clips which retain control rods
assembly.
a. Inside handle control rod.
b. Remote control lower rod.
c. Outside handle control rod.
4. Remove screws retaining lock assembly to door
panel, then remove lock assembly.
5. Install lock by reversing above procedure. Be
sure to replace all clips removed with new clips on
installation.
Inside H andle-Fig. 2D-46
Replacement
7.
Reverse above procedure for installation.
W IN D O W REG ULATO R A SSEM B LY-FIG . 2D45
Replacem ent
1. Remove trim pad, stationary glass, and window
glass as outlined earlier.
2. Remove screws attaching regulator assembly to
door in n e r panel.
3.
door.
Remove regulator assembly through opening in
1. Remove regulator handle, remote control knob
and trim pad as outlined previously.
2. Disconnect control rod from inside handle by
removing clip as shown in figure 2D-46.
3. Remove inside handle by removing four screws
which secure handle to door panel.
4. Replace handle by reversing above procedure.
Install new clip when installing control rod.
R em ote C ontrol-Fig. 2D-47
Replacement
1. Remove regulator handle, remote control knob
and trim pad.
2. Disconnect remote control lower rod from door
lock assembly.
3. Remove two screws securing each remote control
lever to door panel.
4. Remove remote control levers and rods through
door opening.
5. Replace by reversing above procedure.
W EATH ERSTRIP--FIG . 2D -49
The procedure outlined in Front Door W eatherstrip
may be applied to the R ear Side Door Weatherstrip,
shown in figure 2D-49.
Outside H an dle-Fig. 2D -48
REAR DOORS (0 6 ONLY)
Replacement
Adjustments
1. Remove regulator handle, remote control rod
and trim pad.
2. D isengage outside handle control rod from lock
assembly by rem oving clip, as shown in figure 2D-43.
3. Remove two screws securing outside handle to
doo r panel.
4. Remove handle assembly.
5. Replace by reversing above procedure. Be sure
to use new clip when attaching control rod to lock
assembly.
R ear doors may be adjusted in the body
loosening hinge bolts and repositioning
retightening bolts. See figure 2D-53 for
location. R ear door wedges and strikers
adjusted as shown in figure 2D-48.
opening by
door, then
hinge bolt
should be
Glass Run Channel Adjustm ent
Figure 2D-50 illustrates the front run channel. At
the lower end, a slotted bracket provides for in-and-out
adjustment. The screw and locknut at that bracket allow
fore-and-aft adjustment.
Together, this allows proper alignment o f the glass
to the rear glass run channel for full up and down travel.
LOCKS, HANDLES AND RODS
The rear door lock, outside handle, lock cylinder,
control rods and latch are shown in figures 2D-51 and
2D-52. The rods can be disconnected from the lock, latch
or handle by disengaging the retaining clips, as shown.
The lock cylinder is removed in the same m an ner as the
front side door lock cylinder.
REAR D O O R -Fig. 2D-53
Replacement
1. Remove bolts securing check arm bracket to
body pillar.
2. Remove upper and lower hinge bolts, and with
aid from an assistant, remove the rear door.
attaches to the pillar with three screws; the strap is
fastened to the door panel with two screws and an
attaching bar.
REAR D O O R -S TR IK E R AND WEDGE
A D JU S TM E N TS
Figure 2D-54 illustrates the rear door latch strikers
and door wedges. Be sure that adjustments are as shown
to insure p rop er latching o f the rear doors.
CHECK A R M -F IG . 2D-53
Replacement
1. Remove bolts securing check arm bracket to
body pillar.
2.
Remove check arm access cover.
3. With one h an d supporting housing assembly
and insulator on the inside o f the door panel, remove
bolts securing housing assembly to door.
4.
Remove housing, insulator and check arm.
5. To separate check arm from bracket, remove
holding pin connecting the two parts.
3.
Reverse above steps for reinstallation.
REAR DOOR CHECK S TR A P
M odel 0 6
Figure 2D-53 shows the cloth check strap used for
rear doors. The door may be completely opened by
rem oving the strap pin from the bracket. The bracket
6.
above.
To install check arm, reverse the procedure
W E A TH E R S TR IP
W eatherstrip installation is shown in figure 2D-55.
Proper installation is dependent on completely cleaning
all foreign m aterial from old installation and using a
quality cement on the new installation.
Fig. 2D-51--Rear Door Controls
Fig. 2D-52- Rear Door O utside Handle and Lock
Cylinder
W EDGE
A D JU S TM E N T
UPPER
STRIKER
AD JU S TM E N T
.1 7 ± ,0 3 ( 1 1 / 6 4 DRILL)
IN S E C O N D A R Y L A T C H E D
.0 4 M A X . C L E A R A N C E /
IN S E C O N D A R Y L A T C H E D P O S IT IO N
O R 0 1 0 T O T 0 . 0 5 0 IN TER FER EN C E
IN FULL L A T C H E D P O S IT IO N .
Fig. 2D-54--Wedge and S trike r Adjustm ents
Fig. 2D-55 W eatherstrip--L.H. and R.H. Rear Door
ENDGATES (06 AND 14)
Coach models (06) and utility models (14) use
endgates o f similar, yet distinct design. Separate
procedures follow for service on each of these endgates.
7.
To install, reverse removal procedure.
HINGES
Replacement
E N D G A TE ASSEMBLY - (0 6 ) MODELS ONLY
Replacem ent
1. Lower endgate, and removed hinge access
covers. See figure 2D-56.
2. Remove endgate-to-hinge bolts.
3. Remove L.H. torque rod bracket, shown in
figure 2D-57.
4. If equipped with electric powered window,
disconnect wiring harness.
5. Lift endgate to almost closed position and
rem ove support cables.
6. Remove endgate with torque rod.
If necessary to remove hinges, remove endgate as
outlined previously, and proceed as follows:
1. Remove bolts from each o f the hinge assemblies
on the underside o f the body. See figure 2D-56.
2. Remove hinge assemblies. If the hinge pins are
to be removed, note the position o f bushings so they may
be reinstalled in the same position.
3. Reverse procedure to install.
ENDGATE DISASSEMBLY
1. Remove access cover shown in figure 2D-58, to
gain access to interior components.
2. Detach remote control rods from lock assembly
by removing clips.
ACCESS
Fig. 2D-58- Latch and Remote Controls (06 Only)
W A R N IN G : Step 10 must be perform ed if the
window is removed or disengaged from the
regulator lift arms. The lift arms are under
tension from th e counter balance spring, and
can cause injury if the m otor is removed
without locking the sector gears in position.
a. Drill a 1/8 inch hole through the sector gear
and back plate, as shown in figure 2D-59. Install a sheet
metal tapping screw into the hole to lock the sector gears
in position.
b. Remove the regulator motor attaching screws
and remove the motor assembly.
11. From inside the endgate, remove the nuts
fastening the outside handle to endgate and remove the
outside handle. See figure 2D-60.
3. Remove bolts securing lock assembly, and
remove lock assembly.
4. Remove handle assembly bolts and remove
inside handle.
5. Remove R.H. torque rod bracket screws, ligure
2D-57, then remove torque rod from endgate.
6. Remove screws connecting cam assemblies to
sash assembly, ligure 2D-59, then rem ove cam
assemblies.
7. Remove glass from endgate.
8. Unclip and remove inner and outer seal
assemblies.
9. Remove screws connecting window regulator
assembly to endgate, figure 2D-59. and remove regulator.
10. For endgates with electric window, secure the
window regulator lift arms before removing the electricmotor, when the window glass has been removed or
disengaged from the lift arms.
NOTE: If equipped with power tailgate window,
detach wiring harness from motor.
12. Remove side bolts connecting left and right
glass channels to endgate and remove channels.
13. Removed side latch bolts and remove side
latches with control rods. See figure 2D-58.
NOTE: Detach wiring harness from R.H. latch if
so equipped.
14. Separate side latch from control rod by pulling
control rod thru nylon guide.
15. Reverse the above procedure for reassembly
and installation.
Adjustments
Loosen bolts, adjust at either endgate hinge position
or endgate latch, then retighten bolts.
ENDGATE ASSEMBLY~(14) MODELS ONLY
Replacement
1.
Lower endgate, then remove four bolts securing
Fig. 2D -61-Endgate, Hinges and Support (14)
Fig. 2 D -62 -P u llin g Hinge Away From Body (14)
Fig. 2D -60 -Outside Flandle (06 and 14)
hinge to body on each side. See figure 2D-61. Disconnect
wiring harness, if so equipped.
2. Disconnect torque rod anchor plate on each
side. It is necessary to remove lower bolt only, then let
plate swing down. See figure 2D-65.
3. W ith an assistant, raise endgate p art way, then
disconnect support cables from endgate. See figure 2D61.
4. Remove endgate by pulling disconnected hinge
from body, figure 2D-62, then grasping torque rod with
one hand and pulling torque rod over gravel deflector, as
shown in figure 2D-63.
5. Individual com ponents may be removed from
the endgate now, or after reinstallation.
6. To install endgate, reverse the above procedure.
HING E
Replacement
1. Lower endgate and disconnect hinge to be
replaced by removing hinge-to-body bolts. See figure 2D61.
2. At the other hinge, loosen the hinge-to-body
bo its.
3. On the hinge to be replaced, remove the hinge to-endgate bolts.
4. Pull the endgate away from the body several
inches and withdraw hinge from body. Then lift endgate
slightly to allow removal o f hinge from endgate. See
figure 2D-62.
5. To install hinge, reverse the above procedure. Be
BRACKET
SILENCER
TORQUE
ROD
FRAME
Fig. 2D-65 -Torque Rod In sta lla tion (14)
Fig. 2D-63 -Grasping Torque Rod (14)
sure to install hinge into e ndgate first, then into the
body.
7. Lift torque rod up and slide from endgate as
shown in figure 2D-66.
8. Reverse the procedure above for installation.
T O R Q U E ROD
ENDGATE DISASSEMBLY
Replacem ent
1. Lower endgate and remove access cover, as
shown in figure 2D-64.
2. Disconnect torque rod anchor plate. It is
necessary to remove the lower bolt only, then let plate
swing down. See figure 2D-65.
3. Loosen four bolts retaining endgate hinge to
body.
4. Move endgate slightly away from body.
5. Remove torque rod retaining bracket on lower
edge o f endgate. See figure 2D-65.
6. Remove torque rod retaining clip on side edge
o f endgate.
1. Lower endgate and remove acess cover.
2. Disconnect side latch remote control rods from
center control by removing retaining clips. See figure
2D-67.
3. Remove four screws from each side latch, and
withdraw latch and control rod from endgate, as sown in
figure 2D-68.
4. Disconnect control rod from latch.
5. Refer to figure 2D-69 for installation o f latch
control and blockout rod.
6. Disconnect blockout rod from control assembly
by detaching spring and removing two screws retaining
rod to inner panel.
7. Disconnect inside handle control rod from
Fig. 2D 6 7 -Latches and Rods
Fig. 2D 68 Removing Side Latch
Fig. 2D-70--Removing Control Assembly and Inside
control assembly, then remove screws which secure inside
handle to inner panel.
8. Remove three screws which retain remote
control assembly to inner panel.
9. Remove control assembly and inside handle as
shown in figure 2D-70.
10. Refer to figure 2D-71 for window and
regulator installation.
11. Roll window to up position.
12. Disconnect sash from regulator as shown in
figure 2D-72.
13. Remove glass from endgate.
14. Remove four regulator attaching screws and
withdraw regulator from endgate as shown in figure 2D73.
15. Remove outside handle by removing nuts from
inside o f outer panel. See figure 2D-74.
16. Reverse the above steps for reassembly.
Handle
TAILG ATES (03, 63 and 14)
Replacement
Utility vehicles (14) without removable tops utilize a
tailgate shown in figure 2D-75. C hassis/cab (03 and 63)
models have optional pickup units which utilize tailgates
as shown in figures 2D-75 and 2D-76.
The tailgate shown in figure 2D-75 can be removed
by disconnecting both links from the tailgate, removing
screws attaching both trunnions to body, and lifting the
tailgate off the vehicle.
The tailgate shown in figure 2D-76 can be separated
from the vehicle by removing the bolt and lock washer
from each trunnion in carrier box, and removing the
tailgate.
Fig. 2D-73--Removing Regulator
Fig. 2D-72- D isconnecting Sash from Regulator
Fig. 2D-74--Outside Handle
b.
REM O VABLE TO P-FO LDING TO P (1 6 ONLY)
Removal
1. Remove the bracket-to-roof bolt from each o f
the top-to-header panel attaching brackets as shown in
Figure 2D-77.
2. Remove the bolts which retain the top to the
body side panels, shown in figure 2D-78.
3. Lower the rear window into the endgate, and
lower endgate.
4. Lower the door windows.
5. Slide top rearw ard approxim ately 18" to expose
the bottom re a r top-to-pickup box attaching holes.
6. To prevent possible flexing o f the sides on
removal, connect the sides o f the top with support braces
as follows.
a.
Fabricate 2 braces 72" long from wood
square a lum inum tubing. Drill two (2) 3 / 8 " diam eter
holes, 63 inches apart in the brace.
Attach one brace to the holes exposed in Step
7.
c. Slide top forward to expose the front bottom
top-to-pickup box attaching holes.
d.
Attach the second brace to these holes.
7.
With assistance,
rearw ard for removal.
lift
the
top
and
move
M andatory Assembly Sequence (Fig. 2 D -78 )
Removable top must be clamped in direction of
arrow A at pints X and Y. Clam p load must be great
enough to force the removable top against the steel cab
at the attachm ent locations. After clamping, bolting must
start with the rear vertical bolt (1) and then going
forward, install (2), (3) and (4). W hen all but the front
bolt
or (5) are in place, release the clamp and drive the
front bolt. Then drive the horizontal bolts into the steel
cab.
it
Fig. 2D-77--Roof-to-Header Brackets
cases, impossible to completely remove. W hen cleaning
this type of stain or soilage, care must be taken not to
enlarge the soiled area. It is sometimes more desirable to
have a small stain than an enlarged stain as a result of
careless cleaning.
CAUTION: When cleaning interior soft trim
such as upholstery or carpeting, do not use
volatile cleaning solvents such as: acetone,
lacquer thinners, carbon tetrachloride, enamel
reducers, nail polish removers; or such cleaning
m aterials as laundry soaps, bleaches or
reducing agents (except as noted in the
instructions on stain removal). Never use
gasoline or naphtha fo r any cleaning purpose.
These materials may be toxic or flam m able, or
m ay cause damage to interior trim.
SEATS
Cleaning Fabrics with Cleaning Fluid
Care and Cleaning of Interior Soft Trim
This type o f cleaner should be used for cleaning
stains containing grease, oil or fats. Excess stain should
be gently scraped oft' trim with a clean dull knife or
Dust and loose dirt that accumulate on interior
fabric trim should be removed frequently with a vacuum
cleaner, whisk broom or soft brush. Vinyl or leather trim
should be wiped clean with a d am p cloth. N orm al
cleanable trim soilage, spots or stains can be cleaned
with the pro per use o f trim cleaners available through
G e n e ra l Motors dealers or other reputable supply outlets.
Before attem pting to remove spots or stains from
upholstery, determine as accurately as possible the
nature and age o f the spot or stain. Some spots or stains
can be removed satisfactorily with w ater or mild soap
solution (refer to accom panying "R em oval o f Specific
Stains"). For best results, spots or stains should be
rem oved as soon as possible. Some types o f stains or
soilage such as lipsticks, some inks, certain types of
grease, mustard, etc., are extremely difficult and, in some
scraper. Use very little cleaner, light pressure, and clean
cloths (preferably cheese cloth). Cleaning action with
cloth should be from outside of stain towards center and
constantly changing to a clean section o f cloth. W hen
stain is cleaned from fabric, im mediately wipe area
briskly with a clean absorbent towel or cheese cloth to
help dry area and prevent a cleaning ring. If ring forms,
immediately clean entire area or panel section o f the
trim assembly.
NOTE: Sometimes a difficult spot may require a
second application o f cleaning fluid followed
Fig. 2D-78--Removable Top
im m ediately by a soft brush to completely remove
the spot.
Cleaning Fabrics with D etergent Foam
Cleaners
This type o f cleaner is excellent for cleaning general
soilage from fabrics and for cleaning a panel section
w here a minor cleaning ring m ay be left from spot
cleaning. Vacuum area to remove excess loose dirt.
Always clean at least a full trim panel or section o f trim.
Mask adjacent trim along stitch or weld lines. Mix
detergent type foam cleaners in strict accordance with
directions on label o f container. Use foam only on a
clean sponge or soft bristle brush. Do not wet fabric
excessively or rub harshly with brush. W ipe clean with a
slightly d a m p absorbent towel or cloth. Immediately
after cleaning fabric, dry fabric, with a dry towel or hair
dryer. Rewipe fabric with dry absorbent towel or cloth to
Fig. 2D-79--Folding Top Assembly
Fig. 2D-80--Folding Top Side M oldings and Header
Tar
Remove excess with dull knife, moisten with fabric
cleaning fluid, scrape again, rub lightly with additional
cleaner.
restore the luster o f the trim and to eliminate any dried
residue.
Blood
Wipe with clean cloth moistened with cold water.
Use no soap.
Rem oval of Specific Stains
Urine
Candy
Chocolate, use cloth soaked in lukewarm water;
o ther than chocolate, use very hot water. Dry. If
necessary, clean lightly with fabric cleaning fluid.
Sponge stain with lukewarm soap suds from mild
neutral soap and clean cloth, rinse with cloth soaked in
cold water, saturate cloth with one p art household
am m onia water and 5 parts water, apply for 1 minute,
rinse with clean, wet cloth.
C hew ing Gum
Vomitus
H arden gum with ice cube and scrape off with dull
knife. Moisten with fabric cleaning fluid and scrape
again.
Fruit Stains, Coffee, Soft Drinks, Ice Cream and M ilk
W ipe with cloth soaked in cold water. If necessary
clean lightly with fabric cleaning fluid. Soap and water is
not recom m ended as it might set the stain.
Sponge with clean cloth dipped in clean, cold water.
Wash lightly with lukewarm w ater and mild neutral
soap. If odor persists, treat area with w ater-baking soda
solution (1 teaspoon baking soda to one cup o f tepid
water). Rub again with cloth and cold water. Finally, if
necessary, clean lightly with fabric cleaning fluid.
SEAT M O U N T IN G
Catsup
W ipe with cloth soaked in cool water. If further
cleaning is necessary, use a detergent foam cleaner.
Grease, Oil, Butter, M arg arin e and Crayon
Scrape off excess with
cleaning fluid.
dull
knife.
Use
fabric-
Typical Seat M ounting provisions are shown in
figures 2D-82 through 2D-90.
C A U TIO N : See C A U T IO N on page I o f this
section regarding fasteners used on seats and
seat belts.
BODY M O U N T IN G
Paste or Wax Type Shoe Polish
Light application of fabric cleaning fluid.
The sequence of m ounting attachm ents is shown in
figures 2D-91 through 2D-94.
Fig. 2 D -8 5 -D n ve r’s Bucket Seat (14)
Fig. 2D-86--Passenger's Bucket Seat (14)
Fig. 2D -89-R ear Folding Seat (06)
Fig. 2D 9 0 -Rear Bench Seat (14)
MOUNT
1
^M O U N T
MOUNT
4
2
M OUNT
^
1
MOUNT
3
Fig. 2D 94- Body M ounting (14)
G MODELS
INDEX
Front Fnd
W indshield W ip e rs.....................................................
Cowl Ventilator G rille ..............................................
Side Ventilator V a lv e ...............................................
Rear View M i r r o r ......................................................
Bodv Glass
Windshield G la s s ........................................................
Stationary G la s s ..........................................................
Swingout G la s s ............................................................
Front Door
A djustm ents...................................................................
R e p lacem en t..................................................................
W e a th e rstrip ..................................................................
H in g e s.............................................................................
V e n tila to r .......................................................................
Window and R egulator............................................
2D-41
2D-4I
2D-4I
2D-42
2D-43
2D-45
2D-45
2D-45
2D-4(>
2D-46
2D-46
2D-47
2D-48
Locks, Handles, R o d s ...............................................
Sliding Side Door
D e sc rip tio n ...................................................................
A djustm ents..................................................................
Front L a tc h ................................................................
Rear L a tc h .................................................................
Upper Rear H in g e ..................................................
S trik e rs ........................................................................
Rear Door
H in g e ..............................................................................
Remote Control...........................................................
Latches and Rods......................................................
A djustm ents..................................................................
Seats
Drivers S e a t .................................................................
Passenger S e a t.............................................................
Rear S e a t s ....................................................................
2D-48
2D-49
2D-51
2D-51
2D-51
2D-51
2D-51
2D-55
2D-55
2D-55
2D-55
2D-57
2D-58
2D-58
FRONT END
W IN D S H IE L D WIPERS
W indshield wiper units on all models are o f the twospeed electric type. A single w iper motor unit, mounted
to dash panel at top and to left o f engine cover inside
cab, powers both wiper blades. The wiper blade
operatin g link rods and pivot mountings on these models
are located in the outside air inlet plenum chamber.
2. Attach end o f link rod to motor drive and arm.
Secure rod with the two attaching nuts.
3. Install outside air cowl ventilator grille to top of
cowl.
4. Before installing wiper arms, operate wiper
motor m om entarily which should rotate pivot shafts to
park position. Install arms.
Arm Adjustm ent
COWL V E N TILA TO R GRILLE
To adjust sweep o f blades turn on wipers, then note
sweep o f arms. If necessary, remove one or both arms as
follows: Pull outer end of arm away from glass which
will trip lock spring at base of arm and release spring
from undercut o f pivot shaft. W hile holding arm in this
position, pull outward on cap section at base o f arm to
remove arm. Arm can be reinstalled in any one o f
several positions due to serrations on pivot shaft and in
arm cap. See figure 2D-95.
Replacement
1.
2.
3.
4.
Remove
Remove
Remove
Reverse
windshield wiper blades.
screws retaining grille, figure 2D-97.
grille and seal.
above steps to install grille.
W IP E R ARM PIVO T SHAFTS AND LINK
R O D — FIG. 2D-96
Removal
1. Remove windshield wiper arms from pivot
shafts. Procedure for rem oving arms is explained
previously under "A rm Adjustments."
2. Remove screws which attach outside air cowl
ventilator grille to cowl. Carefully remove grille from
cowl.
3. At center o f cowl, remove two attaching nuts
which attach link rod to motor drive. Disengage link
rods from pins.
4. Remove screws which attach each arm transm is
sion pivot shaft assembly to cowl. Remove pivot shaft
assembly with link rod from plenum chamber.
Installation
1.
Place pivot shaft assembly with link rod into
position at cowl bracket. Secure assembly to bracket with
two screws.
Fig. 2D-96--W indshield Wiper Linkage
Replacement
1. Remove screws retaining valve guide to panel,
as shown in figure 2D-98.
2. Remove valve assembly by depressing pins at
top and bottom o f valve.
3. Reverse the above steps for installation.
REAR VIEW M IR R O R S
Inside Rear View Mirror
Replacement
The inside m irror m ay be removed by removing
screw retaining mirror to its glass-mounted bracket, and
lifting m irror off bracket.
Outside Rear View Mirrors
Outside rear view m irro r installations are shown in
figure 2D-100. Occasional tightening o f m ounting and
a ssem bly bolts a n d screws will sharply decrease
occurence o f failure due to door slam m ing or road shock.
Fig. 2D-100--Outside Rear View M irrors
BODY GLASS
W A R N IN G : Always wear gloves when
handling glass.
W IN D S H IE L D GLASS
The windshield is a one-piece type and is retained
in the windshield opening by a moulded ru bb er
w e a th e rstrip . This w e a th e rs trip is sealed in the
w indshield opening and sealed to the windshield glass.
See figure 2D-101.
W hen replacing a cracked windshield glass, it is
very im p o rta n t that the cause o f the glass breakage be
determ ined and the condition corrected before a new
glass is installed. Otherwise, it is highly possible that a
small obstruction or high spot somewhere around the
windshield opening will continue to crack or break the
newly installed windshield, especially when the strain on
the glass caused by this obstruction is increased by such
conditions as wind pressures, extremes o f temperature,
motion o f the vehicle, etc.
The precedure for removal of the windshield applies
to the complete windshield assembly and to other
stationary glass, such as in figure 2D-104.
Removal
NOTE: Refer to figures 2D-14 to 2D-16 in the "CK Models" portion o f this section for illustration
of removal technique.
3. Check flange area for solder, weld high spots, or
hardened spot-weld sealer. Remove all high spots.
4. Check windshield glass to opening, by support
ing glass with six spacers contained in packet J-22577, as
shown in figure 2D-102.
C A U TIO N : Do not strike glass against body
metal. Chipped edges on the glass can lead to
fu tu re breaks.
NOTE: It is necessary to modify the spacers by
cutting off 3 /1 6 " from the back o f the spacer with
a knife, as shown in figure 2D-102.
With the windshield supported and centered in
its opening, check the relationship of the glass to the
body opening flange around the entire perim eter o f the
glass.
6. Check the relationship o f glass to opening as
follows:
a. Inside edge of glass to body flange.
b. Outer edge o f glass to parallel body metal.
7. M ark areas o f body metal or flange to be
reformed, remove glass and correct as necessary.
8. Recheck windshield in its opening and if
satisfactory proceed as follows:
Fig. 2 D -10 1 -W in d sh ie ld Glass
1. Before removing the windshield, mark the
location o f the break on the windshield rubb er channel
and the body. Protect the p a in t finish inside o f the cab.
Mask around the windshield o pening and outside, lay a
suitable covering across the hood and fenders.
N O T E: The windshield glass rub ber weatherstrip is
one piece. The glass is held in a channel within the
weatherstrip.
2. D o not try to remove reveal moldings while
windshield is in body opening. Remove reveal molding
fro m custom w e a th e rs trip re ten tion groove a fter
windshield is removed from body opening.
3. To free windshield ru b b er channel of w eath er
strip loosen the lip o f the w indshield w eatherstrip from
the pinchweld flange along the top and at the sides by
applying firm, controlled pressure to the edge o f the
glass. At the same time assist the lip o f the rub ber
w e atherstrip channel over the pinchweld flange with a
flat bladed tool.
C hecking W indshield Opening
D ue to the expanse an d contour of the windshield it
is im perative in the event of a stress crack that the
windshield opening be thoroughly checked before
installing a replacement windshield. The replacement
glass is used as a template.
1. Check for the following conditions at the
previously marked point o f fracture.
a. Chipped edges on glass.
b. Irregularities in body opening.
c. Irregularities in ru b b e r channel weatherstrip.
2. Remove all sealer from flange and body around
w indshield opening.
Installation
1. Apply sealer to weatherstrip and install on glass.
2. Install a cord around periphery o f weatherstrip,
leaving a loop at the top and the loose ends at the
bottom. See figure 2D-103.
3. Place protective covering over plenum grille,
front fenders and hood.
4. Place windshield and w eatherstrip assembly in
opening. With one technician lightly pushing in on
windshield, another technician within the cab should pull
on the cord as follows:
a. Pull on loose ends until each is within 2" of
its respective upper corner.
b. Pull on loop until cord is within 2" o f the
upper corners.
C H E C K I N G BLOCKS
Fig. 2D 103- Cord Insta lla tion
d.
strip to body.
Seal windshield to weatherstrip and w eather
S W IN G O U T W IN D O W
Removal
1.
2.
3.
w'indow.
4.
Swing out the window. See figure 2D-105.
Remove screws retaining latch to body.
Remove window hinge retaining screws and
Remove latch from glass.
Installation
1. Install latch to glass using escutcheon, spacer,
washer latch and screw. Torque to specifications.
2. Place window into opening and install hinge
retaining screws and window.
3. Install latch to glass.
LATCH S W IN G O U T W IN D O W
Replacement
c.
Finish seating corners by simultaneously 1. Swing out the window.
pulling on both ends o f the cord at each corner. This will
2. Remove latch to body and latch to window
insure proper positioning o f the critical upper corners.
screws and remove latch.
3. Reverse above steps for installation.
FRONT DOOR
DOOR A D J U S T M E N T S
Doors can be adjusted for alignm ent o f clearance in
the cab door opening, and for proper latching. Door
alignm ent adjustments are m ade at the striker bolt, and
at door hinges. The door, when properly located in door
opening, will have equal clearance around its perimeter.
The door should be adjusted in the opening so the edge
of the door across the top and also at the lock side is
parallel with the body opening as nearly as possible.
Hinge Adjustment
D oor hinge bolt holes are oversized to make
adjustment possible. Alignment adjustments can be
made by loosening the proper hinge bolts, aligning door
to pro per position, and tightening bolts securely. See
figure 2D-106. for typical adjustments.
Fig. 2D-107-Loosening S trike r Bolt
Striker Bolt Adjustment
With the use o f J-23457. shown in figure 2D-107, the
striker bolt can be adjusted in any of three ways. See
figure 2D-108.
1. Up and d o w n -T o adjust striker up or down,
loosen bolt, adjust to center of lock entry, and tighten
bolt securely.
N O T E : This adjustment is im portant to assure that
the right proportion o f d o o r’s weight will rest on
striker bolt when door is closed. If bolt is
positioned too high on pillar, rapid w ear will occur
to the lock cam; if too low, an extra load will be
placed on door hinges as well as pull door
downward and out o f alignment.
2. In and O u t-T o adjust striker in and out, loosen
bolt, adjust horizontally to m atch the door surface to the
body surface, and tighten bolt securely.
3. Forward and R e a rw a rd - To make this adjust
ment, loosen striker bolt, shim to desired position, and
tighten bolt securely.
DOOR H IN G E
Remove
1. Remove hinge access hole cover from door
hinge pillar.
2. If removing one hinge, support door in such a
m an n e r that weight is taken off oth er hinge, and that the
door will not move.
3. Remove hinge screws from both body and from
door and remove hinge. See figure 2D-106.
Installation
1. Install hinge to door and body. Snug bolts.
2. Remove door supports.
3. A d ju st d o o r
as o utlined
under
"D oor
A djustm ent".
4. Torque bolts to specifications.
5.
Install hinge access hole covers.
DOOR W E A TH E R S TR IP
Success o f weatherstrip replacement depends e n
tirely upon the quality of the cement used and the care
with which it is applied. All rust, road dirt and grease or
oil must be completely removed as should all old cement
and bits o f old weatherstrip. After removing all foreign
material from door opening surface, wipe down with
prepsol or its equivalent. Use only a good quality cement
which is m ade specially for weatherstrip installation,
following the m a n u fa c tu rer’s directions. Proceed as
follows:
1. Open door and block open.
2. Remove side door weatherstrip.
3. Remove used adhesive from door with adhesive
or cement remover, and remove all plastic nails.
4. Apply adhesive to door.
5. Position weatherstrip by locating p art num ber at
top of vent window, m aking sure that plastic nails align
with holes in door.
6.
the door.
T R IM
Install weatherstrip by pressing each nail into
PANEL, ARM REST AND HANDLES
Removal
1.
Remove screws retaining arm rest to trim panel.
2. Remove door handles with Tool J-7797 and pull
from shaft.
3. Remove trim panel screws and remove panel. If
seal is d am aged, replace seal.
Installation
1. Install trim panel.
2. Install arm rest. Install door handle washers and
handles.
DOOR V E N TILA TO R ASSEMBLY
Removal
N OTE: The channel betwen the door window glass
and door vent is removed as p art of the vent
assembly.
1. Regulate the door window glass to the full down
position.
2.
Remove door handles with Tool J-7797.
3.
Remove trim panel.
4.
Remove rear window run channel screws.
5. Slide door window glass rearw ard away from
ventilator.
6. Remove three screws at the upp er front of the
door, as shown in figure 2D-109.
7. Turn the vent assembly 90° and carefully
remove by guiding up out, as shown in figure 2D-109.
Fig. 2D 1 1 0 -Removing Ventilator
Ventilator Glass Replacement
1. Using an oil can or similar means, squirt
prepsol on the glass filler all around the glass channel or
frame to soften the old seal. W hen the seal has softened,
remove the glass from the channel.
2. Thoroughly clean the inside of the glass channel
with sandpaper, removing all rust, etc.
3. Using new glass channel filler, cut the piece to
be installed two inches longer than necessary for the
channel. Place this piece of filler (soapstoned side o f
filler away from glass) evenly over the edge o f the glass
which will fit in the channel. The extra filler extending
beyond the rear edge of the glass should be pinched
together to hold it in place during glass installation.
NOTE: One side of this filler (the outside of the
roll) is soapstoned. This is the side which goes into
the metal channel.
4. Brush the inside o f the metal glass channel
freely with o rdinary engine oil. This will enable the glass
and filler to slide freely into the channel.
N OTE: Glass should be installed so that rear edge
is parallel to the division post. Allow full cure
before w ater testing.
Installation
NOTE: Replace the door window glass and
regulate to the full down position before installing
the door ventilator assembly.
1. Lower the ventilator assembly into the door
frame. Center into position.
2. Make certain the rub ber lip is positioned before
tightening screws.
3. Slide door glass forward engaging glass in vent
channel.
4.
Reinstall all screws and tighten.
5.
Install and tighten the three screws at the upper
front o f the door.
Adjustm ent
1. Adjust the ventilator adjusting nut by turning
clockwise to increase operating tension, as shown in
figure 2 D - 1 1 I .
2. A fter m aking adjustm ent bend tabs over the hex
nut.
3. Install trim panel.
4. Install door and window regulator handles.
DOOR W IN D O W ASSEMBLY
Replacem ent
1. Completely lower glass to bottom o f door.
2. Remove inside door an d window regulator
handles using Tool J-7797.
3. Remove door arm rest an d trim pad.
4. Mask or cover u pper portion o f door window
fra m e . Remove v e n tila to r assembly as previously
outlined.
5. Slide glass forw ard until front roller is in line
with notch in sash channel. Disengage roller from
channel. See figure 2D-1 12.
6. Push window forward and tilt front portion of
w indow up until rear roller is disengaged.
7. Put window assembly in normal position (level)
and raise straight up and out.
8. Reverse above procedure for installation.
W IN D O W REGULATOR
Replacem ent
1.
2.
3.
4.
panel.
5.
holding
W in d window all the way up.
Remove inside do or handles with Tool J-7797.
Remove door trim pad.
Remove screws securing regulator to inner
Push regulator out o f door opening while
rear o f assembly, then slide assembly to the
notches in the carrier channel and out through the door
access hole.
6.
Install regulator in reverse order o f removal,
lubricate regulator gears with lubriplate or equivalent.
DOOR LOCK—FIGURE 2D-113
Removal
1. Raise window.
2. Remove inside handles with Tool J-7797.
3. Remove trim panel.
4. Remove remote control sill knob.
5. From outside the door remove screws retaining
lock to door edge and lower the lock assembly.
6. Remove screws retaining remote control.
7. Rem ove screws securing glass run guide
channel.
8. Remove lock, push button rod and remote
control rod as an assembly.
4. Secure remote handle.
5. Check all controls for proper operation before
reinstalling trim and handles.
6. Install remote control sill knob.
REMO TE C O N TR O L AND C O N N E C T IN G
ROD -Fig. 2D-113
Replacement
1. Raise door window and remove door trim pad.
2. Remove bolts securing remote control to door
inner panel.
3. Pivot remote inboard slightly, to disengage
connecting rod, and remove remote control from door.
NOTE: Connecting rod can be removed at this
point by disconnecting spring clip from lock.
4. To install, reverse removal procedure.
LOCK CYLINDER ASSEMBLY--FIG. 2D-114
Replacement
Installation
1. T ra n sfer remote rod with clip to new lock.
2. Connect remote door handle rod to lock after
lock is positioned.
3. Secure lock screws.
1. Raise door window and remove door trim pad.
2. With a screwdriver, or other suitable tool, slide
lock cylinder retaining clip (on door outer panel) out o f
engagem ent and remove lock cylinder.
3. To install, reverse removal procedure.
SLIDING SIDE DOOR
D E S C R IP TIO N
T he weight o f the sliding side door is supported by
the up p e r re a r hinge-and-roller assembly, and by the
lower front catch-and-roller assembly. The front and
rear latches retain the door in the locked position, while
the re a r wedge assembly restricts door vibration on
rough road surfaces.
ADJUSTMENTS
C A U T IO N : See C A U T IO N on page 1 o f this
section regarding all sliding door fasteners and
adjustm ents fo u n d below.
T he side door can be adjusted for alignment a n d / o r
clearance in the body o pening and for proper latching.
W h en properly positioned in the body opening, the door
should have equal clearances around its perimeter.
A djustm ents for door positioning and proper latching
can be m ade at the locations shown in figure 2 D - 1 15.
2. Remove upp er rear hinge cover, shown in figure
2 D - 1 16.
3. Loosen upper rear hinge-to-door bolts.
4. Loosen re a r lock striker and door wedge
assembly.
5. Align rear edge o f door up or down, then
tighten upper rear hinge-to-door bolts to specifications.
6. Loosen upper front roller bracket-to-door bolts.
7. Partially close door and align front edge o f door
up or down by loosening front lower hinge-to-door bolts.
W hen door is correctly positioned, tighten bolts to
specifications.
8. Position u pper front roller in center o f track,
then tighten roller bracket to door.
9. Adjust front and rear strikers and rear wedge
assembly as outlined in their respective procedures later
in this section.
In and Out
Front in and out adjustments are provided by means
o f an adjustable lower roller mounting bracket, view D
o f figure 2D-115. and by a slotted upper bracket, view B
U p and down adjustments are provided by means of
o f figure 2 D - 1 15. R ear in and out adjustment is provided
slotted holes located at the upper front roller, view B of
by adjusting the rear latch striker, view E of figure 2Dfigure 2D-112; at the lower front catch-and-roller, view
115. To position the door in or out:
D; and at the upper rear hinge-and-roller assembly, view
A. To reposition the door up or down:
1. Loosen front latch striker.
2. Loosen upper front roller from its bracket.
1.
Partially open door and loosen front latch
striker on pillar.
3. Loosen lower front roller bracket-to-arm bolts.
Up and Down
STRIKER
FORE-AND-AFT ADJUSTMENT SLOTS
UP-AND-DOWN
ADJUSTMENT SLOTS
CENTER ROLLER VERTICALLY
IN TRACK SO IT DOES NOT
CONTACT
THE TRACK fr---- ----IN FULL OPEN
OR FULL
1, ..............J
CLOSED
'
POSITION
UPPER REAR HINGE-AND-ROLLER
SECTION B-B
TOP VIEW
UPPER LEVER.
.LOWER LEVER
UP-AND-DOWN
/
ADJUSTMENT SLOTS
STRIKER,
^ UPPER FRONTSVN'AND-°UT
ROLLER ASSEMBLYJ ad ju stm en t;
FRONT LATCH
STRIKER
FACE VIEW
GUIDE
UP-AND-DOWN
ADJUSTMENT
IN-AND-OUT
ADJUSTMENT
RUBBER-"
CUSHION
LATCH
SECTION C-C
LOWER ROLLERS t
AND CATCH ASM
REAR
REAR LATCH
WEDGE
STRIKER
ASSEMBLY
SECTION
E-E
HOLD-OPEN
& CATCH
3. Center the striker vertically to door striker
opening.
4. Adjust the striker laterally to match outer panel
to the body panel surfaces, view E o f figure 2 D - 1 16.
5. Apply grease to the striker.
6. Gently push the door in until the rear lock
contacts the striker enough to make an impression in the
grease.
7. Open the door and measure the distance from
the rear of the striker head to the impression. The
distance should be between .20 inch and .30 inch. Refer
to view E of figure 2 D - 1 15.
8. Adjust position of striker by a dding or deleting
shims between the striker and the pillar.
9. Adjust rear wedge assembly as outlined later in
this section, and torque all fasteners to specifications.
Upper Rear Hinge-To-Striker Adjustment
Fig. 2D-116--Hinge Cover
4. Adjust front o f door in or out, then tighten bolts
to specifications.
5. Adjust door hold open catch bracket, rear wedge
assembly, rear latch striker, upper front roller and front
latch striker as outlined later in "Adjustm ents".
Fore and Aft
Fore and aft adjustm ent is provided at the upper
r e a r hinge striker by means o f a slotted bracket mounted
to the body, view A o f figure 2 D - 1 15.
1. Partially open door and remove front latch
striker and rear lock striker.
2. Loosen rear wedge assembly.
3. Remove upper rear track cover.
4. Loosen upper rear hinge striker.
5. Move door assembly forward or rearward, then
tighten striker bolts to specifications.
6. Reinstall upper rear track cover.
7. Reinstall front and rear latch strikers.
8. Adjust latch strikers and rear wedge assembly as
outlined below.
Latch Striker Adjustments
Front Striker
1. Loosen front latch striker screws, view C of
figure 2 D - 1 15.
2. Visually align latch-to-striker relationship and
adjust i f necessary.
3. Slide door slowly toward striker. The guide on
the door, just above the latch, must fit snugly within the
rubber-lined opening on the striker assembly.
4. Assure that the latch engages fully into the
striker. Add or delete shims behind the striker as
necessary.
5. Tighten striker screws to specified torque.
Rear Striker
1.
2.
Loosen striker with J-23457.
Loosen rear wedge assembly.
CAUTION: I f door has been removed and is
being reinstalled, adjust striker-to-lower hinge
lever before closing door. Failure to do so may
cause possible lever breakage.
The upper rear hinge must be positioned as shown
in view A o f figure 2D-116, in order to insure proper
latching.
1. The hinge lower lever must contact the striker at
least .06 inch above the lower edge o f the striker tang.
2. The lower lever must extend at least .10 inch
outboard o f the striker tang. A dd or delete shims
between the striker and the body as necessary.
3. If necessary to shim roller away from guide,
shims are added between the nylon block and hinge and
between roller and hinge. They must be installed in
pairs. For example, if one shim is added behind the
nylon block another must be added behind the roller.
Door Hold-Open Catch Adjustment
This catch, mounted on the lower front roller
bracket, holds the door in the full open position. See
figure 2D-117. The catch engages a striker installed at
the rear o f the lower roller channel, view D of figure 2D115.
1. Loosen the screws retaining the catch rod
bracket to bottom o f door.
2. Adjust catch-to-striker engagem ent by sliding
the bracket laterally. Catch should fully engage striker.
Rear Wedge Assembly Adjustment
1. Loosen screws attaching rear wedge assembly to
the body pillar, then close the door to the fully latched
position.
2. Center the wedge assembly on the door wedge,
as shown in figure 2 D - 1 18, and scribe a line around the
wedge assembly.
3. Open the door, and move the wedge assembly
3/16 inch.
Fig. 2D-117--Hold-Open Catch
Fig. 2 D -1 1 9 -Sliding Door Front Latch
Fig. 2 D -11 8 -Adjusting the Rear Wedge Assembly
Fig. 2D-120--Disconnecting Lower Latch Rod from
Latch
F R O N T LATCH ASSEMBLY
Removal
1. Remove trim panel, if so equipped.
2. Remove access cover.
3. Unscrew door lock knob from rod.
4. Disconnect the following rods from latch, shown
in figure 2 D -1 19.
a. Rear latch rods.
b. Lock cylinder rod.
c. Door lock rod.
5. Remove door handle.
6. Remove screws retain in g latch assembly to door.
7. Slide latch rearw ard and lift front o f latch.
Disconnect rod leading to lower hinge door catch by
pushing rod out o f hole an d rotating rod clear o f latch.
See figure 2 D - 1 19.
8. Remove latch assembly from door.
Installation
1. Install latch assembly into door by working latch
assembly behind the lower hinge door catch.
2. Connect lower hinge door catch, lock cylinder
rod, door lock rod, and both rear latch rods.
3. Install latch assembly-to-door attaching screws.
Torque to specifications.
4. Install door lock knob and door handle.
5. Install access cover and trim panel.
6. Adjust door front striker as outlined earlier
under "Adjustm ents".
REAR LATCH A N D /O R LATCH A C T U A T IN G
RODS
Removal
1.
2.
Remove trim panel (if so equipped).
Remove front latch assembly access cover.
Fig. 2D-122--Rear Track Cover
Fig. 2D-121--Sliding Door Rear Latch
3. Disconnect rear latch rods
assembly, shown in figure 2D.
4. Remove rear latch attaching
2 D -1 2 1.
5. Slide rear latch toward front
clips become exposed. Disconnect rod
latch from door.
from front latch
screws. See figure
o f door until rod
clips and remove
Installation
1. Connect rods to latch and
T orque screws to specifications.
2. Connect rods to front latch
3. Install access covers and
equipped).
4. Adjust rear latch striker
under "A djustm ents".
install latch to door.
assembly.
trim panels (if so
as outlined
earlier
UPPER REAR H IN G E
Removal
1. Remove the hinge cover and rear track cover.
See figures 2D-116 and 2D-122.
2. O pen the door.
3.
removal
4.
5.
Disengage spring from bolt, using a spring
tool.
Close the door.
Remove the hinge assembly.
Installation
NOTE: W hen holding hinge assembly as in figure
2D-124. the lower latch must engage cam.
1. Install hinge assembly to door. Torque bolts to
specifications.
2. Check and adjust latch to striker position as
outlined under "Adjustm ents".
3. Open the door and reconnect the hinge spring.
4. Install the rear track cover and hinge cover.
5. Check the operation of the door hinge.
STRIKERS
The front and rea r strikers are shown in figure 2D115. The rear striker can be removed with J-23457 as in
figure 2D-107, and the front striker can be removed by
removing attaching screws. Refer to "A djustm ents"
when reinstalling.
1. Roller
2. Lockwashers
3. N ut
4. Cam
5. Washer
6. Bushing
7. Bushing
8. B olt
9. Plate
10. Upper lines
11. Spacer
12. Spring (Upper Lever)
13. Spring (Low er Level)
14. Lower Lever
15.
16.
17.
18.
19.
20.
Screw
Guide Block
Hinge (Body Half)
N ut
Bushing
Bushing
Fig. 2D-123--Upper Rear Hinge Components
21.
22.
23.
24.
25.
26.
Cam
Bushing
Hinge (D oor Half)
Spring
Spring retainer
Hinge liner
Fig. 2D-124--Checking Assembly of Hinge
REAR DOORS
REAR DOOR HING E STR A P
REAR DOOR HING E
Replacement
Removal
1. Remove strap release pin. See figure 2D-125.
2. Remove screws retaining strap to door.
3. Install strap to door. Torque retaining screws to
specifications.
1. Open door. Support door so that when hinge
screws are removed d oo r weight will be on support.
2. Remove hinge strap release pin.
3. Remove hinge-to-door bolts and remove door
assembly.
4. Remove hinge-to-body bolts and hinge.
Installation
1. Install grom m et into door hinge opening (if
removed).
2. Install hinge into door. Snug bolts.
3. Install seal and retainer on body half o f hinge
(if removed).
4. Install hinge into body opening and install bolts.
5. Take care to compress seal between body and
retainer and snug bolts.
6. Install hinge strap and its retaining pin.
7. Adjust door and torque hinge bolts to
specification.
REAR DOOR REM O TE CO NTRO L
Removal
1. Remove trim panel.
2. Disengage upper and lower latch rods from
control by rem m oving retaining clips. See figure 2D-126.
3. Rem ove rem ote control by rem ov in g its
retaining screws.
Installation
1.
2.
3.
Install remote control screws loosely.
Attach upper and lower control rods.
Rotate remote control lever clockwise, and hold
4.
Adjust latch to strikers.
REAR DOOR O UTSIDE HANDLE
Removal
1. Remove trim panel.
2. Remove door handle retaining screws, handle
and gaskets. See figure 2D-127.
Installation
1. Apply
plunger makes
2. Install
specifications.
3. Install
grease to remote control where handle
contact.
handle and gaskets. Torque screws to
trim panel.
REAR DOOR LOCK CYLINDER
Removal
1.
2.
3.
Remove trim panel.
Remove remote control.
Remove lock cylinder retainer and lock cylinder.
Installation
Fig. 2D-126--Remote C ontrol and Latch
in this position while to rq u in g
specifications.
4. Install the trim panel.
the
screws
to
REAR DOOR UPPER OR LOWER LATCHES
A N D /O R LATCH RODS
Removal
1. Remove trim panel.
2. Disengage rod from remote control assembly.
See figure 2D-126.
3. Remove latch retain in g screws and withdraw
latch and control rod.
4. Remove spring clip retaining rod to latch.
Installation
1.
Install latch rod to latch.
N OTE: W hen reinstalling the lower latch rod to
control, the short straight section attaches to the
latch.
2. Install latch and rod assembly into door and
connect rod to remote control.
3. Install latch retaining screws and torque to
specifications.
1. Install lock cylinder and retainer.
2. Install rem ote control. T orq ue
specifications.
3. Install trim panel.
screws
to
REAR DOOR GLASS AND W E A TH ER S TR IP
Removal and installation procedures are the same as
for the stationary body side windows. Refer to those
procedu res for rear doo r glass and w eath erstrip
replacement.
REAR DOOR A D J U S T M E N T S
NOTE: Door adjustments are provided by slotted
holes, at hinge attachment, in body and door.
1. Remove or loosen door strikers and wedges.
2. Loosen door hinge bolts and adjust door to
provide equal clearances between body and door around
perim eter of door.
3. Adjust door in and out so that door panel is
flush with body.
4. Install door strikers and wedges and adjust as
outlined under door striker adjustment.
REAR DOOR STRIKER AND WEDGE
ADJUSTMENT
CAUTION: See C A U T IO N on page 1 o f this
section regaring Rear Door Striker fasteners.
1. Adjust striker by adding or deleting shims as
necessary to obtain dimension as shown in figure 34G.
This dimension can be checked by applying grease to the
latch and slowly closing door until striker fully engages
latch. Then open door and measure from grease
im pression to bottom o f latch slot. Torque to
specifications.
2. Adjust door wedge by adding or deleting shims
as necessary so that wedge contact ram p on body when
door is closed. See figure 2D-128.
STRIKER A D JU S TM E N T
Fig. 2D -128-R ear Door S triker and Wedge
A d ju stm e nt
SEATS
CAUTION: See C A U T IO N on page 1 o f this
section regarding fasteners used on seats and
seat belts.
4.
Install seat onto seat riser, and torque nuts to
specifications.
SEAT RISER
DRIVERS SEAT
Seat Adjuster
R eplacem ent
1. Remove seat by rem oving nuts securing seat
adjuster to seat riser.
2. Remove adjuster from seat. See figure 2D-129.
3. Install seat adjuster to seat. Torque bolts to
specifications.
Replacement
1. Remove seat and adjusters as an assembly by
removing nuts securing seat to riser.
2. Remove nuts securing seat riser to floor.
3. Install seat riser to floor. Torque nuts to
specifications.
Fig. 2D -129--D river’s Seat
4.
Install seat and torque nuts to specifications.
plates are used. W hen the latch assemblies are depressed,
their cams and the hooks o f the retainers are drawn
tightly onto the anchor pins for secure seat attachment.
PASSENGER S E A T -M O U N T IN G BRACKETS
Removal
Removal
procedure:
1. Remove seat and brackets from seat riser. See
figure 2D-130.
1. Pull up on quick release latches located at lower
front of seat legs (right and left hand sides).
2.
2.
Install brackets to seat. Torque to specifications.
Install seat to seat riser. Torque to specifications.
Removal
2.
seat
an d
m ounting
bracket
as
following
3.
Lift seat up and remove from van.
4.
To replace, reverse steps 1 to 3.
SWIVEL BUCKET SEATS ■ G MODELS
Refer to the illustration in Figure 2D-132 for swivel
Bucket Seat Assembly installation.
Installation
2.
the
an
Remove riser from floor.
1. Install
specifications.
using
C A U TIO N : When replacing seals m ake sure
that seal retainer hooks are fu lly engaged with
anchor pins and latching assembly is fully
depressed into place.
SEAT RISER
1. Remove
assembly.
accomplished
2. Tilt up front o f seat and push seat rearw ard to
clear anchor pins located beneath floor at front and rear
of seat legs.
Remove brackets from seat.
Installation
1.
is
riser
to
floor.
To rqu e
nuts
to
Install seat riser. Torque nuts to specifications.
All models equipped with 2nd, 3rd and 4th bench
seat assemblies feature a quick release m echanism which
facilitates removal o f the seats for added cargo space.
Instead o f the conventional clamp and bolt method
o f seat retention, cam type latch assemblies and hooked
retainers, which fit onto anchor pins in floor anchor
ROOF V E N T - G MODELS
Roof vent installation is illustrated in Figure 2D133.
CARE AN D CLEANING OF SEATS
Instructions on care and cleaning o f interior soft
trim may be found in "C -K Models—Seats", earlier in
this section.
SPECIFICATIONS
BODY
SECTION 2D
C AND K MODELS
FRO NT END
Windshield Wiper Linkage to Plenum ........................ 25 in. lb.
Sunshade S u p p o r t .......................................................... 20 in. lb.
Inside Rear View Mirror to Bracket............................. 45 in. lb.
Outside Rear View Mirror to Door Panel —
Base M i r r o r ............................................................. 25 in. lb.
West Coast Mirror—Lower Bracket to Door . . . 20 in. lb.
—Upper Bracket to Door. . . . 45 in. lb.
END GATE
(0 6 )
Hinges—Hinge to B o d y .................................................. 35 ft. lb.
—Hinge to End Gate.............................................20 ft. lb.
Support Cable B o lts ....................................................... 25 ft. lb.
Torque Rod-Silencer Bracket..................................... 40 in. lb.
—End Support Bracket............................. 90 in. lb.
Latch Assembly to End G a t e ........................................20 ft. lb.
Latch Remote Control Assembly to End Gate . . . . 40 in. lb.
Access Cover .................................................................. 18 in. lb.
Outside Handle .............................................................55 in. lb.
Glass C hannel.................................................................. 45 in. lb.
DOORS
Window Regulator Assembly to Door P a n e l ............. 85 in. lb.
Remote Control Door Lock to Door P a n e l ................45 in. lb.
Lock Striker to Body P ill a r ........................................... 45 ft. lb.
Outside Door Handle........................................................85 in. lb.
Inside Door H a n d l e ........................................................85 in. lb.
Hinges to Body and D o o r ............................................. 35 ft. lb.
Front Door-Window Run Channel
Upper Screw Assembly ........................................85 in. lb.
Lower Bolt Assembly. . ........................................ 18 in. lb.
Front Door-Ventilator Assembly
Top Vent S c r e w ..................................................... 18 in. lb.
Side Vent Screws and S p a c e rs............................. 25 in. lb.
Lower Vent Channel B o l t s .................................. 40 in. lb.
Side Rear Door—Run Channel
Front Upper to D o o r ............................................. 40 in. lb.
Rear Upper to Door ............................................. 20 in. lb.
Front and Rear Lower to Door............................. 85 in. lb.
Lock Lever to Door ............................................. 85 in. lb.
Rear Door—Lock Striker (06) ..................................... 95 in. lb.
Rear Door—Latch L.H. and R.H. to Door (06) . . . . 85 in. lb.
Rear Door—Latch Control Assembly to Door (06)
—Upper A sse m b ly ........................................85 in. lb.
—Lower A ssem bly........................................90 in. lb.
Rear Door—Weatherstrip L.H. ( 0 6 ) ............................. 18 in. lb.
E N D G A T E (1 4 )
Hinges—Body Half and Gate H a l f ................................35 ft. lb.
Support Assembly-Body to End G a t e ........................25 ft. lb.
Torque Rod-Retainer Assembly.................................. 85 in. lb.
—Anchor A sse m b ly .................................. 18 ft. lb.
Latch Assembly to End G a t e ........................................85 in. lb.
la tc h Control Assembly to End Gate ........................ 40 in. lb.
Access Cover..................................................................... 18 in. lb.
Handle to Latch Control A ssem bly............................. 55 in. lb.
Glass Channel Assembly to End Gate ........................85 in. lb.
Cap Assembly to Channel Assembly............................. 24 in. lb.
Striker—Body Mounted ................................................18 ft. lb.
T A I L G A T E (03, 6 3 - w i t h
E63)
Trunnion A ssem b ly ........................................................18 ft. lb.
Linkage and Striker Assembly—Support .................. 25 in. lb.
T A IL G A T E
(03, 6 3 - w i t h E62)
Trunnion A sse m b ly ....................................................... 35 ft. lb.
Chain Support Assembly .............................................90 in. lb.
SEATS
Front Bench Seat
Adjuster-to-Seat ................................................155
Adjuster-to-Floor.................................................. 25
Front Bucket Type (14, 03)
Driver
Adjuster-to-Seat.............................................18
Adjuster-to-Floor ....................................... 25
Passenger (03)
Support-to-Seat.............................................18
Support-to-Floor (F r o n t) .............................25
Support-to-Floor ( R e a r ) ............................. 40
Passenger (14)
Latch Support-to-Seat (Rear) ...................18
Striker-to-Floor (Rear) .............................25
Support (Upper)-to-Seat (Front) ............. 18
Support (Lower)-to-Floor ( F r o n t ) ............. 25
Support (Upper)-to-Support (Lower) . . . . 30
Rear Bench (06, 14)
Support-to-Seat.....................................................18
Support-to-Floor .................................................. 50
Rear Bench (63)
Support-to-Seat.................................................. 150
Support-to-Floor .................................................. 35
Folding Rear Seat (06)
Support Asm-to-Floor....................................... 150
Seat-to-Support A s m .............................................18
in. lb.
ft. lb.
ft. lb.
ft. lb.
ft. lb.
ft. lb.
ft. lb.
ft.
ft.
ft.
ft.
ft.
lb.
lb.
lb.
lb.
lb.
ft. lb.
ft. lb.
In. lb.
in. lb.
in. lb.
in. lb.
BODY MOUNTING (C-K MODELS)-FT. LBS.
Model
(03)
(06)
(14)
(63)
#1
45
35
55
55
#2
45
35
45
35
#3
—
—
35
55
#4
#5
—
35
35
-
#6
—
—
—
35
—
_
-
-
G MODELS
M IR R O R S A N D S U N S H A D E
S L I D I N G S ID E
Inside Rear View Mirror to Bracket ........................15 in. lb.
Outside Rear View Mirror to P a n e l ............................. 40 in. lb.
Sunshade Support to Header P a n e l ............................. 15 in. lb.
S ID E W IN D O W
(S W IN G O U T )
Latch to B o d y .................................................................. 40 in. lb.
Latch to Glass.................................................................. 40 in. lb.
Hinge to B ody.................................................................. 40 in. lb.
F R O N T S ID E
DOORS
Door H in g e s..................................................................... 30 ft. lb.
Door Hinge Access Hole Cover ...................................18 in. lb.
Door Lock S tr ik e r ...........................................................45 ft. lb.
Door Lock to D o o r ........................................................20 ft. lb.
Outside Door H a n d l e ..................................................... 45 in. lb.
DOOR
Remote Control (front latch) to D o o r ........................ 90 in. lb.
Rear Latch to D o o r ........................................................90 in. lb.
Rear Plate to Door ........................................................90 in. lb.
Lower Front Roller and Roller Support
Support-to-Door .................................................. 24 ft. lb.
Support to Roller Bracket ...................................24 ft. lb.
Roller to Roller Bracket........................................ 20 ft. lb.
Catch to Roller B ra c k e t........................................ 45 in. lb.
Upper Front Roller Bracket
Bracket to D o o r ..................................................... 24 ft. lb.
Roller to B r a c k e t .................................................. 20 ft. lb.
Upper Left Hinge (Door Half)
Hinge to D o o r ........................................................25 ft. lb.
Upper Left Hinge (Body Half)
Roller to Hinge........................................................20 ft. lb.
Guide Block to Hinge............................................. 40 in. lb.
Lever Arm-to-Hinge Retaining Nut ................120 in. lb.
Lever Retaining Sc re w ........................................... 40 in. lb.
Striker to Body........................................................20 ft. lb.
Rear Striker Bolt (Body M o u n t e d ) ............................. 45 ft. lb.
Front Striker Retaining Screws (Body Mounted) . . 90 in. lb.
SEATS
REAR
DOOR
Hinge Strap to D o o r ........................................................45
Hinge Strap Bracket to B o d y ........................................45
Hinge (to body and d o o r ) ............................................. 30
Remote Control Retaining Screws ............................. 85
Latch-to-Door Retaining S crew s.................................. 90
Door Strikers-to-Body .................................................. 90
Outside Door H a n d l e ..................................................... 45
Seat Belt to S e a t ............................................................. 37 ft. lb.
in. lb. Passenger and Drivers
Seat to Adjuster (Mounting Bracket) ................18 ft. lb.
in. lb.
ft. lb.
Saat to R i s e r .......................................................... 18 ft. lb.
in. lb.
Seat Riser-to-Floor................................................50 ft. lb.
in. lb. Bench Seats
in. lb.
Seat to Seat S u p p o r t ............................................. 18 ft. lb.
in. lb.
Seat Support to Floor Clam ps............................. 40 ft. lb.
SPECIAL TOOLS
1.
2.
3.
4.
5.
J-2189
J-22585
J-22577
J-7797
J-23457
W eatherstrip T o o l Set
F ro n t D o o r Hinge, B o lt W rench
W indshield C hecking Blocks
D o o r Handle C lip Remover
D o o r S trik e r B o lt Remover and Installer
SECTION 3A
FRONT ALIGNMENT
CONTENTS
G eneral D e sc rip tio n ...................
M aintenan ce and Adjustments
Specifications.................................
3 A- 1
3A-2
3A-6
GENERAL DESCRIPTION
F R O N T A L IG N M E N T
The term " f ro n t alig nm en t" refers to the angular
relationships between the front wheels, the front
suspension attaching parts and the ground.
The pointing in or "toe-in " of the front wheels, the
tilt of the front wheels from vertical (when viewed from
the front of the vehicle) and the tilt o f the suspension
m em bers from vertical (when viewed from the side of
the vehicle), all these are involved in front alignment.
The various factors that enter into front alignment are
covered here each one under its own heading.
CASTER
Caster is the tilting o f the front steering axis either
forward or backward from the vertical (when viewed
from the side o f the vehicle). A backward tilt is said to
be positive ( + ) and a forward tilt is said to be negative
(-).
O n the short and long arm type suspension you
cannot see a caster angle without a special instrument,
but you can understand that if you look straight down
from the top o f the upper control arm to the ground you
would lind that the ball joints do not line up (fore and
aft) when a caster angle other than 0° is present. If you
had a positive caster angle the lower ball joint would be
slightly ahead (toward the front o f the vehicle) o f the
upper ball jo in t center line. In short then, caster is the
forward or backward tilt o f the steering axis as viewed
from a side elevation. Caster is designed into the front
axle assembly on all K series vehicles (l'our-wheel drive),
an d is no n-adjustab le. See caster copy un d e r
A D JU ST M EN TS.
CAMBER
Cam ber is the tilting of the front wheels from the
vertical when viewed from the front o f the vehicle.
W hen the wheels tilt outward at the top, the cam ber is
said to be positive ( + ) . W hen the wheels tilt inward at
the top, the cam ber is said to be negative (—). The
am ount of tilt is measured in degrees from the vertical
and this m easurem ent is called the c am ber angle.
C am ber is designed into the front axle assembly o f all K
series vehicles and is non-adjustable. See cam ber copy
under A D JU ST M E N T S.
TOE-IN
Toe-in is the turning in o f the front wheels. The
actual am ount o f toe-in is normally only a fraction of an
inch. The purpose o f a toe specification is to ensure
parallel rolling o f the front wheels. (Excessive toe-in or
toe-out will cause tire wear). Toe-in also serves to offset
the small deflections o f the wheel support system which
occurs when the vehicle is rolling forward. In other
words, even when the wheels are set to toe-in slightly
when the vehicle is standing still, they tend to roll
parallel on the road when the vehicle is moving. See toein copy under A D JU STM E N T S.
S U B T R A C T S H IM S HERE
'- T O
IN C R E A S E C A STE R
2. Draw a graphic as in Fig. 3A-4 that is
representative o f the fra m e angle (either " u p " in rear or
"d ow n" in rear).
3. D eterm ine the caster angle from the alignment
equipm ent and draw a line that is representative o f the
caster reading.
4. To determine an "actual (corrected) caster
re ad in g " with various fra m e angles and caster readings,
one of the following rules applies:
a. A DOWN IN REAR" frame angle must be
SUBTRACTED from a POSITIVEcaster reading.
b. An UP IN REAR" fram e angle must be
ADDED to a POSITIVE caster reading.
c. A "DOWN IN REAR" fram e angle must be
ADDED to a NEGATIVE caster reading.
d. An "U P IN REAR" fram e angle must be
SUBTRACTED from a NEGATIVE caster reading.
How to Adjust Caster
5. Add or subtract as necessary to arrive at the
corrected caster angle.
6. Measure dim ension " A " (bum p stop bracket to
fram e) and check the specifications for that dimension.
7. Correct the actual caster angle, as arrived at in
Step 4, as necessary to keep within the specifications by
"B ”
IS LESS T H A N
" A " W H E N W H E ELS T O E -IN
Fig. 3A-3-Toe-In A d justm ent
a dding or subtracting shims from the front or rear bolt
on the upper control arm shaft, shown in Figure 3A-2.
Camber
1. D eterm ine the cam ber angle from the align
ment equipment.
2. Add or subtract shims from both the front and
rear bolts to affect a change.
Toe-In
1. D etermine the wheel toe-in from the alignment
equipment.
2. Change the length of both tie rod sleeves to
affect a toe change.
Toe-in can be increased or decreased by changing
the length o f the tie rods. A threaded sleeve is provided
for this purpose.
W hen the tie rods are mounted ahead o f the
steering knuckle they must be decreased in length in
order to increase toe-in. W hen the tie rods are mounted
behind the steering knuckle they must be lengthened in
order to increase toe-in.
See Section 3B for proper tie rod clamp orientation
and positioning.
w n D i7 r> M T A i
H O R IZO N TAL
FRAME ANG LE —
^
D O W |sj
FRAME ANG LE =
CASTER ANGLE READING
=
ACTUAL (CORRECTED) CASTER ANGLE =
FRAME ANG LE =
1° UP
AN G LE READING
ACTUAL (CORRECTED) CASTER ANGLE
+ (2 °)
+ (3 °)
=
=
ACTUAL (CORRECTED) CASTER ANGLE
FRAME ANG LE =
=
=
ANG LE READING
+ ( 2' A° )
+ (1 ° )
V2 0 D O W N
VA°
JOUNCE BUMPER
BRACKET
- (
13/4 °)
UP
CASTER ANG LE READING
ACTUAL (CORRECTED) CASTER ANGLE
- ( l ’/ 4 ° )
= - ( '/4 0)
=
D IM EN SIO N (A)
+ (1 °)
SPECIFICATIONS
W HEEL A L IG N M E N T SP EC IFIC A TIO N S
CASTER*
DIMEN SION “A ' IN INC HES*
MODELS
2 1/2"
2 3 /4 "
3"
+ 2°
CIO
+ 1 1/2° + 1 1/4°
C20.C30
+ 1°
3 1/4"
+ 3/4°
K10,K20,K30
+ 1/2
3 3/4"
4"
4 1/4"
4 1/2"
4 3/4"
5"
+ 1"'
+ 3/4
+ 1/2
+ 1/4"
0:
-1 / 2 C
+ 1/ 4°
0°
-1/4°
-1/2°
-3/4
-1°
-1/4
- 1 /2 '
0 :'
- 1 /4 “
(8°) (NO ADJUSTMENT PROVISION)
G I0.G20.G30
+ 2 1/4"
PI0.P20.P30
+ 2 1/2° + 2 1/4°
MOTOR
HOME
(32)
3 1/2"
+ 1 1/2" + 1 1/4
+5 3/4
+ 2°
+5 1/2
+ 1 1/2" + 1 1 /4 J
+ 2°
+5
+ 1L
+ 3/4
+ 1/2-
+ 1/4"
+1 3/4° + 1 1/2
+ 1
+ 3/4°
+ 1/ 2 0
+4 1/4
+4
+5
+4 1/2
0
+ 1/ 4°
+4
+3 1/2
+3 1/4
+3
i
CAMBER
+ 1/4'
C10.C20.C30
K10,K 20,K 30
NO ADJUSTMENT PROVISION
GI0.G2O.G3O
+ 1/4°
Camber on P-Truck is dependent on dimension ‘A’.
After measuring dimension ‘A ’ set camber as follows:
2 1/2"
2 3/4 "
3"
3 1/4"
3 1/2"
3 3/4"
4"
4 1/4"
4 1/2"
4 3/4"
5"
5 1/4"
P10
0
0
+ 1/4"
+ 1/4°
+ 1/4"
+ 1/4
+ 1/ 4"
0
0"
0°
-1/4"'
-1/2
-3/4"
P20.P30
0
0
+ 1/4°
+ 1/4°
+ 1/4'
+ 1/ 4"
+ 1/4°
+ l/4 ‘
0°
0°
-1/4°
-1/2"
-3/4°
MOTOR
HOME
(32),
0
0
+ 1/4°
+ 1/4°
+ 1/4°
+ 1/4°
0°
0°
0°
-1 /2 °
-3 /4 °
-1°
TOE-IN
CI0.C20.C30
ALIGNMENT TOLERANCES
3/16"
WARRANTY
RESETTING
TARGET
K10,K20,K30
0
REPAIR
G10.G20.G30
3/16"
CHECKING
P10.P20.P30
3/16"
MOTORHOME
P30 (32)
-1 /4 °
5 1/2"
5 /16 ”
PERIODIC
MOTOR
VEHICLE
INSPECTION
CASTER
±1
±1/2°
±2“
CAMBER
± 3 /4 "
± 1 /2 "
±1 1/2°
TOE-IN
± 1/8"
±1/16"
±3/8°
/
SECTION 3B
STEERING
The following caution applies to one or more steps in the assembly
procedure o f components in this portion of the m anual as indicated at
a ppropriate locations by the terminology "See Caution on page l o f this
Section".
CAUTION T H IS F A S T E N E R I S A N IM P O R T A N T A T T A C H IN G P A R T
IN T H A T I T C O U LD A F F E C T T H E P E R F O R M A N C E OF V IT A L
C O M P O N E N T S A N D S Y S T E M S , A N D /O R C O U LD R E S U L T IN
M A JO R R E P A IR E X P E N S E . I T M U S T B E R E P L A C E D W IT H O NE
OF T H E S A M E P A R T N U M B E R OF W IT H A N E Q U IV A L E N T P A R T
IF R E P L A C E M E N T B E C O M E S N E C E S S A R Y . DO N O T U SE A
R E P L A C E M E N T P A R T OF L E S S E R Q U A L IT Y OR S U B S T IT U T E
D E S IG N . TO R Q U E V A L U E S M U S T B E U SE D A S S P E C IF IE D
D U R IN G R E A S S E M B L Y TO A S S U R E P R O P E R R E T E N T IO N OF
T H IS P A R T .
CONTENTS
G e n e ra l D e sc rip tio n .......................................................... 3B-2
D ia g n o s is .............................................................................. 3B-3
Steering L in k ag e.............................................................. 3B-3
M anual Steering G e a r .................................................. 3B-5
Steering Column (C and K ) ......................................... 3B-7
Electrical Analyzer J-23980.......................................... 3B-7
Collision D ia g n o s is ......................................................... 3B-7
Automatic C o lu m n ........................................................ 3B-9
M an u al C o lu m n ........................................................... 3B-12
Tilt C o l u m n .................................................................. 3B-13
Signal Sw itch.................................................................. 3B-14
Power Steering System................................................ 3B-15
External Leak ag e......................................................... 3B-26
M aintenance and A djustm ents................................... 3B-31
L u b ric a tio n ....................................................................... 3B-31
A djustm en ts...................................................................... 3B-31
Steering G e a r - M a n u a l................................................. 3B-31
Steering G e a r High Point C e n te rin g.................... 3B-32
Steering W heel A lig n m en t......................................... 3B-32
Steering Colum n Lower Bearing A d ju stm e n t.... 3B-32
Shifter Tube A djustm en t............................................ 3B-32
Power Steering G e a r ................................................... 3B-33
Belt T en sio n ................................................................... 3B-34
Fluid Level..................................................................... 3B-35
Bleeding System ........................................................... 3B-35
System Checks.............................................................. 3B-36
C om ponent Replacement and R e p a ir s ................... 3B-37
Steering W h e e l............................................................... 3B-37
Steering C o u p lin g .......................................................... 3B-37
Flexible T y p e................................................................ 3B-37
Interm ediate Steering Shafts with Pot Joint
C o u p lin g s........................................................................ 3B-38
Intermediate Steering Shaft with Universal
Joint C o u p lin g s............................................................ 3B-39
Steering G e a r ...............................................................
Pitman Shaft Oil Seal R eplacem ent...................
Directional Signal Switch.........................................
Lock C ylinder...............................................................
Ignition Switch.............................................................
Steering C o lu m n ..........................................................
R em o v al........................................................................
Column Disassembly (Except T ilt) ......................
Column Assembly (Except T i l t ) ............................
Column Disassembly-Tilt..........................................
Column Assembly-Tilt...............................................
Column Installation-M andatory S e q u e n c e ...........
Steering Colum n Service G and P ........................
Upper Bearing G and P ..........................................
Lower Bearing P ........................................................
Directional S w itch......................................................
Tilt Column Bearing H o u s in g ...............................
Column Rem oval.........................................................
Disassembly Standard C o lu m n ............................
Assembly Standard C o lu m n .................................
Disassembly Tilt C o lu m n ......................................
Assembly Tilt C o l u m n ............................................
Column Installation P S e rie s.................................
Column Installation G S e rie s ................................
Steering L in kage............................................................
Tie R od...........................................................................
Relay R o d .....................................................................
Idler A r m .......................................................................
Pitman A r m ..................................................................
Steering Connecting R o d ........................................
Power Steering System ................................................
Power G e a r ...................................................................
P u m p ...............................................................................
Hoses................................................................................
Special Tools......................................................................
3B-40
3B-41
3B-41
3B-43
3B-45
3B-45
3B-46
3B-47
3B-47
3B-50
3B-53
3B-55
3B-56
3B-56
3B-56
3B-56
3B-57
3B-58
3B-59
3B-60
3B-61
3B-61
3B-65
3B-66
3B-66
3B-66
3B-69
3B-70
3B-70
3B-71
3B-7I
3B-71
3B-72
3B-73
3B-78
GENERAL DESCRIPTION
The steering gear is o f the recirculating ball type.
This gear provides for ease o f handling by transmitting
forces from the w orm shaft to the pitm an shaft through
the use o f ball bearings.
The steering column is connected to the steering
g ear by a flexible coupling. This coupling incorporates a
capturing strap which is designed to prevent column-to-
coupling deflection from exceeding the length o f the
coupling alignm ent pins.
The trucks incorporate "F o rw ard Steering" whereas
the steering linkage is located forward o f the front
crossmember. Steering effort is transmitted to left and
right hand adjustable tie rod through a relay rod. The
relay rod is connected to an idler arm on the right and to
the pitm an arm on the left.
CONDITION
Excessive Play or Looseness in
Steering System.
Excessive looseness in tie rod
or intermediate rod pivots, or
excessive vertical lash in idler
support.
POSSIBLE CAUSE
CORRECTION
Front wheel bearings loosely
adjusted.
Adjust bearings to obtain proper
end play.
Worn steering shaft couplings.
Replace part.
Worn upper ball joints.
Check and replace if necessary.
Steering wheel loose on shaft,
loose pitman arm, tie rods,
steering arms or steering linkage
ball studs.
Tighten to specified torque,
or replace if necessary.
Steering gear thrust bearings
loosely adjusted.
Adjust preload to specification.
Excessive over-center lash in
steering gear.
Adjust preload to specification.
Worn intermediate rod or tie rod
sockets.
Replace worn part.
Seal damage and leakage
resulting in loss of lubricant,
corrosion and excessive wear.
Replace damaged parts as
necessary. Properly position upon
reassembly.
CONDITION
Hard Steering — Excessive Effort
Required at Steering Wheel.
Poor Returnability.
POSSIBLE CAUSE
CORRECTION
Low or uneven tire pressure.
Inflate to specified pressures.
Steering linkage or bolt joints
need lubrication.
Lube with specified lubricant.
Tight or frozen intermediate rod,
tie rod or idler socket.
Lube replace or reposition
as necessary.
Steering gear to column
misalignment.
Align column.
Steering gear adjusted too
tightly.
Adjust over-center and thrust
bearing preload to
specification.
Front wheel alignment
incorrect, (manual gear)
Check alignment and correct
as necessary.
Steering linkage or ball joints
need lubrication.
Lube with specified
lubricant.
Steering gear adjusted too
tightly.
Adjust over-center and thrust
bearing preload to
specifications.
Steering gear to column
misalignment.
Align column.
Front wheel alignment
incorrect. (Caster)
Check alignment and correct
as necessary.
CONDITION
Rattle or Chuck in Steering Gear.
POSSIBLE CAUSE
CORRECTION
Insufficient or improper lubricant
in steering gear.
Add lube specified.
Pitman arm loose on shaft or
steering gear mounting bolt loose.
Tighten to specified torque.
Loose or worn steering shaft
bearing.
Replace steering shaft bearing.
Excessive over-center lash or
worm thrust bearings adjusted
too loose.
Adjust steering gear to specified
preloads.
NOTE: On turns a slight rattle
may occur, due to the increased
lash between ball nut and pitman
shaft as gear moves off the center
of “high point” position. This is
normal and lash must not be
reduced to eliminate this slight
rattle.
Poor Returnability
Steering column misaligned.
Align column.
Insufficient or improper lubricant
in steering gear or front suspension.
Lubricate as specified.
Steering gear adjusted too tight.
Adjust over-center and thrust
bearing preload to specifications.
Front wheel alignment incorrect
(Caster)
Adjust to specifications.
CONDITION
Excessive Play or Looseness in
Steering System.
Hard Steering Excessive Effort
Required at Steering Wheel
POSSIBLE CAUSE
CORRECTION
Front wheel bearings loosely
adjusted.
Adjust to obtain proper end play.
Worn upper ball joints.
Check and replace ball joints
if necessary.
Steering wheel loose on shaft,
loose pitman arm, tie rods,
steering arms or steering
linkage ball nuts.
Tighten to specification, replace
if worn or damaged.
Excessive over-center lash.
Adjust over-center preload to
specifications.
Worm thrust bearings
loosely adjusted.
Adjust worm thrust bearing preload
to specifications.
Low or uneven tire pressure.
Inflate to specified pressures.
Insufficient or improper lubricant
in steering gear or front
suspension.
Lubricate as specified. Relubricate at specified intervals.
Steering shaft flexible coupling
misaligned.
Align column and coupling.
Steering gear adjusted too tight.
Adjust over-center and thrust
bearing preload to specifications.
Front wheel alignment
incorrect. (Manual Gear)
Adjust to specifications.
DIAGNOSIS C AND K STEERING COLUMNS
This section contains diagnostic inform ation to help
locate the cause of the problem in the column. Reference
should be m a de to the correct method o f column
disassembly, repair, adjustm ent and reassembly. D a m
aged, broken or deform ed parts must be replaced with
the correct replacement.
G E NER AL IN F O R M A T IO N
evident or whenever the vehicle is being repaired due to
a front end collision. W henever a force has been exerted
on the steering wheel or steering column, or its
components, inspection should also be made. If dam age
is evident, the afftected parts must be replaced.
The inspection procedure for the various steering
column components on C and K trucks is as follows:
Column Support Bracket
All C a n d K models are equipped with function
D am age in this area will be indicated by separation
locking e n e rg y a b so rb in g S teering Colum ns. T he
of
the
m ounting capsules from the bracket. The bracket
columns are o f five basic designs as follows:
will
have
moved forward toward the engine co m pa rt
1.
Synchrom esh - The synchromesh column is
ment and will usually result in collapsing o f the jacket
used on models with the standard transmission and
section o f the steering column.
column m ounted shift levers. The shift tube, within the
outer column jacket, includes two lower shift levers for
C O LUM N JACKET
connection to the transmission control linkage.
Inspect jacket section o f column for looseness, a n d /
2. Floor S hift - This column is used on models
or
bends.
equipp ed with a m anual transmission with the shift lever
on the floor. This column does not incorporate a shift
SHIFTER SHAFT
tube.
Separation o f the shifter shaft sections will be
3 A U T O M A T IC T R A N S M IS S IO N - Available with
internal
and cannot be visually identified. Hold lower
column shift only, Locks the transmission and steering
end
o
f
the
"shifter sh aft" and move "shift lever" on
wheel while in park position and the lock cylinder is in
column
through
its ranges and up and down. If there is
"L o ck " position.
little or no movement of the "shifter shaft", the plastic
4.
T IL T W HEEL O P T IO N - The upper end and
joints are sheared.
steering shaft o f this column is specifically designed to
accom m odate the optional tilt steering wheel. It is
Steering Shaft
available with either m anual (the fourth column type) or
If the steering sh aft plastic pins have been sheared,
autom atic transmission on (the fifth column type).
the shaft will rattle w hen struck lightly from the side and
To p erform diagnostic procedures on the steering
some lash m ay be felt when rotating the steering wheel
colum n upp er end components, it is not necessary to
while
holding the rag joint. It should be noted that if the
remove the column from the vehicle.
steering
shaft pins are sheared due to m inor collision
T he steering wheel, horn components, directional
with no appreciable dam age to other components, that
signal switch, ignition switch and lock cylinder may be
the vehicle can be safely steered; however, steering shaft
removed with the column re m ain in g in the vehicle as
replacement is recom mended.
described in the Service M anual u nder "C om p on ent Part
Because o f the differences in the steering column
Replacem ent".
types, be sure to refer to the set o f instructions below
C A U T IO N : The outer m ast ja c k e t shift tube,
which apply to the column being serviced.
steering shaft a n d instrum ent panel m ounting
M E TH O D TO D E T E R M IN E CO LUM N
bracket are designed as energy absorbing units.
Because o f the design o f these components, it is
COLLAPSE
absolutely necessary to handle the column with
Measure distance between top o f neutral-start switch
care when perform ing any service operation.
window opening and the bottom o f the upper jacket. The
A vo id hammering, jarring, dropping or leaning
correct value is shown below:
on any portion o f the column. When reassem
a. C-Truck 5 11/16" to 5 1/2".
bling the column components, use only the
b. K-Truck 5 11/16" to 5 1/2".
specijied screws, nuts a n d bolts a nd tighten to
specified torque. Care should be exercised not
STEERING C O LU M N ELECTRICAL
to use over-length screws or bolts as they m ay
ANALYZER J -2 3 9 8 0 FOR C AND K SERIES
prevent a portion o f the colum n from
CO LUM NS
compressing under impact.
COLLISION DIA G N O S IS
To determ ine if the energy absorbing steering
column com ponents are functioning as designed, or if
repairs are required, a close inspection should be made.
An inspection is called for in all cases where dam ag e is
A new tool has been developed to help the
technician analyze the steering column wiring harness
for electrical problems. The tool in actuality eliminates
the steering column, related wiring and components; and
replaces them with the tool itself. In this way disassembly
ri
Instrument Panel Bracket Capsule Damage
NOTE: The bolt head must not contact surface “A”. If
contact is made, the capsule shear load w.ill be increased. If
this condition exists replace the bracket.
SU RFA CE “A”
L
= □
=□
A U T O M A T IC T R A N S M IS S IO N C O L U M N S
LOCK S Y S T E M - W I L L
NOT UNLOCK
Cause
Solution
A. Lock bolt damaged.
A. Replace lock bolt.
B. Defective lock cylinder.
C.
B. Replace or repair lock cylinder.
Damaged housing.
C.
Replace housing.
D. Damaged or collapsed sector.
D. Replace sector.
E. Damaged rack.
E. Replace rack.
F. Shear Flange on sector shaft collapsed.
F.
LOCK S YS TE M
Replace.
W IL L N O T LOCK
Cause
Solution
A. Lock bolt spring broken or defective.
A. Replace spring.
B. Damaged sector tooth, or sector installed incorrectly.
C.
Defective lock cylinder.
B. Replace, or install correctly.
C.
Replace lock cylinder
D. Burr or lock bolt or housing.
D. Remove Burr.
E. Damaged housing.
E. Replace housing.
F. Transmission linkage adjustment incorrect.
F. Readjust (see Sec. 7).
G. Damaged rack.
G. Replace rack.
H. Interference betw een bowl and coupling (tilt).
H. Adjust or replace as necessary.
I.
I.
Readjust or replace.
J.
Readjust or replace.
Ignition switch stuck.
J. Actuator rod restricted or bent.
LOCK S Y S TE M - H IG H
EFFO RT
Cause
Solution
A. Lock cylinder defective.
A. Replace lock cylinder.
B. Ignition switch defective.
C.
B. Replace switch.
Rack preload spring broken or deformed.
C.
Replace spring.
D. Burrs on sector, rack, housing, support, tang of shift gate
or actuator rod coupling.
D. Remove Burr.
E. Bent sector shaft.
E. Replace shaft.
F. Distorted rack.
F. Replace rack
G. Misalignment of housing to cover (tilt only).
G. Replace either or both.
Fig. 3 B -5 -A u to m a tic Transm ission Column Diagnosis
o f the column is not perform ed until the problem has
been determ ined to be in the column. By moving the
tester switch, (with the key in the " o n " position), the
various functions m ay be checked. The switch positions
are " O F F " , " H O R N " , " L E F T T U R N " , " R IG H T
T U R N " , "K E Y B U Z Z E R ", and "H A Z A R D " . (Trucks
do not incorporate a Key Buzzer Switch) if the systems
function properly while using the tester, then the
malfunction has been narrowed to the column wiring or
components. W hen this has been determ ined then the
column may be serviced to correct the malfunction.
To
use
the
tool just
unfasten
the
harm onica
LOCK S Y S TE M -
H IG H E F F O R T (C O N T 'D .)
Cause
Solution
H. D istorted coupling slot in rack (tilt).
H. Replace rack.
I.
Bent or restricted actuator rod.
I.
Straighten remove restriction or replace.
J.
Ignition switch mounting bracket bent.
J.
Straighten or replace.
H IG H E F F O R T LOCK C Y L IN D E R - B ETW EEN
" O F F " A N D " O F F -L O C K " P O SITIO N S
Cause
Solution
A. Burr on tang of shift gate.
A. Remove burr.
B. Distorted rack.
B. Replace rack.
S TIC K S IN " S T A R T " P O S ITIO N
Cause
Solution
A. Actuator rod deformed.
A. Straighten or replace.
B. Any high effort condition.
B. Check items under high effort section.
K E Y C A N N O T BE R E M O V E D
IN " O F F -L O C K " P O S IT IO N
Cause
Solution
A. Ignition switch is not set correctly.
A. Readjust ignition switch.
B. Defective lock cylinder.
B. Replace lock cylinder.
LOCK C Y L IN D E R CAN BE R E M O V E D
W IT H O U T D EP R ES S IN G R E T A IN E R
Cause
Solution
A. Lock cylinder with defective retainer.
A. Replace lock cylinder.
B. Lock cylinder without retainer.
B. Replace lock cylinder.
C. Burr over retainer slot in housing cover.
C. Remove burr.
LOCK B O LT H IT S S H A F T LOCK
IN " O F F " A N D " P A R K " P O S ITIO N S
Cause
Solution
A. Ignition switch is not set correctly.
A. Readjust ignition switch.
IG N IT IO N S Y S TE M - E L E C T R IC A L S Y S TE M
W IL L N O T F U N C T IO N
Cause
Solution
A. Defective fuse in “accessory” circuit.
A. Replace fuse.
B. Connector body loose or defective.
B. Tighten or replace.
C. Defective wiring.
C. Repair or replace.
IG N IT IO N S Y S T E M - E L E C T R IC A L S YSTEM W IL L N O T F U N C T IO N (C O N T 'D .)
Cause
Solution
D. Defective ignition switch.
D. Replace ignition switch.
E. Ignition switch not adjusted properly.
E. Readjust ignition switch.
SW ITCH W IL L N O T A C T U A T E M E C H A N IC A L L Y
Cause
Solution
A. Defective ignition switch.
A. Replace igntion switch.
S W ITCH CAN N O T BE S ET C O R R E C T L Y
Cause
Solution
A. Switch actuator rod deformed.
A. Repair or replace switch actuator rod.
B. Sector to rack engaged in wrong to o th (tilt).
B. Engage sector to rack correctly.
N O IS E
IN C O L U M N
Cause
Solution
A. Coupling bolts loose.
B. Column not correctly aligned.
C. Coupling pulled apart.
A. Tighten pinch bolts to specified torque.
B. Realign column.
D. Sheared intermediate shaft plastic joint.
C. Replace coupling and realign column.
D. Replace or repair steering shaft and realign column.
E. Horn contact ring not lubricated.
E. Lubricate with lubriplate.
F. Lack of grease on bearings or bearing surfaces.
F. Lubricate bearings.
G. Lower shaft bearing tight or frozen.
G. Replace bearing. Check shaft and replace if scored.
H. Upper shaft tight or frozen.
H. Replace housing assembly.
I.
Shaft lock plate cover loose.
J.
Lock plate snap ring not seated.
Tighten three screws or, if missing, replace.
CAUTION: Use specified screws. (15 in. lbs.)
J. Replace snap ring. Check for proper seating in groove.
I.
K. Defective buzzer dog cam on lock cylinder.
K. Replace lock cylinder.
L. One click when in “off-lock” position and the steering
wheel is moved.
L. Normal condition - lock bolt is seating.
Fig. 3B-7--Autom atic Transm ission Column Diagnosis
H IG H S T E E R IN G S H A F T E F F O R T
Cause
Solution
A. Column assembly misaligned in vehicle.
A. Realign.
B. Improperly installed or deformed dust seal.
B. Remove and replace.
C. Tight or frozen upper or lower bearing.
C. Replace affected bearing or bearings.
D. Flash on l.D. of shift tube from plastic joint.
D. Replace shift tube.
H IG H S H IF T E F F O R T
Cause
Solution
A. Column not aligned correctly in car.
A. Realign.
B. Improperly installed dust seal.
B. Remove and replace.
C. Lack of grease on seal or bearing areas.
C. Lubricate bearings and seals.
D. Burr on upper or lower end of shift tube.
D. Remove burr.
E. Lower bowl bearing n o t assembled properly (tilt).
E. Reassemble properly.
F. Wave washer w ith burrs (tilt only).
F. Replace wave washer.
IM PR O PER T R A N S M IS S IO N S H IF T IN G
Cause
Solution
A. Sheared shift tube joint.
A. Replace shift tube assembly.
B. Improper transmission linkage adjustment.
B. Readjust linkage.
C. Loose lower shift lever.
C. Replace shift tube assembly.
D. Improper gate plate.
D. Replace with correct part.
E. Sheared lower shift lever weld.
E. Replace tube assembly.
LASH IN M O U N T E D C O L U M N A SS E M B LY
Cause
Solution
A. Instrument panel mounting bolts loose.
A. Tighten to specifications. (20 ft. lbs.)
B. Broken weld nuts on jacket.
B. Replace jacket assembly.
C. Instrument panel bracket capsule sheared.
C. Replace bracket assembly.
D. Instrument panel to jacket mounting bolts loose.
D. Tighten to specifications. (15 ft. lbs.)
E. Loose shoes in housing (tilt only).
E. Replace.
F. Loose tilt head pivot pins (tilt only).
F. Replace.
G. Loose shoe lock pin in support (tilt only).
G.
Replace.
M IS C E L L A N E O U S
Cause
Solution
A. Housing loose on jacket - will be noticed with ignition in
"Off-Lock" and a torque applied to the steering wheel.
A. Tighten four mounting screws - (60 in. lbs.)
B. Shroud loose on shift bowl.
B. Bend tabs on shroud over lugs on bowl.
M A N U A L T R A N S M IS S IO N C O LU M N S
GENERAL INFORMATION
All of the preceding diagnosis information for automatic transmission will apply to the manual transmission. The following
information is supplied in addition to and specifically for manual transmission columns.
D R IV E R C AN LO C K S T E E R IN G
IN
SEC O N D G E A R
Cause
Solution
A. Defective upper shift lever.
A. Replace shift lever.
B.
Defective shift lever gate.
B.
Replace shift lever gate.
C. Loose relay lever on shift tube.
C. Replace shift tube assembly.
D. Use of upper shift lever prior to 1969 model year.
D. Replace with current lever.
H IG H S H IF T E F F O R T
Cause
Solution
A. Column not aligned correctly in car.
A. Realign column.
B.
Lower bowl bearing not assembled correctly.
B.
Reassemble correctly.
C. Improperly installed seal
C. Remove and replace.
D. Wave washer in lower bowl bearing defective.
D. Replace wave washer.
E. Improper adjustment of lower shift levers.
E. Readjust (see Sec. 7).
F. Lack of grease on seal, bearing areas or levers.
F. Lubricate seal, levers and bearings.
G. Damaged shift tube in bearing areas.
G. Replace shift tube assembly.
IM PR O PER T R A N S M IS S IO N S H IF T IN G
Cause
Solution
A. Loose relay lever on shift tube.
A. Replace shift tube assembly.
T IL T C O L U M N S
GEN ERAL INFORMATION
A ll o f the precedin g diagnosis w ill generally apply to tilt colum ns. T h e fo llo w in g is supplied in a d d ition to and
sp ecifically fo r tilt colum ns.
H O U S IN G S C R APPIN G ON BOWL
Cause
Solution
A. Bowl bent or not concentric with hub.
A. Replace bowl.
S T E E R IN G W H EE L LOOSE
Cause
Solution
A. Excessive clearance between holes in support or housing
and pivot pin diameters.
A. Replace either or both.
B. Defective or missing anti-lash spring in spheres.
B. Add spring or replace both.
C. Upper bearing seat not seating in bearing.
C. Replace both.
D. Upper bearing inner race seat missing.
D. Install seat.
F. Loose support screws.
F. Tighten to 60 in. lbs.
G. Bearing preload spring missing or broken.
G. Replace preload spring.
S T E E R IN G W H EE L LOOSE E V E R Y O T H E R
T IL T P O S ITIO N
Cause
Solution
A. Loose tit between shoe and shoe pivot pin.
A. Replace both.
NO ISE W H EN T IL T IN G
COLUM N
Cause
Solution
A. Upper tilt bumper worn.
A. Replace tilt bumper.
B. Tilt spring rubbing in housing.
B. Lubricate.
S T E E R IN G C O L U M N N O T L O C K IN G
A N Y T IL T P O S IT IO N
IN
Cause
Solution
A. Shoe seized on its pivot pin. ivot pin.
A. Replace shoe and-pivot pin.
B. Shoe grooves may have burrs or dirt.
B. Replace shoe.
C. Shoe lock spring weak or broken.
C. Replace lock spring.
S T E E R IN G W H E E L F A IL S T O R E T U R N
TO TOP T IL T P O S IT IO N
Cause
Solution
A. Pivot pins are bound up.
A. Replace pivot pins.
B. Wheel tilt spring is defective.
B. Replace tilt spring.
C.
Turn signal switch wires too tight.
C. Reposition wires.
F ig.-3B -11-S teering Colum n Electrical Analyzer
J -23980
Fig. 3B 12- Checking Fuses on Fuse Block
connector on the column and plug the harness from
J-23980 into the vehicle chassis harness. The "A ", "B",
and " C " term inals on the tester will overhang the chassis
connector. This does not affect the test results. These
terminals are for vehicles with cornering lights. Connect
the single black ju m p e r to a good ground. The tester is
now ready for use (Fig. 3B -11).
T U R N S IG N A L D IA G N O S IS C AN D K
SERIES
W hen a complaint is m ade involving the turn signal
system, it must first be determ ined w hether the problem
is mechanical o r electrical. If mechanical, the switch
itself is at fault and must be repaired or replaced. If
electrical, J-23980 should be used to determine whether
the switch, or the chassis wiring is in need of rep air or
replacement.
This diagnostic procedure has been designed to
guide the mechanic through the proper diagnosis and
re p air of the turn signal system. The service section is to
be used where assembly a n d / o r disassembly procedures
are required. The wiring diagram , found in Section 12,
should be used to trouble shoot the chassis and body
wiring after the problem has been isolated.
The nature o f the customer complaint will generally
point to the problem area.
Fig. 3 B -1 3 -Checking Harm onica Connector on
Column
Electrical
Chassis Electrical
The most common turn signal system problems are
generally electrical and may easily, be fixed by
the replacement of fuses, bulbs or flashers
in both directions. If the lever does not return to the
neutral position, disassemble the upper p art o f the
column until the switch is visible.
2. Check the return from lane change by holding
the lever in lane change and releasing (both left and
right). If the lever does not return to neutral, disassemble
the upper part o f the column.
3. If the hazard w arning button cannot
depressed or released, the switch must be replaced.
be
Switch Visual Inspection
1. With the upper part of the column disassembled
so that the signal switch is visible (Figure 3B-15) check
for missing springs. Replace any spring that is missing,
inspecting the molded pins which secure them. If these
pins are broken, the switch must be replaced.
2. Check the position o f the switch in the bowl. If
it appears cocked or crooked, loosen the securing screws
(3) and visually inspect the switch. If any o f the plastic is
broken or badly deform ed, the switch must be replaced.
Fig. 3B -14-C hecking Hazard W arning Flasher
First make these checks and replace any non
operative components.
3. If the switch appears undam aged, replace it
being careful to seat the pilot into the housing, tighten
the screws to 25 lbs. in. o f torque.
POWER STE ER IN G SYSTEM DIA G N O S IS
1. Check fu se s(F ig u re 3B-12). Replace if blown. If
new fuse blows, replace flasher in system. (There are 2
flashers in the signal switch system. The hazard w arning
flasher and turn signal flasher are located on the fuse
block.
2. Check for secure connection at the chassis to
switch connector. This is the harm onica connector on the
column (Figure 3B-13). Secure if loose. Check all
individual wire terminals for proper seating in the
connector bodies. Term inals should be locked in place.
3. Depress hazard w arn in g button and check all
lights in signal swritch system. Replace any which do not
work. If all lamps light w hen hazard w arning is
depressed, but flashing does not occur, replace hazard
w a rning flasher. (On fuse block) (Figure 3B-14).
4. If all directional lamps light w hen lane change
or turn indicator is actuated, but no flashing occurs,
replace the turn signal flasher.
T he above four steps will, in most cases, cure the
com m on signal switch system troubles. If the system is
still not operating correctly, use J-23980 to determine
w h e th e r the chassis wiring or the signal switch itself is at
fault.
Complaints of faulty steering are frequently the
result o f problems other than the steering gear or pump.
Those areas o f the steering system which can be easily
checked and quickly corrected without disassembly and
overhaul of any m ajor components should be attempted
first.
Conditions such as hard or loose steering, road
shock or vibrations are not always due to the steering
gear or pump, but are often related instead to such
factors low tire pressure and front end alignment. These
factors should be checked and corrected before any
M echanical
1.
If the c u sto m e r’s c o m p la in t indicates the
problem is in the switch, function check as to return
from full left an d full right turns.
Actuate the turn lever into a full turn position in
e ither direction, then turn the steering wheel (motor
on - power steering) at least 1/4 turn in the
direction indicated and then back to center. Do this
LANE
CHANGE
RETURN S P R IN G
SIGNAL SWITCH DIAGNOSIS
C O N D ITIO N
T u rn signal w ill not cancel
POSSIBLE CAUSE
A.
B.
C.
D.
T u rn signal d iffic u lt
to operate
R eposition o r replace
springs as required
D.
A djust switch position
1. If interference is
correct and switch
w ill still not cancel,
replace switch.
2. If interference
cannot be corrected
by switch
adjustm ent, replace
cancelling cam.
T ig h ten m ou n ting
screw (1 2 in-lb)
Replace switch
B.
Y o k e broken or
distorted
Loose o r misplaced
springs
Foreign parts
a n d /o r materials
S w itch m ounted
loosely
B.
A.
B.
C.
Broken lane change
pressure pad or
spring hanger
B roken, missing or
misplaced lane change
spring
Jamm ed base o r wires
T ig h ten to specified
to rq u e (2 5 in-lbs)
Replace switch
C.
A.
E.
Hazard switch cannot
be tu rn ed o ff
B.
A c tu a to r rod loose
D.
T u rn signal w ill not stay
in tu rn position
A.
A.
C.
T u rn signal w ill not
indicate lane change
Loose switch
m ounting screws
Sw itch or anchor
bosses broken
B roken, missing or o ut
o f position d ete n t, retu rn
or cancelling spring
U neven o r incorrect
cancelling cam to
cancelling spring
interference.
( .1 2 0)/sid e
CORRECTION
C.
D.
E.
R eposition or replace
springs
Remove foreign parts
a n d /o r m aterial
T ig h ten m ou n ting
screws ( 2 5 in-lbs)
A.
Replace switch
B.
Replace o r reposition
as required
C.
Loosen m ou n ting
screws, reposition
base o r wires and
retighten screws(2 5 in-lbs)
A.
Foreign m aterial or
loose parts impeding
m ovem ent o f yo k e
A.
Remove m aterial
a n d /o r parts
B.
Broken or missing
detent or cancelling springs
B.
Replace spring
C.
N one o f th e above
C.
Replace switch
A.
Foreign m aterial
between hazard
support cancelling
leg and yoke
A.
Remove foreign m aterial
1. No foreign m aterial
im peding fu n c tio n
o f hazard switch
— replace tu rn
signal switch
SIGNAL SWITCH DIAGNOSIS
C O N D ITIO N
Hazard switch w ill not
stay on o r d iffic u lt
to tu rn o ff
No tu rn signal lights
POSSIBLE CAUSE
A.
B.
C.
Loose switch
m ounting screws
In terference w ith
other com ponents
Foreign m aterial
D.
None o f th e above
D.
A.
D efective or
b lo w n fuse
In o p erative tu rn signal
flasher
Loose chassis to
colum n connector
Disconnect colum n
to chassis connector.
C onnect new switch
to chassis and
operate switch by
hand.
If vehicle lights now
operate n o rm a lly ,
signal switch is
inoperative
If vehicle lights do
not operate check
chassis w irin g fo r
opens, grounds, etc.
A.
B.
B.
C.
D.
E.
T u rn indicator lights
on, but not flashing
CORRECTION
A.
B.
C.
D.
E.
In o p erative turn
.flasher
Loose chassis to
colum n connection
In o p erative tu rn
signal switch
T o determ in e if tu rn
signal switch is
defective, substitute
new switch into
circu it and operate
switch by hand.
If th e vehicle’s lights
operate n o rm ally,
signal switch is
inoperative
If th e vehicle's lights
do not operate,
check light sockets
fo r high resistance
connections, the
chassis w irin g fo r
opens, grounds, etc.
A.
C.
B.
C.
D.
T ighten m ou n ting
screws (2 5 in-lbs)
Remove interference
Remove foreign
m aterial
Replace switch
Replace fuse and
check operation
Replace tu rn signal
flasher
Connect securely,
check operation
Replace signal switch
E.
Repair chassis w irin g
as required using
manual as guide
A.
Replace tu rn flasher
N ote: Th ere are tw o
flashers in th e system.
Consult manual fo r location.
Connect securely
and check operation
Replace tu rn signal
switch
Replace signal switch
B.
C.
D.
E.
Repair chassis w iring
as required using
manual as guide
SIGNAL SWITCH DIAGNOSIS
C O N D ITIO N
F ro n t o r rear tu rn signal
lights not flashing
A.
Burned o u t fuse
A.
B.
Burned o u t or
damaged tu rn signal
bulb
High resistance
connection to ground
at bulb socket
Loose chassis to
colum n connector
Disconnect colum n to
chassis connector.
C onnect new switch
into system and
operate switch
by hand.
If tu rn signal lights
are now on and
flash, tu rn signal
switch is inoperative.
If vehicle lights do
not operate, check
chassis w iring harness
to light sockets fo r
opens, grounds, etc.
B.
C.
D.
E.
F.
Stop light not on when
tu rn indicated
C.
D.
E.
Replace fuse and
check operation
Connect securely and
check op eratio n
Replace signal switch
A.
B.
Loose colum n to
chassis connection
Disconnect colum n to
chassis connector.
C onnect new switch
into system w ith o u t
rem oving old. O perate
switch by hand.
If brake lights w o rk
w ith switch in th e
tu rn position, signal
switch is defective
If brake lights do not
w o rk check connector
to stop light sockets
fo r grounds, opens,
etc.
B.
A.
B.
C.
Burned o u t bulbs
High resistance to
ground at bulb socket
Opens, grounds in
w irin g harness fro m
fro n t tu rn signal bulb
socket to indicator
I ights
Remove o r repair
defective connection
and check o p eration
Connect securely and
check operation
Replace tu rn signal
switch.
Repair chassis w irin g
as required using
manual as guide
Burned o u t fuse
D.
Replace fuse and
check o p eratio n
Replace bulb
F.
A.
C.
T u rn indicator panel
lights n ot flashing
CORRECTION
POSSIBLE CAUSE
C.
D.
Repair connector to
stop light circuits
using manual as guide.
A.
B.
Replace bulbs
Replace socket
C.
Locate and repair as
required. Use shop
manual as guide.
S IG N A L S W IT C H D IA G N O S IS
C O N D IT IO N
T u rn signal lights flash
very slow ly
A.
B.
C.
D.
E.
F.
Hazard signal lights w ill
not flash — tu rn signal
functions no rm ally
C O R R E C T IO N
P O S S IB L E C A U S E
Inoperative tu rn
signal flasher
System charging
voltage low
High resistance ground
at light sockets
A.
Loose chassis to
colum n connection
Disconnect colum n
to chassis connector.
Connect new switch
into system w ith o u t
rem oving o ld . O perate
switch by hand.
If flashing occurs
at normal rate, th e
signal switch is
defective.
If th e flashing rate is
still e xtrem ely slow,
check chassis w irin g
harness fro m the
connector to light
sockets fo r grounds,
high resistance points,
etc.
D.
B.
C.
E.
F.
A.
B low n fuse
A.
B.
Inoperative hazard
w arning flasher
Loose chassis to
colum n connection
Disconnect c o lu m n to
chassis connector.
C onnect new switch
into system w ith o u t
rem oving o ld . Depress
the hazard w arning
b u tto n and observe
th e hazard w arning
lights. If th e y now
w o rk n o rm a lly , th e
tu rn signal switch
is defective.
If the lights do n ot
flash, check w irin g
harness " K " lead
(brow n ) for open
between hazard
flasher and harm onica
connector. If open,
fuse block is defective.
B.
C.
D.
E.
C.
D.
E.
Replace tu rn signal
flasher
I ncrease voltage to
specified. See Sec. 6 Y
Repair high resistance
grounds at light
sockets
C onnect securely and
check operation
Replace signal switch
Locate and repair
as required.
Use manual as guide.
See Section 12
Replace fuse and
check operation
Replace hazard
w arning flasher
Connect securely and
check operation
Replace the tu rn
signal switch
Replace fuse block
(See Sec. 12)
adjustm ent or disassembly o f the power steering gear or
p u m p is attem pted.
System Checks
M any factors affect power operation o f the steering
system, o f which the most com m on are:
1. Fluid level and condition.
2. Drive belt tension.
3. Loose c om ponent mountings.
4. Loose p u m p pulley.
These factors must be checked and corrected before
m aking any further diagnosis o f the steering system. The
need for proper diagnosis cannot be over-emphasized.
A fter the source o f the problem has been found,
determ ine the cause. For example, if the oil level in the
reservoir is found to be low, refill and check the entire
hydraulic system for oil leaks. Refilling the reservoir will
not necessarily correct problem.
Fluid Level
1. R un engine to norm al operating temperature,
then shut engine off. Remove reservoir filler cap and
check oil level to " h o t" m ark on dipstick.
2. If oil level is low, add hydraulic fluid to proper
level on dipstick and replace filler cap.
N OTE: W hen a dd in g or making a complete fluid
change, always use G M power steering fluid or
equivalent.
3. W hen checking fluid level after the steering
system has been serviced, air must be bled from the
system. Proceed as follows:
a. W ith wheels turned all the w ay to the left,
add power steering fluid to "C o ld " mark on dipstick.
b. Start engine, and run ning at fast idle, recheck
fluid level. Add fluid if necessary to "C old" m ark on
dipstick.
c. Bleed system by turning wheels from side to
side without hitting stops. M aintain fluid level just above
internal p u m p casting. Fluid with air in it will have a
light tan or red appearance. This air must be eliminated
from fluid before norm al steering action can be
obtained.
d. Return wheels to center position and continue
to run engine for two or three minutes, then shut engine
off.
e. Road test car to m ake sure steering functions
normally and is free from noise.
f. Recheck fluid level as described in steps 1 and
2, m aking sure fluid level is at " h o t" m ark on dipstick
after the system has stabilized at its normal operating
tem perature approximately 170° to 190°F.
B elt Adjustm ent
W hen adjusting a power steering p u m p belt, never
pry against the pu m p reservoir or pull against the filler
neck. To increase belt tension move the pu m p outward
by prying against the p u m p housing casting extension
directly behind the pum p drive pulley.
A belt that has been previously tensioned is
considered to be a used belt and should be tightened to
75 pounds. A belt that has never been tensioned is
considered to be a new belt and should be tightened to
125 pounds.
Place belt tension gage, J-23600 or equivalent
midway between the pulleys on drive belt being checked.
If the belt tension is incorrect proceed as follows:
1. W hen power steering pum p is driven by a single
belt:
a. Loosen the p u m p attaching bolts and adjust
the belt to correct tension by moving the pu m p outward,
away from the engine.
b. Snug all pu m p mounting bolts and remove
pry bar.
c. Tighten all pum p mounting bolts to specified
torque.
d. Check belt tension and remove the belt
tension gage.
Hydraulic System Checks
The following p rocedure outlines m ethods to
identify and isolate power steering hydraulic circuit
difficulties. The test provides means o f determ ining
whether power steering system hydraulic parts are
actually faulty. This test will result in readings indicating
faulty hydraulic operation, and will help to identify the
faulty component.
Before perform ing hydraulic circuit test, carefully
check belt tension, fluid level and condition o f driving
pulley.
Power Steering Hydraulic System Test
Engine must be at normal operating temperature.
Inflate front tires to correct pressure. All tests are made
with engine idling, check idle adjustment and if
necessary adjust engine idle speed to correct specifica
tions listed in Section 6C and proceed as follows:
1. With engine N O T running disconnect pressure
hose from pum p and install Tool J-5176 using a spare
pressure hose between gauge and pump. G au ge must be
between shut-off valve and pump. Open shut-off valve.
2. Remove filler cap from pum p reservoir and
check fluid level. Fill p u m p reservoir to full mark on
dipstick. Start engine and, m omentarily holding steering
wheel against stop, check connections at Tool J-5176 for
leakage.
3. Bleed system as outlined under M aintenance
and Adjustments.
4. Insert therm om eter (Tool J-5421) in reservoir
filler opening. Move steering wheel from stop to stop
several times until therm om eter indicates that hydraulic
fluid in reservoir has reached tem perature of 150° to
170°F.
CAUTION: To prevent scrubbing fla t spots on
tires, do not turn steering wheel more than fiv e
times without rolling vehicle to change tire-tofloor contact area.
5. Start engine and check fluid level adding any
fluid if required. W hen engine is at norm al operating
temperature, the initial pressure read on the gauge (valve
open) should be in the 80-125 PSI range. Should this
CONDITION
POSSIBLE CAUSE
CORRECTION
SYSTEM NOISE
There is some noise in all power
steering systems.
Common complaints are listed as
follows:
Pump noise-“chirp” .
Loose belt.
Adjust belt tension to specification.
Belt squeal.
Loose belt.
Adjust belt tension to specification.
Gear noise ( “ hissing” sound)
There is some noise in all power steer
ing systems. One of the most common
is a hissing sound most evident at
standstill parking. There is no relation
ship between this noise and perfor
mance of the steering. “ Hiss” may be
expected when steering wheel is at end
of travel or when slowly turning at
standstill.
Do not replace valve unless “ hiss” is
extremely objectionable. Slight “ hiss”
is normal and in no way affects steer
ing. A replacement valve will also exhi
bit slight noise and is not always a cure
for the objection. Investigate clearance
around flexible coupling rivets. Be
sure steering shaft arid gear are aligned
so flexible coupling rotates in a flat
plane and is not distorted as shaft ro
tates. Any metal-to-metal contacts
through flexible coupling will transmit
“hiss" into passenger compartment.
Rattle.
Pressure hose touching other parts of
car.
Adjust hose position.
Loose pump pulley nut
Replace nut, torque to specs.
Pump vanes not installed properly.
Install properly.
Pump vanes sticking in rotor slots.
Free up by removing burrs, varnish or
dirt.
Improper over-center adjustment
Adjust to specifications.
Gear noise (rattle or chuckle).
NOTE: A slight rattle may occur on
turns because of increased clearance
off the “ high point” . This is normal
and clearance must not be reduced
below specified limits to eliminate this
slight rattle.
Loose pitman arm.
Tighten to specifications
Gear loose on frame.
Check gear-to-frame mounting bolts.
Tighten bolts to 70 foot-pounds.
Rattle or chuckle.
Steering linkage looseness.
Check linkage pivot points for wear.
Replace if necessary.
Groan.
Low oil level.
Fill reservoir to proper level.
Groan.
Air in the oil. Poor pressure hose
connection.
Bleed system by operating steering
from right to left full turn.
Check connections, torque to specs.
Growl.
Excessive back pressure caused by
hoses or steering gear, (restriction)
Locate restriction and correct. Replace
part if necessary.
CONDITION
POSSIBLE CAUSE
CORRECTION
Scored pump pressure plates, thrust
plate or rotor.
Replace affected parts, flush system.
Extreme wear of pump cam ring.
Replace affected parts.
Swish in pump
Defective pump flow control valve
Replace valve
Whine in pump
Pump shaft bearing scored.
Replace housing and shaft, flush system
Squawk in gear (not belt)
Dampener “0 ” ring on valve spool cut
Replace “0 ” ring.
Pump growl
Note: Most noticeable at full
wheel travel and stand still parking
SYSTEM OPERATION
Excessive wheel kick-back or loose
steering.
Poor return of steering.
Backlash in steering linkage.
Adjust parts affected or replace worn
parts.
Air in system.
Add oil to pump reservoir and bleed by
operating steering. Check all connections.
Excessive “ over-center” lash.
Adjust to specification.
Loose thrust bearing preload adjust
ment.
Adjust to specification.
Worn poppet valve (Gear)
Replace poppet valve.
Steering gear loose on frame.
Tighten attaching bolts to 70 foot
pounds.
Steering gear flexible coupling too
loose on shaft or rubber disc mounting
screws loose.
Tighten flange pinch bolts to 30 foot
pounds, if serrations are not damaged.
Tighten upper flange to coupling nuts
to 20 foot-pounds.
Steering linkage ball studs worn
enough to be loose.
Replace loose components.
Front wheel bearings incorrectly ad
justed or worn.
Adjust bearings or replace with new
parts as necessary.
Tires under-inflated.
Inflate to specified pressure.
Lower coupling flange rubbing against
steering gear adjuster plug.
Loosen pinch bolt and assemble prop
erly.
Steering wheel rubbing against direc
tional signal housing.
Adjust steering jacket.
Tight or frozen steering shaft bearings.
Replace bearings.
Steering linkage or ball joints binding.
Replace affected parts.
Steering gear to column misalignment.
Align steering column.
Tie rod pivots not centralized.
Adjust tie rod ends as required to
center pivots.
Lack of lubricant in suspension ball
joints and steering linkage
Lubricate and relubricate at proper
intervals
CONDITION
Poor return of steering. (Cont’d.)
Car leads to one side or the other.
(Keep in mind road condition and
wind. Test car on flat road going in
both directions)
POSSIBLE CAUSE
CORRECTION
Steering gear adjustments over
specifications.
Check adjustment with pitman arm
disconnected. Readjust if necessary.
Sticky or plugged valve spool.
Remove and clean or replace valve.
Rubber spacer binding in shift tube.
Make certain spacer is properly seated.
Lubricate inside diameter with sili
cone lubricant.
Improper front suspension alignment.
Check and adjust to specifications.
Tight steering shaft bearings.
Replace bearings.
Front suspension misaligned
Adjust to specifications.
Steering shaft rubbing ID of shift tube.
Align column.
Unbalanced or badly worn steering
gear valve.
Replace valve.
NOTE: If this is cause, steering effort
will be very light in direction of lead
and heavy in opposite direction.
Steering wheel surges or jerks when
turning with engine running especially
during parking.
Momentary increase in effort when
turning wheel fast to right or left.
Hard steering or lack of assist.
Steering linkage not level.
Adjust as required.
Low oil level in pump.
Check oil level, add as necessary.
Loose pump belt.
Adjust tension to specification.
Sticky How control valve.
Inspect for varnish or damage, replace
if necessary.
Insufficient pump pressure.
Check pump pressure. (See pump
pressure test). Replace relief valve if
defective.
Steering linkage hitting engine oil pan
at full turn.
Correct clearance.
Pump belt slipping.
Tighten or replace belt.
Low oil level in pump.
Check oil level, add as necessary.
High internal leakage.
Check pump pressure (Test)
High internal leakage. (Gear or pump)
Check pump
pressure test).
Loose pump belt.
Adjust belt tension to specification.
Low oil level in reservoir.
Fill to proper level. If excessively low,
check all lines and joints for evidence
of external leakage, torque to specs.
pressure. (See pump
CONDITION
Hard Steering or
lack of assist (Continued)
Low oil pressure due to restriction in
hoses:
Low oil pressure due to steering gear:
(See pump pressure test)
POSSIBLE CAUSE
CORRECTION
Lack of lubricant in suspension
or ball joints.
Lubricate, relubricate at proper
intervals.
Tires not properly inflated.
Inflate to recommended pressure.
Steering gear to column misalignment.
Align steering column.
Steering gear adjusted too tight.
Test steering system for binding with
front wheels off floor. Adjust as neces
sary.
Excessive friction in steering linkage.
Check tie rod pivot points for exces
sive friction. Replace the affected
pivot.
Lower coupling flange rubbing
against steering gear adjuster plug.
Loosen pinch bolt and assemble
properly.
Sticky flow control valve.
Replace or clean valve.
Frame bent.
Check frame for proper alignment or
cracking. Repair or replace as neces
sary.
Front springs weak and sagging.
Check standing height. Weak or sag
ging springs should be replaced with
new ones.
Insufficient oil pressure.
If above checks do not reveal cause of
hard steering, diagnose hydraulic
system to determine problem.
Check for kinks in hoses.
Remove kink.
Foreign object stuck in hose.
Remove hoses and remove restricting
object or replace hose.
Pressure loss in cylinder due to
worn piston ring or scored housing
bore.
Remove gear from car for disassembly
and inspection of ring and housing
bore. Replace affected parts.
Leakage at valve rings, valve body
to worm seal.
Remove gear from car for disassembly
and replace seals.
Loose fit of spool in valve body or
leaky valve body.
Replace valve.
Damaged poppet valve.
Replace valve.
POSSIBLE CAUSE
CONDITION
Low oil
pump:
pressure
due
to steering
CORRECTION
Loose belt.
Adjust tension to specification
Low oil level.
Fill reservoir to proper level.
Air in the oil.
Locate source of leak and correct.
Bleed system.
Defective hoses or steering gear.
Correct as necessary.
Flow control valve stuck or inopera
tive.
Remove burrs or dirt or replace.
Loose screw in end of flow control
valve.
Tighten.
Cracked or broken thrust or pressure
plate.
Replace part.
Pressure plate not
ring.
Replace pressure plate.
(See pump pressure test.)
Note:
flat against cam
Steering system externa! leakage
Foaming milky power steering
fluid, low level and possible
low pressure.
Extreme wear of cam ring.
Replace parts, flush system
Scored pressure plate, thrust plate or
rotor.
Replace parts. (If rotor, replace with
rotating group kit), flush system
Vanes not installed properly.
Install properly. Radius edge to outside.
Vanes sticking in rotor slots.
Free-up by removing burrs, varnish or
dirt.
Air in the fluid, and loss of
fluid due to internal pump
leakage causing overflow.
Check for leak and correct. Bleed
system. Extremely cold temperatures
will cause system aeriation should
the oil level be low. If oil level
is correct and pump still foams,
remove pump from vehicle and
separate reservoir from housing.
Check welsh plug and housing for
cracks. If plug is loose or housing
is cracked, replace housing.
Fig. 3B-24~Power Steering System Diagnosis
A HIGH PRESSURE HOSE FROM PUMP
B ADDITIONAL HIGH PRESSURE P/S
HOSE TO GEAR
C TOOL J-5176
Fig. 3B-25-C hecking Power Steering Pressures
pressure be in excess o f 200 PSI - check the hoses for
restrictions and the poppet valve for proper assembly.
6. Close gate valve fully 3 times. Record the
highest pressures attained each time.
C A U TIO N : Do not leave valve fully closed for
m ore than 5 seconds as th e pump could be
damaged internally.
4. Check hose connections - tighten if necessary.
5. Verify exact point o f leakage.
Example:Torsion bar, stub shaft and adjuster seals
are close together; exact leakage point could be confused.
Example: The point oil drips from is not necessarily
the leakage point - oil overflowing from reservoir for
instance.
6. W h en service is required:
A. Clean leakage area upon disassembly.
B. Replace leaking seal.
C. Check c o m pon e nt sealing surfaces for
damage.
D. Reset bolt torque to specifications where
required.
Some o f the customer complaints associated with the
power steering system may be reported as:
1. Oil leakage on garage floor.
2. Oil leaks visible on steering gear, pump, or
anywhere else on the left side of engine compartment.
3. Growling noise especially when parking or when
engine is cold.
4. Loss of power when parking.
5. Heavy steering effort.
For the purpose o f trouble shooting complaints o f
this nature, assume that there is an external leak in the
power steering system.
Leakage Diagnosis (Fig. 3 B -2 6)
a. If the pressures recorded are within the listed
specs and the range of readings are within 50 PSI, the
This section is a guide, which when used in
p u m p is functioning within specs. (E X . Spec. 900 - 1500
conjunction
with your service m anual will enable you, a
PSI - readings - 1270 - 1275 - 1280).
service
mechanic,
to locate, identify, and repair leaks in
b. If the pressures recorded are high, but do not
the power steering system. It contains:
repeat w ithin 50 PSI, the flow controlling valve is
A. D iagram o f the complete power steering system
sticking. Remove the valve, clean it and remove any
with
the areas of potential leakage identified.
burrs using crocus cloth or fine hone. If the system
B.
Recommended procedure for locating external
contains some dirt, flush it. If it is exceptionally dirty,
leakage in the vehicle.
both the pum p and the gear must be completely
C. Areas o f leakage to be checked, which can be
disassembled, cleaned, flushed and reassembled before
serviced
at once.
further usage.
D.
Part replacement recommendations.
c. If the pressures recorded are constant, but
E. D iagram o f the actual areas where leakage will
more than 100 PSI, below the low listed spec., replace the
be observed and the action recommended to repair this
flow control valve and recheck. If the pressures are still
leakage.
low, replace the rotating group in the pump.
7 If the pu m p checks within specifications, leave
Leakage Check
the valve open an d turn (or have turned) the steering
The purpose o f the diagnostic procedure is to pin
wheel into both corners. Record the highest pressures
point the location o f the leak. The method outlined in
and com pare w ith the m axim um pu m p pressure
this m anual can be followed to locate the leak and repair
recorded. If this pressure cannot be built in either (or
one) side o f the gear, the gear is leaking internally and
In some cases you will be able to locate the leak
must be disassembled an d repaired. See the current
easily. However, seepage type leaks may be more difficult
Overhaul Manual.
to isolate. For seepage leaks, the following method is
8.
Shut off engine, remove testing gauge, spare
recommended.
hose, reconnect pressure hose, check fluid level a n d /o r
A. With the vehicle’s engine off, wipe the complete
make needed repairs.
power steering system dry (gear, pump, hoses, and
connections).
Pow er Steering System External Leakage
B. Check oil level in p u m p ’s reservoir and adjust
General Procedure
as directed in m aintenance section.
1. W ipe suspected area dry.
C. Start engine and turn steering wheel from stop
2. Check for overfilled reservoir.
to stop several times. D o not hold in corner for any
length o f time as this can dam age the power steering
3. Check for oil aeration and overflow.
RESERVOIR DEFECTS
RESERVOIR CAP
DRIVE SHAFT
RETURN HOSE & CLAMPS
DEFECT
RESERVOIR
" 0 " RING
ADJUSTER PLUG
"O " RING
TORSION BAR
" 0 " RING
RING &
STUD/BOLT " 0 " RINGS
PRESSURE HOSE
PRESSURE & RETURN PORTS
STUB SHAFT
SEAL
SIDE COVER " 0 " RING
ADJUSTER LOCK NUT
BALL PLUG
END COVER " 0 " RING
PITMAN SHAFT
SEAL
HOUSING DEFECT
pump. It is easier if someone else operates the steering
wheel while you search for the seepage.
Housing or Cover Seepage - Both the power steering
gear and pu m p assemblies are leakage checked before
D. Find the exact area of leakage.
E. Refer to the diagnostic chart
recom m ended method of repair.
shipment. However, occasionally oil seepage m ay occur
from the gear or pum p other than the seal areas. If this
type of leakage is found, replace the leaking part.
The following diagram s have been prepared to show
the potential areas o f leakage. If leakage occurs in the
zones shown, replace the part listed using the service
manual as a guide.
to
find
the
Quick Fixes
The purpose o f this section is to acquaint you with
the types o f leakage which can be repaired very easily. It
contains inform ation on reservoir oil level, the hoses and
the hose connections.
An overfilled pu m p reservoir can be a cause for
leakage complaint. The oil in the steering system
expands as heated during norm al usage. If overfilled the
excess is forced thhrough the b reath er cap hole and may
be sprayed over the engine by air blast. O perate the
engine and steering system until normal operating
tem perature is obtained. Remove the reservoir cap and
check the graduated level on the dipstick. Adjust the oil
level as required.
Seepage at the hose connections can be a cause for
leakage com plaint and can be due to loose connection
nuts. If leakage is observed at the hose connections, and
the nut is not cross threaded, tighten the nuts at the gear
to 30 foot pounds.
The nut at the power steering pu m p should be
tightened to 40 foot pounds. If tightening to this torque
does not stop the leak, refer to the diagnostic chart.
If either the return hose or the pressure hose leaks,
replace the hose.
Component Replacement
Lip seals, which seal rotating shafts, require special
treatm ent. This type of seal is used on the steering gear
at the p itm a n shaft, at the stud shaft, and on the drive
shaft o f the pump. W hen leakage occurs in one o f these
areas, always replace the seal(s), after inspecting and
thoroughly cleaning the sealing surfaces. Replace the
shaft only if very severe pitting is found. If the corrosion
in the lip seal contact zone is slight, clean the surface of
the shaft with crocus cloth. Replace the shaft only if the
leakage can no t be stopped by smoothing with crocus
cloth first.
Steering Gear Leakage Diagrams (Fig. 3B -27)
Pay particular attention to the exact source of
leakage as an im proper diagnosis will result in an
ineffective repair.
1. Replace adjuster plug " O " R IN G SEAL.
2. Replace dust and stub shaft seals. Refer to
above on stub shaft seal ride.
3. Replace rotary valve assembly.
4. Seat ball flush with punch and restake. If
seepage persists, replace housing.
5. Replace both pitman shaft seals. Refer to above
on seal ride area o f p itm an shaft.
6. Replace end plug " O " ring seal.
7. Tighten nut to 35 pounds foot. Replace nut if
leakage persists.
8. Replace side cover "O " ring seal.
9. If leakage persists upon tightening the fitting
nut (30 foot pounds), replace brass connector and reface
hose tube flare. If leakage is due to d am aged threads
(cross threaded), replace brass connector. Repair fitting
nut or replace hose as required. If housing threads are
badly stripped, replace housing.
Pump Leakage Diagrams (Fig. 3 B -28)
10. Tighten hose fitting nut to 40 pounds foot. If
leakage persists, replace discharge fitting and reface hose
tube flare or replace hose as required.
11. Tighten fitting to 35 pounds foot. If leakage
persists, replace both " O " ring seals.
12. Replace reservoir " O " ring.
13. Replace drive shaft seal. Refer to above on
seal ride area of drive shaft.
14. Replace reservoir.
15. Check oil level. If leakage persists with the
level right and the cap tight, replace the cap.
MAINTENANCE AND ADJUSTMENTS
Lubrication
The m anual steering gear is factory-filled with
steering gear lubricant. Seasonal change o f this lubricant
should not be perform ed and the housing should not be
drain e d no lubrication is required for the life of the
steering gear.
Every 36,000 miles, the m anual gear should be
inspected for seal leakage (actual solid grease - not just
oily film ) If a seal is replaced or the g ear is overhauled,
the gear housing should be refilled with 1051052 (13 oz.
container) Steering Gear Lubricant which meets GM
Specification GM 4673M , or its equivalent.
N O T E : Do not use EP Chassis Lube, which meets
G M Specification GM 6 0 3 1M, to lubricate the gear
DO NOT OVER-FILL the gear housing.
6. Turn the steering wheel gently in one direction
until stopped by the gear; then turn back on e-half turn.
CAUTION: Do not turn the steering wheel hard
against the stops when the steering linkage is
disconnected from the gear as damage to the
ball guides could result.
7. M easure and record "b e arin g d ra g " by applying
a torque wrench with a socket on the steering wheel nut
and rotating through a 90° arc (fig. 3B-30).
NOTE: Do not use a torque wrench having a
maximum torque reading o f more than 50 inch
pounds.
8. Adjust "thrust bearing p relo ad " by tightening
the adjuster plug until the proper "thrust loading
The steering linkage un der norm al conditions
should be lubricated with any w ater resistant EP
type chassis lubricant every 7,500 miles or six
months, whichever occurs first. Lubricate every
3,000 miles or two months whichever occurs first
when operating in dusty or muddy conditions or if
the vehicle is used "off-road". Lubrication points
an d additional info rm atio n on the chassis lubricant
recom m en ded can be found in Section 0—General
Info rm atio n and lubrication.
Adjustm ents
CAUTION: See Caution on page one o f this
section regarding the fasten ers referred to in
steps 9d a nd 10.
Manual Steering Gear
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fa sten er referred to in
step 10.
Before any adjustments are made to the steering
gear attem pt to correct complaints o f loose or hard
steering, or other wheel disturbances, a careful check
should be m ade of front end alignment, shock absorbers,
wheel balance and tire pressure for possible steering
system problems. See Diagnosis in sections 3A and 3B.
C orrect a d ju stm e n t o f steering g ear is very
im portant. W hile there are but two adjustmentss to be
made, the following procedure must be followed step-bystep in the orde r given.
1. Disconnect the battery ground cable.
2. Raise the vehicle.
3. R em ove the p itm a n arm nut. M a rk the
relationship o f the p itm an arm to the p itm an shaft.
Remove the pitm an arm with Tool J-6632 or J-5504 as
shown in Figure 3B-50.
4. Loosen the steering gear adjuster plug locknut
an d back the adjuster plug off 1/4 turn (fig. 3B-29).
5. Remove the horn shroud or button cap.
Fig. 3B 2 9 -Steering Gear A djustm ent Points-Typical
pre lo ad " is obtained (See specifications section). W hen
the p rop er preload has been obtained, tighten the
adjuster plug locknut to specifications and recheck
torque. If the gear feels " lu m p y " after adjustment, there
is probably dam ag e in the bearings due to severe impact
or im prop er adjustment; the gear must be disassembled
and inspected for replacem ent o f dam aged parts.
9. Adjust "over-center p re lo a d " as follows:
a. Turn the steering wheel gently from one stop
all the way to the other carefully counting the total
n u m b e r o f turns. Turn the wheel back exactly half-way,
to center position.
b. Turn the lash adjuster screw clockwise to take
out all lash between the ball nut and pitm an shaft sector
teeth and then tighten the locknut.
c. Check the torque at the steering wheel, taking
the highest read in g as the wheel is turned through center
position. See the Specifications Section for proper over
center preload.
d. If necessary, loosen locknut and readjust lash
adjuster screw to obtain pro p e r torque. Tighten the
locknut to specifications and again check torque reading
through center o f travel.
N O T E : If m axim um specification is exceeded, turn
lash adjuster screw counterclockwise, then come up
on adjustm ent by turning the adjuster in a
clockwise motion.
10. Reassemble the p itm a n arm to the p itm an
shaft, lining up the marks m ade during disassembly.
T orque the p itm a n shaft nut to sspecifications.
CAUTION: I f a clamp type pitm an arm is used,
spread the pitm an arm ju s t enough, with a
wedge, to slip the arm onto the pitm an shaft.
Do not spread the clamp more than required to
slip over pitm an shaft with hand pressure. Do
not ham m er the p itm a n arm onto the pitm an
shaft. Be sure to install the hardened steel
washer before installing the nut.
11. Install the horn button cap or shroud and
connect the battery ground cable.
12 Lower the vehicle to the floor.
S teering Gear High Point C entering
1. Set front wheels in straight ahead position. This
can be checked by driving vehicle a short distance on a
flat surface to determ ine steering wheel position at which
vehicle follows a straight path.
2. W ith fro nt wheels set straight ahead, check
position o f mark on w o rm sh aft designating steering gear
high point. This mark should be at the top side o f the
shaft at 12 o ’clock position and lined up with the mark
in the coupling lower clamp.
3. O n C, G and P series if gear has been moved off
high point w hen setting wheel in straight ahead position.
Loosen adjusting sleeve clamps on both left and right
h a nd tie rods, then turn both sleeves an equal nu m b e r of
turns in the same direction to b ring gear back on high
point.
N O T E: T urning the sleeves an unequal num ber of
turns or in different directions will disturb the toein setting o f the wheels.
4. On K series if the gear has been moved off high
point when setting wheels in straight ahead position.
Loosen adjusting sleeve clamps on the connecting rod
then turn sleeve to bring gear back on high point.
5. Readjust toe-in as outlined in Section 3A (if
necessary).
6. Be sure to properly orient sleeves an d clamps as
shown in figures 3B-104, 3B-106 and 3B-109 when
fastening and torqueing clamps to proper specifications.
Steering W heel Alignm ent
NOTE: On all series vehicles check steering gear
for high point centering before checking steering
wheel alignment.
1. Set wheels in straight ahead position by driving
vehicle a short distance.
2. Note steering wheel position. If off more than 1
inch from center (fig. 3B-31), remove steering wheel as
outlined u nder "Steering Wheel - Rem oval", center high
point on gear, reposition and reinstall the wheel.
Steering Column Lower Bearing Adjustm ent
G and P Series
1. Loosen clamp on steering shaft.
2. Applying 50 lb. force to the steering wheel end
o f the steering shaft, adjust clamp to o btain clearances
indicated in Figure 3B-32.
3. Tighten clamp bolt to specified torque.
Shifter Tube Adjustm ent G and P Series
3-Speed Transm ission
1. Loosen adjusting ring attaching screws and
clamp bolt.
2. Rotate adjusting ring to give .005" end play
between adjusting ring and first and reverse shifter lever
(fig. 3B-33).
Fig. 3B-34--Shift Tube A djustm ent-A utom atic
Transmission
Power Steering G ear Adjustm ent Procedure
Fig. 3B-32--Steering Column Lower Bearing
A djustm ent
Adjustment of the steering g ear in the vehicle is
discouraged because o f the difficulty encountered in
adjusting the worm thrust bearing preload and the
confusing effects of the hydraulic fluid in the gear. Since
a gear adjustment is m ade only as a correction and not
as a periodic adjustment, it is better to take the extra
time and make the adjustment correctly the first time.
Since a handling stability complaint can be caused
by im properly adjusted worm bearings as well as an
im proper gear over-center adjustment, it is necessary
that the steering g ear assembly be removed from the
vehicle and both thrust bearing and over-center preload
be checked and corrected as necessary. An in-vehicle
check o f the steering gear will not pin-point a thrust
bearing looseness.
Thrust Bearing Adjustment
Fig. 3B-33--Shift Tube A djustm ent-3 Speed M anual
Transm ission
3.
Tighten attaching screws and clam p bolt.
Automatic Transmission
1. Place the shift tube lever in " N e u tra l" or
"D rive ".
2. Loosen adjusting ring clam p screws and rotate
the shift tube adjusting ring to obtain .33" to .36"
clearance between the shift tube lever and adjusting ring
(fig. 3B-34).).
3. Tighten the adjusting ring clamp screws to 70 in.
lbs.
If a gear is known to contain the new thrust bearing
parts, thrust bearing adjustment in service is simplified.
Recomm ended procedure:
1. D rain power steering fluid from gear by
rotating the stub shaft full travel in both directions
several times.
2. Loosen and remove adjuster plug lock nut (Fig.
3B-35 and 3B-36).
3. Using spanner wrench J-7624, turn the adjuster
plug in (clockwise) until the plug and thrust b earing are
firmly bottomed approximately 20 foot-pounds (Fig. 3B37).
4. Mark the housing even with one o f the holes in
the face o f the adjuster plug (Fig. 3B-38).
5. Measure back (CCW direction) 1/2 inch and
place a second mark on the housing (Fig. 3B-39).
6. Turn adjuster plug counterclockwise until the
hole in the face o f the adjuster plug, which was even
Fig. 3B-37- B ottom ing Adjuster Plug
Fig. 3B-35--Loosening Lock Nut
Fig. 3B-38--M arking Housing
Pump Belt Tension
1.
Loosen pivot bolt and pum p brace adjusting
nuts.
Fig. 3B 36 -Removing Lock Nut
CAUTION: Do not move pum p by prying
with the first mark is in line with second mark (Fig. 3Bagainst
reservoir or by pulling on filler neck.
40).
2. Move pump, with belt in place until belt is
7.
Tighten lock nut securely. Hold (or have held)
tensioned to specifications as indicated by Tool J-23600
adjuster plug to maintain alignm ent of hole with mark
(Fig. 3B-42).
(Fig. 3B-41).
Fig. 3B-39-M easure Back and Remark Housing
F ig . 3 B - 4 1 --T ig h te n L o c k N u t
Fig. 3B-40 -Align Hole W ith Second M ark
3.
Tighten p u m p brace adjusting nut. Then tighten
pivot bolt nut.
Fluid Level
1. Check oil level in the reservoir by checking the
dipstick when oil is at operating temperature. O n models
e quipped with remote reservoir, the oil level should be
m a in tain ed approximately 1/2 to 1 inch from top with
wheels in full left turn position.
2. Fill, if necessary, to prop er level with G M
Power Steering Fluid or equivalent.
Fig. 3B -42-C hecking Belt Tension w ith J-23600
Bleeding Hydraulic System
1. Fill oil reservoir to pro per level and let oil
rem ain undisturbed for at least two minutes.
2.
Start engine and run only for about two seconds.
3.
Add oil if necessary.
4. Repeat above procedure until oil level remains
constant after run ning engine.
5. Raise front end o f vehicle so that wheels are off
the ground.
6. Increase engine speed to approximately 1500
rpm.
7. T urn the wheels (off ground) right and left,
lightly contacting the wheel stops.
8. Add oil if necessary.
9. Lower the vehicle and turn wheels right and left
on the ground.
10. Check oil level and refill as required.
11. If oil is extremely foamy, allow vehicle to stand
a few minutes with engine off and repeat above
procedure.
a. Check belt tightness an d check for a bent or
loose pulley. (Pulley should not wobble with engine
running.)
b. Check to make sure hoses are not touching
any other parts o f the truck, particularly sheet metal
except w here design calls for a clamp.
c. Check oil level, filling to proper level if
necessary, following operations 1 through 10. This step
an d Step " D " are extremely im p ortant as low oil level
a n d / o r air in the oil are the most frequent causes of
objectional p u m p noise.
d. Check the presence o f air in the oil. If air is
present, attem pt to bleed system as described in
operations 1 through 10. If it becomes obvious that the
pu m p will not bleed after a few trials, proceed as
outlined und er Hydraulic System Checks.
Hydraulic System Checks
T he following p ro c e d u re outlines m ethods to
identify and isolate power steering hydraulic circuit
difficulties. The test provides means o f determ ining
w heth er power steering system hydraulic parts are
actually faulty. This test will result in readings indicating
faulty hydraulic operation, and will help to identify the
faulty component.
Before perfo rm in g hydraulic circuit test, carefully
check belt tension, fluid level and condition o f driving
pulley.
Pow er S teering Hydraulic System Test
Engine must be at norm al operating temperature.
Inflate fron t tires to correct pressure. All tests are made
with engine idling, check idle adjustment and if
necessary adjust engine idle speed to correct specifica
tions listed in Section 6C and proceed as follows:
1. With engine NOT ru n nn in g disconnect pressure
hose from pum p and install Tool J-5176 using a spare
pressure hose between gauge and pump. G auge must be
between shut-off valve and p u m p (Fig. 3B-43), Open
shut-off valve.
2. Remove filler cap from pum p reservoir and
check fluid level. Fill pum p reservoir to full mark on dip
stick. Start engine and, m om entarily holding steering
wheel against stop, check connections at Tool J-5176 for
leakage.
A HIGH PRESSURE HOSE FROM PUMP
B ADDITIONAL HIGH PRESSURE P/S
HOSE TO GEAR
C TOOL J-5176
Fig. 3B 43 Checking Power Steering Pressures
3. Bleed system as outlined under Maintenance
and Adjustments.
4. Insert therm om eter (Tool J-5421) in reservoir
filler opening. Move steering wheel from stop to stop
several times until therm om eter indicates that hydraulic
fluid in reservoir has reached tem perature of 150 to
170 F.
CAUTION: To prevent scrubbing fla t spots on
tires, do not turn steering wheel more than Jive
times without rolling vehicle to change tire-tofloor contact area.
5. Start engine and check fluid level adding any
fluid if required. W hen engine is at norm al operating
temperature, the initial pressure read on the gage (valve
open) should be in the 80-125 PSI range. Should this
pressure be in excess of 200 PSI - check the hoses for
restrictions and the poppet valve for proper assembly.
6. Close gate valve fully 3 times. Record the
highest pressures attained each time.
CAUTION: Do not leave valve fully closed fo r
more than 5 seconds as the pum p could be
dam aged internally.
a. If the pressures recorded are within the listed
specs and the range o f readings are within 50 PSI, the
pum p is functioning within specs. (Ex. Spec. 1250 - 1350
PSI - readings - 1270 - 1275 - 1280).
b. If the pressures recorded are high, but do not
repeat within 50 PSI, the flow controlling valve is
sticking. Remove the valve, clean it and remove any
burrs using crocus cloth or fine hone. If the system
contains some dirt, flush it. If it is exceptionally dirty,
both the pum p and the gear must be completely
disassembled, cleaned, flushed and reassembled before
further usage.
c. If the pressures recorded are constant, but
more than 100 PSI, below the low listed spec., replace the
flow control valve and recheck. If the pressures are still
low. replace the rotating group in the pump.
7. If the pu m p checks within specifications, leave
1. Place the steering wheel onto the steering shaft,
the valve open and turn (or have turned) the steering
aligning the marks made at removal.
wheel into both corners. Record the highest pressures
2. Position into place and secure to proper torque
an d com pare with the m axim um pum p pressures and
com pare with the m axim um p u m p pressure recorded. If
with washer and nut. Install snap ring.
this pressure cannot he built in either (or one) side of the
3. Install belleville spring, receiving cup, bushing
gear, the g ear is leaking internally and must be
and attaching screws.
disassembled and repaired. See the current Overhaul
4. Install horn button assembly.
M anual.
5. Connect battery ground cable.
8.
Shut off engine, remove testing gauge, spare
Removal C and K Series
hose, reconnect pressure hose, check fluid level a n d / o r
1. Disconnect battery ground cable.
make needed repairs.
2. Remove horn button cap.
C O M P O N E N T R E P L A C E M E N T A N D REPAIRS
3. Remove snap ring and steering wheel nut.
4. Using tool J-2927. thread puller anchor screws
S teering W heel
into holes provided on steering wheel. T urn center bolt
Removal G and P Series
o f tool clockwise to remove wheel.
!. Disconnect battery ground cable.
2. Remove horn button or shroud, receiving cup.
belleville spring and bushing and mark steering wheel to
steering shaft relationship.
3. Remove snap ring, steering shaft nut and
washer.
4. Use Tool J-2927 to remove wheel (Fig. 3B-44).
Installation
CAUTION: See C A U T IO N on page I o f this
section regarding the fastener referred to in
step 2.
Directional signal control assembly must be in
neutral position when assem bling steering wheel
to prevent dam age to cancelling cam and
control assembly.
NOTE: Do not ham m er on puller.
centering adapters need not be used.
The
tool
Installation
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fasteners referred to in
step I.
1. With turn signal in neutral position, align marks
and set wheel onto steering shaft. Torque steering shaft
nut to specifications and install snap ring.
CAUTION: Do not over torque shaft nut or
steering wheel rub may result.
2. Place steering wheel horn button on wheel and
snap into proper position.
3. Connect battery ground cable.
Steering Coupling (Flexible Type Fig. 3B -45)
Removal
1. Remove the coupling to steering shaft flange
bolt nuts.
2. Remove the coupling clamp bolt.
CAPTURING
STRAP
COUPLING TO
STEERING SHAFT
FLANGE BOLTS
N OTE: This is a special bolt and will require a 12
pt. socket or box wrench.
3. Remove the steering g ear to fra m e bolts and
lower the steering g ear f a r enough to remove the flexible
coupling.
N O T E : It is not necessary to disconnect the pitm an
arm from the pitm an shaft.
4. T a p lightly on the flexible coupling with a soft
mallet to remove the coupling from the steering gear
wormshaft.
Installation
CAUTION: See C A U T IO N on page I o f this
section regarding the fa sten ers referred to in
steps 2, 4 a nd 5.
1. Install the flexible coupling onto the steering
gear w orm shaft, aligning the flat on the shaft with the
flat in the coupling.
N O T E : Push the coupling onto the w orm shaft until
the coupling reinforcem ent bottoms against the
end o f the worm.
2. Install the special bolt into the split clamp and
torque to specifications.
N O T E: The bolt must pass through the shaft
undercut.
3. Place the steering gear into position, guiding the
flexible coupling bolts into the p rop er holes in the
steering shaft flange.
4. Install and tighten the steering gear to fram e
bolts.
5. Install the coupling to flange bolt nuts and
washers and torque to specifications. Be sure to maintain
a coupling to flange dim ension o f .250" to .375". The
coupling alignm ent pins should be centered in the flange
slots.
In term ed iate S teering Shafts With Pot Joint
Couplings
Removal (Fig. 3B-46)
1. Remove the lower shaft flange to flexible
coupling bolts.
2. Remove upper shaft to interm ediate coupling
bolt
LOWER
SHAFT
SEAL
BEARING
BLOCKS
t
SB
Fig. 3B 4 7 -C hecking Coupling Pin Centering
3.
If necessary, remove the steering gear to fram e
bolts and lower the steering gear far enough to remove
the interm ediate shaft assembly.
NOTE: It is not necessary to remove the pitman
arm from the pitm an shaft.
Disassembly
1. Mark cover to shaft relationship. Pry off" snap
ring and slide cover from shaft.
2. Remove bearing blocks and tension spring from
pivot pin.
3. Clean grease off pin and end o f shaft. Scribe
location mark on pin on same side as cham fer in shaft.
4. Supporting shaft assembly securely, with c h a m
fer up, press pin out o f shaft with arb or press.
CAUTION: Do not drive pin out with hammer.
This will cause sticky or binding bearings when
reassembled.
5. Remove seal clamp and slide seal off end of
shaft.
COVER
SNAP
RING
Assembly
CLAMP
UPPER
SHAFT
CLAMP
TENSION
SPRING
NUT
1. Be sure all parts are free o f dirt. Slide seal onto
steering shaft. With lip o f seal against step in shaft
clamp seal.
2. Press pin back into shaft from cham fered side.
Locate pin in shaft using scribe m ark as reference.
CAUTION: Pin m ust be centered within .012
in. or binding in the coupling will result.
3. Check centering of pin (fig. 3B-47).
a. Place just enough 3 / 8 " flat washers on pin to
prevent hearing block from bottom ing when installed.
b. Measure distance from end o f pin to top of
bearing with micrometer.
c. Remove bearing and washers and place same
bearing and washers on other end o f pin. Measure
distance from end of pin to top o f bearing. If
microm eter readings in Steps b and c differ more than
.012. repeat last part o f Step 2 and recheck.
4. Apply a liberal am ount o f wheel bearing grease
to inside and outside of bearing blocks and inside of
cover.
5.
Position tension spring and bearing blocks on
pin.
6. Slide cover over b e a r in g blocks aligning
reference mark on cover with mark on shaft. Install seal
into end o f cover and secure with snap ring retainer.
Fig. 3 B -4 9 -Steering Gear M ounting-M otor Home
Typical
Installation
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fasten ers referred to in
steps 1, 3 and 4.
Interm ediate Steering Shaft With Universal
Joint Couplings
Removal (Fig. 3B-48)
3. Install the steering gear to fram e bolts and
torque to specifications.
1. Set front wheels in straight ahead position. This
can be done by driving the vehicle a short distance on a
flat surface.
2. Mark upper universal jo in t yoke to steering
shaft relationship and lower yoke to steering gear
w orm shaft relationship.
3. Remove both upper and lower universal yoke
pinch bolts.
4. Remove steering gear to frame bolts and lower
the gear.
4. Install the flexible coupling to steering shaft
flange bolt lockwashers and nuts. Check that the
coupling alignm ent pins are centered in the flange slots
and then torque the coupling bolts to specifications.
NOTE: It is not necessary to disconnect the pitm an
arm from the steering gear pitm an shaft.
5. Remove the interm ediate steering shaft and
universal jo int assembly.
1. Install the interm ediate shaft assembly onto the
steering shaft, aligning the flat on the shaft with the flat
in the coupling. Install the pot jo in t clamp bolt and
torque to specifications.
2. Lift the steering gear into position, guiding the
flexible coupling bolts into the shaft flange holes.
Disassembly
1. If the upper or lower half o f the intermediate
steering shaft is to be replaced, proceed as follows:
a. W ith the sh aft assembly on a bench,
straighten the tangs on the dust cap. Separate the upper
and lower portions o f the shaft assembly.
b. Remove the felt washer, plastic washer and
dust cap. Discard the felt washer.
2. If the trunnion assemblies are to be replaced,
proceed as follows:
a. Remove the snap rings retaining the trunnion
bushings in one of the yokes.
b. Support the yoke on a bench vise and drive
out one bushing by tapping on the opposite bushing
using a soft drift and hammer.
c. Support the other side of the yoke and drive
out the rem aining bushing as in Step b above.
d. Move the yoke on the trunnion as necessary
to separate the upper and lower yokes.
e. Remove the trunnion from the lower yoke as
outlined in Steps a through d above. Remove and
discard the seals.
Assembly
1. If the yoke trunnions were removed, reassemble
as follows:
a. Place the new trunnion into the lower yoke.
b. Place new seals onto the trunnion and then
press the new bushings into the yoke and over the
tru nnion hubs far enough to install the snap rings.
c. Install the snap rings.
d. Repeat Steps a through c to attach the upper
yoke to the trunnion.
2. Reassemble the interm ediate shaft assembly as
follows:
a. Place the dust cap, plastic w asher and a new
felt seal over the shaft on the lower yoke assembly.
b. Align the arrow on the lower yoke assembly
sh aft with the arrow on the upper yoke assembly tube
and push the two assemblies together.
c. Push the dust cap, plastic washer and felt
w asher into position on the lower end o f the upper yoke
assembly an d bend the tangs o f the dust cap down
against the yoke tube.
Installation
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fasten ers referred to in
steps 1, 3 a n d 4.
1. Align the m arks m ade at removal and assemble
the interm ediate shaft lower yoke onto the steering gear
w orm shaft. Install the pinch bolt and torque to
specifications.
N O T E : The pinch bolt must pass through the shaft
undercut. If a new yoke was installed, the slit in the
yoke should be up (12 o ’clock position).
2. Raise the steering gear into position while
guiding the upper yoke assembly onto the steering shaft.
N O T E: The marks on the coupling and steering
shaft must align. If a new yoke was installed,
assemble the upper yoke to the steering shaft with
the steering wheel in straight ahead position (gear
must be on high point).
3. Install the steering gear to fram e bolts and
torque to specifications.
4. Install the upper yoke to steering shaft pinch
bolt and torque to specifications.
N O T E : The pinch bolt must pass through the shaft
undercut.
S teering Gear
Removal
1. Set the front wheels in straight ahead position
by driving vehicle a short distance on a flat surface.
2. Rem ove the flexible coupling to steering shaft
flange bolts (C-K models) or the lower universal joint
pinch bolt (P models). M ark the relationship o f the
universal yoke to the w orm shaft.
3. M a rk the relationship o f the pitm an arm to the
Fig. 3B-50-Rem oving Pitm an Arm -Typical
pitm an shaft. Remove the pitm an shaft nut or pitman
arm pinch bolt and then remove the p itm an arm from
the pitm an shaft using Puller J-6632 (fig. 3B-50).
4. Remove the steering gear to fram e bolts and
remove the gear assembly.
5. C-K Models - Remove the flexible coupling
pinch bolt and remove the coupling from the steering
gear w ormshaft.
Installation
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fasteners referred to in
steps la, 1c, Id, le, 2b, 2c and 3.
1.
C-K Models
a. Install the flexible coupling onto the steering
gear w ormshaft, aligning the flat in the coupling with the
flat on the shaft. Push the coupling onto the shaft until
the w orm shaft bottoms on the coupling reinforcement.
Install the pinch bolt and torque to specifications.
NOTE: The coupling bolt must pass through the
shaft undercut.
b. Place the steering gear in position, guiding
the coupling bolt into the steering shaft flange.
c. Install the steering gear to fram e bolts and
torque to specifications.
d. If flexible coupling alignm ent pin plastic
spacers were used, make sure they are bottomed on the
pins, torque the flange bolt nuts to specifications and
then remove the plastic spacers.
e. If flexible coupling alignment pin plastic
spacers were not used, center the pins in the slots in the
steering shaft flange and then install and torque the
flange bolt nuts to specifications.
2. P Models
a.
Place the steering gear in position, guiding
the worm shaft into the universal joint assembly and
lining up the marks made at removal.
NOTE: If a new gear was installed, line up the
8. Install a new side cover gasket onto the gear
housing.
9. Install the side cover onto the lash adjuster
screw by reaching through the threaded hole in the side
cover with a small screwdriver and turning the lash
adjuster screw counter- clockwise until it bottoms and
turns back in 1/4 turn.
N OTE: T he pinch bolt must pass through the shaft
10. Install the side cover bolts and torque to
undercut.
specifications.
3.
Install the pitm an arm onto the p itm an shaft,
11. Install the lash adjuster screw locknut, perform
lining up the m arks m ade at removal. Install the p itm an
steerin gear adjustm ent and install the pitm an arm as
shaft nut or p itm an arm pinch bolt and torque to
outllined under "M ain te n a n c e and Adjustments".
specifications.
NOTE: On K series install the gear into the vehicle
CAUTION: I f a clamp type pitm an arm is used,
using previously outlined procedure.
spread the pitm an arm ju s t enough, with a
Directional Signal Switch
wedge, to slip the arm onto the pitm an shaft.
Do not spread the clamp more than required to
The directional signal switch can be removed with
slip over pitm an arm onto the pitm an shaft. Be
the steering column in the vehicle and without disturbing
sure to install the hardened steel washer before
any o f the column mountings.
installing the nut.
C and K Series
mark on the w orm shaft with the slit in the
universal jo int yoke.
b. Install the steering gear to fram e bolts and
torque to specifications.
c. Install the universal jo in t pinch bolt and
torque to specification.
Pitm an Shaft Seal R eplacem ent
Removal
M a n u a l Steering Gear
1. Remove the steering wheel as outlined under
"S^.ering Wheel - Removal".
2. Remove the column to instrum ent panel trim
cover.
3. Position screwdriver blade into cover slot. Pry
up and out to free cover from lock plate.
4. Screw the center post o f Lock Plate Compressing
Tool J-23653 onto the steering shaft as fa r as it will go.
Compress the lock plate by turning the center post nut
clockwise (fig. 3B-51). Pry the round wire snap ring out
o f the shaft groove and discard the ring. Remove Tool
J-23653 and lift the lock plate off the end o f the shaft.
A faulty seal may be replaced without removal o f
steering gear from C, G and P trucks by removing
p itm a n arm as outlined under M aintenance and
Adjustmens - Steering G e a r Adjustments and proceed as
follows:
N O T E : O n K series vehicles remove the gear from
the vehicle first.
1. Rotate the steering wheel from stop to stop,
counting the total n u m b e r of turns. Then turn back
exactly half-way, placing the gear on center (the
w orm sh aft flat should be at the 12 o ’clock position).
2. Remove the three self-locking bolts attaching
side cover to the housing and lift the pitm an shaft and
side cover assembly from the housing.
3. Pry the p itm an shaft seal from the gear housing
using a screwdriver and being careful not to dam age the
housing bore.
CAUTION: Inspect the lubricant in the gear fo r
contam ination I f the lubricant is contam inated
in any way, the gear m ust be removed fro m the
vehicle a n d completely overhauled as outlined
in the Overhaul M anual.
4. Coat the new pitm an sh aft seal with Steering
G e a r L ubricant meeting G M Specification GM4673M
(or equivalent). Position the seal in the pitm an shaft
bore and tap into position using a suitable size socket.
5. Remove the lash adjuster lock nut. Remove the
side cover from the pitm an shaft assembly by turning
the lash adjuster screw clockwise.
6. Place the pitm an shaft in the steering gear such
that the center tooth o f the pitm an shaft sector enters the
center tooth space o f the ball nut.
7. Fill the steering gear housing with Steering
G e a r Lubricant meeting G M Specification GM 4673M
(or equivalent).
CAUTION: I f the column is being disassembled
on the bench, with the snap ring removed the
shaft could slide out o f the lower end o f the
m ast jacket, dam aging the shaft assembly.
5. Slide the directional signal cancelling cam,
J-23653
harness cover by pulling toward the lower end o f the
column, be careful not to dam age the wires.
11.
Remove the three switch m ounting screws and
pull the switch straight up, guiding the wiring harness
and cover through the column housing (fig. 3B-53).
Installation
CAUTION: It is extremely important that only
the specified screws, holts and nuts be used at
assembly. Use o f overlength screws could
prevent a portion o f the assembly fro m
compressing under impact.
1.
All except Tilt - Be sure that the wiring harness
is in the protector. Feed the connector and cover down
through the housing and under the m ounting bracket
(column in vehicle).
Tilt - Feed the connector down through the housing
Fig. 3B-52- Removing D irectional Signal Wire
Protector
Fig. 3B -54--lnstalling Switch Connector Onto Jacket
Clips
Fig. 3B-53--Removing D irectional Signal Switch
Assem bly
upper bearing preload spring and thrust washer off the
end o f the shaft.
6. Remove the directional signal lever screw and
remove the lever.
7. Push the hazard w a rn in g knob in and unscrew
the knob.
8.
Remove the three switch m ounting screws.
9. All Columns - Pull the switch connector out of
the bracket on the jacket and feed switch connector
through column support bracket and pull switch straight
up, guiding the wiring harness through the column
housing and protector.
10. Remove wire protector by pulling downward
out o f column with pliers using tab provided (fig. 3B-52).
Tilt Column - Position the direction signal and
shifter housing in the "low " position. Remove the
and un der the m ounting bracket. Then install the
cover on the harness.
2. Install the three m oun ting screws and clip the
connector to the bracket on the jacket (fig. 3B-54).
3. Install the column to instrum ent panel trim
plate.
4. Install the hazard w a rn in g knob and directional
signal lever.
5. M ake certain that the switch is in " N e u tra l" and
the hazard w a rning knob is out. Slide the thrust washer,
upper bearing preload spring and cancelling cam onto
the upper end o f the shaft.
6. Place the lock plate onto the end of the shaft.
Screw the center post of Lock Plate Compressing Tool
J-23653 onto the steering shaft as far as it will go. Place
a NF.W snap ring over the center post. Place the "C " bar
over the center post and then compress the lock plate by
turning the nut clockwise. Slide the new snap ring down
the tapered center post and into the shaft groove (fig.3B55). Remove Tool J-23653.
ADAPTER
A N T I-T H E F T R IN G
LO C K C Y L IN D E R
SLEEVE
IG N I T IO N
L O C K C Y L IN D E R
Fig. 3B-57--lgm tion Lock Cylinder-Exploded
CAUTION: Always use a new snap ring when
reassembling.
7. Place cover on the lock plate and snap into
position.
8. Install the steering wheel as outlined under
"S teering W heel-Installation".
SLOT
BOLT
M UST PROTRUDE
FROM
SL EE V E
Fig. 3B-58- Ignition Lock Cylinder Assembly
Lock Cylinder (C and K Series)
The lock cylinder is located on the upper right h a n d
side o f the column. The lock cylinder should be removed
in the " R U N " position only.
Removal
1. Remove the steering wheel as outlined under
"Steering Wheel - Rem oval".
2. Remove the directional signal switch as outlined
under "Directinal Signal Switch - Removal".
N OTE: It is not necessary to completely remove
the directional signal switch from the column. Pull
the switch rearw ard fa r enough to slip it over the
end of the shaft - do not pull the harness out o f the
column.
Fig. 3B -56-Lock Cylinder Removal
3. Insert a small screwdriver or similar tool into
the turn sig nal housing slot as shown in Figure 3B-56.
K eeping the tool to the right side o f the slot, break the
the lock cylinder assembly, push the ignition key the rest
of the way in and rotate the lock cylinder clockwise.
4. Rotate the lock counter-clockwise into "L O C K "
position.
5. Place the lock in a brass jawed vise or between
two pieces o f wood (fig. 3B-59).
NOTE: If a vise is used, place cloth around the
knob to prevent m arring the knob surface.
6. Place the ad ap ter ring onto the lower end o f the
cylinder so that the finger o f the ad a p te r is located at the
step in the sleeve and the serrated edge o f the ad apter is
visiblle after assembly to the cylinder and before
"staking" (fig. 3B-60). The key must be free to rotate at
least 1/3 of a circle (120°).
Fig. 3B-59--lgm tion Lock Cylinder Installed in a Vise
1 / 8 ” FLAT END
PUNCH
NOTE: Tap the adapter onto the cylinder until it is
stopped at the bottom o f the cylinder flats (cylinder
will extend above ad apter approximately 1/16").
7. Using a small flat punch, at least 1/8 " in
diameter, stake the lock cylinder over the adap ter ring in
four places just outboard o f the four dimples as shown in
Figure 3B-60.
8. Check lock operation before reinstalling vehicle.
Installation
(4) DIMPLES
ADAPTER R IN G
A G A IN ST STEP
IN SLEEVE
Fig. 3 B -6 0 -In s ta llin g A dapter Ring
1. Hold the lock cylinder sleeve and rotate the
knob clockwise against the stop. Insert the cylinder into
the housing bore with the key on the cylinder sleeve
aligned with the keyway in the housing. Push the
cylinder into abutm ent o f cylinder and sector. Hold an
.070" drill between the lock bezel and housing. Rotate
the cylinder counterclockwise, m a intaining a light
pressure until the drive section o f the cylinder mates
with the sector. Push in until the snap ring pops into the
grooves and lock cylinder is secured in the housing.
Remove the .070" drill. Check lock cylinder for freedom
of rotation.
2. Install the Direction Signal Switch and Steering
Wheel as outlined previously in this section.
housing Hash loose and at the same time depress the
spring latch at the lower end of the lock cylinder. With
the latch depressed, the lock cylinder can be removed
from the housing.
Assembly (Fig. 3B-57)
1. Place the key part way into the lock cylinder
assembly. Place the wave w asher and anti-theft ring onto
the lower end of the lock cylinder.
N O TE : If the key is installed all the way into the
lock cylinder, the plastic keeper in the lock cylinder
protrudes and prevents installation o f the sleeve
assembly.
2. M ake sure that the plastic keeper in the sleeve
assembly protrudes from the sleeve (fig. 3B-58).
3. Align the lock bolt on the lock cylinder and the
tab on the anti-theft washer and the slot in the sleeve
assembly (fig. 3B-58). Push the sleeve all the way onto
SWITCH IN LOCK POSITION
3.
Reinstall the steering column assembly follow
ing the "M an d a to ry Installation Sequence" outlined later
in this section.
Steering Column
Fig. 3B-62--Steering Column Cover and Seal
Ignition Switch (C and K Series)
T he ignition switch is mounted on top of the column
jacket n ear the front o f the dash. F o r anti-theft reasons,
the switch is located inside the channel section of the
brake pedal support and is completely inaccessible
w ithout first lowering the steering column (see steering
column removal).
T he switch is actuated by a rod and rack assembly.
A portion of the rack is toothed and engages a gear on
the end of the lock cylinder, thus enabling the rod and
rack to be moved axially (with respect to the column) to
actuate the switch w hen the lock cylinder is rotated.
Removal
1. Lower the steering column as outlined under
"S teering Column R em oval" later in this section. It is
not necessary to remove the steering wheel.
CAUTION: I f the steering column is not
rem oved fr o m the vehicle, be sure that it is
properly supported, before proceeding.
2. The switch should be positioned in "Lock"
position before removing. If the lock cylinder has
already been removed, the actuating rod to the switch
should be pulled up until there is a definite stop, then
moved down one detent, which is the "L ock" position.
3. Remove the two switch dBrews and remove the
switch assembly.
Installation
1. Before replacing the switch, be sure that the lock
is in the "L ock" position (fig. 3B-61); if it is not, a
screwdriver (placed in the locking rod slot) can be used
to move the switch to "Lock".
2. Install the activating rod into the switch and
assemble the switch on the column; tighten the m ounting
screws.
CAUTION: Use only the specified screws since
over-length screws could prevent a portion o f
the assembly from compressing under impact.
All models which are equipped with the Function
Locking Energy Absorbing Steering Columns are one of
five basic designs.
1. Synchromesh - The synchromesh column is
used on models with the standard transmission and
column m ounted shift levers. The shift tube, within the
outer column jacket, includes two lower shift levers for
connection to the transmission control linkage. This
column does not lock the transmission when the lock
cylinder is in the "lock" position.
2. Floor Shift - This column is used on models
equipped with a m anual transmission with the shift lever
on the floor. This column does not lock the transmission
w hen the lock cylinder is in the "lock" position.
3. Automatic Column Shift - This column has a
single lower shift lever for shifting the automatic
transmission.
The transmission is locked in Park when the lock
cylinder is in "Lock".
4. Tilt Column Option automatic transmission T he upper end and steering shaft o f this column is
specifically designed to accommodate the optional tilt
steering wheel. The lower portion o f the column is the
same as in item nu m b e r 3.
5. Tilt Column Option Manual Transmission - This
column is the same as the automatic transmission tilt
column except incorporating provisions for the manual
transmission shifting and the transmission is not locked
when the lock cylinder is in "L ock" position.
To perform service procedures on the steering
column upper end components, it is not necessary to
remove the column from the vehicle.
The steering wheel, horn components, directional
signal switch, and ignition lock cylinder m ay be removed
with the column re m ain in g in the vehicle as described
earlier in this section.
CAUTION: The outer mast ja c ke t shift tube,
steering shaft a n d instrument panel m ounting
bracket are designed as energy absorbing units.
Because o f the design o f these components, it is
absolutely necessary to handle the column with
care when perform ing any service operation.
A void hammering, jarring, dropping or leaning
on any portion o f the column. When reassem
bling the column components, use only the
specified screws, nuts and bolts and tighten to
specified torque. Care should be exercised in
using over-length screws or bolts as they m ay
prevent a portion o f the column fr o m
compressing under impact.
Inspection
To determ ine if the energy absorbing steering
column components are functioning as designed, or if
repairs are required, a close inspection should be made.
Inspection is called for in all cases where dam age is
evident or w henever the vehicle is being repaired due to
a front end collision. W henever a force has been exerted
on the steering wheel or steering column, or its
components, inspection should also be made. If dam age
is evident, the affected parts must be replaced.
The inspection procedure for the various steering
column com ponents on all C and K Series Trucks is as
follows:
Column Support B racket
D am a ge in this area will be indicated by separation
o f the m ounting capsules from the bracket. The bracket
will have moved forward toward the engine co m p art
m ent and will usually result in collapsing o f the jacket
section o f the steering column.
Column Jac ke t
Inspect jacket section o f column for looseness, a n d /
or bends.
Fig. 3B-64 -Steering Column to Dash Panel-C,K
P
Typical
S h ifte r S h a ft
Separation o f the shifter shaft sections will be
internal and cannot be visually identified. Hold lower
end o f the "shifter sh aft" and move "s h ift lever" on
colum n through its ranges and up and down. If there is
little or no m ovem ent o f the "shifter shaft", the plastic
joints are sheared.
Steering S h a ft
If the steering shaft plastic pins have been sheared,
the shaft will rattle when struck lightly from the side and
some lash m ay be felt w hen rotating the steering wheel
while holding the rag joint. It should be noted that if the
steering shaft pins are sheared due to m inor collision the
vehicle can be safely steered; however, steering shaft
replacem ent is recommended.
Because of the differences in the steering column
Fig. 3B-65--Steering Columns to Dash Panel-G
types, be sure to refer to the set o f instructions below
which apply to the column being serviced.
C and K Columns
Removal
Fig. 3B-63--Autom atic Transm ission Indicator
Connection-CK-Typical
NOTE: Front o f dash mounting plates must be
loosened whenever the steering column is to be
lowered from the instrument panel.
1. Disconnect the battery ground cable.
2. Remove the steering wheel as outlined under
"Steering Wheel Removal".
3. Remove the nuts and washers securing the
flanged end o f the steering shaft to the flexible coupling.
4. Disconnect the transmission control linkage
from the column shift tube levers.
5. Disconnect the steering column harness at the
connector. Disconnect the neutral-start switch and back
up lamp switch connectors if so equpped.
6. Remove the floor pan trim cover screws and
remove the cover.
7. Remove the screws securing the two halves of
the floor pan cover; then remove the screws securing the
halves and seal to the floor pan and remove the covers
(fig. 3B-64 and 3B-65).
8. Remove the transmission indicator cable, if so
e qu pp ed (fig. 3B-63).
9. Move the front seat as fa r back as possible to
provide m axim um clearance.
10. Remove the two column bracket-to-instrument
panel nuts and carefull remove from vehicle. Additional
help should be obtained to guide the lower shift levers
through the firewall opening.
C and K Series Except T ilt Columns(Fig. 3 B -6 6 )
Disassembly
N OTE: G and P Series columns differ from those
shown in Figures 3B-66 thru 3B-74.
1. Remove the four dash panel bracket-to-column
screws and lay the bracket in a safe place to prevent
da m a ge to the m ounting capsules.
2. Place the column in a vise using both weld nuts
o f either Set A or B as shown in Figure 3B-67. The vise
jaw s must clam p onto the sides o f the weld nuts
indicated by arrows shown on Set B.
CAUTION: Do not place the column in a vise
by clam ping onto one weld nut o f both sets A
a n d B or by clam ping onto the sides not
indicated by arrows, since damage to the
column could result.
3. Remove the Directional Signal Switch. Lock
Cylinder, and Ignition Switch as outlined previously in
this section.
4. Column Shift Models - Drive out the upper shift
lever pivot pin and remove the shift lever.
5. Remove the upper bearing thrust washer.
Remove the four screws attaching the turn signal and
ignition lock housing to the jacket and remove the
housing assembly (fig. 3B-68).
6. Remove the thrust cap from the lower side of
the housing.
7. Lift the ignition switch actuating rod and rack
assembly, the rack preload spring and the shaft lock bolt
and spring assembly out of the housing (fig. 3B-69).
8. Remove the shift lever detent plate (shift gate).
9. Remove the ignition switch actuator sector
through the lock cylinder hole by pushing firmly on the
block tooth o f the sector with a blunt punch or
screwdriver (fig. 3B-70).
10. Remove the gearshift lever housing and shroud
from the jacket assembly (transmission control lock tube
housing and shroud on floor shift models).
11. Remove the shift lever spring from the
gearshift lever housing (lock tube spring on floor shift
models).
12. Pull the steering shaft from lower end o f the
jacket assembly.
13. Remove the two screws holding the back-up
switch or neutral-safety switch to the column and remove
the switch.
14. Remove the lower bearing retainer clip (fig.
3B-71).
15. Automatic and Floorshift Columns - Remove
the lower bearing retainer, bearing adapter assembly,
shift tube thrust spring and washer. The lower bearing
m ay be removed from the ad apter by light pressure on
the bearing outer race. Slide out the shift tube assembly.
Manual Transmission - Column Shift - Remove the
lower bearing adapter, bearing and the first reverse
shift lever. The lower bearing may be removed from
the adapter by light pressure on the bearing outer
race. Remove the three screws from bearing at the
lower end and slide out the shift tube assembly.
Remove the gearshift housing lower bearing from
the upper end o f the mast jacket.
Assembly-All Except Tilt Columns
NOTE: Apply a thin coat of lithium soap grease to
all friction surfaces.
1. Install the sector into the turn signal and lock
cylinder housing. Install the sector in the lock cylinder
hole over the sector shaft with the tang end to the
outside o f the hole. Press the sector over the shaft with a
blunt tool.
2. Install the shift lever detent plate onto the
housing.
3. Insert the rack preload spring into the housing
from the bottom side. The long section should be toward
the handwheel and hook onto the edge of the housing
(fig. 3B-72).
4. Assemble the locking bolt onto the crossover
arm on the rack and insert the rack and lock bolt
assembly into the housing from the bottom with the
teeth up (toward hand-wheel) and toward the centerline
o f the column (fig. 3B-69). Align the 1st tooth on the
sector with the 1st tooth on the rack; if aligned properly,
the block teeth will line up when the rack assembly is
pushed all the way in.
5. Install the thrust cup on the bottom hub of the
housing.
6. Install the gearshift housing lower bearing.
Insert the bearing from the very end o f the jacket.
Aligning the indentations in the bearing with the
projections on the jacket (fig. 3B-73).
CAUTION: I f the bearing is not installed
correctly, it will not rest on all o f the stops
provided.
7. Install the shift lever spring into the gearshift
lever (or lock tube) housing. Install the housing and
shroud assemblies onto the upper end o f the mast jacket.
Rotate the housing to be sure it is seated in the bearing.
8. With the shift lever housing in place, install the
turn signal and lock cylinder housing onto the jacket.
The gearshift housing should be in " P a r k ” position and
the rack pulled downward. Be sure the turn signal
housing is seated on the jacket and drive the four screws.
DESIGN J INTERMEDIATE
ON SOME MODEIS ARE
PERMANENUY STAKED
ANO MUST BE SERVICED
AS AN ASSEMBLY
DESIGN 1
BUSHING
Key No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
-
Part Name
C O LUM N ASM
HO USING ASM
RACK ASM
SPRING
SECTOR
S H A FT
CLIP
SW ITCH
B EA R IN G
WASHER
SCREW (4)
R E T A IN IN G RING
NUT
CO VER ASM (SHIPPED S E PA R A TELY)
R IN G
LOCK
CAM ASM
SPRING
SCREW (3)
Key No.
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
-
Part Name
SWITCH ASM
PROTECTOR WIRE
HOUSING
CUP
BOLT ASM
WASHER
GAT E
SCREW (2)
JACKE T ASM
SWITCH ASM, IG N I T I O N
SCREW (2)
BOWL ASM
SPRING
BOWL
SH R O U D
BEA RING
JACKE T ASM
SE A L-D A S H
TUBE ASM
Key No.
Part Name
39 -
W ASHER
40 -
S P R IN G
41 -
ADAPTER
42 -
R E T A IN E R
43 -
B E A R IN G
44 -
R IN G
45 -
S H A F T ASM
46 -
C L IP
47 -
S H A F T ASM
48 -
C O U P L IN G A S M
49 -
B OLT
50 -
NUT
51 -
R IN G
52 -
S P R IN G
53 -
B E A R IN G (2 )
54 -
A B R A S IO N S H IE L D
55 -
BOL~
56 -
NU'
SH IF T G A T E
RACK
LO CK
LO CK
B O LT
B O LT
S P R IN G
TH R U ST
CUP
SEC TO R
Fig. 3B-67 In sta llin g Steering Column in Vise
Fig. 3B-69- Turn Signal Housing Assembly
Fig. 3B-68--Removing Turn Signal Housing
Fig. 3B-70--Removing Ignition Switch A ctuator Sector
9. Press
assembly.
the
lower
bearing
into
the
ad apter
10. Insert the shift tube assembly into the lower
end of the jacket and rotate until the upper shift tube
key slides into the housing keyway.
11. Automatic and Floor shift Columns - Assemble
the spring and lower bearing and adapter assembly into
the bottom o f the jacket. Holding the ad ap ter in place,
install the lower bearing reinforcem ent and retainer clip.
Be sure the clip snaps into the jacket and reinforcem ent
slots.
12. Manual Transmission - Column Shift - Loosely
attach the three screws in the jacket and shift tube
bearing.
Assemble the 1st-Reverse lever and lower bearing
and a d a p te r assembly into the bottom of the jacket.
Holding the adapter in place, install the bearing
reinforcem ent and retaining clip. Be sure the
retaining clip snaps into the jacket and reinforce
ment slots.
Place a.005" shim between the I st-Reverse lever and
lever spacer and turn the upper shift tube bearing
down and tighten the three screws. Remove the shim
(fig. 3B-74).
13. Install the neutral-safety or back-up switch as
outlined in Section 12 o f this manual.
14. Slide the steering shaft into the column and
install the upper bearing thrust washer.
15. Install the turn signal switch, lock cylinder
assembly and ignition switch as previously outlined in
this section.
16.
Install the shift lever and shift lever pivot pin.
17.
Remove the column from the vise.
18. Install the dash bracket to the column; torque
the screws to specifications.
Fig. 3B-71--Removing Lower Bearing Retainer
Fig. 3 B -7 3 -In sta llin g Gearshift Housing Lower
Bearing
Fig. 3 B -7 2 -In s ta llin g Rack Preload Spring
Fig. 3B-74--Adjusting Lower Bearing-Typical
Disassembly-Tilt Columns (Fig. 3B-75)
N O TE : Steps 3-14 may be perform ed with the
steering column in the vehicle.
1. Remove the four screws retaining the dash
mounting bracket to the column and set the bracket
aside to protect the breakaway capsules.
2. M ount the column in a vise using both weld nuts
o f either Set A or B as shown in Figure 3B-67. The vise
jaws must clamp onto the sides of the weld nuts
indicated by arrows shown on Set B.
CAUTION: Do not place the column in a vise
by clam ping onto only one weld nut, by
clam ping onto one weld nut o f both Sets A and
B or by clamping onto the sides not indicated
by arrows, since dam age to the column could
result.
3.
Remove
the
directional
signal
switch,
lock
cylinder and ignition switch as outlined previously in this
section.
4. Remove the filt release lever. Drive out the shift
lever pivot pin and remove the shift lever from the
housing.
5. Remove the three turn signal housing screws
and remove the housing.
6. Install the tilt release lever and place the column
in the full " u p " position. Remove the tilt lever spring
retainer using a 3 phillips screwdriver that just fits into
the slot opening. Insert the phillips screwdriver in the
slot, press in approximately 3 /1 6 " , turn approximately
1 /8 turn counterclockwise until the ears align with the
grooves in the housing and remove the retainer, spring
and guide (fig. 3B-76).
7. Remove the pot jo in t to steering shaft clamp
bolt and remove the intermediate shaft and pot joint
assembly.
Push the upper steering shaft in sufficiently to
Fig. 3B-75
Column
STEERING
Tilt Steering
Assembly-CK
Typical
19.
Sector Shaft
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
Lock Shoe Pin
37.
38.
39.
40.
41 .
42.
43.
44.
45.
46.
47 .
48.
49.
50.
51.
52.
Shaft N u t
Cover
Lack Plate R etaining Ring
17.
4.
Lock Plate
5.
6.
C a n c e llin g Cam
Bearing Preload Spring
7.
Turn Signal Screws
8.
9.
Turn Signal Switch
Protector Cover
10.
11.
Upper Bearing Seat
Upper Bearing Race
12.
Turn S ig n a l Housing Screws
1 3 . Turn Signal Housing
1 4 . T ilt Lever O p en ing Shield
15.
Upper Bearing
16- Shaft Lock Bolt
Bearing Housing
T ilt Lever Spring R etainer
T ilt Lever Spring
T ilt Lever Spring G u id e
Lock Bolt Spring Screw
Sector Snap Ring
Sector
Bearing Housing Pivot Pine
Shoe Release Springs
Spring
Shoe Release Lever Pin
Shoe Release Lever
Lower Bearing
Ig nition Sw itch Rack Spring
36.
Ig n itio n S w itc h Rod
Upper Steering Shaft
C en terin g Spheres
C en ter Sphere Spring
Lower Steering Shaft
5 3 . Ig nition Switch
5 4 . M ast J a c k e t
5 5 . N e u tra l-S a fe ty or B ack-U p
56. R etainer
57.
S hift Tube
Bearing Housing Support Screws
58.
59.
Lower Bearing A dapter
Lower Bearing
Bearing Housing Support
60.
Lower Bearing Reinforcem ent
Pin
• Pot J o in t Bolt
62. N ut
Shift Tube Index Plate Screws
Shift Tube Index Plate
63.
64.
65.
Pot Join t C over
Seal R etaining Ring
Bearing Spring
Support W ave Washer
66.
67.
Bearing Blocks
Pot J o in t Seal
G e a rsh ift Lever Spring
68.
In term ed iate Shaft
Support R e ta in in g Ring
Support Thrust Washer
Support P late Lock
G e a rsh ift Lever Housing
Ig nition Switch Screws
3B-51
Lock Bolt Spring
Lock Shoes
35. Ig nition S w itch Rack
18.
1.
2.
3.
Fig. 3B-77-R em oving Bearing Housing Pivot Pins
Fig. 3B-79--Replacing Lock Bolt Spring
Fig. 3B 80 Removing Sector Drive Shaft
remove the steering shaft upper bearing inner race
a n d seat. Pry off the lower bearing retainer clip and
remove the bearing reinforcement, bearing and
bearing a d a p te r assembly from the lower end of the
mast jacket.
8. Remove the upper b earing housing pivot pins
using Tool J -2 1854-1 (fig. 3B-77).
9. Install the tilt release lever and disengage the
lock shoes. Remove the bearing housing by pulling
upward to extend the rack full down, and then moving
the housing to the left to disengage the ignition switch
rack from the actuator rod.
10. Remove the steering shaft assembly from the
upper end of the column.
11. Disassemble the steering shaft by removing the
centering spheres and the anti-lash spring.
12. Remove the transmission indicator wire, if so
equipped.
13. Rem ove the four steering sh aft be a rin g
housing support to gearshift housing screws and remove
the b earing housing support. Remove the ignition switch
actuator rod.
14. Remove the shift tube retaining ring with a
screwdriver and then remove the thrust washer.
15. Install Tool J-23072 into the lock plate, making
sure that the tool screws have good thread engagem ent
in the lock plate. Then, turning the center screw
clockwise, force the shift tube from the housing (fig. 3B78). Remove the shift tube (transmission control lock
tube on floor shift models) from the lower end of the
mast jacket. Remove Tool J-23072.
CAUTION: When removing the shift tube, be
sure to guide the lower end through the slotted
opening in the mast jacket. I f the tube is
allowed to interfere with the ja cket in any way,
dam age to the tube and jacket could result.
16. Remove the bearing housing support lock plate
by sliding it out o f the jacket notches, tipping it down
toward the housing hub at the 12 o ’clock position and
sliding it under the jacket opening. Remove the wave
washer.
17. All Columns - Remove the shift lever housing
from the mast jacket (transmission control lock tube
housing on floor shift models). Remove the shift lever
spring by winding the spring up with pliers and pulling
it out. On floor shift models, remove the spring plunger.
18. Disassemble the bearing housing as follows:
a. Remove the tilt lever opening shield.
b. Remove the lock bolt spring by removing the
retaining screw and moving the spring clockwise to
remove it from the bolt (fig. 3B-79).
c. Remove the snap ring from the sector drive
shaft. With a small punch, lightly tap the drive shaft
from the sector (fig. 3B-80). Remove the drive shaft,
sector and lock bolt. Remove the rack and rack spring.
d. Remove the tilt release lever pin with a punch
and ham mer. Remove the lever and release lever spring.
To relieve the load on the release lever, hold the shoes
inward and wedge a block between the top o f the shoes
(over slots) and bearing housing.
e. Remove the lock shoe retaining pin with a
punch and ham m er. Remove the lock shoes and lock
shoe springs.
NOTE: With the tilt lever opening on the left side
and shoes facing up, the four slot shoe is on the
left.
f. Remove the bearings from the bearing
housing only if they are to be replaced. Remove the
separator and balls from the bearings. Place the housing
on work bench and with a pointed punch against the
back surface o f the race, carefully ham m er the race out
o f the housing until a bearing puller can be used. Repeat
for the other race.
Assembly-Tilt Columns
Apply a thin coat of lithium grease to all friction
surfaces.
RACK
ACTUATOR
Fig. 3ES-82 In sta llin g Bearing Housing
e. Install the lock bolt and engage it with the
sector cam surface. Then install the rack and spring. The
block tooth on the rack should engage the block tooth on
the sector (fig. 3B-81). Install the external tilt release
lever.
f. Install the lock bolt spring and retaining screw
(fig. 3B-76). Tighten the screw to 35 in. lbs.
2. Install the shift lever spring into the housing by
windng it up with pliers and pushing it into the housing.
On floor shift models, install the plunger, slide the
gearshift lever housing onto the mast jacket.
3. Install the bearing support lock plate wave
washer.
4. Install the bearing support lock plate. Work it
into the notches in the jacket by tipping it toward the
housing hub at the 12 o ’clock position and sliding it
under the jacket opening. Slide the lock plate into the
notches in the jacket.
5. Carefully install the shift tube into the lower
end o f the mast jacket. Align keyway in the tube with the
key in the shift lever housing. Install the wobble plate
end o f Tool J-23073 into the upper end of the shift tube
far enough to reach the enlarged portion o f the tube.
T hen install the ad apter over the end o f the tool, seating
it against the lock plate. Place the nut on the threaded
end o f the tool and pull the shift tube into the housing
(fig. 3B-83). Remove Tool J-23073.
CAUTION: Do not push or tap on the end o f
the shift tube. Be sure that the shift tube lever
is aligned with the slotted opening at the lower
end o f the m ast jacket or damage to the shift
tube and mast jacket could result.
SHIFT B O W L
6.
Install the bearing support thrust washer and
J 23073-3
J 23073 4
retaining
ring by pulling the shift lever housing up far
LOCK
PLATE
W A V E -enough to compress the wave washer.
J 23073-1
W ASHER
7. Install the bearing support by aligning the "V "
in the support with the "V" in the jacket. Insert the
screws through the support and into the lock plate and
J 23073-2
FLAT
torque to 60 lbs. in.
W ASHER
U P PE R SHIFT T U BE
8. Align the lower bearing adap ter with the
notches in the jacket and push the adap ter into the lower
end of the mast jacket. Install lower bearing, bearing
Fig. 3 B -8 3 -In s ta llin g Shift Tube
reinforcem ent and retaining clip, being sure that the clip
1.
If the b earing housing was disassembled, repeatis aligned with the slots in the reinforcement, jacket and
adapter.
the following steps:
9. Install the centering spheres and anti-lash spring
a. Press the bearings into the housing, if
in the upper shaft. Install the lower shaft from the same
removed, using a suitable size socket. Be careful not to
side of the spheres that the spring ends protrude.
da m a ge the housing or bearing during installation.
10. Install the steering shaft assembly into the shift
b. Install the lock shoe springs, lock shoes and
tube from the upper end. Carefully guide the shaft
shoe pin in the housing. Use an approxim ate .180" rod
through the shift tube and bearing.
to line up the shoes for pin installation.
11. Install the ignition switch actuator rod through
c. Install the shoe release lever, spring and pin.
the shift lever housing and insert in the slot in the
N O T E : To relieve the load on the release lever,
bearing support. Extend the rack downward from the
hold the shoes inw ard and wedge a block between
bearing housing.
the top of the shoes (over slots) and bearing
12. Assemble the bearing housing over the steering
housing.
shaft and engage the rack over the end o f the actuator
rod (fig. 3B-82).
d. Install the sector drive shaft into the housing.
13. With the external release lever installed, hold
Lightly tap the sector onto the shaft fa r enough to install
the lock shoes in the disengaged position and assemble
the snap ring. Install the snap ring.
the bearing housing over the steering shaft until the
pivot pin holes line up.
14. Install the pivot pins.
15. Place the bearing housing in the full " u p "
position and install the tilt lever spring guide, spring and
spring retainer. W ith a suitable screwdriver, push the
retainer in and turn clockwise to engage in the housing.
16. Install the upper bearin g inner race and race
seat.
17. Install the tilt lever opening shield.
18. Remove the tilt release lever,install the turn
signal housing and torque the three retaining screws to
45 lbs. in.
19. Install the tilt release lever and shift lever.
Drive the shift lever pin in.
20. Install the lock cylinder, turn signal switch and
ignition switch as outlined previously in this section.
21. Align the groove across the upper end of the
pot jo in t with the flat on the steering shaft. Assemble the
interm ediate shaft assembly to the upper shaft. Install
the clamp and bolt and torque the nut to specifications.
CARROT
STEERING
C O LU M N
CAPSULE
N O TE : The clam p bolt must pass through the shaft
und er cut.
22. Install the neutral-safety switch or back-up
switch as outlined in Section 12 o f this manual.
23. Install the four dash panel bracket to column
screws and torque to specifications.
CAUTION: Be sure that the slotted openings in
the bracket (for the m ounting capsules) fa c e
the upper end o f the steering column.
Fig. 3B-84--Steering Column Installation-CK
COLUMN INSTALLATIONMANDATORY SEQUENCE
8.
Remove plastic spacers from flexible coupling
pins.
C and K SERIES VEHICLES (Fig. 3B -84)
M an d ato ry Instructions
1. Assemble lower dash cover (A) and upper dash
cover (B) to seal (C) with "C a rro ts" (part o f seal).
2. Attach bracket (D) to jacket and tighten four
bolts (E) to specified torque.
M an d ato ry Installation Sequence
1. Position column in body and position flange to
rag joint and install lock washers and nuts (F) (May be
tightened to specified torque at this time).
N OTE: Coupling (G) on m anual steering must be
installed prior to column installation.
2. Loosely assemble (2) capsules nuts (H) at the
instrum ent panel bracket (D).
3. Position lower clamp (J) and tighten attaching
nuts (K) to specified torque.
4. Tighten two nuts ( H ) at capsules to specified
torque.
5. Install seal (C) and covers (A and B) to dash.
6. Install attaching screws (L) and tighten to
specified torque.
7. Tighten two nuts (F) at capsules to specified
torque if not already done.
9. Install transmission indicator cable on column
automatics.
10. Install the instrum ent panel trim cover.
11. Connect the transmission control linkage at the
shift tube levers.
12. Install the steering wheel as outlined previously
in this section.
13. Connect the battery ground cable.
M andatory System Requirem ents
1.
Pot jo in t operating angle must be 1 1/2 °± 4°.
2. Flexible coupling must not be distorted greater
than ± .06 due to pot joint bottoming, in either
direction.
STEERING COLUMN SERVICE
FOR G AND P SERIES
S TEERING C O LU M N UPPER BEARING G AND P SERIES
Standard Column
Removal
1. Remove
section.
steering wheel
as outlined
in
2.
Remove directional signal cancelling cam.
3.
Pry out upper bearing.
this
Installation
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fasten ers referred to in
step 1.
Fig. 3B-85- Removing W iring Flarness Protector
1. Replace all com ponent parts in reverse order of
removal making sure that directional switch is in neutral
position before installing steering wheel. Torque steering
wheel nut to specifications.
T ilt Column
The upper bearings on the tilt column are spun into
the bearing housing assembly. If the bearings indicate
need of replacement, the entire bearing housing must be
replaced. See "T ilt Steering Colum n - Disassembly and
A ssembly" for the correct replacem ent procedure.
STE ER IN G C O LU M N LOWER BEARING
P SERIES
Removal
1. Remove the interm ediate steering shaft and
universal jo in t assembly as outlined earlier in this
section. Remove the preload spring clamp and spring
from the end o f the steering shaft.
2.
Pry out the lower bearing assembly.
Installation
Fig. 3B 86--Removing Wires from Connector
D IR E C TIO N A L SIG N A L S W ITCHG AND P SERIES C O LU M N S
If the directional signal switch must be replaced, the
steering column does not have to be removed from the
vehicle.
Removal
CAUTION: See C A U T IO N not on page I o f
this section regarding fasteners referred to in
step 2.
1. Place the new bearing over the end o f the
steering shaft and press into position in the column.
2. Install the preload spring and clamp and torque
the clamp bolt nut to specifications while m a intaining
the dim ension shown in Fig. 3B-32. Reinstall the
interm ediate shaft and universal jo in t assembly as
outlined under "In term ed iate Steering Shaft with
Universal Joint Couplings - Installation".
1. Remove the steering wheel as outlined under
"Steering Wheel - Removal".
2. Remove the directional signal switch cancelling
cam and spring.
3. Remove the column to instrum ent panel trim
plate (if so equipped).
4. Disconnect the directional signal switch wiring
harness at the half-moon connector.
5. Pry the wiring harness protector out of the
column retaining slots as shown in Figure 3B-85.
6. M ark the location of each wire in the half-moon
connector and then remove each individual wire from
the cover flange (fig. 3B-87). Turn the tool center screw
clockwise to pull the cover from the housing.
10.
Remove the three directional signal switch
mounting screws and then carefully remove the switch
assembly from the column while guiding the wiring
harness through the opening in the shift lever housing.
Installation
Fig. 3B 87 Removing D irectional Signal Housing
Cover
Fig. 3B-88--Preparing W ire Retaining Tabs for
In stallation
the connector using Tool J-22727 (fig. 3B-86). Insert the
tool into the lower end of the connector an d push in until
the tool bottoms on the connector. Remove the tool and
then pull the wire from the connector.
7. Remove the directional signal lever screw and
remove the lever.
8. Push in on the hazard w arning light knob and
then unscrew and remove the knob.
9.
Tilt Columns Only
a. Automatic Transmission Models - Remove the
P R N D L dial screws and remove the dial and indicator
needle. Remove the cap and dial illumination bulb from
the housing cover.
b.
Unscrew and remove the tilt release lever.
c. Assemble Tool J-22708 inside the directional
signal housing cover; push in until the tangs lock inside
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fasteners referred to in
step 9.
1. W rap the ends o f the directional signal switch
wires with tape and then guide them through the
opening at the lower left hand side o f the bearing
housing (tilt columns) out the lower end o f the shift lever
housing and under the dash seal.
2. Place the directional signal switch in position
and install the three mounting screws; torque to 25 lbs.
in. after screw head has been firmly seated.
3. Tilt Columns Onlya. Align the openings in the directional signal
switch cover with the proper lever positions and tap the
cover into place using a plastic ham m er.
b. Install the tilt release lever.
c. Automatic Transmission Model - Install the
P R N D L dial, pointer, dial illumination bulb and cap.
4. Install the directional signal switch lever and
hazard w arning knob.
5. Bend the wire retaining tabs slightly outward on
each wire in the wiring harness as shown in Figure 3B88; this will provide proper retention o f the wire in the
half-m oon connector.
6. Install each wire in its marked location in the
half-m oon connector. Push in until square part o f clip is
flush with the bottom side o f the connector. Connect the
directional signal switch wiring harness.
7. Snap the wiring harness protector into the
column retaining slots.
8. Install the directional signal cancelling cam and
spring.
9. Install the steering wheel as outlined under
"Steering Wheel - Installation".
10. Install the column to instrument panel trim
plate (if so equipped).
T IL T CO LUM N BEARING H O U S IN G
ASSEMBLY - G A N D P SERIES
Removal (Column in Vehicle)
1. Disconnect the battery ground cable.
2. Remove the steering wheel as outlined under
"Steering Wheel - Removal".
3. Remove the directional signal switch as outlined
under "Directional Signal Switch - Removal".
4. Column Shift Models - Using a suitable size
punch, drive out the shift lever pivot pin and remove the
shift lever.
5. Install the tilt release lever and place the column
in the full " u p " position. Remove the tilt lever spring
and retainer using a screwdriver that just fits into the slot
opening. Insert the screwdriver into the slot, push in
approxim ately 3 /1 6 ", rotate clockwise approximately 1/8
turn until the retainer ears align with the grooves in the
housing and remove the retainer and spring.
6. Remove the steering shaft bearing locknut using
Socket J-22599. Remove the upper bearing race seat and
race.
7. Remove the two b earing housing pivot pins
using Tool J - 2 1854.
8. Pull up on the tilt release lever (to disengage the
lock shoes) and remove the bearing housing.
If the b earing housing is being replaced or it is
necessary to disassemble the bearing housing,
proceed as follows:
a. Press the upper and lower bearings out of the
housing.
b. Using Puller J-5822 and Slide H am m er
J-2619, pull the bearing races fro m the housing.
c. Remove the tilt release lever.
d. Drive out the shoe release pivot pin using
Tool J-22635 or a suitable punch. Remove the lever
spring and remove the wedge.
e. Using a suitable size punch, drive out the lock
shoe retaining pin. Remove the shoes and shoe springs.
If the up per steering shaft, lower steering shaft, or
centering spheres are being removed, proceed as follows:
9. To remove the steering shaft assembly through
the u pper end o f the column. If it is necessary to
disassemble the shaft, proceed as follows:
a. To remove the lower steering shaft first
disconnect the shaft at the pot jo in t coupling clamp.
b. T urn the u pper shaft 90° to the lower shaft
and slide the upper shaft and centering spheres from the
lower shaft.
c. Rotate the centering spheres 9 0 : and remove
the centering spheres and preload spring from the upper
shaft.
If the bearing housing support is being replaced,
proceed as follows:
10. Remove the four bearing housing support
screws and remove the support.
Assembly
CAUTION: See caution note on page 7 o f this
section regarding the fa steners referred to in
steps 3, 9 and 11.
1. Assemble the steering shaft as follows:
a. Lubricate and assemble the centering spheres
and preload spring.
b. Install the spheres into the upper (short) shaft
and rotate 90 °.
c. Install the lower shaft 90 to the upper shaft
and over the centering spheres. Slowly straighten the
shafts while compressing the preload spring.
2. Install the shaft assembly into the housing from
the upper end.
3. Install the lower shaft to the pot jo in t coupling
clamp. Install the coupling clam p bolt and torque to
specifications.
N O T E : The coupling bolt must pass through the
shaft undercut.
4.
Assemble the bearing housing as follows:
a. Press the new upper and lower bearing races
into the bearing housing.
b. Lubricate and install the bearings into the
bearing races.
c. Place the lock shoe springs in position in the
housing. Install each shoe in place and compress the
spring until a suitable size straight punch can be used to
hold the shoe in position (it may be necessary to acquire
assistance to install the shoes). Once the shoes are in
place, drive in the shoe retaining pin.
d. Install the shoe release lever and drive in the
pivot pin.
e. Install the tilt release lever.
f. Lubricate the shoes and release lever.
5. Install the bearing housing assembly to the
support. Hold the tilt release lever in the " u p " position
until the shoes have fully engaged the support. Lubricate
and install the bearing housing pivot pins. Press the pins
in flush with the housing.
6. Place the housing in the full " u p " position and
then install tilt spring and retainer (tapered end o f
spring first). Push into the housing approximately 3 /1 6 "
and rotate counterclockwise 1/8 turn.
7. Lubricate and install the upper bearing race,
race seat and locknut. Tighten the locknut (using Socket
J-22599) to remove the lash and then carefully further
tighten 1/16 to 1/8 o f a turn (column must be in straight
ahead position).
8. Remove the tilt release lever.
9. Install the directional signal switch as outlined
under "Directional Signal Switch - Installation".
10. Column Shift Models - Install the shift lever
and pivot pin.
11. Install the steering wheel as outlined under
"Steering Wheel - Installation".
12. Check electrical and mechanical functioning o f
column.
S TEERING C O L U M N -G A N D P SERIES
Removal (Fig. 3B-89)
1. Disconnect the battery ground cable.
2. Column Shift Models - Disconnect transmission
shifter rods at the lower end of the column.
3. G Models - Remove the interm ediate steering
shaft flange to flexible coupling bolts.
P Models - Remove the interm ediate steering shaft
upper universal yoke to steering shaft pinch bolt.
Mark the coupling to shaft relationship.
4. Remove column clamp screw(s) on engine side
of firewall, if equipped, and remove or slide the clamp
down the column.
5. From inside the vehicle, remove the screws from
the toe pan cover and slide the cover and seal up the
column.
6. Remove the steering wheel as outlined under
"S teering W heel-Removal", and reinstall the shaft nut
and washer.
7. All Columns - Disconnect the directional signal
w iring harness. S tandard Column with Automatic
CLUTCH A N D BRAKE
PEDAL SUPPORT
PROTR U SIO N
EX SLOT
V IE W A
Fig. 3B-89--Steering Column InstaIlation-G Series
Transm ission - Disconnect the conductor tube (for
transmission indicator) at the instrum ent panel.
Tilt C olum n with A u to m a tic T ra nsm issio n Disconnect the single wire at the fuse block and
unclip it from the parking brake bracket.
8. Remove the cap screws from the column support
bracket at the dash panel.
9. Carefully lower and then withdraw the column
assembly, rotating so that the shift levers clear the toe
p an opening.
Standard Colum n (Fig. 3 B -9 0)
Disassembly
N O TE: For floor shift transmission models, omit
Steps 4, 14, 15 and 16.
1. Remove the steering wheel nut and lock washer
and then slide the steering shaft assembly from the lower
end o f the column.
2. G Models - Remove the lower bearing preload
spring and clam p from the steering shaft.
P Models - Remove the lower bearing preload
spring and clamp.
3. Remove the back-up lamp switch.
4. Drive out the shift lever pivot pin and remove
the shift lever.
5. Remove the directional signal cancelling cam.
Remove the directional signal switch lever.
6. Remove the column wiring harness cover.
7. Remove the directional signal switch screws.
8. Rotate the directional signal switch housing
counterclockwise and remove the housing from the
column.
NOTE: The housing and switch cannot be fully
removed from the column until the shift lever
housing is removed.
9. Remove the plastic thrust washer assembly and
then remove the shift lever housing (or extension
housing) from the column.
10. Separate the directional signal switch, switch
control support assembly, directional signal housing and
shift lever housing (or housing extension) assemblies.
11. Press the steering shaft upper bearing out o f
the switch contact support.
12. Remove the shift lever housing (or extension
housing) seat and bushing from the upper end of the
column.
13. Remove the bolt and screws from the adjusting
ring clamp and remove the clamp, adjusting ring and
lower bearing. Press the lower bearing out of the
adjusting ring.
14. 3-Speed Columns - Remove lst-reverse shift
lever and lever spacer.
Automatic Columns - Remove the selector plate
clamping ring screws (3).
15. Place the column u p rig h t on the floor,
supporting it with two pieces of wood. Place a block o f
wood on the upper end o f the shift tube. Press down on
G A & PA 1 0 0 -
1 . U p p e r S te e rin g S h a ft
13.
S h ift T u b e F e lt W a s h e r
25.
T u rn S ig n a l S w itc h S c re w
2.
S h ift H o u s in g B u sh in g
1 4.
S h ift T u be A s s e m b ly
26.
T u rn S ig n a l S w itc h
3.
B ush in g S ea t
15.
S h ift L e v e r S p a c e r
27.
S te e rin g S h a ft U p p e r B e a rin g
4.
M ast J a c k e t
1 6.
ls t- R e v e r s e S h if t L e v e r
28.
S w itc h C o n t a c t S u p p o rt
5.
C o lu m n C o v e r
1 7.
A d ju s t in g Ring
29.
T u rn S ig n a l H o u s in g
6.
B a c k - U p L am p S w it c h S cre w
18.
S h a ft L o w e r B e a rin g
30.
T u rn S ig n a l S w itc h L e v e r S cre w
7.
B a c k - U p L am p S w itc h
1 9.
L o w e r B e a rin g P re lo a d S p rin g
31 . T u rn S ig n a l S w itc h L e v e r
8.
T oe Pan S e a l R e ta in e r
20.
P re lo a d S p rin g C la m p
32.
9.
Toe Pan S e a l
21.
N u t and L ockw a sh er
33.
P la s tic T h ru s t W a s h e r
A d ju s t in g R ing C la m p S cre w s
22.
S te e rin g S h a ft N u t
34.
S h ift L e v e r H o u s in g
1 1.
N u t and Lockw asher
23.
Lockw asher
35.
S h ift L e v e r Pin
1 2.
A d ju s t in g R ing C la m p B o lt
24.
T u rn S ig n a l C a n c e llin g C a m
36.
S h ift L e v e r
10.
R u b b e r R ing
F ig . 3 B -9 0 --S ta n d a rd C o lu m n —T y p ic a l G & P
the shift lever with foot while tapping on the wood block
to withdraw the tube from the column jacket.
N O TE: In some tolerance stack-up cases it may be
necessary to use a press. Be careful not to dam age
the tube or jacket.
16. Remove the felt seal from the shift tube.
17. Remove firewall clamp, toe p a n seal and dash
panel seals from the jacket.
Assembly
N O TE : In the following assembly sequence use any
general purpose lithium soap grease for lubricating
those components so indicated.
1. Install the dash panel seal, toe panel and firewall
clamps over the end of the jacket.
2. Lubricate all bearing surfaces on the shift tube.
3. Place the felt seal onto the shift tube (next to
spring) and then place the shift tube in the jacket.
4. 3-Speed Columns - Tem porarily install spacer,
1st-reverse shift lever and lower adjusting ring. Place a
block of wood on top of the adjusting ring and tap until
the shift tube bottoms. Remove adjusting ring, shift lever
and spacer.
Automatic Columns - Align the three holes in the
selector plate with the three holes in the jacket,
position the clamping ring and install the three
screws.
NOTE: The shift tube spring retainer must be
bottomed against the jacket stops.
5. 3-Speed Columns-Lubricate and install the
spacer and 1st-reverse shift lever (tang o f lever towards
top of column).
6. Install lower bearing in the adjusting ring and
then install the adjusting ring, clamp and screws.
7. Install the shift lever housing (or extension
housing) seat and bushing to upper end of housing.
8. Thread directional signal switch wiring harness
through the switch and lever (or extension) housings,
lubricate the inner d iam eter o f the shift housing, and
then place the shift lever (or extension) housing onto the
up per end o f the column.
9. Install the switch housing plastic w asher
assembly. Press the upper bearing into the switch contact
support.
10. Install the directional signal switch housing,
contact support, bearing and switch and torque the
switch screws to 25 lbs. in.
11. Install the column wiring harness cover and
back-up lamp switch.
12. Install the directional signal and gearshift
levers.
13. Adjust the shift tube as outlined under "Shifter
Tube A djustm ent."
14. Loosely install the lower bearing preload
spring and clamp.
15. Slide the steering shaft assembly up through
the column assembly. Install the directional signal
cancelling cam, steering shaft nut an d lock washer.
T ilt Colum n (Fig. 3 B -91)
Disassembly
1. If the column is removed from the vehicle, place
the column in a bench vise using Holding Fixtures
J-22573 (fig. 3B-92).
CAUTION: Clamping the column directly in a
vise, could result in a dam aged column.
2. Remove the directional signal switch as outlined
under "D irectional Signal Switch-Removal".
3. Remove the lower steering shaft and pot joint
assembly and lower bearing and adapter assembly as
outlined under "Low er Bearing and A dapter-Rem oval".
4. C olum n Shift Models - Using a suitable size
punch, drive out the shift lever pivot pin and remove the
shift lever.
5. Install the tilt release lever and place the column
in the full " u p " position. Remove the tilt lever spring
and retainer using a screwdriver that just fits into the slot
opening (fig. 3B-93). Insert the screwdriver clockwise
approxim ately 1/8 turn until the retainer ears align with
the grooves in the housing and remove the retainer and
spring.
6. Remove the steering shaft bearing locknut using
socket J-22599. Remove the u pper bearing race seat and
race.
7. Remove the two bearing housing pivot pins
using Tool J-21854 (fig. 3B-94).
8. Pull up on the tilt release lever (to disengage the
lock shoes) and remove the bearing housing. If it is
necessary to disassemble the b earing housing, proceed as
follows:
a. Press the upper an d lower bearings out of the
housing.
b. Using Puller J-5822 and Slide H a m m e r J-2619
pull the bearing races from the housing (fig. 3B-95).
c. Remove the tilt release lever.
d. D rive out the shoe release lever pivot pin
using Tool J-22635 or a suitable punch (fig. 3B-96).
Remove the lever spring and remove the wedge.
e.
Using a suitable size punch, drive out the lock
shoe retaining pin. Remove the shoes and shoe springs.
9. Remove the steering shaft assembly through the
upper end o f the column. If it is necessary to disassemble
the shaft proceed as follows:
a. T urn the upper shaft 90° to the lower shaft
and slide the upper shaft and centering spheres from the
lower shaft.
b. Rotate the centering spheres 90° and remove
the center spheres and preload spring from the upper
shaft.
10. Remove the four bearing housing support
screws and remove the support.
Column Shift Models - If the shift tube index plate
must be removed, remove the two retaining screws
and remove the plate.
11. Remove the shift tube retaining ring with a
screwdriver (fig. 3B-97). Remove the thrust washer.
12. Remove the neutral-safety or back-up lam p
switch screws and remove the switch.
13. Rework Shift Tube Removing Tool J-22551 by
removing 1 /2 " from the pilot end of the tool (Fig. 3B98). This allows the shift tube to be pushed further out of
the housing and will not affect the use o f the tool on
other columns.
14. Remove the shift tube assembly using Tool
J-22551 (fig. 3B-99). Insert the hooked end o f the tool
into the notch in the shift tube just below the shift lever
housing key. Pilot the sleeve over the threaded end o f
the tool and into the upper end o f the shift tube. Force
the shift tube out o f the housing by turning the nut onto
the tool. If the shift tube is not completely free when the
nut is bottomed on the threads, complete the removal by
hand.
CAUTION: Do not ham mer or p u ll on the shift
tube during removal. On column shift models,
guide the lower shift lever through the slotted
opening in the column to prevent damage to the
tube or column.
15. Remove the lock plate by sliding out of the
column notches, tipping the plate downward toward the
housing (to compress the wave washer) and then
removing as shown in Figure 3B-100. Remove the wave
washer.
16. Remove the shift lever housing.
17. Column Shift Models - Remove the shift lever
spring by winding the spring up with pliers.
18. If necessary, remove the dash panel seal,
m ounting plate and the instrum ent panel seal from the
column jacket.
Assembly
NOTE: W hen lubricating components during the
following installation sequence, use any general
purpose lithium soap grease.
1. Install the dash panel seal, m ounting plate and
the instrument panel seal on the column.
2. Colum n Shift Models - Press a new shift lever
spring into the shift lever housing.
3B-62
COVER
SHAFT ASSY
------RACE
W ED G E
SHAFT
SCREW (3)
SPRING
" \ PIN DOWEL
\
\
\
BEARING A S S Y .\
RETAINER
/
\
*y>
\
\
SPRING ( 2 ) - . \
PIN RELEASE —
U
\
\
o \
^
SUPPORT
\
“
CLIP
TUBE
ASSY. SHIFT
^
-p r '
SPRING TILT
*•
( 2 ) PIN PIVOT
BOW L ASSY
PROTECTOR
WIRE
SCREW
JACKET DASH
SEAL RETAINER
DASH SEAL
SCREW (4)
P
/" S P R IN G
PLATE
RETAINER
THRUST WASHER
\
PLATE LOCK
W A V E WASHER
BOWL
SEAL
LEVER
ADAPTER
RETAINER
BEARING
MANUAL
Column-G
BEARING AS SY . —
JACKET
SUPPORT
ASSY.
qg,
SHOE RELEASE------ *
SPHERE
CENTERING (2)
SHAFT
®
\
YOKE
SERVICE
H O U S IN G ----- H O U S IN G
ASSY,
BEARING
BUMPER (3 ) \
SPRING RELEASE.
SHAFT
ASSY. STEERING
TRUCK
Fig. 3B-91- Tilt Steering
JACKET
A S S Y .-
S W ITC H ASSY.
^
LIGHT
rx
e
INSTRU. PANEL
O P E N IN G C O V E R - ,
Fig. 3B-92 Securing Column with J-22573
Fig. 3B-94- Removing Bearing Housing Pivot Pin
STEERING SHAFT
BEARING LO CKNUT
J -5 8 2 2
J-2 619
TILT LEVER
SPR IN G RETAINER
Fig. 3B-93--Removing T ilt Spring and Retainer
Fig. 3B-95-R em oving Bearing Race
3. Slide the shift lever housing over the upper end
o f the column.
6. Pull up on the shift lever housing (to compress
the wave washer) and install the thrust w asher and
retaining ring. Be sure the ring is seated in both slots of
the shift tube.
7. Lubricate the I.D. of the bearing housing
support and install the support, aligning the bolt holes in
the support with the bolt holes in the lock plate. Install
the four support screws and torque to 45 in. lbs.
8. Assemble the steering shaft as follows:
a. Lubricate and assemble the centering spheres
and preload spring.
b. Install the spheres into the upper (short) shaft
and rotate 90 °.
c. Install the lower shaft 90° to the upper shaft and
over the centering spheres. Slowly straighten the shafts
while compressing the preload spring.
9. Install the shaft assembly into the housing from
the upper end.
10. Install the lower bearing and adapter, bearing
4. Place the wave washer and lock plate in
position. Work the lock plate into the notches by tipping
the plate toward the housing (compressing the wave
washer) at the open side o f the column. Lubricate the
lock plate and upper end o f the shift tube.
5. Carefully install the shift tube into the lower
end o f the column (make sure the foam seal is at lower
end o f the shift tube). Align the keyway in the tube with
the key in the shift lever housing and complete
installation o f the shift tube using Tool J-22549 (fig. 3B101). The shift lever housing key must bottom in the
shift tube slot to be fully installed. Remove Tool J-22549
from the column. Lubricate and push foam seal in flush
with column housing.
CAUTION: Do Not ham m er or force the tube
when installing in the column.
Fig. 3ES-96 -Removing Release Lever Pivot Pin
Fig. 3B 98--Revised Shift Tube Removing Tool
J-22551
Fig. 3B-97 Removing Shift Tube Retaining Ring
Fig. 3B-100--Removing Lock Plate Assembly
until the shoes have fully engaged the support. Lubricate
and install the bearing housing pivot pins. Press the pins
in flush with the housing.
13. Place the housing in the full " u p " position and
then install tilt spring and retainer (tapered end o f
spring first). Push into the housing approximately 3 /1 6 "
and rotate counter clockwise 1/8 turn.
14. Lubricate and install the upper bearing upper
race, race seat and locknut. Tighten the locknut (using
Socket J-22599) to remove the lash and then further
tighten 1/16 to 1/8 o f a turn (column must be in straight
ahead position).
15. Remove the tilt release lever.
16. Install the directional signal switch as outlined
under "Directional Signal Switch-Installation".
17. Column Shift Models - Install the shift lever
and pivot pin.
18. Install the neutral-safety or back-up lamp
switch.
19. Remove the column from the bench vise.
COLUMN INSTALLATION
M andatory Sequence P Series (Fig. 3B -89)
CAUTION: See C A U TIO N note on page 1 o f
this section regarding the fasteners referred to
in steps 1, 2, 3 an d 10.
1. Applying 50 lbs. force on the steering wheel end
o f the steering shaft, adjust the lower bearing preload to
allow steering shaft end play as indicated in Figure 3B38. Tighten the shaft clamp on pot joint bolt to
specifications.
2. From the passenger side of the dash panel,
carefully insert the lower end o f the steering column
through the toe panel opening.
G uide the steering shaft into the universal yoke,
lining up the marks made at removal. Install the
Fig. 3B-101 In sta llin g S hift Pin Tube
reinforcement, wire clip, pot jo in t coupling and lower
shaft as described under "Low er Bearing Installation".
11. Assemble the bearing housing as follows:
a. Press the new upper and lower bearing races
into the bearing housing.
b. Lubricate and install the bearings into the
b earing races.
c.Place the lock shoe springs in position in the
housing. Install each shoe in place and compress the
spring until a suitable size straight punch can be used to
hold the shoes in position (it m ay be necessary to acquire
assistance to install the shoes). Once the shoes are in
place, drive in the shoe retaining pin.
d. Install the shoe release lever and drive in the
pivot pin.
e. Install the tilt release lever.
f. Lubricate the shoes and release lever.
12. Install the bearing housing assembly to the
support. Hold the tilt release lever in the " u p " position
Fig. 3B -103 -Tilt Column S h ift Indicator Light
yoke pinch bolt and torque to specifications. The
pinch bolt must pass through the shaft undercut.
3. Position and attach the lower clam p mounting
bracket to the firewall. Locate the steering column
protrussions against the toe p a n bracket while at the
same time, aligning protrusion in brake an d clutch pedal
support with index slot in the steering column, as shown
in Figure 3B-89. Install the column to bracket clamp and
torque the clam p bolt to specifications.
N O TE : The toe pan bracket must not override the
protrusions on the steering column.
4. Position the steering column to dhas panel
bracket, install the attaching bolts and torque to
specifications.
5. If plastic spacers were used on the flexible
coupling alignm ent pins, remove the spacers after all
bolts have been properly torqued.
6. Install the seal at the toe pan and then install
the toe pan bracket screws; torque to specifications.
7. Install the dash panel trim plate (if so
equipped).
8. Connect the transmission shift linkage on
column shift models.
9. All Colum ns - Connect the directional signal
wiring harness.
S ta n d ard Column with Automatic Transmission Connect the conductor tube (for transmission
indicator) at the instrum ent panel (fig. 3B-102).
10. Install steering w heel as ou tlined u nd e r
"S teering W heel-Installation".
11. Connect battery ground cable.
steering shaft (A). Position the spring and clamp to
m aintain the dimension as shown in Figure 3B-38.
2. Install the plastic spacers onto the flexible
coupling alignment pins.
3. From inside the vehicle, carefully insert the
lower end o f the column through the toe pan opening
guiding the steering shaft flange onto the flexible
coupling. Install and torque the glange to coupling bolts.
4. Locate the index slot in the column jacket with
the protrusion on the clutch and brake pedal support.
5. Loosely install the column dash bracket and
screws.
6. Push the column down until the steering shaft
flange bottoms on the plastic spacers on the flexible
coupling and then torque the dash bracket screws.
7. Remove the plastic spacer from the alignment
pins using a wire hook. Check the rag jo in t to steering
shaft flange clearance (.25" to .325"), if not within
specifications, the dash bracket screws must be loosened
and the column raised or lowered as required. Retorque
the bracket screws.
CAUTION: The alignment pin plastic spacers
must be removed before the vehicle can be
driven.
8. Push the tow pan seal to the toe pan, install and
torque the m ounting screws.
9. All Columns Connect the directional signal
switch wiring harness.
Automatic Columns-Connect the conductor tube (for
transmission indicator) to the instrum ent panel.
10. Install the steering wheel as outlined under
"Steering Wheel Installation".
11. Connect the transmission linkage.
12. Connect the battery ground cable.
S TEERING LINKAG E
CAUTION: See C A U T IO N on page 1 o f this
section regarding all fasteners referred to in
servicing steering linkage components.
Tie Rods
Removal
1. Raise vehicle on hoist.
2. Remove cotter pins from ball studs and remove
castellated nuts.
3. To remove outer ball stud, tap on steering arm
at tie rod end with a h a m m er while using a heavy
h a m m e r or similar tool as a backing (fig. 3B-105).
4. Remove inner ball stud from relay rod using
same procedure as described in Step 3.
5. To remove tire rod ends from tie rod, loosen
clamp bolts and unscrew end assemblies.
M an d ato ry Installation S equence-G Series
CAUTION: See C A U T IO N on page I o f this
section regarding the fasten ers referred to in
steps 3 and 10.
1.
Adjust the column lower bearing preload by
applying a force on the steering wheel end o f the
Installation
CAUTION: See the C A U T IO N on page I o f
this section regarding the fasteners referred to
in steps 4 and 6.
NOTE: Tie rod adjuster components often become
rusted in service. In such cases, it is recommended
RELAY ROD
IDLER ARM
ASSEMBLY
TIE ROD
ASSEMBLY
[A ] iCAUtlORI A ll clam ps must be b e tw e e n &
cle a r o f dim ples b e fo re to rq u in g nut.
KNUCKLE
[~B~| E xposed socket th re a d le n g th must be
STEERING GEAR
equal w ith in ± .0 6 at e a ch end o f a d
justing sleeve on L.H. & R.H. tie ro d asm.
P IT M A N A R M 1
[ C ] A ll bolts must be in stalled in d ire ctio n s
C-SERIES
show n - Figs. 104 and 104B
/
sO k ":
X i- -
^ iu
ADJUSTABLE C O N N E C T IN G ROD
IDLER ARM
ASSEMBLY
STEERING
ARM
RELAY ROD
TIE ROD
ASSEMBLY
TIE ROD
KNUCKLE'
STEERING GEAR
ASSEMBLY
->
STEERING GEAR
P IT M A N '
ARM
STEERING'
ARM
PITM A N ARM
VANS
K-SERIES
■SUPPORT ASSEMBLY
GEAR M O U N T IN G
BRACKET
SUPPORT
SUPPORT ASSEMBLY
LEFT IDLER
ARM
V'®-
"N d
RELAY ROD
IDLER ARM
ASSEMBLY
P ITM A N
ARM
KNUCKLE
C O N N E C T IN G
ROD
'STEERING GEAR
MOTOR HOME
P ITM A N ARM
ASSEMBLY
MOTOR HOME
Fig. 3B-105--Ball Stud Removal-Typical
that if the torque required to remove the nut from
the holt afte r breakaway exceed 7 pounds, discard
the nuts and bolts. Apply p enetrating oil between
the clamp and tube and rotate the clamps until
they move freely. Install new bolts and nuts having
the same p a rt n u m b e r to assure pro p e r clamping at
the specified nut torque.
CAUTION:A s a guide to correct orientation o f
the inner tie rod end relative to the outer tie rod
end, rotate both ends to the extremes o f travel
in the same direction before clamping. The
position o f each tie rod end m ust be m aintained
as the clamps are tightened to ensure free
movement o f each joint. Return the rod
assembly to midposition o f its travel. This
should result in the inner and outer bait studs
being retained in a parallel relationship with
the intermediate (relay) rod and steering
knuckle (arm) respectively. The following
procedure should be used when installing tie
rods.
1. If the tie rod ends were removed, lubricate the
tie rod threads with EP Chassis lube and install ends on
tie rod making sure both ends are threaded an equal
distance from the tie rod.
2. Make sure that threads on ball studs and in ball
stud nuts are perfectly clean and smooth. Check
condition o f ball stud seals; replace if necessary.
NOTE: Tool J-24434 may be used to install ball
stud seals.
If threads are not clean and smooth, ball studs may
turn in tie rod ends when attem pting to tighten nut.
3. Install ball studs in steering arms and relay rod.
N O T E Slot in adjuster
sleeve must not be
w ith in this area o f
clamp jaws.
Clamps must be between
& clear o f dimples before to rq u in g nut.
C A U T IO N
T IE ROD ’ADJU STER
SLEEVE
SLO T
REARW ARDR O T A TIO N
N O T E Locate clamps
w itn in tolerance shown.
V IE W
A
RELAY
STEERING K N U C K LE
N O T E Equal w ith in three threads,
must be visible at inner and outer
ends o f adjuster sleeve when assembled
to steering knuckle.
N O T E Locate clamps
w itn in tolerance shown.
•TIGHT
Slot in adjuster
sleeve must not be w ith in
this area o f clamp jaws.
NOTE
H O R IZ O N T A L
LINE
.005 M IN . GAP
T IG H T '
C A U T I O N Clamp ends may
touch when nuts are torqued
to specifications, but gap
adjacent to adjuster sleeve
must not be less than
m inim um dim ension shown.
VIE W
B
C,K & P
OUTER
A
.005
M IN . GAP
A D JU S TE R
SLEEVE SLOT
R EAR W AR D
R O T A TIO N
VIE W
A
C A U T I O N Clamp ends may
touch when nuts are torqued
to specifications, b u t gap
adjacent to adjuster sleeve
must n o t be less than
m inim um dim ension shown.
VIE W
B
in Figure 3B-107. C enter protractor bubble indicator and
record reading.
d. Rotate tie rod end clockwise (down) to
m axim um position. Center protractor bubble indicator
and record reading.
e. Com pare protractor readings obtained in
Speps c and d. Total rotation of tie rod assembly should
measure at least 35 °.
f. If rotation is less than 35 loosen one tie rod
sleeve clamp and rotate both tie rod ends to their
maximum limit both ends must be rotated in the same
direction
Fig. 3B-107--Tie Rod Inspection
4. Install bass stud nut, tighten to specifications
and install new cotter pins; see Specifications Section at
rear o f this Section. Lubricate tie rod ends.
N O T E: N ever back off nut to align the cotter pin,
always tighten nut to next slot that lines up with
hole in stud.
5. Adjust toe-in as described in Section 3A.
Before tightening the tie rod
adjusting sleeve clamp holts, be sure that the
following conditions have been met:
a. The sleeve clamps must be positioned between
the locating dimples at either end o f the sleeve.
b. T he clamps must be positioned within the
a ngular travel indicated in Figure 3B-106.
c. The relationship o f the clamp slot with the slit
in the sleeve should be m ain tain ed as shown in Figure
3B-106.
d. Rotate both inner and outer tie rod housing
rearw ard to the limit o f ball joint travel before
tightening clamps. Tighten clamps to specifications.
Return tie rod assembly to the center of travel.
e. All procedures for alignment, adjustment and
assembly of tie rods applies to each side.
f. Check each assembly to be sure that a total
travel o f at least 35° can be obtained using a bubble
protractor and a pair o f vise grips (Fig. 3B-107).
CAUTION:
g. Tighten tie rod clamp and again rotate both
ends to their m axim um limits, repeating Steps c and d.
This recheck of total rotation will result in a m inim um of
35 ! travel.
h. A fte r o b ta in in g the correct a m o u n t o f
rotation (35 ° or greater), position the outer tie rod end
approximately midway in this travel.
II' rotating checks, outlined above, reveal a rough or
lumpy feel, the inner or outer tie rod end assembly may
have excessive wear and should be replaced.
If all of the above mentioned conditions are met,
proper tie rod installation is assured.
Relay Rod
Removal
1. Raise vehicle on hoist.
2. Remove in n e r ends of the tie rods from relay
rod as described under "Tie Rod-Removal".
3. Remove the cotter pins from the p itm an and
idler arm ball studs at the relay rod. Remove the
castellated nuts.
4. Remove the relay rod from the pitm an and idler
arms by tapping on the relay rod ball stud bosses with a
hammer, while using a heavy h am m er as a backing (fig.
3 B-105).
5. Remove the relay rod from the vehicle.
Installation
CAUTION: See the C A U T IO N on page 1 o f
this section regarding the fasteners referred to
in steps 2 and 3.
1. Make sure that threads on the ball studs and in
the ball stud nuts are perfectly clean and smooth. Check
condition of ball stud seals; replace if necessary.
NOTE: If threads are not clean and smooth, ball
studs may turn in sockets when attempting to
To ensure proper in sta llatio n , it is necessary to
tighten nut.
p erfo rm the following inspection after any change of toe
2. Install the relay rod to the idler arm and pitm an
setting or removal o f any ball stud:
arm ball studs, making certain the seals are in place.
1.
Check the total rotation o f the tie rod assemblyInstall and torque the nut to specifications and then
using the following procedure:
install the cotter pin.
a. Lubricate inner and outer tie rod ends.
NOTE: Never back off the nut to align cotter pin,
b. Attach vise grip pliers to the outer tie rod
always tighten nut to next slot that lines up with
end.
hole in stud.
c. Rotate outer tie rod end counterclockwise (up)
to m axim um position. Attach bevel protractor as shown
3. Install the tie rods to the relay rod as previously
Inspection
described u nd er "T ie. Rod- Installation". Lubricate the
tie rod ends.
4. Lower the vehicle to the floor.
5. Adjust toe-in (see Section 3A) and align steering
wheel as described previously in this section under
"Steering Wheel A lignm ent and High Point Centering".
Idler Arm
Use o f the pro p e r diagnosis and checking procedure
is essential to prevent needless replacement o f good idler
arms.
1. Raise the vehicle in such a m a n n e r as to allow
the front wheels to rotate freely and the steering
m echanism freedom to turn. Position the wheels in a
straight ahead position.
2. Using a push pull type spring scale located as
n ear the relay rod end o f the idler arm as possible, exert
a 25 lb. force upw ard and then downward while noticing
the total distance the end of the arm moves. This
distance should not exceed ” 1/8 inch for a total
acceptable m ovem ent o f 1/4 inch (Figure 3B-108). It is
necessary to ensure that the correct load is applied to the
arm since it will move more w hen higher loads are
applied. It is also necessary that a scale or ruler be rested
against the fram e and used to determine the am ount of
m ovem ent since observers tend to over-estimate the
actual movem ent w hen a scale is not used. The idler arm
should always be replaced if it fails this test.
N O T E : Jerking the right front wheel and tire
assembly back and forth thus causing an up and
down m ovem ent in the idler arm is not an
acceptable method o f checking since there is no
control on the am ount o f force being applied.
Caution should be used in assuming shimmey
complaints are caused by loose idler arms. Before
suspecting suspension or steering components, techni
cians should eliminate shim my excitation factors, such as
dynam ic imbalance, run-out or force variation o f wheel
and tire assemblies and road surface irregularities.
Removal
1. Raise vehicle on a hoist.
2. Remove the cotter pin an d castellated nut from
ball stud at the relay rod. Remove the ball stud from the
relay rod by tapping on the relay rod boss with a
ham m er, while using a heavy h a m m e r as a backing (fig.
3B-105).
3. Remove the idler arm to fram e bolt and remove
the idler arm assembly.
Installation
CAUTION: See the C A U T IO N on page 1 o f
this section regarding the fasteners referred to
in steps 1 and 3.
1. Position the idler arm on the fram e and install
the m ounting bolts (special plain washers under bolt
heads); torque the nuts to specifications.
2. M ake sure that the threads on the ball stud and
in the ball stud nut are perfectly clean and smooth.
Check condition o f ball stud seal; replace if necessary.
NOTE: If threads are not clean and smooth, ball
stud m ay turn in the socket when attem pting to
tighten nut.
3. Install the idler arm ball stud in the relay rod,
making certain the seal is positioned properly; install the
nut and torque to specifications.
NOTE: Never back off nut to align cotter pin,
always tighten nut to the next slot that lines up
with the hole in the stud.
4. Install cotter pin.
5. Lower the vehicle to the floor.
Pitm an Arm
Removal
1. Raise vehicle on hoist.
2. Remove cotter pin from p itm an arm ball stud
and remove nut.
3. Remove pitm an arm or relay rod from ball stud
by tapping on side o f rod or arm (in which the stud
mounts) with a h a m m e r while using a heavy h a m m e r or
sim ilar tool as a backing (fig. 3B-105). Pull on linkage to
remove from stud.
4. Remove p itm an arm nut from p itm an shaft or
clamp bolt from p itm an arm, and mark relation o f arm
position to shaft.
5. Remove pitm an arm, using Tool J-6632 or
J-5504 (Fig. 3B-50).
Installation
CAUTION: See the C A U T IO N on page 1 o f
this section regarding the fasteners referred to
in steps 3 and 4.
1.
Install p itm a n arm on p itm an shaft, lining up
the marks made upon removal.
CAUTION: I f a clamp type p itm a n arm is used,
spread the pitm an arm ju s t enough, with a
wedge, to slip arm onto pitm an shaft. Do not
spread pitm an arm more than required to slip
over p itm a n shaft with hand pressure. Do not
ham m er or damage to steering gear m ay result.
Be sure to install the hardened steel washer
before installing the nut.
NOTE: For proper alignment and orientation o f
connecting rod clamps see figure 3B-109.
POWER S TEERING SYSTEM
Pow er Steering Gear
Removal
2. Make sure that threads on ball studs and in ball
stud nuts are clean and smooth. Check conndition o f ball
stud seals; replace if necessary.
N O TE : If threads are not clean and smooth, ball
studs m ay turn in sockets when attem pting to
tighten nut.
3. Install pitm an shaft nut or p itm an arm clamp
bolt and torque to specifications.
4. Position ball stud onto p itm an arm or relay rod.
Install nut and torque to specifications.
5. Install cotter pin.
N O T E : N ever back off nut to align cotter pin,
always tighten nut to next slot that lines up with
hole in stud.
6.
Lubricate ball studs.
7.
Lower the vehicle to the floor.
Installation (Fig. 3B-110)
S teering C onnecting Rod
Removal
1. Remove cotter pins from ball studs and remove
castellated nuts.
2. Remove ball studs from steering arm and
p itm a n arm boss with a heavy h a m m e r and striking
other side o f boss with lighter h am m er (similar to
method shown in (fig. 3B-105).
Installation
CAUTION: See the C A U T IO N on page 1 o f
this section regaring the fasteners referred to in
step
1. Make sure that threads on ball studs and in ball
stud nuts are clean and smooth. Check condition of ball
stud seals-replace if necessary.
N O TE : If threads are not clean and smooth, ball
studs may turn in connecting rod when attem pting
to tighten nut.
2. Install ball studs in steering arm and pitm an
arm. Be sure to install the long end of the connecting rod
assembly to the p itm a n arm.
3. Install
specifications.
ball
stud
nuts
and
torque
to
N O TE: N ever back off nut to align cotter pin,
always tighten nut to next slot that lines up with
hole in stud.
4.
1. Disconnect hoses at gear. W hen hoses are
disconnected, secure ends in raised position ot prevent
d rainage of oil. C ap or tape the ends o f the hoses to
prevent entrance o f dirt.
2. Install two plugs in g ear fittings to prevent
entrance of dirt.
3. Remove the flexible coupling to steering shaft
flange bolts (G, C and K models) or the lower universal
jo in t pinch bolt (P models). Mark the relationship of the
universal yoke to the stub shaft.
4. Mark the relationship o f the p itm an arm to the
p itm an shaft. Remove the pitm an shaft nut or pitman
arm pinch bolt and then remove the pitm an arm from
the pitm an shaft using Puller J-6632 (fig. 3B-50).
5. Remove the steering gear to fram e bolts and
remove the gear assembly.
6. G, C and K Models - Remove the flexible
coupling pinch bolt and remove the coupling from the
steering gear stub shaft.
Install cotter pins and lubricate ball studs.
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fasteners referred to in
steps 1, 3, 4 an d 5.
1. Install the flexible coupling onto the steering
gear stub shaft, aligning the flat in the coupling with the
flat on the shaft. Push the coupling onto the shaft until
the stub shaft bottoms on the coupling reinforcement.
Install the pinch bolt and torque to specifications.
NOTE: The coupling bolt must pass through the
shaft undercut.
2. Place the steering gear in position, guiding the
ccoupling bolt into the steering shaft flange.
3. Install the steering gear to fram e bolts and
torque to specifications.
4. If flexible coupling alignment pin plastic spacers
were used, make sure they are buttomed on the pins,
tighten the flange bolt nuts to specifications and then
remove the plastic spacers.
5. If flexible coupling alignment pin plastic spacers
were not used, center the pins in the slots in the steering
shaft flange and then install and torque the flange bolt
nuts to specifications.
P Models
a. Place the steering gear in position, guiding
the stub shaft into the universal joint assembly and
lining up the marks m ade at removal.
NOTE: If a new gear was installed, line up the
mark on the stub shaft with the m ark on the
universal yoke.
b. Install the steering gear to fram e bolts and
torque to specifications.
CAUTION:
ENDS OF ADJUSTABLE
T I E ROD MUST BE HELD IN CORRECT
RELA TIO N SH IP TO EACH OTHER
AFTER ADJUSTMENT WITHIN + 2 ° .
CAUTION:
CLAMPS MUST BE
BETWEEN AND CLEAR OF
DIM PLES BEFORE TORQUING
NUT.
NOTE:
STEER IN G CONNECTING
ROD MUST BE IN STALLED WITH
LONG END FORWARD.
S T E E R IN G G E A R
.10
A SSEM BLY
CLAM P
V IE W
NOTE:
SLOT OF
ADJUSTER TUBE MAY
BE IN ANY PO SITIO N
ON ARC SHOWN BUT NOT
CLOSER THAN .1 0 TO THE EDGE
OF CLAMP JAWS OR BETWEEN THEM
A
A D JU S T E R TU BE
Fig. 3B-109--Adjustable Connecting Rod Assembly-K Series
A ll Models
6. Install the pitm an arm onto the pitm an shaft,
lining up the marks made at removal. Install the pitm an
shaft nut or pitman arm pinch bolt and torque to
specifications.
7. Remove the plugs and caps from the steering
gear and hoses and connect the hoses to the gear.
Tighten the hose fittings to specified torque.
Power Steering Pump (Fig. 3B-111
through 3B-117)
Removal
Fig. 3B 1 1 0 -Power Steering Gear M ounting-Typical
c.
Install
torque to specification.
the
universal jo in t pinch
bolt
N OTE: The pinch bolt must pass through the shaft
undercut.
1. Disconnect hoses at pump. W hen hoses are
disconnected, secure ends in raised position to prevent
drainage o f oil. C ap or tape the ends o f the hoses to
prevent entrance o f dirt.
On Models with rem ote reservoir, disconnect
reservoir hose at pum p and secure in raised
and position. Cap hose pum p fittings.
2. Install two caps at pum p fittings to prevent
drainage of oil from pump.
3. Loosen bracket-to-pump m ounting nuts.
4. Remove pu m p belt.
292
L-6
G
2 0 -3 0
C
1 0 -3 0
K
20
P
2 0 -3 0
Fig. 3B-112--Power Steering Pump 292 L-6
5.
Remove pu m p from attaching parts and remove
pu m p from vehicle.
Installation
1. Postion pum p assembly on vehicle and install
attaching parts loosely.
2. Connect and tighten hose fittings.
3. Fill reservoir. Bleed pu m p by turning pulley
backward (counter-clockwise as viewed from front) until
air bubbles cease to appear.
4. Install pu m p belt over pulley.
5. Tension belt as outlined under "P um p Belt
T ension-A djustm ent" in this section.
6. Bleed as outlined und er "Bleeding Power
Steering Systems."
Fig. 3B-114--Power Steering Pump C, K
P Series
Power Steering Hoses
W hen servicing the power steering hoses be sure to
align the hoses in their correct position as shown in Figs.
3B-118—3B-133.
It is im portant that the power steering hoses be
installed correctly. Hoses installed out of position may be
subjected to chafing or other abuses during sharp turns.
Do not twist hoses unnecessarily during installation.
CAUTION: Do not start engine with any power
steering hose disconnected.
Bleeding Power Steering Systems
W hen a power steering pum p or power gear has
been installed, the air that has entered the system must
be bled out before the vehicle is again operated. If air is
allowed to rem ain in the power steering fluid system,
moisy and unsatisfactory operation of the system will
result. Bleed air from the hydraulic system as follows:
350
V -8
M O TO R HOM E
Fig. 3B-115-Power Steering Pump-350 V-8 Motor
Home
Fig. 3B-116 -Power Steering Pump-454 V-8
N O TE : W hen power steering fuid is added to
power steering system, only clean new power
steering fluid should be used.
1.
re m a in
2.
3.
Fill oil reservoir to proper level and let oil
undisturbed for at least two minutes.
Start engine and run momentarily.
A dd oil, if necessary.
4. Repeat above procedure until oil level remains
constant a fte r ru nning engine.
5. Raise front end o f vehicle so that wheels are off
the ground.
6. T u rn the wheels (off ground) right and left,
lightly contacting the wheel stops.
7. A dd oil if necessary.
8. Lower the vehicle and turn wheels right and left
on the ground.
9. Check oil level and refill as required.
10. If oil is extremely foamy, allow vehicle to stand
a few m inutes with engine off and repead above
procedure.
a. Check belt tightness and check for a bent
pulley. (Pulley should not wobble with engine running.).
b. Check to make sure hoses are not touching
any other parts o f the vehicle, particularly sheet metal.
c. Check oil level, filling to proper level if
necessary, following operations 1 through 10. This step
and Step " d " are extremely im po rtant as low oil level
a n d / o r air in the oil are the most frequent causes o f
objectionable pum p noises.
d. Check the presence o f air in th e oil. Air will
show up as milky app e a rin g oil. If air is present, attempt
to bleed system as described in operations 1 throught 10.
11. The presence o f trapped air in the system will
cause the fluid level in the p u m p to rise when the engine
is turned off. Continue to bleed system until this
condition no longer occurs.
4 5 4 V -8
MOTOR HOME
Fig. 3B 117 -Power Steering Pump-454 V-8 Motor
Home
o orientate pressure hose
when installing, rotate pipe
ends to rest against pump
support lower.
V IE W
2 5 0 or 2 9 2
G 10-30
A
Speedo cable and parking brake
cable to be routed above power
steering pipes and maintain
clearance.
L-e
Fig. 3B-118--Power Steering Hose Routing
Fig. 3B-11 9 -Power Steering Hose Routing
Rotate hose assembly - - - - hydraboost housing as:
before tigh tening nut.
V IE W
A
Ml
C LE A R A N C E
Rotate hose assembly
against steering gear
housing before
tightening nut.
Hose assembly must be
installed against steering
gear cover.
2 9 2 L-6
G 30
W /H Y D R A B O O S T
B
Fig. 3B-121--Power Steering Hose Routing
Fig. 3B-120--Power Steering Hose Routing
A
OF PUMP
6 INCHES
)° T O
V IE W
V IE W
A
A
2 9 2 L-6
P 2 0 -3 0
W /V A C U U M
PO W ER B R A K E S
3 0 5 or 3 5 0
P 2 0 -3 0
W /PO W E R
VACUUM
BRAKES
V -8
15°
To orien ta te pressure
hose when installing,
rotate pipe ends to
rest against steerinq
mp housing.
V IE W
Speedo cable and
parking brake
cable to be routed
above power
steering pipes and
m aintain clearance.
A
Clamp must be instal
w ith b o lt head tow ard
fro n t of vehicle.
3 0 5 , 35 0 , 4 0 0 V -8
G 1 0 -3 0
Fig. 3B-124 -Power Steering Hose Routing
Rotate hose assembly
against hydraboost
housing assembly
before tigh tening nut.
Rotate hose assembly,
against steering gear
housing before
tigh tening nut.
V IE W
V IE W
A
B
3 5 0 or 4 0 0 V -8
G 3 0 W /H Y D R A B O O S T
M IN IM U M
C LEAR AN C E
Hose assembly must be
installed against steering
gear cover.
3 5 0 V -8
C 30
W /H Y D R A B O O S T
Fig. 3B-1 2 6 -Power Steering Hose Routing
Fig. 3B-127--Power Steering Hose Routing
m ust be installed parallel
w ith in ± 3° o f brace.
Hose must be
located against
pum p
assembly
INCHES
V IE W
f
A
Hose assembly
must be located
against hydra
boost m ounting
bracket.
NCH
V IE W
A
V IE W
3 5 0 V -8
M O TO R HOME
454
V -8
C 1 0 -3 0
EXCEPT H Y P R A PQQST
Route Pipe A ssem bly-lnlet
parallel to
o f steering gear.
V IE W
A
4 5 4 V -8
C 30
W /H Y D R A B O O S T
EXCEPT
S
4 .5 6 A X L E
Hose assembly must
be installed against
steering gear cover.
Fig. 3B-130-Pow er Steering Hose Routing
V IE W
90 INCH
V IE W
Fig. 3B 131-Pow er Steering Hose Routing
Hose must be located
against pum p
A
V IE W
454
V -8
C 2 0 -3 0
W /V A C U U M POWER
B R A K E S A N D 4 .5 6 A X L E
Route pipe assembly-inlet
outboard 15°to parallel
o f steering gear.
Fig. 3B 132- Power Steering Hose Routing
4 5 4 V -8
M O TO R HOM E
must be
located against hydraboost
m ounting bracket.
Fig. 3B-133--Power Steering Hose Routing
SPECIFICATIONS
M A N U A L S T E E R IN G G E A R
S T E E R IN G G E A R R A T IO S
Power
Manual
Components
G 10-30
Thrust Bearing
Preload
6 to 11
lbs. in.
C1p i 03°
K 10-20
P20 - 30
Vehicle
Gear
Ratio
Gear
Ratio
Overall
Ratio
G 10-20
24:1
29.4:1
to
36.7:1
14:1
G 30
24:1
29.4:1
to
36.4:1
14:1
21.4:1
to
26.5:1
Overall
Ratio
21.4:1
to
26.7:1
P10
24:1
29.1:1
to
35.5:1
17.5:1
21.2:1
to
25.7:1
P20-30
24:1
29.1:1
to
35.3:1
17.5:1
21.2:1
to
25.7:1
M o to r Hom e
-
C 10
C20-30
16.0:1
to
21.9:1
24:1
29.1:1
to
37.0:1
16:1
to
13:1
16.9:1
to
20.2:1
24:1
29.4:1
to
36.3:1
16:1
to
13:1
17.2:1
to
20.6:1
24:1
K 10-20
14:1
-
24.6:1
to
28.0:1
16:1
to
13.1
13.2:1
to
17.2:1
Adjuster Plug
Lock Nut
Over Center
Preload
4 to 6
lbs. in.
9 to 12
lbs. in.
85 lbs. ft.
5 to 11
lbs. in.*
Over Center
Lock Nut
4 to 10
lbs. in.*
9 to 13
lbs. in.*
25 lbs. ft.
Total Steering
Gear Preload
18 lbs. in.
Max.
14 lbs. in.
Max.
25 lbs. in.
Max.
*In excess of thrust bearing preload.
P O W E R S T E E R IN G G E A R
Components
Steering Gear Ball Drag
All C, P, K and G
3 lbs. in. Max.
Thrust Bearing Preload
1/2 to 2 lbs. in.*
Adjuster Plug Locknut
80 lbs. ft.
Over-Center Preload
5 lbs. in.
Over-Center Adjusting
Screw Locknut
35 lbs. ft.
Total Steering Gear Preload
14 lbs. in. Max.
*In excess of ball drag.
**In excess of ball drag and thrust bearing preload.
P O W E R S T E E R IN G P U M P P R E S S U R E S
Vehicle
Pressure
C10-30
1200 - 1300 psi
G 10-20
900 - 1000 psi
G30
1200 - 1300 psi
P10-30
1200 - 1300 psi
M o to r Hom e & K
1350 - 1450 psi
Special Tools
JL
J.
f
T
ri
i
10
I
«
15
16
I
17
19
*
21
22
28
76
1.
J 6632
2.
J 5504
3.
4.
5.
J ■23073
J 23072
J 5176
J -5822
J ■8433
J -21854
J -23653
-5421
5860
21239
J ■2927
J 1614
7539
7624
-4245
-22670
6.
7.
8.
9.
10 .
11.
12.
13.
14.
15.
16.
17.
18.
27
29
I
33
30
Pitman Arm Puller
Pitman Arm Puller
S hift Tube Installer
S hift Tube Remover
Oil Pressure Gauge
Wormshaft Bearing Cup Remover
Pump Pulley Remover (Cast Pulley)
Column Pivot Pin Remover
Lock Plate Compressor
Thermometer
Torque Wrench Adapter
Pump Pulley Remover (Stamper Pulley)
Steering Wheel Puller
Sector Shaft Bushing Remover
Ball Retainer
Spanner Wrench
#23 Internal Pliers
Pump Shaft Seal Installer
35
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
J-6222
J-23600
J-8947
J 5755
J-2619
J-8092
J-6278
J-6278-2
J 7079-2
J-8524T
J-8524-2
J-6219
J-22407
J-8937
J 6217
J-23980
Shaft Seal Protector
Belt Tension Gauge
Rack-Piston Seal Compressor
Wormshaft Bearing Race Installer
Slide Hammer
Handle
Pitman Shaft Bearing Remover
Pitman Shaft Bearing Installer
Handle
Adjuster Plug Bearing Installer
Adjuster Plug Bearing Remover
Pitman Shaft Seal Installer
Pitman Shaft Bearing Installer
Ball Seal Remover
Connector Seat Installer
Steering Column Electrical Analyzer
Torque Wrenches
SPECIAL TOOLS
3
r
10
12
13
15
14
17
T'
22
20
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
J-6632
J-5504
J-5176
J-5822
J-5860
J-22670
J-6222
J-9226
J-7576
J-21239
J-2927
J 1614
J-7539
J-7624
J-4245
J -23600
J-5755
J 2619
21
23
4 *
31
28
27
29
P itm an A rm P uller
Pitm an A rm P uller
Pressure Gauge
W orm sha ft Bearing C up Puller
T o rq u e W rench A d a p te r
Pum p S h a ft Seal Installer
S ha ft Seal P ro te c to r
P itm an S h a ft Bushing Replacer
R ack-Piston Seal Com pressor
Pum p P ulle y Rem over
Steering Wheel P uller
S ecto r S h a ft Bushing Remover
Ball Retainer
Spanner W rench
#23 Intern al Pliers
B elt Tension Gauge
W orm sha ft Bearing C up In sta lle r
Slide Ham m er
32
33
34
30
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
J-6278
J-6278-2
J-7079-2
J-8524-1
J-8524-2
J 6 2 19
J -6 2 1 7
J-5421
J-22407
J-22727
J -22708
J-22573
J-22599
J-21854
J-22551
J-22549
P itm an S h a ft Bearing Rem over
P itm an S h a ft Bearing In sta lle r
D rive Handle
A d ju s te r Plug Bearing In sta lle r
A d ju s te r Plug Bearing Rem over
P itm an S h a ft Seal Installer
C o nn ector Seat In sta lle r
T h e rm o m e te r
P itm an S h a ft Bearing In sta lle r
T e rm in a l Rem over
T u rn Signal Cover Remover
Steering C o lu m n H o ld in g F ix tu re
L o ck N u t S ocket
P ivot Pin Rem over
S h ift T ube R em over
S h ift T ube Installer
T o rq u e Wrenches
SECTION 3C
FRONT SUSPENSION
The following caution applies to one or more steps in the assembly
procedure o f components in this portion o f the m anual as indicated at
a ppropriate locations by the terminology "See Caution on page 1 o f this
section".
CAUTION: T H IS F A S T E N E R I S A N IM P O R T A N T A T T A C H IN G
P A R T IN T H A T I T C O U LD A F F E C T T H E P E R F O R M A N C E OF
V IT A L C O M P O N E N T S A N D S Y S T E M S , A N D /O R C O U LD R E S U L T
IN M A JO R R E P A IR E X P E N S E . I T M U S T BE R E P L A C E D W IT H
O N E OF T H E S A M E P A R T N U M B E R OF W IT H A N E Q U IV A L E N T
P A R T IF R E P L A C E M E N T B E C O M E S N E C E S S A R Y . DO N O T U SE A
R E P L A C E M E N T P A R T OF L E S S E R Q U A L IT Y OR S U B S T IT U T E
D E S IG N . TO R Q U E V A L U E S M U S T B E U SE D A S S P E C IF IE D
D U R IN G R E A S S E M B L Y TO A S S U R E P R O P E R R E T E N T IO N OF
T H IS P A R T .
C O N TE N TS OF TH IS SEC TIO N
I
F ront Suspension (C-G-P Series)............................................... 3C-1
F ront Suspension (K-Series)......................................................... 3C-24
FRONT SUSPENSION, TWO-WHEEL DRIVE
INDEX
G eneral D escription.......................................................... 3C-1
M aintenance and A d ju s tm e n ts .................................... .3C-3
D ia g n o s is .............................................................................. 3C-4
C om ponent Parts R eplacem ent..................................... 3C-15
Wheel Hubs, B earin g s................................................ .3C-15
Shock A b s o r b e r ............................................................. .3C-15
S tabilizer........................................................................... .3C-16
Coil S p r i n g .......................................................................3C-16
U pper Control A rm S h a f t.........................................
Lower Control A rm S h a f t ........................................
Upper Control A r m ....................................................
Lower Control A r m .....................................................
Ball Jo in t..........................................................................
Steering K n u ck le...........................................................
Suspension U n it.............................................................
Specifications........................................................................
Special T o o ls .......................................................................
3C-17
3C-17
3C-18
3C-19
3C-21
3C-23
3C-23
3C-38
3C-39
GENERAL DESCRIPTION
C-G-P Series
The C-G -P Series trucks incorporate an independent
coil spring front suspension system, as shown in Figures
3C-1 and 3C-2. The control arms are o f unequal length
(S.L.A. Type).
These control arms are connected to the steering knuckle
through pivoting ball joints.
This suspension system consists of upper and lower
control arms pivoting on steel threaded or rubber
A coil spring is located between the lower control
arm and a formed seat in the suspension crossmember,
thus the lower control arm is the load carrying member.
Double acting shock absorbers are also attached to the
bushings on upper and lower control arm shafts. The
lower control arms and connect with the fram e to the
lower control arms are attached to the crossmember. The
upper control arms are attached to a fram e bracket.
rear on the upper end. The front wheel bearings are
tapered roller type and are used on all models.
^9
C-10
G-10-20
C-20-30
G-30
P-10-30
Fig. 3C -l--Front Suspension, C P Series
SHOCK
ABSORBER
LOWER
CONTROL
ARMS
Fig. 3C-2--Front Suspension
G-30-Typical
MAINTENANCE AND ADJUSTMENTS
CAUTION: See C A U T IO N on page I o f this
section regarding the fasteners referred to in
the m aintenance and adjustm ent procedures
below.
W HEEL BEARING S-CH EC K A D JU S T M E N T
CAUTION: Tapered roller bearings are used on
a ll series vehicles a nd they have a slightly loose
fe e l when properly adjusted. A design fea tu re o f
front wheel taper roller bearings is that they
m ust N E V E R be pre-loaded. D am age can
result by the steady thrust on roller ends which
comes from preloading.
1.
arm.
Raise vehicle and support at front lower control
2. Spin wheel to check for unusual noise or
roughness.
3. If bearings are noisy, tight, or excessively loose,
they should be cleaned, inspected and relubricated prior
to adjustment. If it is necessary to inspect bearings, see
"W heel Hubs, Bearings" under "C o m p on en t Parts
Replacement."
NOTE: To check for tight or loose bearings, grip
the tire at the top and bottom and move the wheel
assembly in and out on the spindle. Measure
movement o f h ub assembly. If m ovem ent is less
than .001" or greater than .005", adjust bearings
per adjustment procedure.
4. H A N D "S N U G -U P 1
THE NUT
5. LOOSEN NUT UNTIL EITHER HOLE
IN THE SPINDLE LINES UP WITH
A SLOT IN THE N U T -T H E N
INSERT COTTER PIN.
NOTE: BEND ENDS O F COTTER PIN
A G A IN S T NUT, CUT OFF EXTRA
LEN G TH T O PREVENT
INTERFERENCE W IT H DUST CA P .
3. BACK OFF NUT
UNTIL JUST LOOSE
PO S ITIO N .
2. TIG HTEN THE NUT T O
12 FT. LBS. FULLY SEAT
BE A R IN G S - THIS
O V E R C O M E S A N Y BURRS
O N THREADS.
6. W H EN THE BEARING IS PROPERLY
ADJUSTED THERE WILL BE FROM
. 0 0 1 - . 0 0 5 INCHES END-PLAY
(LOOSENESS).
Fig. 3C-3--Wheel Bearing A djustm ent
A D J U S T M E N T OF W HEEL BEARING S
(FIG . 3C -3)
1. Remove h ub cap or wheel disc from wheel.
2. Remove dust cap from hub.
3. Remove cotter pin from spindle and spindle nut.
4. Tighten the spindle nut to 12 ft. lbs. while
turning the wheel assembly forw ard by hand to fully seat
the bearings. This will remove any grease or burrs which
could cause excessive wheel bearing play later. See Fig.
3C-3.
5. Back off the nut to the "just loose" position.
6. H and tighten the spindle nut. Loosen spindle
nut until either hole in the spindle lines up with a slot in
the nut. (Not more than 1/2 flat).
7. Install new cotter pin. Bend the ends o f the
cotter pin against nut, cut off extra length to ensure ends
will not interfere with the dust cap.
8. Measure the looseness in the hub assembly.
There will be from .001 to .005 inches end play when
properly adjusted.
9. Install dust cap on hub.
10. Replace the wheel cover or hub cap.
11. Lower vehicle to floor.
12. Perform the same operation for each front
wheel.
DIAGNOSIS
SHOCK ABSORBER
DIAGNOSIS
ON VEHICLE CHECKS
(Follow the Procedures Outlined Below in the O rder
Indicated).
Prelim inary Inspection and Ride Test:
Tire Pressure
Check tire pressure com pare to vehicle specifications
and adjust as required. Poor vehicle control and ride
com plaints are caused in m an y cases by im pro per tire
inflation.
Special Suspension Equipment
Check Service Parts Identification Sticker for any
special suspension equipm ent; such as, a heavy duty
suspension. Vehicles equipped with this type o f option
have a somewhat stiffer or harsh ride, and this should be
kept in m ind during the following tests. If complaint
about stiffness should occur while vehicle is still new
(under 5,000 miles), owner should be advised to have
ride rechecked after 7,000 to 8,000 miles.
Vehicle Load Conditions
Note any exceptional load conditions under which
the owner normally operates the vehicle; such as, large
tool boxes full o f tools, pick up bed full etc. If
exceptional loading is apparent, check the distribution of
this weight. Note if it is all toward one side o f the
vehicle or at the extreme rear of the vehicle. Reposition
load as required to obtain a more uniform weight
distribution.
Check Vehicle Ride and Handling
After completing previous checks, ride vehicle with
owner to determ ine if problem has been corrected or to
definitely establish type o f problem that still exists. If
H ARD STEERING
Probable Cause
Probable Remedy
a.
Ball joints and steering linkage need lubrication
a.
b.
Low or uneven front tire pressure
b. Inflate tires to the proper recommended pressure
Lubricate ball joints and linkage
c.
Power steering partially or not operative
c.
d.
Steering gear not properly adjusted
d. Adjust steering gear
e.
Incorrect front wheel alignment (manual steering)
e.
a.
Ball joints and steering linkage need lubrication
a.
Lubricate at proper intervals
b.
Low or uneven front or rear tire pressure
b.
Inflate tires to the proper recommended pressure
Adjust wheel bearings
Check power steering components for proper operation
Check and align front suspension
POOR D I R E C T I O N A L S T A B I L I T Y
c.
Loose wheel bearings
c.
d.
Steering Gear not on high point
d. Adjust steering gear
e.
Incorrect front wheel alignment (caster)
e.
Check and align front suspension
f.
Broken springs
f.
Replace springs
g-
Malfunctioning sfiock absorber.
g-
Diagnose shock absorbers.
h
Replace stabilizer or link
h. Broken stabilizer bar, or missing link
FRONT WHEEL SHIMMY
(SMOOTH ROAD SHAKE)
a.
Tire and wheel out of balance, or out of round
a.
Balance tires, check run-out
b. Worn or loose wheel bearings
b.
Adjust wheel bearings
c.
c.
Replace tie rod end
d. Worn ball joints
d.
Replace ball joints
e.
e.
Diagnose shock absorbers
Worn tie rod ends
Malfunctioning shock absorber
V E H I C L E P U L L S T O O N E SI DE
(NO BRAKING ACTION)
a.
Low or uneven tire pressure
a.
Inflate tires to the proper recommended pressure
b.
Front or rear brake dragging
b.
Adjust brakes
c.
Broken or sagging front spring
c.
Replace sp'ring
d. Incorrect front wheel alignment (Camber)
EXCESSIVE P L A Y
a.
Incorrect steering gear adjustment
b. Worn steering gear parts
d. Check and align front suspension
IN S T E E R I N G
a.
Adjust steering gear
b. Overhaul Gear
NOISE IN F R O N T END
Probable Remedy
Probable Cause
a.
Ball joints and steering linkage need lubrication
a.
Lubricate at recommended intervals
b. Shock absorber loose or bushings worn
b. Tighten bolts and/or replace bushings
c . Worn control arm bushings
c.
Replace bushings
d. Worn tie rod ends
d.
Replace tie rod ends
c.
e.
Adjust or replace wheel bearings
Tighten all stabilizer bar attachments
Worn or loose wheel bearings
f.
Loose stabili/er bar
f.
o
Loose wheel nuts
g- Tighten the wheel nuts to proper torque
h.
Spring improperly positioned
h.
Reposition
i.
Loose suspension bolts
i.
Torque to specifications or replace
W HEEL TR A M P
a.
Balance wheels
b. Tire and wheel out of round
b.
Replace tire
c . Blister or bump on tire
c.
Replace tire
d.
d.
Replace shock absorber
a.
Tire and wheel out of balance
Improper shock absorber action
EXCESSIVE OR U N E V E N T IR E WEAR
a.
Underinflated or overinflated tires
a.
Inflate tire to proper recommended pressure
b.
Improper toe-in
b.
Adjust toe-in
c.
Wheels out of balance
c.
Balance wheels
d.
Hard Driving
d.
Instruct driver
Over loaded vehicle
e.
Instruct driver
e.
SC U FFED TIR ES
Toe-in incorrect
a.
Adjust toe-in to specifications
b.
Excessive speed on turns
b.
Advise driver
c.
Tires improperly inflated
c.
Inflate tires to proper recommended pressure
d.
Replace arm
a.
d. Suspension arm bent or twisted
CUPPED TIR ES
a.
Front shock absorbers defective
b. Worn ball joints
c.
Wheel bearings incorrectly adjusted or worn
d. Wheel and tire out of balance
e.
Excessive tire or wheel runout
a.
Replace shock absorbers
b.
Replace ball joints
c.
Adjust or replace wheel bearings
d.
Balance wheel and tire
e.
Compensate for runout
"D O G '
T R A C K IN G
Probable Cause
Probable Remedy
LEAF TYPE REAR SPRING
a.
Rear leaf spring broken
a.
Replace spring
b.
Bent rear axle housing
b.
Replace housing
c.
Frame or underbody out of alignment
c.
Align frame
Damaged rear suspension arm and/or worn bushings
a.
Replace suspension arm and/or bushings
b.
Frame out of alignment
b. Align frame
c.
Bent rear axle housing
c.
a.
Steering column alignment
COIL TYPE REAR SPRING
a.
Replace housing
R E T U R N A B IL IT Y POOR
a.
See Section 3bin shop manual for proper alignment
b. Steering linkage needs lubrication
b.
Lubricate chassis
c.
c.
Replace idler arm
Idler arm bushing worn
d. Steering gear adjustment
d. Adjust gear as outlined in Section3bof shop manual
e.
Power steering gear valve spool binding
e.
See Section3bin shop manual
f.
Obstruction within power steering gear
f.
See Section3bin shop manual
g-
Check and reset if necessary
g- Improper caster setting (negative)
E R R A T IC STE ER IN G ON BR AK E A P P LIC A TIO N
a.
Low or uneven tire pressure
a.
Inflate tires to proper recommended pressure
b.
Front wheel bearing incorrectly adjusted
b.
Adjust bearing as necessary
c.
Brakes incorrectly or unevenly adjusted
c.
Adjust brakes as necessary
d.
Front spring sagged
d. Check shop manual for proper riding heights and
replace spring if necessary
e.
Steering gear off high point
e.
Check and correct steering if necessary
f.
Incorrect or uneven caster
f.
Check and adjust caster as necessary
g-
Leaking wheel cylinders
g-
Replace (See sec. 5)
BALL JO IN T D IAG NO STIC PROCEDURE
problem still exists (poor handling, bottoming, noise,
ride sway, etc.), proceed.
• shocks m ay have glossy paint on them. Do
not confuse this paint with a leak condition.
• a slight trace o f shock fluid around the seal
cover area is not cause for replacement. The
shock seal is engineered to perm it a slight
seepage to lubricate the rod. The shock absorber
has reserve fluid to compensate for the slight
seepage.
• shocks are sometimes incorrectly diagnosed
as leakers due to oil spray originating from some
other source. If in doubt, wipe the wet area from
and manually operate shock as described in Step
(2). Fluid will reappear if shock is leaking.
Inspecting and Testing the Shocks
T hree procedures are included in this step. Thet are
(a) Bounce Test, (b) Inspecting Shock M ountings for
Noise (Looseness) and (c) M anually O perating Shocks to
D eterm ine if Shocks are Weak, Leaking Hydraulic Fluid,
a n d / o r if Shocks have an Internal Noise Condition.
IM PORTANT: Test procedures (b) and (c)
require vehicle to be on a hoist that supports
wheels or rear axle housing and front lower
control arms.
2.
Bounce Test
N OTE: It may be necessary with certain types o f
shock mountings to fabricate a bracket that can be
installed on a shock to enable a technician to
securely grip the shock w hen manually operating
the shock. See Figure 3C-9 for suggested methods
of providing tem porary grip.
This test should help the mechanic to isolate the
following shock defects:
• binding condition internally
• verify leaking shock
• im proper or defective valving
(a) If suspected problem is in front shocks,
disconnect both front shock lower mountings and stroke
each shock as follows: G rip the lower end o f the shock
securely and pull down (rebound stroke) then push up
(compression stroke). The control arms will limit the
movement o f the front shocks during the compression
stroke. Com pare the rebound resistance between both
front shocks, then com pare the compression resistance. If
a noticeable difference can be felt during either stroke,
usually the shock having the least resistance is at fault.
(b) If shock has an internal noise condition,
N OTE: This is only a com parison type test to help
locate the suspected shock or noise condition
before proceeding.
Test each front and rear shock by bouncing each
corner o f the vehicle. This can usually be done by lifting
up and pushing down on the end of the bum per near
each corner o f the vehicle until m axim um movement up
and down is reached. Then let go o f bum per and observe
if the up and down motion stops very quickly. II' up and
down motion continues longer at one corner when
c om pared to opposite corner (example, both front
shocks), the one having the longer up and down motion
m ay be suspect. Do Not com pare front to rear. If
com plaint is noise, this test should help to locate the
suspected area.
Inspecting Shock Mountings
If noisy a n d / o r loose shock m ountings are
suspected, place vehicle on hoist that supports wheels and
check all mountings for the following conditions:
(1) W orn or defective gromm ets
(2) Loose m ounting nuts
(3) Possible interference condition
(4) Bump stops missing
If no a p p a re n t defects are noted in this step but
noise condition still exists when vehicle is bounced up
and down, proceed.
Inspecting Shocks for Leaks and
Manually Operating Shocks
This procedure is sub-divided into two general
areas, (1) Inspecting Shocks for Loss of Hydraulic Fluid
an d (2) M anually O perating Shock. It should aid the
technician to localize defective shocks caused by internal
noise in the shock, weak, leaking, etc.
1.
Inspecting
Hydraulic Fluid
Shocks
for
Possible
Loss
(a) Disconnect each shock lower mounting as
required and pull down on the shock until it is fully
extended.
(b) Inspect shocks for leaks in seal cover area.
Shock fluid is a very thin hydraulic fluid and has a
characteristic odor and dark brown tint (Figure 3C-8).
Certain precautions should be observed when
inspecting shocks for leaks:
Manually Operating Shocks
of
TYPICAL FRONT SHOCK
TYPICAL REAR SHOCK
DUST T U B E O T
BOTTOM
M O UNT \
BO TTO M'
M O UNT
ROD EXTENDED
(REBOUND) x
SHOCK
COLLAPSED
BOTTOM
M O UNT
ROD EXTENDED
(REBOUND) '
TOP END
DOWN
SHOCK -«
COLLAPSED
a
BOTTOM
M 0 U N T\^^
INVERT.
THEN COLLAPSE
TOP END
DOWN
• < >
INVERT. THEN C O LLA PSE
POSITION FOR PURGING AIR FROM SHOCK ABSORBER
Fig. 3C-10--Position for Purging A ir From Shocks
Bench Test Procedure
extend shock fully, then exert an extra pull. If noisy
shock should be replaced.
O th e r noise co nd itio ns that re qu ire shock
replacem ent are:
• a grunt or squeal after one full stroke in both
directions
• a clicking noise on fast reverse
• a skip or lag at reversal near mid-stroke
IM PORTANT: W hen air adjustable shocks
are being manually operated, the air line
must be disconnected at the shock absorber.
BENCH CHECKS
T he bench checks are recom m ended if the proper
type hoist is not available to perform the “on c a r” tests,
or if there is still some doubt as to w hether the shocks
are defective. In addition, the bench test allows a more
thorough visual inspection.
Bench check procedures are discussed for three
general types of shocks.
SPIRAL GROOVE RESERVOIR
IM PORTANT: If this type o f shock has been
stored or allowed to lay in a horizontal
position for any length o f time, an air void
will develop in the pressure ch am ber o f the
shock absorber. This air void if not purged,
can cause a technician to diagnose the shock
as defective. To purge the air from the
pressure chamber, proceed as follows: (Refer
to Figure 3C-10)
(a) Holding the shock in its norm al vertical
position (top end up), fully extend shock.
(b) Hold the top end o f the shock down and fully
collapse the shock.
(c) Repeat Steps (a) and (b) at least five (5) times
to assure air is purged.
1. This is a comparison type test. If possible,
o btain a new or known good shock with same part
n u m b e r as shock und er test.
2. With shocks in vertical position (top end up),
clamp bottom mounts in vise.
CAUTION: Do not clamp on reservoir tube or
m ounting threads.
3. Manually pum p each shock by h an d at various
rates of speed and compare resistance o f suspected shock
with the new one.
NOTE: Rebound resistance (extending the shock)
is normally stronger than the compression resist
ance (approximately 2:1). However, resistance
should be smooth and constant for each stroking
rate.
4. Observe or listen for the following conditions
that will indicate a defective shock:
• a skip or lag when reversing stroke at mid travel.
• seizing or binding condition except at extreme
end o f either stroke.
• a noise, such as a grunt or squeal, after
completing one full stroke in both directions.
• a clicking type noise at fast reversal.
• fluid leakage.
5. To check for a loose piston, completely extend
shock to full rebound; then exert an extra hard pull. If a
give is felt, a loose piston is indicated and shock should
be replaced.
PLIACELL OR GENETRON
Pliacell and G e netron are some o f the trade names
used to indicate a gas-filled cell in the shock reservoir.
The reservoirs o f Pliacell and G e netron shocks are
smooth, com pared to the spiral groove type. The cell
takes the place of air in the reservoir. Thus, aeration or
foam ing of the fluid is eliminated, as air an d fluid
cannot mix.
Due to this feature, these shocks should be bench
checked in an inverted position (top end down). If, when
stroked, a lag is noticed, it means the gas-filled cell has
been ruptured, and the shock should be replaced. If no
lag is noticed, the re m ain der o f the bench check is the
same as given in the Spiral Groove Reservoir, Section 1,
Bench Check Procedure.
AIR A D JUSTAB LE SHOCKS
This type o f shock contains an air cham ber like the
spiral groove reservoir type, and must have the air
p urged from the working cham ber. See Section 1, Spiral
G roove Reservoir. A fter air has been purged from shock,
proceed as follows:
(a) C lam p lower shock m ounting ring in vise in
vertical position with larger d iam eter tube at the top.
(b) Pum p unit by hand at different rates o f speed.
Smooth resistance should be felt through the length of
the stroke. Since the units are normally pressurized, the
sound o f air bubbles or a gurgling noise is norm al
(c) The re m a in d e r o f the bench check is the same
as given in the Spiral Groove Reservoir, Section 1, Bench
Check Procedure.
BEARINGS AND RACES
BENCH D IA G N O S TIC PRO CEDURE
This section describes com m on types of bearing
distress and their causes. Illustrations are included to
help diagnose the cause o f distress and comments are
provided to help make elfective repairs.
Consider The Following Factors When
Diagnosing Bearing Distress:
1. Note G eneral Condition o f all parts during
teardown and examinations.
2. Classify the failure with the aid o f these
illustrations where possible.
3. D etermine the cause. Recognizing the cause will
permit correction o f the problem and prevent a repeat
failure o f the same type.
4. M ake all repairs following re c o m m e n d ed
procedures.
Com m on Causes For Bearing Distress
Include The Following:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Im proper adjustm ent or preloading.
M ounting or teardown abuse.
Im proper m ounting methods.
Inadequate or wrong lubricants.
Entrance o f dirt or water.
W ear from dirt or metal chips.
Corrosion or rusting.
Seizing or sm earing from overload.
Overheating causing tempering.
Frettage o f bearing seats.
Brinelling from impact loads and shipping.
M anu facturin g defects.
BEARINGS AND RACES
F R O N T W HEEL, P IN IO N , DIFFER ENTIA L SIDE A N D REAR W HEEL ROLLER B E A R IN G S
DIAGNOSIS
EXCESS NOISE C O M P L A IN T
D IA G N O S T IC PRO CEDURE
1.
2.
Road Test
3.
4.
5.
1.
2.
Tire Noises
3.
4.
5.
Engine or
Exhaust
Noises
Test for
Wheel Bearing
Noise
Test for
Differential
Bearing Noise
1.
2.
3.
4.
1.
2.
3.
4.
1.
2.
3.
4.
1.
2.
Test for
Pinion Bearing
Noise
3.
4.
5.
6.
7.
Check tires for irregular wear
Check tire pressure
Check lubricant level
Drive to warm-up rear axle
Test at various speeds in drive, float, coast and cornering
Change tire pressure to minimize noises
Drive over different road surfaces
Smooth black-top minimizes tire noise
Cross switch tires, if necessary
Snow tire treads and studs caused added noises
Drive slightly above speed where noise occurs, place transmission in neutral
Let engine speed drop to idle
Stop car
Run engine at various speeds
Drive car at low speed on a smooth road
Turn car to develop left and right motions, traffic permitting
Noise should change due to cornering loads
Jack-up wheels to verify roughness at wheels
Drive car at low speed on a smooth road
Constant low pitch bearing noise may be heard
Noise should not change in reversing turns
Noise pattern should vary with wheel speed
Roughness or whine noise should increase with speed
Noise pitch should be higher than differentials
Test on smooth road to minimize tire noises
Test at various speeds in drive, float, and coast
Rear pinion bearing noise may be louder on acceleration
Front pinion bearing noise may be louder on deceleration
Gear noises tend to peak in a narrow speed range
FRONT
WHEEL BEARING DIAGNOSIS
C O N S ID E R T H E F O L L O W IN G F A C TO R S W H EN D IA G N O S IN G B E A R IN G C O N D IT IO N :
1.
G E N E R A L C O N D IT IO N O F A L L PA R TS D U R IN G D IS A S S E M B LY A N D IN SPEC TIO N .
2.
C L A S S IF Y T H E F A IL U R E W IT H TH E A ID OF T H E IL L U S T R A T IO N S .
3.
D E T E R M IN E T H E C AUSE.
4
M A K E A L L R E P A IR S F O L L O W IN G R E C O M M E N D E D PRO C ED U R ES.
Mil *
ABRASIVE
ROL LER
WEAR
Ill I V \
GALLING
BENT
CAGE
P A T T E R N ON R A C ES A N D R O L L E R S C A U S E D BY
FtfJE A B R A S IV E S .
M E T A L SM EARS O N R O L L E R EN D S DUE TO O V E R H E A T ,
L U B R IC A N T F A IL U R E OR O V E R L O A D (W AGON 'S)
CAGE D A M A G E DUE TO IM PRO PER H A N D L IN G
O R T O O L USAGE.
C L E A N A L L PA R T S A N D H O U S IN G S . C H E C K SEALS
A N D B E A R IN G S A N D R EPLACE IF L E A K IN G , R O U G H
O R N O IS Y .
REPLAC E B E A R IN G
C HECK SEA LS A N D CHECK
FOR PROPER L U B R IC A T IO N .
REPLA C E B E A R IN G .
%
Q
*
ABRASIVE
A
ST EP
%
WEAR
P A T T E R N ON R O L L E R EN D S C A U S E D BY
F IN E A B R A S IV E S .
C L E A N A L L PA R T S A N D H O U S IN G S . C H EC K SEALS
A N D B E A R IN G S A N D REPLACE IF L E A K IN G , R O U G H
O R N O IS Y .
ETCHING
B E A R IN G SU R FA C E S APPEAR G R A Y OR G R A Y IS H
BLACK IN CO LO R W IT H R E L A T E D E T C H IN G AW A Y
O F M A T E R IA L U S U A L L Y A T R O L L E R SPA C IN G .
BENT
CAGE
CAG E D A M A G E D UE TO IM PR OPER H A N D L IN G
OR TO O L U SA G E.
REPLACE B E A R IN G .
REPLACE B E A R IN G S
C H EC K SEA LS A N D CHECK
FOR PROPER L U B R IC A T IO N .
f ill 1
INDENTATIONS
S U R F A C E D EPR ESSIO NS O N RA C E A N D R O L L E R S
C A U S E D BY H A R D P A R T IC L E S O F F O R E IG N M A T E R IA L .
CAGE
WEAR
W EAR A R O U N D O U T S ID E D IA M E T E R O F C A G E A N D
R O L L E R POCKETS C A U S E D BY A B R A S IV E M A T E R IA L
M ISALIG NM EN T
O U T E R RACE M IS A L IG N M E N T DUE T O F O R E IG N
OBJECT.
A N D IN E F F IC IE N T L U B R IC A T IO N .
C L E A N A L L P A R T S A N D H O U S IN G S . C H EC K SEALS
A N D R EPLA C E B E A R IN G S IF R O U G H OR N O IS Y .
C L E A N R E L A T E D PA R TS A N D H O U SIN G S.
C H ECK SEA LS A N D R EPLA C E B E A R IN G S .
C LE A N R E L A T E D PA R TS A N D R EP LA C E B E A R IN G .
M A K E SU R E RACES A R E PR O P E R L Y SE A T E D .
FRONT WHEEL BEARING DIA G N O SIS
CRACKED INNER
RACE
FATIGUE
SPALLING
RACE C R A C K E D D U E T O IM P R O PER F IT ,
C O C K IN G , O R POOR B E A R IN G SEATS.
F L A K IN G OF S U R FA C E M E T A L R E S U L T IN G FROM
F A T IG U E .
REPLA C E B E A R IN G A N D C O R R E C T B E A R IN G
S EA TS.
R EPLA CE B E A R IN G
FRETTAGE
C O R R O S IO N S ET UP BY S M A L L R E L A T IV E
M O V E M E N T O F PA R TS W IT H N O L U B R IC A T IO N .
REPLACE B E A R IN G . C L E A N R E L A T E D PA R TS.
C H EC K SEA LS A N D C H EC K FO R PRO PER L U B R IC A T IO N .
(C O N T’D)
BRINELLING
S U R FA C E IN D E N T A T IO N S IN R A C E W A Y C A U S E D BY
R O LLE R S E IT H E R U N D E R IM P A C T L O A D IN G OR
V IB R A T IO N W H IL E THE B E A R IN G IS N O T R O T A T IN G .
-C L E A N A L L R E L A T E D PAR TS.
REPLACE B E A R IN G IF R O U G H O R N O IS Y .
ST AI N
DISCOLORATION
HEAT
DISCOLORATION
D IS C O L O R A T IO N C A N R A N G E FR O M L IG H T BROWN
TO B LAC K C A U S E D BY IN C O R R E C T L U B R IC A N T OR
M O IS T U R E .
H E A T D IS C O L O R A T IO N C A N R A N G E F R O M F A IN T
Y E L L O W TO D A R K BLUE R E S U L T IN G FR O M O V E R
L O A D (W A G O N 'S) O R IN C O R R E C T L U B R IC A N T .
RE-USE B E A R IN G S IF S T A IN S CAN BE R E M O V E D BY
L IG H T P O L IS H IN G OR IF N O E V ID E N C E O F O VER
H E A T IN G IS O B S E R V E D .
E XC E S S IV E H E A T CAN CAUSE S O F T E N IN G O F RACES
OR R O LLE R S .
TO C HECK FO R LOSS O F TE M P E R ON RAC ES OR
C H EC K SEA LS A N D R E L A T E D PA R TS FOR D A M A G E .
R O LLE R S A SIM P LE F IL E T E S T M A Y BE M A D E . A
F IL E D R A W N O V E R A T E M P E R E D P A R T W IL L G RAB
A N D CUT M E T A L , W H E R E A S , A F IL E D R A W N O V E R A
H A R D P A R T W IL L G L ID E R E A D IL Y W IT H N O M E T A L
C U T T IN G .
R EPLA CE B E A R IN G S IF O V E R H E A T IN G D A M A G E IS
IN D IC A T E D . C H E C K SEALS A N D O T H E R PARTS.
SMEARS
S M E A R IN G O F M E T A L D U E TO SLIPPA G E.
SLIPPAG E C A N BE C A U S E D BY POOR F IT S .
L U B R IC A T IO N , O V E R H E A T IN G , O V E R L O A D S
OR H A N D L IN G D A M A G E .
R EPLA C E B E A R IN G S , C L E A N R E L A T E D PA R TS
A N D C H EC K F O R PRO PER F IT S A N D
L U B R IC A T IO N
COMPONENT PARTS REPLACEMENT
W HEEL HUBS, BEA R IN G S (Fig. 3 C -1 4)
Removal C, G and P Series
1. Raise vehicle on hoist and remove wheel and
tire assembly. Remove dust cap from end o f hub and
w ithdraw cotter pin.
2. Remove the brake caliper and h an g by wire to
the suspension.
CAUTION: Do not allow the caliper assembly
to hang by the brake fle x line.
3. Remove h ub and disc assembly.
4. Remove outer b earing from hub. The inner
bearing will remain in the hub and may be removed by
prying out the inner grease seal.
5. W ash all parts in cleaning solvent.
Inspection
1. Check all bearings for cracked bearing cages,
w orn or pitted rollers.
2. Check bearing races for cracks o r scoring, check
brake discs for out-of-round or scored conditions and
check bearing outer races for looseness in hubs.
Repairs
Replacem ent o f Bearing Cups
If necessary to replace an outer race, drive out old
race from the hub with a brass drift inserted behind race
in notches in hub. Install new race by driving it into hub
with the p rop er race installer J-8457, J-8458. J-8849 or
J-9276-2. Remove and install the inner race in the same
m anner.
CAUTION: Use care when installing new race
to start it squarely into hub, to avoid distortion
a n d possible cracking.
Thoroughly lubricate bearing assemblies with new
high melting point wheel-bearing lubricant. Remove any
excess iubricant.
N OTE: Be sure bearing parts have been th o r
oughly cleaned and air-dried.
Wheel S tud Replacem ent (Fig. 3C -14)
N OTE: Use a piece o f w ater pipe or other similar
tool to support the hub while pressing a wheel stud
either in or out.
Installation
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fasteners referred to in
steps 3, 4 and 5.
1. Pack inner and outer wheel bearings with
recom m ended grease (see Section 0).
2. Place inner bearing in hub and install new seal
assembly, tap ping into place with soft ham m er.
3. Position hub and disc on spindle and install
outer bearing, pressing it firmly into position in hub.
Install hub w asher and finger tighten nut.
4. Install brake caliper see section 5.
5. Install wheel and tire, and adjust wheel bearings
as outlined under W heel Bearings—Adjust, then lower
vehicle to floor.
SHOCK ABSORBER
Removal (Fig. 3C-15)
1. Raise vehicle on hoist.
2. Remove nuts and eye bolts securing upper and
lower shock absorber eyes.
3. W ithdraw shock absorber and inspect rubber
eye bushings.
assembly.
If
defective,
replace
shock
absorber
Installation
Place shock absorber into position over m ounting
bolts or into mounting brackets. Install eye bolts and
nuts and torque as shown in Specifications Section.
Lower vehicle to floor.
S TA B IL IZE R BAR
Removal (Fig. 3C-16)
1. Raise vehicle on hoist and remove nuts and
bolts attaching stabilizer brackets and bushings at frame
location.
2. Remove brackets and bushings at lower control
arms and remove stabilizer from vehicle.
Fig. 3C 17--Rem oving Coil Spring w ith Tool J-23028
Inspection
Inspect ru b b e r bushings for excessive w ear or
a g in g - r e p la c e w here necessary. Use ru b b e r lubricant
w hen installing bushings over stabilizer bar.
COIL SPRING
Removal (Fig. 3C-17)
Installation
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fasten ers referred to in
step 2.
N O TE : Slit in bar to fram e bushings should be
facing forward.
1. Place stabilizer in position on fram e and install
f ram e brackets over bushings. Install nuts and bolts
loosely.
2. Install brackets over bushings at lower control
arm location. Be sure brackets are positioned properly
over bushings. Torque all nuts and bolts to specifications.
3. Lower vehicle to floor.
1. Place vehicle on hoist and place jack stands
under frame, allowing control arms to hang free.
2. Disconnect shock absorber at lower end and
move aside. Disconnect the stabilizer bar attachments to
the lower control arm.
3. Bolt Tool J-23028 to a suitable jack.
4. Place tool under cross-shaft so that the cross
shaft seats in the grooves of the tool. As a safety
precaution install and secure a chain through the spring
and lower control arm.
5. Raise the jack to remove tension on the lower
control arm cross-shaft and remove the two “ U ” bolts
securing the cross-shaft to crossmember.
WARNING: The crosshaft and lower control
arm keeps the coil spring compressed. Use
care when lowering.
6. Lower control arm by slowly releasing the jack
until spring can be removed. Be sure all compression is
relieved from spring.
7. Remove spring.
Installation
CAUTION: See C A U TIO N on page 1 o f this
section regarding the fasteners referred to steps
.? and 4.
1. Properly position spring on the control arm, and
lift control arm using jack and tool J-23028.
2. Position control arm cross-shaft to crossmember
and install “ U ” bolts and attaching nuts. Make certain
front indexing hole in cross-shaft is lined up with
crossmember attaching saddle stud.
3.
Torque nut to specifications.
4. Install shock absorber to lower control arm and
install stabilizer bar.
5.
Remove tool J-23028 and safety chain.
6.
Lower vehicle to floor.
U PPER C O N TR O L ARM IN N E R P IVO T
S H A FT A N D /O R B U S H IN G R EPLA C EM EN T
C 2 0 -30 , G 3 0 and P 10-30 (S teel Bushings)
Pivot Shaft Removal
6.
from arm.
Remove the shaft end nuts and remove shaft
Bushing Replacement (Steel Bushings)
1. Remove grease fittings from bushing outer ends
and unscrew bushings from control arm and shaft.
2. Slide new seal on each end of shaft and insert
shaft into control arm.
3. Start new bushings on shaft and into control
arm. Adjust shaft until it is centered in control arm. then
turn bushings in and torque to specifications. Figure 3C19 shows correct final positioning o f shaft. Check shaft
for free rotation and install grease fittings.
Installation
1. Raise
assembly.
2.
vehicle
and
remove
tire
and
wheel
Support the lower control arm with a floor jack.
N O TE : Position jack un der the ball joint assembly
or as n e a r as possible and still have good support.
3.
Loosen the upper control arm shaft end nuts
before loosening the shaft to fram e attaching nuts.
4. Loosen the shaft to fram e nuts and remove the
caster an d c am b er shims.
N O T E : Tape the shims together
removed and mark for position.
as
they
are
5. Remove the pivot shaft to fram e nuts but do not
allow the arm to swing too fa r away from the frame.
N OTE: Use a safety chain to retain the arm in a
close relationship to the frame. See Fig. 3C-18.
CAUTION: See C A U T IO N on page I o f this
section regarding the fasteners referred to in
steps 3, 5 and 6.
NOTE: W hen installing the upper control arm be
sure to properly position the special aligning
washers to the pivot shaft with convex and concave
sides together.
1. Install the shaft to the control arm and install
end nuts. Do not torque nuts at this time.
2. Position cross shaft to fram e bolts and start
cross shaft nuts.
3. Torque the shaft end nuts. See Fig. 3C-19 for
proper spacing.
NOTE: The shaft should rotate by hand after the
nuts are torqued.
4. Install caster and c a m b e r shim in their
appropriate places.
5. Torque the cross-shaft to fram e nuts.
6. Remove the safety chain and install the tire.
7. Lower vehicle to the floor.
LOWER C O N TR O L ARM IN N E R P IVO T
SHAFT A N D /O R B USHING REPLACEM EN T
C 20-30, G 30, P 10 -3 0 (Steel Bushings)
Lower—Removal (Fig. 3C-18)
1. Raise vehicle and support the fram e so that
control arms hang free.
2. Position an adjustable floor jack under the
control arm inboard o f spring and into depression in
lower arm.
3. Install a chain over upper arm (Fig. 3C-18).
Inboard o f stabilizer and outboard o f shock absorber as
a safety measure.
4. Disconnect shock absorber at lower control arm.
5. Loosen shaft end nuts.
6. Remove “ U ” bolts.
7. Lower jack just enough to get at shaft.
8. Remove shaft end nuts and remove shaft.
Bushing Replacement (Steel Bushings)
1.
Remove grease fittings from ends of bushings
and unscrew bushings from shaft and control arm.
Remove shaft and seals.
2. Slide new seal on each end of shaft and insert
sh aft into control arm.
3. S tart new bushings on shaft and into control
arm. Adjust shaft until it is centered in control arm. then
turn bushings in and torque to specifications. Check
sh aft for free rotation. Figure 3C-20 shows correct final
positioning o f shaft.
Installation
CAUTION: See C A U T IO N on page I o f this
section regarding the fa steners referred to in
steps 4 a nd 5.
1. Install shaft to control arm and install end nuts.
Do not torque nuts at this time.
2. Raise jack and position shaft into crossmember
saddle. Be sure to index hole in shaft to mate with bolt
head in saddle.
3. Install “ U ” bolts. Do not torque nuts at this
time.
4. Torque cross-shaft end nuts.
N O T E: The shaft should roate by hand after the
nuts are torqued.
5. Torque “ U ” bolt nuts.
6. Remove safety chain.
7. Lower vehicle to floor.
U PPER C O N TR O L ARM ASSEMBLY
All Removal
1. Raise vehicle on hoist, remove wheel and tire
assembly and support lower control arm assembly with
adjustable jackstand.
2. Remove cotter pin from upper control arm ball
stud and loosen stud nut one turn.
3. Loosen upper control arm ball stud in steering
knuckle, using Tool J-23742 position as shown in Figure
3C-21. Remove the nut from the ball stud and raise
upper arm to clear steering knuckle.
NOTE: It is necessary to remove the brake caliper
assembly and wire it to the fram e to gain clearance
for tool J-23742. See section 5 for proper
procedure.
4.
Remove nuts securing control arm shaft to
frame. W ithdraw control arm assembly.
N OTE: Tape shims together and tag for proper
relocation w'hen control arm is reinstalled.
remove
"J
RE MO VE
UPPER
■
LO W ER
HE A V Y
FLAT
WASHER
J -2 3 7 4 2
J-23742
Upper Control Arm Inner Pivot Shaft a n d /
or Bushing R eplacem ent
CIO, G10-20 (Rubber Bushings)
Removal (Fig. 3C -22)
1. Remove the upper control arm using the
preceding procedure and m ount the control arm in a
vise.
2. Install remover J-24435-l, receiver J-24435-3
and " C " clamps J-24435-7 as shown in Figure 3C-22.
3. Tighten the clamp to draw out the old bushing.
Discard old bushing.
4. The pivot shaft may now be removed from the
control arm assembly.
5. Reposition the control arm in the vise and
repeat the removal procedure on the rem aining bushing.
Bushing Installation
1. Again using " C " clamp J-24435-7 and installers
J-24435-4 (outer) and J-24435-5 (inner) tighten clamp to
install bushing onto control arm.
2. Install pivot shaft into inside d iam eter of first
installed bushing.
3. Install rem ain in g bushing as shown in Figure
3C-23 and described in step 1.
4. Remove tools and install control arm on vehicle
following p ro c e d u re described below. Torque all
fasteners to proper specifications.
Upper Control Arm Installation
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fa steners referred to in
steps 1, 2 a nd 3.
N OTE: W hen installing the upper control arm be
sure to position the special aligning washers to the
pivot shaft with concave and convex sides together.
J -2 4 4 3 5 -7
J -2 4 4 3 5 -3
J— 2 4 4 3 5 - 1
1. Place control arm in position on bracket and
install nuts. Before tightening nuts, insert caster and
cam ber shims in the same order as w hen removed.
Torque the nuts to specifications.
NOTE: A normal shim pack will leave at least two
(2) threads o f the bolt exposed beyond the nut. If
two (2) threads cannot be obtained: Check for
dam aged control arms and related parts. Difference
between front and rear shim packs must not exceed
.30 inches. F ron t shim pack must be at least .24
inches.
Always tighten the thinner shim packs’ nut first for
im proved shaft to fram e clam ping force and
torque retention.
2. Insert ball jo in t stud into steering knuckle and
install nut. Torque stud nut to specifications and install
cotter pin.
3. Install brake caliper assembly if removed (see
section 5).
4. Remove adjustable support from under lower
control arm. Install wheel and tire assembly.
5. Lower the vehicle to the floor.
LOWER C O N TR O L ARM ASSEMBLY
Removal
1. Raise vehicle on hoist and remove spring as
outlined under spring removal.
N OTE: Support the inboard end o f the control arm
a fter spring removal.
2. Remove cotter pin from lower ball stud and
loosen stud nut one turn.
3. Install Ball Stud Rem over J-23742, position
large cup end of the tool over the upper ball stud nut
and piloting the threaded end of tool on end o f the lower
ball stud. Extend bolt from Tool J-23742 to loosen lower
1. Raise vehicle on hoist and support the fram e so
that the control arm s hang free.
2. Position an adjustable floor jack u nd e r the lower
control arm inbo ard of spring and into depression of
control arm.
3. Install a chain over the upper arm inboard of
the stabilizer and outboard o f shock absorber as a safety
measure.
4. Disconnect shock and stabilizer bar attachments
at lower control arm.
5. Loosen shaft end nuts.
6. Remove " U " bolts that retain the inboard end
o f the lower control arm.
7. Lower jack SLOW LY to release spring com pres
sion (Fig. 3C-24) and gain clearance to remove bushings.
Fig. 3C-24~Lowering C ontrol Arm for Bushing
WARNING: Be sure all
released from coil springs.
compression
is
Replacement
ball stud in steering knuckle. W hen stud is loosened,
remove tool and nut from lower stud.
N O T E : It is necessary to remove the brake caliper
assembly and wire it to the fram e to gain clearance
for tool J-23742. See section 5 for proper
procedure.
4. Remove the lower control arm.
Low er C ontrol Arm Inner Pivot Shaft a n d /
or Bushing R eplacem ent-O n Vehicle
8. Remove the stakes on the front bushing using
tool J-22717 or equivalent tool.
9. Bushings m ay now be replaced. Install "C "
clamps J-24435-7 and receiver J-24435-3 with remover
J-2.4435-2 and spacer J-24435-6 as shown in Figure 3C25.
10. Tighten the "C " clamp to remove the bushing.
11. Remove tools and discard old bushing.
12. Pivot shaft may now be removed if necessary.
13. Remove second bushing (leave pivot shaft in to
pilot tool) by the same method as in steps 8-12.
Bushing Installation (Fig. 3C -26)
CIO, G10-20 (Rubber Bushings)
Removal (Figs. 3C -24 , 3 C -25)
N O TE : If just bushings or pivot shaft are to be
replaced the lower control arm does not have to be
removed from the vehicle.
CAUTION: See C A U TIO N on page 1 o f this
section regarding the fasteners referred to in
step 5.
1. Install new bushings as shown in Figure 3C-26
using spacer J-24435-6, installer J-24435-4 and "C "
clamp J-24435-7.
2. Turn clamp in until bushing seats firmly.
CAUTION: Be sure spacer J -24435-6 is in
position as shown in Figure 3C-26 to avoid
collapsing control arm during assembly.
3. Install one bushing then insert the pivot shaft
and install second bushing.
4. Stake front bushing at least in two places w hen
installed.
5. Install the lower control arm to the vehicle as
described u nder "Lower Control Arm - Installation",
being sure to torque all fasteners to the proper
specification.
Lower Control Arm Installation
CAUTION: See C A U T IO N on page I o f this
section regarding the fa sten ers referred to in
steps 2 a n d 3.
1. Install lower ball stud through steering knuckle
and tighten nut.
2. Install spring and control arm as outlined under
spring installation.
3. Torque lower control arm ball stud to specifica
tions an d install cotter pin.
4. Install brake caliper assembly if removed (see
section 5).
5. Lower the vehicle to the floor.
2. Remove cotter pin from upper ball stud and
loosen stud nut (two turns) but do not remove nut.
3. Install J-23742 between the ball studs as shown
in Figure 3C-27.
NOTE: It is necessary to remove the brake caliper
assembly and wire it to the fram e to gain clearance
for tool J-23742. See section 5 for the proper
procedure.
CAUTION: Before proceeding with Step 4, be
sure lower control arm is supported as pointed
out in Step I .
4. Extend bolt from Tool J-23742 to loosen ball
stud in steering knuckle. W hen stud is loose, remove tool
and stud nut.
5. Center punch rivet heads and drill out rivets.
6. Remove the ball jo in t assembly.
Installation
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fasteners referred to in
steps /, 3 and 6.
1. Install new service ball joint, using bolts and
nuts supplied with joint, to upper arm. Torque nuts to 45
ft. lbs.
2. Mate ball stud to steering knuckle an d install
stud nut.
BALL J O IN T S E R V IC E -O N VEHICLE
3. Torque the ball stud nut as follows:
A. 10 Series 40—60 ft. lbs. plus additional torque
Ball J o in t— Inspection
to align cotter pin not to exceed 90 ft. lbs. Never back off
T he upper ball stud is spring loaded in its socket.
to align cotter pin.
This minimizes looseness at this point and compensates
B. 20—30 Series 80—100 ft. lbs. plus additional
for normal wear, if the upper stud has any perceptible
torque to align cotter pin not to exceed 130 ft. lbs. Never
lateral shake, or if it can be twisted in its socket with the
back off to align cotter pin.
fingers, the upper ball jo in t should be replaced.
4. Install new cotter pin.
5. Install lube fitting and lube new joint.
Upper—Removal
6. Install brake caliper assembly if removed (see
1.
Raise vehicle on hoist. If a fram e hoist is used,section 5).
it will be necessary to support the lower control arm with
7. Install tire and wheel assembly.
a floor jack.
8. Lower the vehicle to the floor.
Ball Joint— Inspection
REM O VE
Lower
U P P ER
J- 2 3 7 4 2 ,
Lower ball joints are a loose fit when not connected
to the steering knuckle. W e a r m ay be checked without
disassembling the ball stud, as follows:
1. Support weight o f control arms at wheel hub
and drum.
2. Accurately measure distance between tip o f ball
stud and tip o f grease fitting below ball joint.
3. Move support to control arm to allow wheel hub
and d rum to hang free. Measure distance as in Step 2. If
the difference in measurements exceeds .094” (3 /3 2 ” ) for
all models, ball jo in t is w orn and should be replaced
(Fig. 3C-28).
Lower—Removal
1.
Raise vehicle on a hoist. If a fram e hoist is used
it will be necessary to support the lower control arm with
a floor stand.
CUT TO O L O N
FIT PIPE O N
TO O L
D O T T E D LINE
J -9 5 1 9 -1 0
3 " W ATER
2 5/e " H IG H
Fig. 3C-28- Checking Lower Ball Joint
Fig. 3C-30- A lteration to Tool J-9519-10
2. Remove the tire and wheel assembly.
3. Remove the lower stud cotter pin and loosen
(two turns) hut do not remove the stud nut.
4. Install J-23742 between the ball studs as shown
in Figure 3C-27.
the ball stud and support the upper arm with a block of
wood so that assembly is out o f working area.
N O TE : It is necessary to remove the brake caliper
assembly and wire it to the frame to gain clearance
for tool J-23742. See section 5 for proper
procedure.
CAUTION: Before proceeding with Step 5, be
sure lower control arm is supported as pointed
out in Step 1.
5. Extend bolt from Tool J-23742 to loosen ball
stud in steering knuckle. W hen stud is loosened, remove
tool and ball stud nut.
6. Pull the brake disc and knuckle assembly up off
CAUTION: Do not put stress on the brake line
fle x hose.
7. Install Tools J-9519-10 an d J-9519-7 as shown in
Fig. 3C-29.
NOTE: It will be necessary to alter Tool J-9519-10
as illustrated in Fig. 3C-30 and install a 3" I.D.
pipe as shown if working on a 20 or 30 series
vehicle.
8. Turn hex head screw until ball jo in t is free of
control arm.
9.
Remove tools and the ball joint.
Installation (Fig. 3C-31)
CAUTION: See C A U TIO N on page 1 o f this
section regarding the fasteners referred to in
steps 4, 5 and 7.
1. Start the new ball joint into the control arm and
install J-9519 and J-9519-9 as shown.
N OTE: Position bleed vent in rubber boot facing
inward.
2. Turn hex head screw until ball jo in t is seated in
control arm.
3. Lower the upper arm and mate the steering
knuckle to the lower ball stud.
4. Install brake caliper assembly if removed (see
Section 5).
W A TER PIPE
5. Install ball stud nut and torque as follows. All
Series, 80—100 ft. lbs. plus additional torque to align
cotter pin hole not to exceed 130 ft. lbs. maximum.
N ever back off to align cotter pin.
6.
Install a lube fitting and lube the joint.
notch to insert cotter pins. Do not loosen nut to
insert cotter pin. Refer to Ball Joint text fo r
proper nut installation sequence.
3. Reverse rem aining removal procedure, and
tighten splash shield m ounting bolt. Tighten two caliper
assembly m ounting bolts to 35 ft. lb. torque.
4. Adjust wheel bearings as outlined u nder Front
W heel Bearing Adjustment.
5.
Tighten wheel nuts to 75 ft. lb.
CRO SSM EM BER AND S U SPEN SIO N U N IT
Com ponent parts of the front suspension may be
serviced separately as outlined in the preceding service
operations. However, if extensive service is to be
perform ed to crossmember, frame, etc., the unit can be
removed and installed as follows:
7.
Install
vehicle to floor.
lire
and
wheel
assembly
and
lower
1. Place vehicle on hoist and remove the shock
absorber from the lower control arm.
S TE ER IN G KNUCKLE
2.
It is recom m ended that vehicle be raised and
supported as on a twin-post hoist so that the front coil
spring rem ains compressed, yet the wheel and steering
knuckle assembly rem ain accessible. If a fram e hoist is
used, support lower control arm with an adjustable
jackstan d to safely retain spring in its curb height
position.
Removal
1. Raise vehicle on hoist and support lower control
arm as noted above.
2. Remove wheel and tire assembly.
3. Remove caliper as outlined under “ Front Wheel
Hub - R e m o v a l” .
4. Remove disc splash shield bolts securing the
shield to the steering knuckle. Remove Shield.
5. Refer to Section 3B-Steering for service removal
operations.
6. Remove u pper and lower ball stud cotter pins
and loosen ball stud nuts. Free steering knuckle from
ball studs by installing Special Tool J-23742. Remove
ball stud nuts and withdraw steering knuckle.
Installation
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fa sten ers referred to in
steps 2, 3, 4 and 5.
1. Place steering knuckle in position and insert
upper and lower ball studs into knuckle bosses.
CAUTION: Steering knuckle hole, ball stud and
nut should be fr e e o f dirt a n d grease before
tightening nut.
2. Install ball stud nuts and tighten nut
specifications. (See Specification Section.)
CAUTION: I f necessary,
Removal (Fig. 3C-32)
tighten
one more
to
Remove idler arm and pitm an arm.
3. Support engine and remove front engine m ount
center bolts.
4. Separate m ain brake feeder line from cross
m em ber tee.
5. Remove bolts retaining crossmember hangers to
fram e side rails.
6. If equipped with brake support struts remove
bolts retaining struts to crossm ember and fram e and
remove.
7.
Remove bolts securing crossm em ber to fram e
bottom rail an d lower the assembly from vehicle.
Installation
CAUTION: See C A U T IO N on page I o f this
section regarding the fa sten ers referred to in
steps I, 2,
4, 5, 6 a n d 7.
1. Jack crossmember into position under fram e
and install fram e bottom rail mounting bolts.
2. Install bolts securing crossmember hanger to
fram e and torque nuts. See specifications.
3. Position engine on front mount and install
m ounting bolt and torque (see Section 6).
4.
Install the shock absorber.
5. Install
removed.
brake
support
struts
if
previously
6. Connect front brake m ain feeder line and bleed
brakes as described in Section 5.
7.
Install idler arm and pitm an arm (see Section
9).
8. Check and Adjust front end alignm ent as
outlined under “ M aintenance and Adjustm ents” in this
section.
9.
Lower the vehicle to the floor.
FRONT SUSPENSION, FOUR-WHEEL DRIVE
SERIES K10, K20, K30
INDEX
G e n e ra l D escription........................................................
M ainten ance and A d ju stm e n ts..................................
Ball Joint A d ju s tm e n t...............................................
Bearing Lubrication....................................................
Wheel Bearing A d ju s tm e n t.....................................
C om ponent Replacement- ...........................................
Hubs, Free-W heeling (K id. K 2 0 ).........................
Hubs, Locked (KIO. K20, K.30)............................
3C3C3C3C3C3C3C3C-
24
27
27
28
28
29
29
30
S p in d le .............................................................................3 C - 3 0
Steering Knuckle (KIO, K 2 0 ) ................................ .3 C -3 1
Steering Knuckle (K 30)............................................ 3 C -3 3
Shock A b s o r b e r ........................................................... 3 C -3 6
Stabilizer B a r ............................................................... 3 C -3 6
L eaf S p r i n g .................................................................. 3C- 37
Specifications..................................................................... 3 C -3 8
Special T o o ls .................................................................... 3 C -3 9
GENERAL DESCRIPTION
Front drive axles used on KIO, K20, and K30 trucks
have several styles o f wheel-end construction.
At the wheel ends o f the axle tubes, two types of
steering knuckle attachment are used. Figures 3C-1K and
3C-2K show the KIO and K20 knuckle attached with ball
joints. Figure 3C-3K shows the king-pin attachm ent used
in K30. The tapered upper king pin fits in a tapered
nylon bushing. The lower king pin is part o f the bearing
cap, and this king pin rides in a tapered roller bearing.
All trucks with full-time four-wheel drive use a
locked hub. as shown in Figure 3C-1K (for KIO, K20),
and in Figure 3C-3K (for K30). A free-wheeling hub is
used on trucks equipped with part-time four-wheel drive.
The free-wheeling hub (for KIO, K20) is shown in Figure
3C-2K. This hub allows the driver to manually engage or
disengage the hub from the axle shafts.
R \
a
1.
2.
3.
4.
5.
6.
7.
8.
9.
H U B CAP
S N A P R IN G
H U B D R IV E G E A R
S P R IN G
LO C K N U T
L O C K -A D J . N U T
P IN -A D J . N U T
A D J U S T IN G N U T
PRESSURE P LA TE
10.
11.
12.
13.
14.
15.
16.
17.
18.
O U T E R -W H E E L B E A R IN G
IN N E R -W H E E L B E A R IN G
S P IN D L E
S P IN D L E B E A R IN G
SEAL
H U B - A N D - D IS C A S M
O IL S E A L
SPACER
DUST S E A L
Fig. 3C-1K--K10, K20 w ith Locked Hub and Ball Joints
19.
20.
21.
22.
23.
24.
25.
26.
DEFLEC TO R
A X L E OUTER SH AFT
KN U CKLE
A D J U S T IN G S L E E V E
UPPER B A L L J O IN T
YOKE
LO W ER B A L L J O IN T
R E T A IN IN G R IN G
1.
2.
3.
4.
5.
6.
7.
8.
9.
10 .
11.
R E T A IN IN G P L A T E
" 0 " R IN G
A C T U A T O R KNOB
R E T A IN IN G P L A T E B O L T
A X L E S H A F T S N A P R IN G
A C T U A T IN G C A M B O D Y
IN T E R N A L S N A P R IN G
O U T E R C L U T C H R E T A IN IN G R IN G
A X L E S H A F T S L E E V E A N D C L U T C H R IN G
IN N E R C L U T C H R IN G
S P R IN G
LO C K N U T
L O C K -A D J . N U T
P IN -A D J . N U T
A D J U S T IN G N U T
PRESS U R E P L A T E
O U T E R -W H E E L B E A R IN G
18. IN N E R -W H E E L B E A R IN G
19. S P IN D L E
20 . S P IN D L E B E A R IN G
21. SEAL
22 . H U B -A N D -D IS C ASM
12 .
13.
14.
15.
16.
17.
Fig. 3C-2K- K10, K20 w ith Free-Wheeling Hub and Ball Joints
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
O IL S E A L
SPACER
DUST S E AL
D EFLEC TO R
A X L E O UTER SH A FT
KNU CKLE
A D J U S T IN G S L E E V E
UPPER B A L L J O IN T
YOKE
LO W ER B A L L J O IN T
R E T A IN IN G R IN G
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
HUBCAP
S N AP R IN G
H U B D R IV E G E A R
A D J U S T IN G N U T ASM
LO C K N U T
LO C K T A N G
A D J U S T IN G N U T
W ASHER
O U T E R W H E E L B E A R IN G
IN N E R W H E E L B E A R IN G
SEAL
H U B -A N D -D IS C A SM
S P IN D L E
11.
12.
13 .
14.
15.
16.
17.
18.
19.
20 .
21.
22 .
23.
S P IN D L E B E A R IN G
SEAL
D EFLEC TO R
SPACER
LU B E F IT T IN G
UPPER B E A R IN G CAP
PRESSURE S PR IN G
GASKET
B U S H IN G , K IN G -P IN
K IN G -P IN
YOKE
OUTER A X LE SH AFT
G R E A S E R E T A IN E R
LO W ER B E A R IN G
SEAL
B E A R IN G CAP
LU B E F IT T IN G
Fig. 3C-3K-K30 w ith Locked Hub and King-Pins
MAINTENANCE AND ADJUSTMENTS
BALL J O IN T A D J U S T M E N T (K 10, K 20)
indepen dent m ovem ent o f each steering knuckle.
Front axle ball jo in t adjustm ent is generally
necessary only w hen there is excessive play in steering,
irregular w ear on tires or persistent loosening o f the tie
rod is observed.
1. Raise vehicle on hoist then place jack stands just
inside o f front springs.
2. Disconnect connecting rod and tie rod to allow
3.
Apply a fish-scale to the tie rod mounting hole
o f the steering knuckle arm. W ith the knuckle assembly
in the straight-ahead position, determ ine the right angle
pull required to keep the knuckle assembly turning after
initial break-away. This pull should not exceed 25 lbs.,
for each knuckle assembly, in either direction. See
Figure 3C-4K.
Fig. 3 C -4K -D ete rm inin g Front Axle Ball Joint A djustm ent
2. Torque the inner adjusting nut to 50 foot
4.
If the effort exceeds 25 lbs., remove the upper
pounds, while rotating the hub-and-disc to seat the
ball stud nut, and loosen the ball stud adjusting sleeve as
bearings. Use Tool J-6893 and A dap ter J-23446 or
required. Re-torque the ball stud nut and recheck the
J-6893-01 for K10, K20; use J-26878 for K30. Back off
turning effort.
the inner adjusting nut and retorque to 35 ft. lbs. while
the hub is being rotated.
BEARING L U B R IC A T IO N
3. Back off the inner adjusting nut again 3/8 turn
Front W heel Bearings
maximum.
a. For K10 and K20, assemble adjusting nut lock
Spindle Bearings
by aligning nearest hole in lock with adjusting nut pin.
Install outer lock nut an d torque to 50 ft. lbs. (minimum).
W hen ev er front wheel bearings are lubricated, the
b. For K30, assemble lockwasher and outer
spindle needle bearings should also be lubricated, with
locknut. Torque outer locknut to 65 ft. lbs. (minimum).
the same chassis grease. U nder norm al conditions, the
Bend one ear of lockwasher over the inner nut a
lubrication interval should be 12,000 miles; off-road use
m inim um o f 30 °. Bend one ear o f lockwasher over the
such as in mud or w ater will require shorter intervals.
outer nut a m inim um o f 60°.
The spindle bearings are accessible after removing the
spindle, as shown in Figure 3C-6K.
NOTE: Hub assembly should have .001 to .010
inch end play, for all K10, K20 and K30 models.
4. If vehicle is equipped with locked hubs, install
1.
A fter lubricating the wheel bearings and the the hub cap assembly. If the vehicle is equipped with
spindle bearings, install the hub-and-disc, an d the outer
free-wheeling hubs, refer to free-wheeling hub assembly
wheel bearing to the spindle.
and installation procedures.
WHEEL BEARING A D J U S T M E N T
COMPONENT REPLACEMENT
HUB REPLACEMENT
CAUTION: See CAUTION on page 1 o f this
section regarding the fasteners in the following
procedures fo r hub replacement.
b. Remove the inner and outer bearing cups
using a brass drift an d hammer.
c. Clean, inspect and lubricate all parts as
required.
Servicing A ctuating Parts
FREE-W HEELING HUBS
K10, K 20 (P A R T -T IM E )
Hub Rem oval
1. T u rn actuator lever to set hub to " L O C K "
position (Fig. 3C-5K) and raise vehicle on hoist.
2. Remove six retaining plate bolts and remove
re ta in in g plate actuating knob and " O " ring.
3. R em ove in ternal sn ap ring, outer clutch
retain in g ring and actuating cam body.
4. Relieve pressure on the axle shaft snap ring and
remove snap ring.
5. Remove the axle shaft sleeve and clutch ring
assembly and inner clutch ring and bushing assembly.
6. Remove pressure spring and spring retainer
plate.
7. Remove the wheel bearing outer lock nut, lock
ring, and wheel bearing inner adjusting nut using Tool
J-6893 and A dap ter J-23446 or Tool J-6893-01.
1. Remove actuator knob and " O " ring from
retaining plate, discard " O " ring and replace with a new
" O " ring during assembly.
2. Slide inner clutch ring an d bushing assembly
from axle sleeve and clutch ring assembly.
3. Wash all parts in solvent and air dry.
4. Inspect all parts for wear, cracks or broken
teeth.
5. Replace all " O " rings during assembly.
6. Place new " O " ring seal on actuator knob.
Apply Lubri-plate, or equivalent, to " O " ring and place
actuator knob in retaining plate.
Installation of Hub
NOTE: All parts should be lubricated for normal
operation during assembly with an ample am ount
o f high speed grease. Lubrication M U ST be
applied to prevent deterioration before the unit is
placed in service.
1. Assemble the outer wheel bearing cup into the
N O T E : If the disc or other brake components
wheel hub using Installer J-6368 and D river Handle
require repairs or replacement, refer to Section 5.
J-8092.
8. Remove the hub-and-disc assembly, outer wheel
2. Assemble the inner wheel bearing cup into the
bearing and the spring retainer plate.
wheel hub using Installer J-23448 and D river Handle
a.
Remove the oil seal and inner bearing cone
J-8092.
from the hub using a brass drift and tapping with a
3. Pack the wheel bearing cone with a high melting
h am m er. Discard the oil seal.
point type wheel bearing grease and insert the cone into
the cup.
4. A fter lubricating the wheel bearings, install the
hub-and-disc and the bearings to the spindle.
5. Torque the inner adjusting nut to 50 foot
pounds, while rotating the hub-and-disc to seat the
bearings. Use Tool J-6893 and A dapter J-23446 or
J-6893-01. Back off the inner adjusting nut and retorque
to 35 ft. lbs. while the hub is being rotated.
6. Back off the inner adjusting nut again 3 /8 turn
maximum. Assemble the adjusting nut lock by aligning
the nearest hole in lock with the adjusting nut pin. Install
outer lock nut and torque to 50 ft. lbs. (minimum).
NOTE: Hub assembly should have .001 to .010
inch end play.
7. Install spring retainer plate (flange side facing
bearing) over spindle nuts and seat retainer against
bearing outer cup.
8. Install pressure spring into position. Large O.D.
seats against spring retaining plate.
NOTE: Spring is an interference fit. W hen spring
is seated, spring extends past the spindle nuts by
approximately 7 /8 ".
9. Place inner clutch ring and bushing assembly
into axle shaft sleeve and clutch ring assembly and
install as an assembly onto the axle shaft. Press in on
assembly and install axle shaft snap ring.
NOTE: Install 7/16 x 20 bolt in axle shaft end and
pull outward on axle shaft to aid in installing snap
rings.
10. Install actuating cam body (cams facing
outward), outer clutch retaining ring and internal snap
ring.
11. Install " O " ring on retaining plate and install
actuating knob and retaining plate.
N O T E : Install actuating knob with knob in
" L O C K " position—grooves in knob must fit into
actuator cam body.
12. Install six cover bolts and seals, and torque to
30 ft. lbs.
13. T urn knob to " F R E L " position to check for
proper operation.
14. Lower vehicle to floor.
b.
Install new grease seal into inboard end of
hub. Use J-24428 for K30.
4. A fter lubricating the wheel bearings, install the
hub-and-disc and the bearings to the spindle.
5. Torque the inner adjusting nut to 50 ft. lbs.
while rotating the hub-and-disc , to seat the bearings.
Back off the inner adjusting nut and retorque to 35 ft.
lbs. while the hub is being rotated.
6. Back off the inner adjusting nut again 3 /8 turn
maximum.
a.
For K10 and K2Q assemble the adjusting nut
lock by aligning the nearest hole in lock with the
adjusting nut pin. Install outer lock nut and torque to 50
ft. lbs. (minimum).
b For K30, assemble lockwasher and outer
locknut. Torque outer locknut to 65 ft. lbs. (minimum).
Bend one ear o f lockwasher over the inner nut a
minim um of 30 °. Bend one ear o f lockwasher over outer
nut, a m inim um o f 60 °.
LOCKED HUBS
K IO , K20, K30 (FU LL-TIM E )
Rem oval and Service
1. Remove the hub cap and snap ring.
2. Remove the drive gear and, on KIO and K20,
the pressure spring. Place a hand over the drive g ear and
use a screwdriver to pry the gear out.
3. Remove the wheel bearing outer lock nut, lock
ring, and wheel bearing inner adjusting nut using Tool
J-6893 and A dapter J-23446 or tool J-6893-01 for KIO,
K20; use J-26878 for K30.
N O T E: If the disc or other brake components
require repairs or replacement, refer to Section 5.
4. Remove the hub-and-disc assembly, outer wheel
bearing and the spring retainer plate.
a. Remove the oil seal and inner bearing cone
from the hub using a brass drift and tapping with a
ham m er. Discard the oil seal.
b. Remove the inner and outer bearing cups
using a brass drift and ham m er.
c. Clean, inspect and lubricate all parts as
required.
Installation
1. Assemble the outer wheel bearing cup into the
wheel hub.
a. Use installer J-6368 and Driver Handle J-8092
for KIO, K20.
b. Use J-8608 for K-30.
2. Assemble the inner wheel bearing cup into the
wheel hub.
a. Use J-23448 and Driver Handle J-8092 for
KIO, K20.
b. Use J-22306 for K-30.
3. Pack the wheel bearing cone with a high melting
point type wheel bearing grease.
a. Insert the cone into the cup.
NOTE: Hub assembly should have .001 to .010
inch end play, for all K10, K20 and K30 models.
CAUTION: See CAUTION on page 1 o f this
section.
7. Install the pressure spring (on K10 and K20),
drive gear, snap ring and hub cap.
SPINDLE
Removal
1. Remove the hub-and-disc assembly as outlined
earlier.
2.
Remove the spindle retaining bolts.
3. Remove the spindle and bronze thrust washer
by tapping the end o f the spindle lightly with a soft
h am m er to break it loose from the knuckle as shown in
Figure 3C-6K. Replace the thrust washer if excessive
wear has occurred.
Servicing Spindle Components
1. Secure the spindle in a vise by locating on the
high step diameter. Be sure that the machined surface o f
the spindle will not be dam aged by the vise jaws.
2. Remove the oil seal.
3. Remove the needle roller bearing.
4. Place the spindle in a vise on the high step and
install needle roller bearing.
a. Use J-23445 and Drive Handle J-8092 for
K10, K20.
b. Use J-21465-17 for K-30.
5. Install grease seal onto slinger with lip toward
spindle.
6. Relubricate the needle b earing and the spindle
end with a high melting point type wheel bearing grease.
Installation
1. Install the bronze thrust washer over the axle
shaft with the c h a m fe r toward the slinger and install the
spindle as shown in Figure 3C-7K.
2. Assemble spindle to knuckle.
NOTE: Torque spindle nuts to 25 ft. lbs. (K10, 20);
torque to 60 ft. lbs. (K30).
C A U TIO N : See CAUTION on page 1 o f this section.
KNUCKLE
K 10, K 20, (W IT H BALL J O IN T S )
Rem oval
1. R em ove hub an d spindle co m p on ents as
outlined earlier.
2. If the steering arm is to be removed, disconnect
the tie rod.
a. Remove cotter pin.
b. Loosen tie rod nuts and tap on nut with a soft
h a m m e r to break the studs loose from the knuckle arm.
c. Remove nuts and disconnect the tie rod.
CAUTION: I f it is necessary to remove the
CHAMFER
TOW ARD
Fig. 3C-8K-R em oving Steering Arm Nuts
steering arm, discard the self-toeking nuts (Fig.
3C-8K) an d replace with new nuts at assembly.
3. Remove the cotter pin from the upper ball
socket nut.
4. Remove the retaining nuts from the upper and
lower ball sockets as shown in Figure 3C-9K.
5. Remove the knuckle assembly from the yoke by
inserting a suitable wedge-shaped tool between the lower
ball stud and the yoke and tapping on the tool to release
the knuckle assembly. Repeat as required at the upper
ball stud location.
Ball Joint Service
CAUTION: Do not remove the yoke upper ball
stud adjusting sleeve unless new ball studs are
being installed. I f it is necessary to loosen the
sleeve to remove the knuckle, do not loosen it
more than two threads using Spanner J -23447
as shown in Figure 3C -I4K . The nonhardened
J-23454-1
FLAT WASHER
(HIDDEN)
J-951 9 -1 0
Fig. 3C-10K--Removing Lower Ball Joint
threads in the yoke can he easily dam aged by
the hardened threads in the adjusting sleeve i f
caution is not used during knuckle removal.
N OTE: Remove the lower ball joint snap ring
before beginning. Lower ball joint must be
removed before any service can be perform ed on
the upper ball joint.
1. Remove the lower ball jo in t using tools J-951910, J-23454-1, and sleeve J-6382-3 or equivalent as shown
in Figure 3C-10K.
N O T E: If Tool J-6382-3 is not available, a suitable
tool may be fabricated from 2 -1 /2 " O.D. steel
tubing with 3 /1 6 " wall thickness, cut 2 -1 /2 " long.
2. Remove the u pper ball joint using tools J-951910, J-23454-1, and sleeve J-6382-3 or equivalent as shown
in Figure 3C-11K.
3. Install the lower ball jo int into the knuckle.
M ake sure that the lower ball jo in t (the joint without
Fig. 3 C -12 K -In sta llin g Lower Ball Joint
cotter pin hole in the stud end) is straight. Press the stud
into the knuckle until properly seated using tools J-951910. J-23454-2, and J-6382-3 or equivalent as shown in
Figure 3C-I2K and install snap ring.
4.
Install the upper ball jo in t into the knuckle.
Press the stud into the knuckle until properly seated
using Tools J-95 19-10, J-23454-2, and J-6382-3 or
equivalent as shown in Figure 3C-13K.
Installation
C AU TIO N : See CAUTION on page 1 o f this
section regarding the fasteners in the following
steps.
1. Position the knuckle and sockets to the yoke.
Install new nuts finger tight to the upper (the nut with
the cotter pin slot) and lower ball socket studs.
2. Push up on the knuckle (to keep the ball socket
from turning in the knuckle) while tightening the lower
socket retaining nut. Torque lower nut to 70 ft. lbs.
3. Torque the yoke upper ball stud adjusting sleeve
to 50 ft. lbs. using S p a nne r J-23447. See Figure 3C-14K.
4. Torque the upper ball socket nut to 100 ft. lbs.
BALL JO IN T
J-23454 -1
J-6382-3
J -2 3 4 5 4 -2
J-9519-10
J-951 9 - 1 0
J -2 3 4 4 7
Fig. 3C-14K--Ball Stud A d ju stin g Sleeve
Fig. 3C-16K--Knuckle w ith King Pins
as shown in Figure 3C-15K. A fter torquing the nut, do
not loosen to install cotter pin, apply additional torque,
if necessary, to line up hole in stud with slot in nut.
5. If the tie rod and steering arm were removed:
a. Assemble the steering arm using the three
stud adapters and three new self-locking nuts. Torque the
nuts to 90 ft. lbs.
b. Assemble the tie rod to the knuckle arm.
Torque the tie rod nuts to 45 ft. lbs. and install cotter
pin.
KNUCKLE
K 30 (W IT H KING P IN S )
Rem oval (Fig. 3 C -1 6K )
1.
Remove the hub and spindle as outlined earlier.
If necessary, tap lightly with a rawhide h a m m e r to free it
from the knuckle. Check bronze spacer located between
Fig. 3C-17K-Rem oving Spindle
Fig. 3C-19K-Rem oving Cap, Spring and Gasket
Fig. 3C-21K--Removing Tapered Bushing
axle shaft jo in t assembly and bearing. If w ear is evident,
replace with a new one. See Figure 3C-17K.
2. Remove four nuts from upper king pin cap.
Remove nuts alternately as compression spring will force
cap up. Refer to Figure 3C-18K.
3. Remove cap, compression spring, and gasket, as
shown in Figure 3C-19K. Discard gasket, replace with
new one at time o f assembly.
4. From the underside o f the knuckle, remove four
cap screws from the lower king pin bearing cap. Remove
the bearing cap-and-lower king pin. See Figure 3C-20K.
5. Remove upp er king pin tapered bushing and
knuckle from yoke. Remove king-pin felt seal. See
Figure 3C-21K. Remove knuckle.
6. Remove u pp e r king-pin from yoke with large
breaker b a r and J-26871, as seen in Figure 3C-22K.
NOTE: Torque specification is 500-600 ft. lbs.
7. Remove lower king pin bearing cup, cone,
Fig. 3C-22K--Removing Upper King Pin
Fig. 3C-24K- In sta llin g Grease Retainer
Fig. 3C -26K --lnstalling Upper King-Pin
grease retainer, and seal all at the same time, as shown
in Figure 3C-23K. Discard seal and replace with new one
at time of assembly. If' grease retainer is dam aged,
replace with new one at time o f assembly.
new lower king pin b earing oil seal, using J-22281, as
shown in Figure 3C-25K.
Installation
CAUTION: See CAUTION on page 1 o f this
section regarding the fasteners in the following
steps.
1. Assemble new grease retainer and lower king
pin bearing cup, using J-7817, as shown in Figure 3C24K.
2. Fill the area in grease retainer with specified
grease, then grease the b earing cone and install. Install
N OTE: Do not distort oil seal. It will protrude
slightly from the surface o f yoke flange when fully
installed.
3. Install upper king-pin, using J-26871 as shown
in Figure 3C-26K. Torque to 500-600 ft. lbs.
4. Assemble felt seal to king pin, assemble knuckle,
assemble tapered bushing over king pin. as shown in
Figure 3C-27K.
Fig. 3C-28K --lnstalling Lower Bearing Cap-and-King Pin
5. Assemble lower bearing cap-and-king pin with
four cap screws. Tighten cap screws alternately and
evenly; see Figure 3C-28K. Torque cap screws to 70-90
ft. lbs.
6. Assemble compression spring on upper king pin
bushing. Assemble b earing cap, with new gasket, over
four studs. Tighten nuts alternately and evenly. Torque
nuts to 70-90 Lb. Ft. See Figure 3C-29K.
SHOCK ABSORBER
Removal (Fig. 3C-30K)
1. Raise vehicle on hoist.
2. Remove nuts and eye bolts securing upper and
lower shock absorber eyes.
3. W ithdraw shock absorber and inspect rubber
eye bushings. If defective, replace shock absorber
assembly.
Installation
Place shock absorber into position over m ounting
Fig. 3C-30K--Shock Absorber A tta ch m en t
bolts or into m ounting brackets. Install eye bolts and
nuts and torque as shown in Specifications Section.
Lower vehicle to floor.
S TA B ILIZE R BAR-TYPICAL
Removal (Fig. 3C-31K)
1. Raise vehicle on hoist and remove nuts and
bolts attaching stabilizer brackets and bushings at fram e
location.
2. Remove brackets and bushings at lower spring
anchor plates and remove stabilizer from vehicle.
Inspection
Inspect rub ber rushings for excessive w ear or agingreplace where necessary. Use r u b b e r lubricant when
installing bushings over stabilizer bar.
Installation
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fasteners referred to in
step 2.
5. Remove front spring eye bolt.
6. Remove spring-to-axle u-bolt nuts a n d remove
spring, lower plate and spring pads.
7. Remove shackle to spring bolt an d remove
bushings and shackle.
Bushing R eplacem ent
1. Place spring on press and press out bushing
using a suitable rod, pipe, or tool.
2. Press in new bushing; assure that tool presses on
steel outer shell o f bushing. Install until bushing
protrudes an equal am ount on each side o f spring.
Spring Inserts (Liners) or Leaf R eplacem ent
Fig. 3C-32K--Leaf Spring Assembly
NO TE: Slit in bar to fram e bushings should be
facing forward.
1. Place stabilizer in position on fram e and install
fram e brackets over bushings. Install nuts and bolts
loosely.
2. Install brackets over bushings at lower control
arm location. Be sure brackets are positioned properly
over bushings. T orque all nuts and bolts to specifications.
3. Lower vehicle to floor.
LEAF S PR IN G AND B U S H IN G S
Removal
1.
2.
3.
spring.
4.
Raise vehicle on hoist.
Place adjustable lifting device under axle.
Position axle so that all tension is relieved from
Remove shackle upper retaining bolt.
1. Place spring in vise and remove clips.
2. Remove center bolt. Open vise slowly, allowing
spring to expand.
3. W ire brush, clean, and inspect for broken
leaves.
4.
Replace leaf or liners.
Installation
CAUTION: See CA U TIO N note on page one o f
this section regarding the fasteners referred to
in steps 5 and 6.
1. Install spring shackle bushings into spring and
attach shackle. Do not tighten bolt.
2. Position spring upper cushion on spring.
3. Insert front o f spring into frame and install
bolt. Do not tighten.
4. Install shackle bushings into fram e and attach
rear shackle. Do not tighten bolt.
5. Install lower spring pad and spring retainer
plate. Torque bolts to specifications.
6. Torque front and rear spring eye and shackle
bolts to specifications.
7. Remove stands and lower vehicle to floor.
SPECIFICATIONS
F R O N T S U S P E N S IO N B O L T T O R Q U E (F t. Lbs.) $
CP-10
CP-20-30
L o w e r C o n tro l Arm S h a ft U -Bolt
85
85
U pper C o n tro l A rm S h a ft N uts
70
105
L o w e r C o n tro l A rm Bushing Steel
U pper Ball Join t N ut
L o w er Ball Join t N ut
C rossm em ber to S id e Rail
C rossm em ber to B o tto m R ail
G-30
-
45
85
-
70
105
-
140
$$
N ew
Used
190
115
-
w /Spacer 160
N o Spacer 95
w /Spacer 190
N o Sp acer 1 1 5
$$
N ew
Used
280
130
-
w /Spacer 280
N o Sp acer 13 0
w /Spacer 280
N o Sp acer 130
140
C o n tro l A rm R u b b er Bushings
U pper C o n tro l A rm Bushing Steel
-
G-10-20
K-AII
*50
**9 0
**10 0
*50
**90
**90
**90
**90
* *9 0
***8 0
65
65
—
65
65
100
100
-
100
100
C rossm em ber B rake S u p p o rt Struts
60
60
ANCHOR
PLATE
-iso
25
S ta b ilizer Bar to C o n tro l A rm
25
25
S ta b ilizer Bar to Fram e
25
25
.55
140
140
65
75
60
65
75
S h o ck A b so rb er U pper End
S h o ck A b so rb er L o w e r End
B rake Splash Shield to K n u ck le
W heel Bearing A d ju stm en t
W heel Bearing Preload
W heel Bearing End M ovem ent
60
120 l a Lbs.
120 In. Lbs.
25
120 l a Lbs.
120 l a Lbs.
-
-
-
Inner # - 35
O uter -5 0
Zero
Zero
Zero
Zero
.001 - .005”
.001 - .005”
.001 - .0 1 0 "
.00 1 - .005
C alip er M oun ting B o lt
35
35
35
35
Spring - F ro n t E y e Bolt
-
-
90
-
Spring - R ear E ye Bolt
-
-
50
—
-
-
50
-
-
-
15 0
-
Spring - Front Support to Frame
—
—
25
—
Suspension Bumper
15
15
25
15
Stabilizer to Spring Plate
-
-
130
-
Spring - T o R ear Sh ack le B o lt
Spring -
*
*■*
***
#
$
$$
To A x le U -Bolt
Plus additional torque to align cotter pin. Not to exceed 90 ft. lbs. maximum.
Plus additional to rque to align cotter pin. Not to exceed 130 ft. lbs. maximum.
Plus additional torque to align cotter pin.
Back nut off to align cotter pin at nearest slot.
All specifications are given in foot pounds of Torque unless indicated otherwise.
CIO, G10-20 Rubber Bushings; C20-30, G30, P10-30 Steel Bushings.
SPECIAL TOOLS
1.
2.
3.
4.
5.
J-8457
J-8458
J-8849
J-9276-2
Bearing
Bearing
Bearing
Bearing
J-24435-1
th ru 7
Bushing Replacem ent
C 10, G 10-20
Race
Race
Race
Race
Installer
Installer
Installer
Installer
6.
7.
8.
9.
10.
11.
J-8092
J-9519-9
J-9519-7
J -9519-10
J-23028-01
J-23742-1
D river Handle
Ball J o in t Installer
Ball J o in t Remover
" C " C lam p
Spring Remover
Ball J o in t Remover
SECTION 3D
REAR SUSPENSION
The following caution applies to one or more steps in the assembly
procedure o f components in this portion of the m anual as indicated at
the a pp ro pria te locations by the terminology "See Caution on page l of
this Section".
CAUTION: T H IS F A S T E N E R I S A N IM P O R T A N T A T T A C H IN G
P A R T IN T H A T I T C O U LD A F F E C T T H E P E R F O R M A N C E OF
V IT A L C O M P O N E N T S A N D S Y S T E M S , A N D /O R C O U LD R E S U L T
IN M A JO R R E P A IR E X P E N S E . I T M U S T BE R E P L A C E D W IT H
O N E OF T H E S A M E P A R T N U M B E R OR W IT H A N E Q U IV A L E N T
P A R T IF R E P L A C E M E N T B E C O M E S N E C E S S A R Y . DO N O T U SE A
R E P L A C E M E N T P A R T OF L E S S E R Q U A L IT Y OR S U B S T IT U T E
D E S IG N . TO R Q U E V A L U E S M U S T BE U SED A S SP E C IF IE D
D U R IN G R E A S S E M B L Y TO A S S U R E P R O P E R R E T E N T IO N OF
THI S PART.
INDEX
G en eral D e sc rip tio n ........................................................................
C om pon en t Parts R e p la c e m e n t..................................................
Shock A b s o r b e r s ..........................................................................
Stabilizer S h a f t.............................................................................
L eaf Spring Assembly...............................................................
Specifications......................................................................................
GENERAL DESCRIPTION
All 10-30 series vehicles use a leaf spring/solid rear
axle suspension system. Typical systems are illustrated in
Fig. 3D-1, 3D-2 and 3D-3.
The rear axle assembly is attached to multi-leaf
springs by " U " bolts. The spring front eyes are attached
to the fram e at the front hangers, through rubber
bushings. The rear ends o f the springs are attached to
the fram e by the use o f shackles which allow the spring
to "change its length" while the vehicle is in motion.
Control arms are not used with leaf springs.
Ride control is provided by two identical direct
double acting shock absorbers angle-mounted between
the fram e and brackets attached to the axle tubes.
3D -1
3D-2
3D-2
3D-3
3D-4
3D-8
Fig. 3D -2-T ypical G-Truck Rear Suspension
Fig. 3D -3-T ypical P-30 H.D. Truck Rear Suspension
COMPONENT PARTS REPLACEMENT
shock absorber by removing nut and washers shown, and
bolt on G-models.
SHO CK ABSORBERS
Replacement
Refer to Figs. 3D-4 through 3D-8 for specific
vehicle m o unting provisions.
1. Raise vehicle on hoist, and support rear axle.
2. If equipped with air lift shock absorbers, bleed
air from lines. Disconnect line from shock absorber.
3.
At
the
upper
m ounting
location,
disconnect
4. At the lower mounting location, remove nut,
washers and bolt as shown.
5.
Remove shock absorbers from vehicle.
6. To install shock absorber, place into position
and reattach at upper m ounting location. Be sure to
install nuts and washers as shown.
Fig. 3D-6 -Shock Absorber-G-10, 20, 30
7. Align lower end o f shock absorber with axle
bracket, and install bolt, washers and nut, as shown.
8. Tighten nuts to specifications.
CAUTION: See C A U T IO N on page 1 o f this
section regarding shock absorber fasteners.
9. If equipped with airlift shock absorbers, inflate
to 10-15 pounds m inim um air pressure.
Fig. 3D-8--Shock Absorber-P30
10.
Lower vehicle and remove from hoist.
S TA B ILIZE R SHAFTS
Refer to Fig. 3D-9, 3D-10 and 3D-11 for specific
rear stabilizer shaft m ounting on C and P models.
Replacement
1.
Raise vehicle on hoist and support rear axle.
N O TE :
Route Parking Brake C a b le
Fig. 3D-10~Rear Stabilizer Shaft-C-20(43), C-30
2. Remove nut, washer and grom m et from link
bolt at the fram e side m e m b e r on each side.
3. W ith draw link bolt, washers, grommets and
spacer.
4. R em ove brackets from a n c h o r plates by
rem oving attaching screws.
5. Remove stabilizer shafts.
6. Reverse above steps to install stabilizer shaft.
O n installation, position shaft so parking brake cable is
routed over stabilizer.
7. T orque all bolts to specifications.
CAUTION: See C A U T IO N on page I o f this
section, regarding stablizer fasteners.
8. Lower hoist and remove vehicle.
LEAF S P R IN G ASSEMBLY
R efer to Figs. 3D-12, 3D-13, 3D-14 and 3D-15 for
specific leaf spring m ounting provisions o f C, K, G and
P models. Fig. 3D-17 illustrates a typical U-bolt anchor
plate in s ta lla tio n w ith the m a n d a to r y tighten in g
sequence.
CAUTION: See C A U T IO N on page 1 o f this
section, regarding le a f spring fasteners.
Removal
1. Raise vehicle on hoist so that tension in spring
is relieved.
2. Loosen, but do not remove, spring-to-shackle
retaining nut.
3. Remove nut and bolt securing shackle to spring
hanger.
4. Remove nut and bolt securing spring to front
hanger.
5. Remove " U " bolt retaining nuts, withdraw " U "
Fig. 3D-ll--Rear Stabilizer Shaft-P30
bolts and spring plate from spring-to-axle housing
attachment.
6. W ithdraw spring from vehicle.
7. Inspect spring. Replace bushings, rep air or
replace spring unit as outlined in this section.
Bushing Replacement
1. Place spring on press and press out bushing
using a suitable rod, pipe or tool as shown in Fig. 3D-16.
2. Press in new bushing; assure that tool presses on
steel outer shell o f bushing.
N OTE: R ear Spring, Front Eye—Heavy Duty leaf
springs on C20 and C30 trucks use a staked- inplace front eye bushing. Before this bushing is
pressed out o f the spring, the staked locations must
be straightened with a chisel or drift. After a new
bushing is installed, it must be staked in three
equally spaced locations.
Fig. 3D-12 -Rear Spring Installation-G Models
Spring Leaf Replacement
1. Place spring assembly in a bench mounted vise
and remove spring clips.
2. Position spring in vise jaws, compressing leaves
at center and adjacent to center bolts.
3. File peened end o f center bolt and remove nut.
O pen vise slowly to allow spring assembly to expand.
4. W ire brush and clean spring leaves. Inspect
spring leaves to determ ine if replacem ent is required;
also replace defective spring leaf liners at this time.
5. Align center holes in spring leaves by means o f
a long d rift a n d compress spring leaves in a vise.
6. Remove drift from center hole and install a new
center bolt. Peen bolt to retain nut.
7. Align spring leaves by tapping with ham m er,
then bend spring clips into place or install bolts and
spacer if so equipped.
N O T E : Spring clips should be bent sufficiently to
m ain tain alignment, but not tight enough to bind
spring action.
Leaf Spring Installation
1. Position spring assembly to axle. Make sure
spring is in position at both spring hangers.
N O T E : T he shackle assembly must be attached to
the rear spring eye before installing shackle to rear
hanger.
2. Install spring retainer plate and " U " bolts.
Loosely install retaining nuts, but do not torque at this
time.
3. Jack fram e as required to align spring and
shackle with spring hangers.
4. Install shackle bolt an d nut and again reposition
spring, if necessary to align front eye. Install front eye
bolt and nut. Torque h ang er and shackle fasteners to
specifications.
NOTE: Make certain that the bolts are freeturning in their bushings prior to torquing.
5. Lower vehicle so that weight o f vehicle is on
suspension components and torque U-bolt nuts to
specifications.
6. Lower vehicle and remove) from hoist.
U-Bolt and Anchor Plate Installation
Fig. 3D-17 illustrates the m a n dato ry sequence o f
tightening U-bolt nuts. Tighten diagonally opposite nuts
to 40-50 foot pounds, then tighten all nuts as shown to
specifications.
CAUTION: See C A U T IO N on page 1 o f this
section, regarding " U”-Bolt fasteners.
SHACKLE REPLACEM ENT
1. Raise vehicle on hoist. Place adjustable lifting
device under axle.
2. Remove load from spring by jacking frame.
3. Loosen spring-to-shackle retaining bolt, but do
not remove.
4. Remove shackle-to-frame bracket retaining bolt
then remove shackle bolt from spring eye.
5. Position shackle to spring eye and loosely install
retaining bolt. Do not torque retaining bolt at this time.
6. Position shackle to fram e bracket and install
retaining bolt.
7. Rest vehicle weight on suspension components
and torque both shackle bolt reta in in g nuts to
specifications.
CAUTION: See C A U T IO N on page I o f this
section, regarding these fasteners.
8. Lower vehicle and remove from hoist.
N O TE: " U " BOLTS MUST BE LOCATED
AROUND THE A X L E TUBE SO T H A T
THE LEGS PASS THE SPRING SEAT
W ITH IN .060.
SPECIFICATIONS
TORQUE SPECIFICATIONS
Spring-to-Axle “ U ” Bolt Nuts
140
Leaf Spring
—Front Bushing Bolt
110
P
G
C-K
(ill)
G20
G30
120
120
150
9 0 /1 3 5 *
P10
P20
P30
140
140
170 (E xc. w /3 /4 ” Bolt)
2 0 0 (W /3 /4 ” Bolt)
110
(G 3 1 6 .. .90)
110
90/1.35*
( G 3 1 6 .. .90)
Shock Absorber
—Upper A ttachm ent
140
75
—Lower Attachm ent
115
75
—Rear Shackle Bolt
110
PIO
P20
P30
25
140
50
115
Propeller Shaft
To Rear Axle (Strap)
To Rear A xle (“ U ” B olt)
Bearing Support-to-Hanger
Hanger-to-Frame
12-17
18-22
20-30
40-50
12-17
18-22
20-30
—
12-17
18-22
20-30
—
Rear Stabilizer-to-Anchor Plate
20-30
—
20-30
* 9 0 F t . L bs. w h e n t i g h t e n i n g t h e n u t .
1 3 5 F t . L bs. w h e n t i g h t e n i n g t h e b o l t.
SECTION 3E
WHEELS AND TIRES
INDEX
G eneral D escription
3E-1
M a in te n a n c e
3E-2
W heel R eplacem ent C onsideration
3E-2
W heel N u t T o rq u e s
3E-2
T ire Inspection and R o ta tio n
3E-2
Tire Inflation Pressure
3E-2
Service O p e ra tio n s
3E-6
C o rrecting Irregular Tire W e a r
3E-6
W heel Rem oval and In s talla tio n
3E-7
Tire M ounting and D e m o u n tin g
3E-8
Dual W heel A ttac h m e n t P 30 0 M odels....................................................................................................... ..3E-9
GENERAL DESCRIPTION
The 1977 truck is equipped with a wide range of
tube or tubeless type tires and wheels selected according
to the truck Gross Vehicle W eight Rating (GV W R) and
NOTE: On four-wheel drive vehicles all tires must
be o f equal size (but not necessarily ply rating) and
o f same tread configuration.
type o f service. The dual rear wheel option is available
TUBELESS TIRES
on Series 30 trucks. The factor installed bias belted tires
These tire have an inner liner which, i f punctured,
tends to cling to the penetrating object form ing a partial
seal until the object is removed from the tire. It is
essential to conduct a periodic pressure check according
to the tire inflation tables on the following pages plus a
visual tire inspection to detect im bedded objects which
might otherwise go unnoticed and cause serious casing
damage.
are
selected
to
provide
the
best
all
around
tire
perform an ce for all normal operations. All tires are
m anu factured
for
co nfiguration
and
use
on
load
wheels
c a rry in g
of
specific
capacity.
size,
W hen
replacing a worn or dam aged tire it is essential that you
use a replacem ent tire o f the same size and load rating
as that with which
m anufactured.
Use
the vehicle was equipped when
of
any other size o f
tire
may
seriously affect ride, handling, ground clearance, tire
clearance an d speedom eter calibration. Similarly, use of
wheels with offsets other than recommended, or use of
w hat are commonly referred to as "reversed rim s" may
seriously
overload
wheel
bea rin g s
or
other
axle
components causing rapid w ear or failure o f these parts
and void
the vehicle warranty. To achieve best all
around vehicle handling perform ance belted tires and
bias ply tires should not be mixed on the same truck.
Because o f possible adverse effects on vehicle handling,
do not mix radial ply tires with other type tires on the
same vehicle.
TUBE TIRES
Some commercial vehicles are equipped (at customer option) with synthetic rubber tires and tubes.
I
OUTER
W HEEL
W HEEL
HUB
FRONT & REAR
W/SINGLE REAR
FRONT
W /D U A L REAR
DUAL REAR
Fig. 1--Wheel A ttachm ents
Fig. 2 -T ire Rotation
MAINTENANCE
W HEEL R E P LA C E M E N T C O N S ID E R A T IO N S
WHEEL N U T TORQUES
Wheels must be replaced if bent, heavily rusted,
leak air, or if lug nuts continually loosen. Do not
straighten bent wheels or use inner tubes in leaking
wheels used with tubeless tires. The wheels originally
equipped on the vehicle will provide optim um life up to
the m axim um load and inflation pressures as shown in
the Wheel Code and Limits Chart. M axim um loads,
m axim u m inflation pressures, wheel identification codes,
and wheel sizes are stam ped on each wheel.
On a new vehicle or after the wheel has been
changed, the wheel nut torque must be checked at 100,
1,000 and 6,000 miles and every 6,000 miles thereafter.
W h e n rep la c in g wheels for any reason, the
replacem ent wheels should be equivalent in load
capacity, inflation pressure capacity, diameter, width,
offset, and m o unting configurations to those originally
installed on the vehicle.
A wheel of im pro per size or type may adversely
affect load carrying capacity, wheel and bearing life,
brake cooling, sp e e d o m e te r/o d o m eter calibration, vehi
cle ground clearance, and tire clearance to the body and
chassis. Replacem ent with " u s e d " wheels which may
have been subjected to harsh operating conditions or
very high mileage is not recommended. These wheels
m ay fail prem aturely without any prior visual indication.
N O T E : The use of wheels a n d / o r tires with higher
load carrying capacity than originally equipped on
the vehicle does not necessarily increase the
G A W R ’s or the G V W R o f the vehicle. Wheels
having diameters ran ging from 16 inch through
19.5 inch diam eter tha t have also been certified for
radial tire application up to the maxim um load and
m axim um tire pressure wheel limits shown in the
W heel Code and Limits Chart have the word
" r a d ia l" stamped on the rim. Wheels in the 16 inch
through 19.5 inch d ia m e te r range without the
" r a d ia l" identification stam p are not to be used
with radial tires.
TIR E IN S P E C TIO N AND R O TA TIO N
Front and rear tires perform different jobs and can
wear differently depending on the type o f roads driven,
individual driving habits, etc. To obtain m axim um tire
life, tires should be inspected and rotated regularly.
Bias-belted tires should be rotated every 7,500 miles
(passenger car type tires); 6,000 miles (truck type tires).
Radial tires should be rotated at the first 7,500 miles and
then at least every 15,000 miles th ereafter (passenger car
type tires); first 6,000 miles then every 12,000 miles
(truck type tires). For the longest tire life, any time
irregular w ear is noticed, the tires should be inspected
and rotated and the cause o f the uneven w ear corrected.
Be certain to check wheel nut tightness and to adjust the
tire pressures, front and rear, after rotation to agree with
those recomm ended in the tire inflation charts.
The outer tire on a dual wheel will skid or drag on a
turn because o f the difference in the turning radii o f the
inner and outer tires. This results in faster w ear o f the
outer tire. In general, the tire with the largest diam eter
or least w ear whould be at the outside o f each dual
wheel. In addition, when trucks are operated continu
ously on high crown roads an increase in air pressure of
from 5 to 10 PSI in the outside tire o f each dual
produces m aximum tire life.
IN FLA TIO N PRESSURE
The m axim um cold inflation pressures for the
factory installed tires are listed on the VIN plate. Tires
must be inflated to these pressures when the G V W R or
an axle G A W R is reached. Im proper tire inflation
pressures for the load the vehicle is carrying can
adversely affect tire life and vehicle performance.
DUAL WHEEL
T Y P IC A L W H E E L
M A X IM U M
\
L O A D /M A X IM U M
/P R E S S U R E STAMP
R IM SIZE: D IA . X W ID T H
W HEEL CODE
LETTERS
O P TIO N A L
L O C A T I O N S FO R
M A X IM U M LO AD /
/M A X IM U M
PR ES SU R E
STAMPS
SINGLE WHEEL
T Y P IC A L W H E E L
M A X IM U M
LOAD,
M a x im u m
STAMP
pressure
O P T IO N A L L O C A T IO N S
FOR M A X I M U M L O A D /
'M A X I M U M
PR ES SU R E S T A M P
R IM S I Z E : D I A . X W I D T H
Fig. 3--Wheel Code Location
Too low an air pressure can result in tire
o verloading , a b n o rm a l tire wear, adverse vehicle
handling, and reduced fuel economy. The tire flexes
more a n d can build up excessive heat, w eakening the tire
and increasing susceptibility to dam age or failure. Too
high an air pressure can result in abnorm al wear, harsh
vehicle ride, and increased susceptibility to dam age from
road hazards. Lower inflation pressures should be used
only with reduced vehicle loads and the rear tire pressure
should be equal to or greater than the front pressure on
single wheel application. A fter determ ining the load on
each tire by weighing the vehicle on a scale, the correct
cold inflation pressures for the actual tire loads can be
obtained from the T ire /W h e el Load and Inflation
Pressure C hart shown in this section.
Tire inflation pressures should be checked at least
monthly when the tires are "cold" and when changing
the load the vehicle is carrying.
TIRE/WHEEL LOAD & INFLATION PRESSURE
PASSENGER TYPE TIRES FOR LIGHT TRUCKS USED IN HIGHWAY SERVICE
W heel Code
R ally /S p o k e
T ire
Size
Load
Range
24
26
28
30
32
XT
XT
BC, C R , X T
BC, C R , X T
XT
BC, C R
BC, C R
XT
XT
A H , BM, DS, CS
A H , BM, DS, CS
A H , BM, DS, CS
A H , BM, D S, CS
—
E78-15
F78-15
G78-15
G 78-15
G R 78-15
H 78-15
H 78-15
J78-15
JR 78-15
L78-15
L R 78-15
L78-15
L R 60-15
8.2 5 -1 5
B
B
B
D
B
B
D
B
B
B
C
D
B
D
1081
1163
1254
1254
1254
1372
1372
1436
1436
1527
1527
1527
1527
1254
1127
1218
1309
1309
1309
1436
1436
1500
1500
1590
1590
1590
1590
1309
1181
1272
1363
1363
1363
1500
1500
1563
1563
1663
1663
1663
1663
1363
1227
1318
1418
1418
1418
1554
1554
1627
1627
1727
1727
1727
1727
1418
1270
1360
1470
1470
1470
1605
1605
1690
1690
1790
1790
1790
1790
1470
R egular
XU, XH, DT
XH, DT
XU, XH, DT
X U , X H , DT
XH, DT
XU, X H, DT
AX, FT
FT
FT
AX, FT
AX, FT
AX, FT
—
XU, XH, DT
_____________ T ire Load L im its a t Various In fla tio n Pressures
36
38
40
1527
1572
1618
1663
1663
1718
1772
1827
1854
1854
1905
1905
1972
2025
1527
1572
1618
1663
34
NOTE: The load at maximum inflation pressure stamped on the tire sidewall of passenger tires will differ from the load shown in this table. This is in accordance with Tire and Rim
Association standards requiring a reduced loading factor of approximately 9 1% for passenger type tires used on trucks and multipurpose passenger vehicles.
TIRES FOR LIGHT TRUCKS USED IN HIGHWAY SERVICE
T IR E S USE D AS SIN G L E S
W heel Code
R eg u lar
j j re
Size
Rally
Load
Range
T ire Load Lim its a t V ariou s In fla tio n P ressures
30
35
40
45
50
55
60
65
70
75
2560
2670
2780
2 540
2680
2800
34
36
38
1890
1960
2020
70
75
TU B E TYPE TIR E S M O U N T E D ON 5 ° TA PER ED BEAD SEAT R IM S
—
—
—
---—
—
—
X L .B R
A X ,F T
A X ,F T
X L .B R
AM
AM
AM
6.5 0-16
7.00-15
7.00-15
7.0 0 -1 6
7 .5 0 -1 6
7.5 0 -1 6
7.5 0 -1 6
1270
1350
1350
1430
1620
1620
1620
C
C
D
C
C
D
E
1390
1480
1480
1560
1770
1770
1770
1500
1610
1610
1680
1930
1930
1930
1610
1720
1720
1800
2060
2060
2060
1830
1940
2040
2190
2190
2310
2310
2440
2440
TUB ELESS TIR E S M O U N T E D ON 15° TAPERED BEAD SEAT DROP CENTER R IM S
FA
8.19-5
-
D
-
-
-
-
2110
2270
2 410
W ID E BASE TU B E L E S S T IR E S U SE D AS SIN G LE S
W heel Code
R ally /S p o k e
T ire
blze
Load
Range
AH , BM, DS, C S
A H , BM, DS, CS
10-15
10-15
B
C
R egular
BS
BS
XH,
XH,
FT,
BU, D K ,
DK,
DK,
BU,
DK,
DK,
DK,
DT
DT
AX
FK
FK
FK
FK
FK
FK
FK
FK
DK, FK
FK
DJ
DJ
BH
BH
XT
XT
—
_
____
—
—
—
—
—
—
____
—
—
—
—
C 78-15L T
G 78-15L T
7.00-15L T
8 .0 0 -1 6 .5
8 .0 0 -1 6 .5
8 .0 0 -1 6 .5
8 .0 0 R -1 6 .5
8 .0 0 R - l 6.5
8 .7 5 -1 6 .5
8 .7 5 -1 6 .5
8 .7 5 -1 6 .5
8 .7 5 R -16.5
8 .7 5 R -l 6.5
9 .5 0 -1 6 .5
9 .5 0 -1 6 .5
1 0-16.5
1 0-16.5
* 2 6 8 0 @ 8 0 psi
T ire Load L im its a t V ariou s In fla tio n Pressures
20
22
30
35
D
E
1080
1310
1350
1360
1360
1360
C
—
1180
1430
1480
1490
1490
1490
1360
1360
1720
1720
1720
1570
1570
2030
2030
2010
2010
c
c
c
c
D
___
C
1570
1570
1570
D
E
D
—
E
D
E
___
C
D
1860
1860
1840
1840
24
26
1540
1540
1620
1620
40
45
1280
1550
1610
1610
1610
1610
1490
1490
1850
1850
1850
1720
1720
2190
2190
2170
2170
1370
1660
1720
1730
1730
1730
1610
1610
1990
1990
1990
1850
1850
2350
2350
2330
2330
30
32
1760
1760
1830
50
55
60
1840
1840
1730
1730
1945
1945
2045
2045
2145
1840
1945
2045
2110
2110
1990
1990
2500
2500
2240
2240
2110
2110
2650
2650
2350
2350
2240
2240
2780
2780
2480
2620
2750
28
1690
1690
65
2240
2330
2470
2350
2350
2570
2680
2470
2570
2920
3050
3170
TIRE/WHEEL LOAD & INFLATION PRESSURE
TIRES FOR LIGHT TRUCKS USED IN HIGHWAY SERVICE (Cont’d)
TIRES USED AS DUALS
W heel Code
Regular
Rally
Ti re
Size
Load
Range
T ire Load Lim its at Various Inflation Pressures
30
35
40
50
45
55
60
65
70
75
2175
2260
2360
2570
2 6 8 0 (#)
TUBE TYPE TIRES MOUNTED ON 5° TAPERED BEAD SEAT RIMS
YW
YW
YW
YW
YW
DW, FJ
DW, FJ
D W , FJ
__
—
—
—
-—
---
CM
F B , UH
UH
__
—
—
6 .5 0 -1 6
7 .0 0 -1 6
7 .0 0 -1 6
7 .5 0 - 1 6
7 .5 0 - 1 6
8 .7 5 - 1 6 .5
8 .7 5 - 1 6 .5
8 .7 5 - 1 6 .5
C
C
D
C
D
C
D
E
1120
1260
1260
1430
1430
1380
1380
1380
1225
1365
1365
1565
1565
1515
1515
1515
1320
1475
1475
1690
1690
1630
1630
1630
1420
1580
1580
1815
1815
1750
1750
1750
1685
1780
1870
1930
2040
2140
1855
1855
1970
1970
2070
2070
TUBELESS TIRES MOUNTED ON 15° TAPERED BEAD SEAT DROP CENTER RIMS
8 -1 7 .5
8 -1 9 .5
8 -1 9 .5
D
D
E
1445
—
—
1575
—
—
1820
1990
1990
1700
1850
1850
1935
2110
2110
2050
2230
2230
2155
2350
2350
2460
2460
(#) 2 7 8 0 @ 8 0 PSI
W ID E BASE TUBELESS TIRES USED AS DUALS
W heel Code
Regular
F J,
F J,
F J,
F J,
F J,
F J,
F J,
F J,
FJ,
DW
DW
DW
DW
DW
DW
DW
DW
DW
Rally
—
—
—
—
—
-—
-—
Tire
Size
Load
Range
8 .0 0 - 1 6 .5
8 .0 0 -1 6 .5
8 .0 0 R - 1 6 .5
8 .0 0 R -1 6 .5
8 .7 5 - 1 6 .5
8 .7 5 - 1 6 .5
8 .7 5 - 1 6 .5
8 .7 5 R -1 6 .5
8 .7 5 R -1 6 .5
C
D
C
D
C
D
E
D
E
Tire Load Limits at Various Inflation Pressures
30
35
40
45
1195
1195
1310
1310
1195
1195
1515
1515
1515
1380
1380
1415
1415
1310
1310
1630
1630
1630
1515
1515
1520
1520
1415
1415
1750
1750
1750
1630
1630
—
--
1380
1380
1380
—
50
55
60
65
1620
1520
1520
1710
1800
1620
1710
1800
1855
1855
1750
1750
1970
1970
1855
1855
2070
2070
1970
1970
2175
2070
2070
70
75
2260
2360
2175
2260
*
* 2 3 6 0 @ 8 0 PSI
1.
The “ cold ” tire inflation pressure rating applies
to the tire pressure when the vehicle has not
been driven for three hours or m ore, or driven
less than one m ile.
2.
It is normal for tire pressures to increase 4-8
PSI, or m ore, when the tires becom e “h o t”
from driving, D o n ot “ b leed ” or reduce tire in
flation pressures after driving your vehicle.
Bleeding serves to reduce “ cold ” inflation
pressure and increase tire flexin g which can
result in tire damage and failure.
For sustained driving over 75 mph with pas
senger car typ e tires, cold inflation pressures
should be increased 4 PSI above the recom
m ended cold inflation pressures in the Tire/
Wheel Load and Inflation Pressure Chart for
the load being carried up to a m axim um o f 32
PSI for load range B tires, 3 6 PSI for load
range C, and 4 0 PSI for load range D. Sus
tained speeds above 75 mph are n ot recom
m ended when the 4 PSI adjustm ent exceeds
the m axim um pressures stated above.
3.
4.
For sustained driving over 65 mph w ith truck
typ e tires* cold inflation pressures should be
increased 10 PSI above th ose specified in the
Tire/W heel Load and Inflation Pressure charts
for the load being carried. Do not exceed the
m axim um w heel capacity show n in the Wheel
Code & Limits Chart. Sustained speeds above
65 MPH are n ot recom m ended where the 10
PSI pressure increase w ould exceed this m axi
m um w heel capacity.
For special operating con d ition s such as carry
ing slide-in campers or other high center of
gravity loads, cold inflation pressures may be
increased up to 10 PSI above those show n in
the table. The total increase in cold inflation
pressures, how ever, m ust not exceed the m axi
mum w heel capacity show n on the Wheel Code
& Limits Chart.
PROPERLY IN F LA TE D
PROPERLY IN F LA TE D BIAS
R A D IA L TIRE
O R BIAS-BELTED TIRE
5.
When using passenger car type snow tires cold
inflation pressures should be increased 4 PSI
(truck typ e sn ow tires, 10 PSI) above the rec
om m ended pressures for the load being carried.
However, do not exceed the m axim um wheel
capacity show n in the Wheel Code & Limits
Chart. Sustained speeds above 75 MPH with
passenger car typ e snow tires (65 MPH with
truck type sn ow tires) are n ot recom m ended.
6.
Alw ays use a tire pressure gauge (a pock et
typ e gauge is recom m ended) when checking
inflation pressures. Radial tires may have the
appearance o f being under-inflated when at
recom m ended cold inflation.
7.
Be sure to re-install the tire inflation valve
caps, if so equipped, to prevent dirt and m ois
ture from entering the valve core which could
cause air leakage.
W H E E L C O D E A N D L IM IT S
WHE EL LIM ITS
CODE
* Passenger car tires have 15 inch or smaller
w heel size and have no “ LT” designation
m olded in sidewall. Light truck type tires have
“ LT” m olded in the sidew all and/or are larger
than 15 inch in w heel size.
Load Range
A
B
C
D
E
Replaces Ply Rating
2
4
6
8
10
DT
XH
XU
FT
AX
XT
BC
CR
AH
BM
BS
CS
DS
BR
XL
YW
AM
BU
DK
DW
FJ
FK
DJ
BH
CM
FB
UH
FA
SIZE OF
WHEEL
15 x
15 x
15 x
15 x
15 x
15 x
15 x
15 x
15 x
15 x
15 x
15 x
15 x
16 x
16 x
16 x
16 x
16.5
16.5
16.5
16.5
16.5
16.5
16.5
17.5
19.5
19.5
19.5
6JJ
6JJ
6JJ
6JJ
6JJ
672JJ
7JJ
7JJ
8JJ
8JJ
8JJ
8JJ
8JJ
5K
5K
6KS
6 ’/ 2LS
x 6
x 6
x 6
x 6
x 6.75
x 6.75
x 8.25
x 5.25
x 6
x 6
x 6.75
MAX.
M AX.
LOA D (LBS) PRESS (PSD
1670
1670
1670
1910
2040
1690
1670
1670
1910
1910
1760
2030
2030
1800
1800
2440
2780
1730
2350
2680
2680
2680
3170
2750
2155
2540
2780
2850
55
55
55
70
70
40
40
40
40
40
40
40
40
55
55
75
85
55
70
85
85
85
85
70
70
80
95
90
SERVICE OPERATIONS
C A U T IO N : Servicing o f tires mounted on
multi-piece rims requires proper tools, safety
equipment and specialized training. Severe
injuries can result from improper servicing
techniques. It is recommended that tires on
multi-piece rims be serviced only by competent
personnel with proper equipment or by
competent truck tire repair shops.
C O R R E C T IN G IRREGULAR TIRE WEAR
Heel and Toe W ear
This is a saw-toothed effect where one end o f each
tread block is worn more th a n the other. The end that
wears is the one that first grips the road w hen the brakes
are applied.
Heel and toe w ear is less noticeable on rear tires
than on front tires, because the propelling action o f the
rear wheels creates a force which tends to wear the
opposite end of the tread blocks. The two forces,
propelling an d braking, m ake for more even wear o f the
rear tires, w hereas only the braking forces act on the
front wheels, and the saw-tooth effect is more noticeable.
A certain am ount of heel and toe wear is normal.
Excessive wear is usually due to high speed driving and
excessive use of brakes. The best remedy, in addition to
cautioning the owner on his driving habits, is to
interchange tires regularly.
Side W ear
This may be caused by incorrect wheel camber,
underinflation, high cambered roads or by taking
corners at too high a rate o f speed. The first two causes
are the most common. C am ber w ear can be radily
identified because it occurs only on one side o f the
treads, whereas underinflation causes wear on both sides.
C am ber wear requires correction o f the cam ber first and
then interchanging tires. There is, o f course, no
correction for high cam bered roads. Cornering w ear is
discussed further on.
M isalignm ent W ear
This is w ear due to excessive toe-in or toe-out. In
either case, tires will revolve with a side motion and
scrape the tread ru bb er off. If misalignment is severe, the
ru bber will be scraped off o f both tires; if slight, only
one will be affected. The scraping action against the face
o f the tire causes a small feather edge of rubber to
ap p e a r on one side of the tread and this feather edge is
certain indication o f misalignment. The remedy is
readjusting toe-in, or rechecking the entire front end
alignm ent if necessary.
Uneven W ear
U neven or spotty wear is due to such irregularities
as unequal caster or camber, bent front suspension parts,
out-of-balance wheels, brake drum s out o f round, brakes
out o f adjustm ent or other mechanical conditions. The
rem edy in each case consists of locating the mechanical
defect and correcting it.
C ornering W ear
W hen a truck makes an extremely fast turn, the
weight is shifted from an even loading on all wheels to
an abn orm al load on the tires on the outside o f the curve
and a very light load on the inside tires, due to
centrifugal force. This unequal loading may have two
unfavorable results.
First the rear tire on the inside of the curve may be
relieved of so much load that it is no longer geared to
the road and it slips, grinding off the tread on the inside
half o f the tire at an excessive rate. This type of tire
shows much the same appearance of tread w ear as tire
w ear caused by negative camber.
Second the transfer o f weight may also overload
the outside tires so much that they are laterally distorted
resulting in excessive wear on the outside h alf o f the tire,
producing a type o f wear like that caused by excessive
positive camber.
C o rnerin g wear can be most easily distinguished
from ab no rm al cam ber w ear by the rounding of the
outside shoulder or edge o f the tire and by the
roughening o f the tread surface which denotes abrasion.
C o rn erin g w ear often produces a fin or raised
portion along the inside edge o f each row in the tread
pattern. In some cases this fin is almost as pronounced as
a toe-in fin, and in others, it tapers into a row o f tread
blocks to such an extent that the tire has a definite "step
w e a r" appearance.
T he only rem edy for cornering wear is proper
instruction o f operators. D riving more slowly on curves
an d turns will avoid g rinding ru b b e r off tires. To offset
norm al cornering w ear as much as possible tires should
be interchanged at regular intervals.
Wheel and Tire Balancing
It is desirable from the standpoints o f tire wear and
vehicle ride and handling ease to m a intain proper
balance o f wheel and tire assemblies on all models. This
may be accomplished by either o f the two types o f
balancing systems in currect use which balance wheels
either on the vehicle or off. The "o n the vehicle" type,
however, is the more desirable in that all rolling
components (brake drums, bearings, seals, etc.) are
included in the balancing procedure and thereby have
any existing unbalance corrected.
Truck Wheel Balance Weights
All 1977 truck wheels equipped with a tubular side
ring (rolled flange rim) on the outboard side o f the
wheel rims require special design weights to fit. D ynam ic
balancing can be accomplished through use o f these
special balance weights which are designed only for
installations on the outboard side o f these wheels.
Conventional weights fit only the inboard side o f these
wheels.
Static Balance
Static balance (sometimes called still balance) is the
equal distribution o f weight o f the wheel and tire
assembly about the axis o f rotation in such a m anner
that the assembly has no tendency to rotate by itself,
regardless o f its position. For example: A wheel with
chunk o f dirt on the rim will always rotate by itself until
the heavy side is a the bottom. Any wheel with a heavy
side like this is statically out of balance. Static unbalance
o f a wheel causes a hopping or pounding action (up and
down) which frequently leads to wheel "flutter" and
quite often to wheel " tra m p " .
Dynamic Balance
Dynam ic balance (sometimes called running balance
means that the wheel must be in static balance, and also
run smoothly at all speeds.
To insure successful, accurate balancing, the
following precautions must be observed:
• Wheel and tire must be clean and free from all
foreign matter.
• The tires should be in good condition and
properly mounted with the balance mark on the tire, if
any, lined up with the valve.
• Bent wheels that have runout over 1/16" should
be replaced.
• Inspect tire and wheel assembly to determine if
an eccentric o r out-of-round condition exists. Note that
this condition, if severe, cannot be "balanced out". An
assembly which has an out-of-round condition exceeding
3 /1 6 " on tire sizes through 19.5" is not suitable for use
on the front o f the vehicle. Its use on the rear should be
governed by its general condition and whether the
roundness defect seriously detracts from overall ride
quality.
• W hen balancing wheels and tires, it is recom
mended that the instructions covering the operation o f
the wheel balancer being used be closely followed.
• W hen balancing truck type nylon tires, tires
must be hot (run for several miles) before raising vehicle
to balance so that flat spot is elimated. A tire which is
flat spotted will be incorrectly balanced.
WHEEL REMO VAL AN D IN S TA LLA TIO N
Jacking Instructions
Place vehicle jack supplied or recom m ended as
follows: To raise a rear wheel, place jack under axle
housing; to raise fron t wheel o f C, G, P models, place
jack under lower control arm pivot; to raise front wheel
of K models, place jack under front axle near spring
seat.
Dual and Single Wheels
W hen installing the tire and wheel on the vehicle,
the following procedure should be followed:
A fter wheel nuts are p ut on loosely, turn the wheel
until one nut is at the top o f the bolt circle; tighten the
nut just snug. Snug up the re m aining nuts criss-cross to
m inim ize runout, then tig h te n the nuts to the
recom m ended torque alternately and evenly to avoid
excessive runout.
W hen installing wheels on vehicles with dual rear
wheels:
1. Install inner and outer wheel and clamp ring on
rear, or wheel and clamp ring on front (be sure pins on
clam p ring face outboard).
2. Install and snug nuts finger tight.
3. T orque nuts to specified torque in sequence
shown in Figure 4.
Lateral runout should not exceed 1 /8 " on front
wheel or 3 /1 6 " on rear wheel.
Matching Side and Lock Rings
Side and lock rings o f different rim types are not
interchangeable. Some m ay ap p ea r to be, but they do
not fit peoperly on the rim base. Serious accidents have
resulted from the use of m ismatched rings. Rim base
and rings must be matched according to m anufacturer,
size and type. This info rm atio n is stamped on each part.
Installing Synthetic Tubes
When tube and flap are not
properly lubricated a n d mounted, they will
stretch thin in the tire bead a nd rim region.
This will cause premature failure.
1. Before installing tube in tire, clean inside of
casing thoroughly.
2. Insert tube in tire and inflate until it is nearly
rounded out.
3. Inspect rim for rust scale and bent flanges-clean rust scale and straighten flanges where necessary.
4. U sing a brush or cloth swab, apply a solution of
neutral vegetable oil soap to the inside and outside of
CAUTION:
tire beads and also the the rim side o f the tube. Do not
allow soap solution to run down into tire.
5. W hen m ounting tire and tube on a drop center
rim, follow the standard procedure. Be sure tire is
centered on rim so that beads are out o f rim well before
inflating. Do not allow tire to h ang loosely on wheel
while inflating.
6. Center valve and pull it firmly against the rim.
Hold in this position and inflate until tire beads are
firmly seated on rim against flanges.
7. Completely deflate tire by removing valve core.
8. Reinflate tire to recom m ended pressure.
TUBELESS TIRES
Tubeless tires mounted on one piece full drop center
rims are standard on some trucks. These tires have a
safety inner liner which if punctured, tends to cling to
the penetrating object forming a partial seal until the
object is removed from the tire.
The mounting and dem ounting of tubeless truck
tires will present no problem when a ru bb er lubricant,
such as Ru-Glyde or equivalent is applied to tire beads
and rim flanges. Ru-Glyde or equivalent in addition to
materially assisting in mounting and dem ounting also
prevents rusting at the tire sealing area and thus
prevents tires from adhering to the wheel.
CAUTION: A hammer, or tools with sharp
edges, should never be used to demount or
mount tubeless tires as damage to rim flange or
tire sealing bead may result.
Inspection for Leaks
1. With wheel assembly removed from vehicle,
inflate the tire to recom m ended operating pressure.
2. Check for leaks at rim bead by placing wheel
and tire horizontal and allowing w ater to stand in groove
between rim and tire. Check for large leaks by lowering
assembly into water tank or running water over tire.
Demounting
1. Remove vlave core to completely deflate tire.
With tire lying flat on floor, loosen beads from rim seats
by walking around on tire with heels at points close to
rim. With wide side o f rim down, apply tire lubricant to
top bead. With stops toward rim, insert spoon ends of
two tire irons about 10" apart. While standing on tire to
hold bead in gutter, pull one tool toward center of rim.
2. Hold one iron in position with foot and pull
second iron toward center o f rim. Progressively work
bead off rim, taking additional bites if necessary.
3. Stand assembly in vertical position. Lubricate
second bead. At top o f assembly insert straight end of
tire iron between bead and back flange o f rim at about a
45 degree angle.
4. Turn iron so that it is perpendicular to rim. Pry
second bead off.
Mounting
All tubeless ties will be mounted as follows:
1. Inspect rim to insure bead seats are clean and
smooth. Then place rim on floor with wide side down
ond lubricate first bead o f tire and upper bead seat of
rim.
2. Push first bead into well o f rim and onto rim as
fa r as possible. Using straight end of tire iron and with
stop resting on rim flange, work rem aining section of
first bead over rim.
3. Hold second bead in well by standing on tire.
W hen necessary, push section o f bead into rim well and
anchor with vise-grip pliers by pinching pliers on rim
flange. Using spoon end o f tire iron with stop toward
rim, work progressively around bead using small bites
until bead slips over flange onto rim base. If necessary,
insert second tire iron and lubricate last 6 " o f bead
before completing.
4.
Check valve to be certain that hex nut at the
valve base is tight. Inflate tire to recom m ended operating
pressure. Check assembly for air leaks.
A T T A C H M E N T OF DUAL WHEELS ON P 300
MODELS
To assure secure attachment o f the dual disc wheels,
it is im p ortant that all dirt or rust scale be removed from
the m ating surface o f the wheels, hub, and clamp ring as
well as the stud and nut. PO W ER DRIVE N U T S TH EN
M A N U A L L Y IN SPEC T T O R Q U E A T 130-180 FT.
LBS. M A N U A L T O R Q U E ONLY: 150-200 FT. LB.
SECTION 4A
PROPSHAFT
The following caution applies to one or more steps in the assembly
procedure o f components in this portion o f the m anual as indicated at
appropriate locations by the terminology "See Caution on page l of this
Section".
C A U TIO N : T H I S F A S T E N E R I S A N I M P O R T A N T A T T A C H I N G
P A R T I N T H A T I T C O U L D A F F E C T T H E P E R F O R M A N C E OF
V IT A L C O M P O N E N T S A N D S Y S T E M S , A N D / O R CO U LD R E S U L T
IN M A J O R R E P A I R E X P E N S E . I T M U S T B E R E P L A C E D W I T H
O N E O F T H E S A M E P A R T N U M B E R OF W I T H A N E Q U I V A L E N T
P A R T I F R E P LA C E M E N T B E C O M E S N E C E S S A R Y. DO N O T U S E A
R E P L A C E M E N T P A R T OF L E S S E R Q U A L I T Y OR S U B S T I T U T E
D E S IG N . T O R Q U E V A L U E S M U S T B E U S E D A S S P E C IF IE D
D U R I N G R E A S S E M B L Y TO A S S U R E P R O P E R R E T E N T I O N OF
TH IS PART.
CONTENTS
G e n e ra l D e s c rip tio n ......................................................... 4A-1
Universal Jo in ts ............................................................... 4A-1
Propeller S h a ft................................................................. 4A-2
D ia g n o sis.............................................................................. 4A-3
O n C ar Service.................................................................. 4A-5
Specifications..................................................................... 4A-15
GENERAL DESCRIPTION
Universal Joints
The simple universal jo in t is basically two Y-shaped
yokes connected by a crossmember called a spider. The
spider is shaped like an X and arms that extend from it
are called trunnions. See figure 4A-1.
The spider allows the two yoke shafts to operate at
an angle to each other. W hen torque is transmitted at an
angle, through this type o f joint, the driving yoke rotates
at a constant speed while the driven yoke speeds up and
slows down twice per revolution. This changing of
velocity (acceleration) o f the driven yoke increases as the
angle between the two yoke shafts increases. This is the
prime reason why single universal joints are not used for
angles greater than three to four degrees. At four
degrees, for example the change o f velocity is .5%. At ten
degrees it is 3%. If the universal joint were set at 30
degrees and the driving yoke were turning at 1000 RPM
the velocity o f the driven yoke would change from 856
RPM to 1155 RPM in one q uarter o f a revolution. In the
rem aining quarter revolution the velocity would change
from 1155 RPM to 866 RPM.
On a one-piece drive shaft this problem can be
eliminated by arranging two simple universal joints so
that the two driving yokes are rotated 90 degrees to each
other. However the angle between the drive and driven
yokes must be very nearly the same on both joints for
this to work. Refer to figure 4A-2. This allows the
alternate acceleration and deceleration o f one jo in t to be
offset by the alternate deceleration and acceleration o f
the second joint. W hen the two joints do not run at
approximately the same angle, operation can be rough
and an objectionable vibration can be produced.
Universal joints are designed to consider the effects
I
Fig. 4A-2--Universal Joints Arranged for Constant
Velocity
of various loadings
acceleration. W ithin
universal joints will
However, when the
operational life o f the
and rear axle windup, during
the design angle variations the
operate safely and efficiently.
design angles are exceeded the
joints m ay decrease.
The bearings used in universal joints are the needle
roller type. The needle rollers are held in place on the
trunnion by round bearing cups. The bearing cups are
held in the yoke by either (depending on the
m anufacturer) snap rings or plastic injection. These
joints usually are lubricated for life and cannot be
lubricated while on the vehicle.
Constant Velocity Joint—Double Cardan
Joint
As mentioned previously, the simple universal joint
will operate efficiently through small angles only. Also,
two simple universal joints phased properly and
operating through the same angle will transm it constant
velocity. W h en a large angle is encountered in a
driveline, a simple universal jo in t will introduce two
vibrations in each revolution. It is in this situation that a
constant velocity jo in t is used.
Essentially, the constant velocity joint is two simple
universal joints closely coupled by a coupling yoke,
phased properly for constant velocity.
A centering ball socket between the joints maintains
the relative position o f the two units. This centering
device causes each o f the two units to operate through
one-h alf o f the complete angle between the drive shaft
and differential carrier. See figure 4A-3.
N O T E : The ball/socket on this Constant Velocity
jo in t requires periodic lubrication. A lubrication
fitting is provided fo r this purpose, and is
illustrated later in this section.
Fig. 4A-3--Ball-Socket Location
Propeller Shafts
The propeller shaft is a steel tube which is used to
transmit power from the transmission output shaft to the
differential. To accommodate various model, wheelbase
and transmission combinations, drive shafts differ in
length, diam eter and the type o f splined yoke. On some
models the drive shaft is made up o f concentric steel
tubes with ru b b e r elements between.
Each shaft is installed in the same m anner. A
universal joint and splined slip yoke are located at the
transmission end o f the shaft, where they are held in
alignment by a bushing in the transmission rear
extension. The slip yoke permits fore and aft movement
of the drive shaft as the differential assembly moves up
and down. The spline is lubricated internally by
transmission lubricant or grease. An oil seal at the
transmission prevents leakage and protects the slip yoke
from dust, dirt and other harm ful material.
Since the drive shaft is a balanced unit, it should be
kept completely free of undercoating and other foreign
material which would upset shaft balance.
Both one piece and two piece propeller shafts are
used depending on the model. All are tubular and use
needle bearing type universal joints.
On models that use a two piece shaft, the shaft is
supported n ear its splined end in a ru bb er cushioned ball
bearing which is mounted in a bracket attached to a
frame crossmember. The ball bearing is p erm anently
lubricated and sealed.
F our wheel drive models use a front propeller shaft
incorporating a constant velocity joint.
PROPELLER SHAFT AND UNIVERSAL JOINT DIAGNOSIS
Checking and Correcting
Propeller Shaft Unbalance
1. Place vehicle on a twin post hoist so that the
re a r wheels are free to rotate.
2. Remove both rear tire an d wheel assemblies and
brake drums.
C A U T IO N : Use care not to apply brakes with
drums removed.
3.
Visually inspect propshaft, U-Joints and attach
ments for m ud undercoating o r other discrepancies.
Make necessary corrections prior to running.
4. With vehicle running in gear at the indicated
speed where disturbance is at its peak, observe the
intensity of the disturbance.
5. Stop engine and disconnect drive shaft from
com panion flange. Reinstall shaft by rotating it 180°
from its original position. D eterm ine which position o f
the com panion flange gives the best balance.
6. Install rear drums and wheels, and road test
vehicle for final check o f balance. If balance is still
unacceptable, replace drive shaft.
D IA G N O S T IC C H A R T
C O M P L A IN T
PO SSIBLE CAUSE
Leak at front slip yo ke.
a.
Rough outside surface on splined
yoke.
N O TE: An occasional drop o f
lubricant leaking from splined
yoke is normal and requires no
attention.
b.
Defective transmission rear oil
seal.
Knock in drive line, clunking
noise when car is operated
under floating condition at
10 mph in high gear or
neutral.
C O R R E C T IO N
a.
Replace seal i f cut by burrs on yo ke.
Minor burrs can be sm oothed by careful
use o f crocus cloth or honing w ith a
fine stone. Replace y o k e if outside
surface is rough or burred badly.
b.
Replace transmission rear oil seal.
c.
Bring transmission oil up to proper
level after correction.
a. Worn or damaged universal
joints.
a.
Disassemble universal joints, inspect
and replace worn or damaged parts.
b.
b.
Replace differential case and/or side
gears as required.
Side gear hub counterbore in
differential worn oversize.
Ping, Snap or Click in drive
line.
a.
Loose upper or lower control
arm bushing bolts.
a.
Tighten bolts to specified torque.
NOTE: Usually occurs on
initial load application after
transmission has been put
into gear, either forward or
reverse.
b.
Loose companion flange.
b.
Remove companion flange, turn 180°
from its original position, apply white
lead to splines and reinstall. Tighten
pinion nut to specified torque.
C O M P L A IN T
Roughness, Vibration or
Body Boom at any speed.
NOTE: With tachometer
installed in car, determine
whether propeller shaft is
cause of complaint by
driving through speed range
and note the engine speed
(rpm) at which vibration
(roughness) is most
pronounced. Then, shift
transmission to a different
gear range and drive car at
same engine speed (rpm)
at which vibration was
noted before. Note the
effect on the vibration.
If vibration occurs at the
same engine speed (rpm),
regardless of transmission
gear range selected, drive
shaft assembly is not at
fault, since the shaft
speed (rpm) varies.
If vibration decreased, or
is eliminated, in a
different gear range but
at the same engine speed
(rpm), check the
possible causes:
C O R R E C T IO N
P O S S IB L E C A U S E
a. . Bent or dented drive shaft.
a. Replace.
b. Undercoating on drive shaft.
b. Clean drive shaft.
c. Tire unbalance. (30-80 mph, not
throttle conscious)
c. Balance or replace as required.
d. Excessive U-bolt torque.
d. Check and correct to specified torque.
e. Tight unive rsal j oints.
e. Impact yokes with a hammer to free
up. Overhaul joint if unable to free up
or if joint feels rough when rotated by
hand.
f. Worn universal joints.
f.
g. Burrs or gouges on
companion flange. Check
snap ring locating surfaces
on flange yoke.
g. Rework or replace companion flange.
h. Drive shaft or companion
flange unbalance.
h. Check for missing balance weights
on drive shaft. Remove and
reassemble drive shaft to companion
flange, 180° from original position.
i.
Excessive looseness at slip
yoke spline.
i.
Replace necessary parts.
j.
j.
Drive shaft runout (50-80 mph
throttle conscious)
Check drive shaft runout at front and
rear. Should be less than specified. If
above, rotate shaft 180° and recheck.
If still above specified, replace shaft.
Overhaul, replacing necessary parts.
Roughness usually at low speeds,
light load, 15-35 mph.
a. U-bolt clamp nuts excessively
tight.
a. Check and correct torque to that
specified. If torque was excessive
or if brenelled pattern on trunnions
is evident, replace joints.
Scraping noise.
a. Slinger, companion flange, or
end yoke rubbing on rear axle
carrier.
a. Straighten slinger to remove
interference.
Roughness on heavy
acceleration (short duration.)
a. Double cardan joint ball seats
worn. Ball seat spring may be
broken.
a. Replace joint and shaft assembly.
Roughness -- above 35 mph
felt and/or heard.
a. Tires unbalanced or worn.
a. Balance or replace as required.
UNIT REPAIR
PROPELLER SHAFT
Two methods are used to retain the propeller shaft
to the dilferential pinion flange. One method utilizes
" U " bolts, and the other is a strap attachment. Refer to
figures 4A-6 and 4A-7.
Removal
1. Raise vehicle on hoist. Mark relationship o f
shaft to com panion flange and disconnect the rear
universal jo in t by removing tru m m io n bearing " U " bolts
or straps. T ap e bearing cups to trunnion to prevent
d ro p ping and loss o f bearing rollers.
2. For models with two-piece shafts remove bolts
retaining bearing support to hanger.
3. Slide pro peller sh aft fo rw ard disengaging
trunnion from axle flange, then slide assembly rearward
disengaging from transmission.
N OTE: F or models using strap o r U-bolt
attachm ents to transmission or transfer case use
same removal procedure as above.
Universal Joints
On models with between center slip propshaft it is
im p o rta n t th a t c om po ne n ts are m a rk e d p rio r to
dissassembly for pro p e r phasing. Arrows are stamped on
assemblies as shown in Fig. 4A-8.
NOTE: The universal joints are o f the extendedlife design and do not require periodic inspection
or lubrication; however, when these joints are
disassem bled, repack b earings and lubricate
reservoir at end o f trunnions with high-melting
point wheel bearing lubricant use care not to
dam age or dislodge seals from trunnion.
Snap Ring Type
Disassembly
1. Remove bearing lock rings from trunnion yoke.
2. Support trunnion yoke on a piece o f 1-1/4" I.D.
pipe on an arb or bed.
NOTE: Due to length o f the propeller shaft it may
be more convenient to use a bench vise, for
removal and installation, instead o f an arbo r press.
In this case, proceed with disassembly and
assembly procedure as with an arbor press Fig. 4A9 and 4A-10.
3. Using a suitable socket or rod, press on trunnion
1. T r u n n io n
2. Seal
3.
B e a rin g s
4. W asher
5.
6.
Cap
S n a p R in g
Fig. 4A-9--Bearing Cup Removal w ith Vise
Fig. 4 A -ll--U n iv e rs a l Joint Repair Kit
until bearing cup is almost out. G rasp cup in vise and
work cup out of yoke. See figures 4A-9 and 4A-10.
Partially install other cup. Align trunnion into cup, and
press cups into yoke.
2. Install lock rings.
N OTE: The bearing cup cannot be fully pressed
out.
4. Press trunnion in opposite direction and remove
o th er cup as in Step 3.
5. Clean and inspect dust seals, bearing rollers,
and trunnion. Relubricate bearings as indicated in
Section 0.
N OTE: In addition to packing the bearings, make
sure that the lubricant reservoir at the end o f each
trunnion is completely filled with lubricant. In
filling these reservoirs, pack lubricant into the hole
so as to fill from the bottom (use o f squeeze bottle
is recom m ended). This will prevent air pockets and
ensure an adequate supply o f lubricant.
Reassembly Fig. 4A-11
1.
Position trun nion into yoke. Paritally install
b earing cup into yoke. Start trunnion into bearing cup.
Injected Plastic Type
Disassembly
NOTE: N ever clamp drive sh aft tubing in a vise as
the tube may be dented. Always clamp on one of
the yokes, and support the shaft horizontally.
Avoid da m a g in g the slip yoke sealing surface.
Nicks may dam age the bushing or cut the seal lip.
1. Support the drive shaft in a horizontal position
in line with the base plate o f a press. Place the universal
joint so that the lower ear o f the shaft yoke is supported
on a 1-1/8" socket. Place the cross press, J-9522-3, on the
open horizontal bearing cups, and press the lower
bearing cup out o f the yoke ear as shown in figure 4A12. This will shear the plastic retaining the lower bearing
cup.
2. If the bearing cup is not completely removed,
onelift the cross and insert Spacer J-9522-5 between the seal
l '/ g " SOCKET
TO SUPPORT
YOKE EAR
BUT MUST
CLEAR
BEARING
CUP
and bearing cup being removed, as shown in figure 4A13.
Complete the removal of the bearing cup, by
pressing it out o f the yoke.
3. Rotate the drive shaft, shear the opposite plastic
retainer, and press the opposite bearing cup out o f the
yoke as before, using Spacer J-9522.
4. Disengage cross from yoke and remove.
N O TE : Production universal joints cannot be
reassembled. There are no bearing retainer grooves
in production bearing cups. Discard all universal
jo in t parts removed.
5. Remove the rem ains o f the sheared plastic
bearing retainer from the ears o f the yoke. This will aid
in reassembly o f the service jo in t bearing cups. It usually
is easier to remove plastic if a small pin or punch is first
driven through the injection holes.
6. If the front universal jo in t is being serviced,
remove the pair of b earing cups from the slip yoke in
the same m anner.
Reassembly
A universal jo in t service kit is used w hen
reassembling this joint. See figure 4A-14. This kit
includes one pregreased cross assembly, four service
bearing cup assemblies with seals, needle rollers,
washers, grease and four bearing retainers.
M ake sure that the seals are in place on the service
bearing cups to hold the needle rollers in place for
handling.
1. Remove all o f the rem ains o f the sheared plastic
b earing retainers from the grooves in the yokes. The
sheared plastic may prevent the bearing cups from being
pressed into place, and this prevent the bearing retainers
from being properly seated.
2. Install one bearing cup p a rt way into one side of
the yoke, and turn this yoke ear to the bottom.
3. Insert cross into yoke so that the trunnion seats
freely into b earing cup as shown in figure 4A-15.
ROLLER B EA R IN G S
B E A R IN G RETAINER
Fig. 4A-14 Repair Kit
4. Install opposite bearing cup part way. Make sure
that both trunnions are started straight and true into
both bearing cups.
5. Press against opposite bearing cups, working the
cross all o f the time to check for free movement of the
trunnions in the bearings. If there seems to be a h an g
up, stop pressing and recheck needle rollers, to determine
if one or more o f them has been tipped un der the end o f
the trunnion.
6. As soon as one bearing retainer groove clears
the inside o f the yoke, stop pressing and snap the
bearing retainer into place as shown in figure 4A-16.
7. Continue to press until the opposite bearing
retainer can be snap ped into place. If difficulty is
encountered, strike the yoke firmly with a h a m m e r to aid
in seating bearing retainers. This springs the yoke ears
slightly. See figure 4A-17.
8. Assemble the other half o f the universal jo int in
the same manner.
5.
Assemble bearing support as follows:
a. Install inner deflector on propeller shaft, if
removed, and prick punch deflector at two opposite
points to make sure it is tight on shaft.
b. Fill space between in ner dust shield and
bearing with lithium soap grease.
c. Start bearing and slinger assembly straight on
shaft journal. Support propeller shaft and, using suitable
length o f pipe over splined end o f shaft, press bearing
and inner slinger against shoulder on shaft.
d. Install dust shield over shaft, small diam eter
first and press into position against outer slinger.
e. Install rub ber cushion onto bearing.
f. Install bracket onto cushion.
g. Install retaining strap.
Installation of Propshafts
Fig. 4A -16--lnstalling Snap Ring to Retain Trunnion
9.
C h e c k th e fr e e d o m o f r o ta tio n o f b o th sets o f
tru n n io n s o f the cro ss. I f to o tig h t, a g a in ra p the y o k e
e a r s as d e s c r ib e d a b o v e . T h is w ill lo o se n th e b e a r in g s
a n d h e lp s e a t th e b e a r in g re ta in e r s .
C ENTER S U P P O R T B E A R IN G —FIG. 4A -1 8
C A U T IO N : See C A U T IO N on page 1 o f this
section regarding Center Support Bearing
fasteners.
1.
R e m o v e d u st sh ie ld .
2. R e m o v e
b e a r in g s u p p o rt.
s tra p
r e t a in in g
r u b b e r c u s h io n
3. P u ll s u p p o r t b r a c k e t fr o m
p u ll c u s h io n fr o m b e a r in g .
4.
fr o m
r u b b e r c u s h io n an d
P u ll b e a r in g a s s e m b ly fr o m s h a ft.
N O TE : W h e n re installing prop sh afts, it is
necessary to place the shafts into particular
positions to assure proper operation. This is called
phasing.
All models with 32 splines use an alignment key, as
shown in figure 4A-19, to obtain p rop er phasing.
The shafts can mate only in the correct position.
G and K models with 16 splines must be phased as
shown in figure 4A-20.
1. For models with one piece propeller shafts, slide
shaft into transmission and attach rear U -jointto axle.
2. For C-P models with two-piece propeller shafts,
proper phasing is accomplished with the alignm ent key,
shown in figure 4A-19.
3. F or G -K models with two piece shafts, install
front h alf into transmission and bolt support to
crossmember.
a. Slide grease cap and gasket onto rear splines.
b. Rotate shaft so front U-joint trunnion is in
correct position. See figure 4A-20.
c. Take rear propeller shaft and before install
ing, align U-joint trunnions as shown in figure 4A-20.
Attach rear U-joint to axle. Tighten grease cap.
d. Torque bearing support to crossmem ber and
U -joint to axle attachments.
C O N S T A N T VELOCITY UNIVERSAL J O IN T
(Snap Ring Type) RETENSIO N
Disassembly
1. Remove auxiliary front propeller shaft from
vehicle.
2. Remove rear trunnion snap rings from center
yoke. Remove grease fitting.
3. Place propeller shaft in vice as shown in figure
4A-21. Drive one rear trunnion bearing cap from center
yoke as shown in figure 4A-21 until it protudes
approxim ately 3 /8 " .
NOTE: Keep rear portion o f propeller shaft up to
avoid interference o f rear yoke h alf with center
yoke.
Fig. 4A -1 8 -Propeller Shaft, Universal Joint and Bearing Support
A L IG N M E N T
4. Once the bearing cup protrudes 3 /8 " , release
vice. G rasp protruding portion o f cup in vice and strike
center yoke as shown in Figure 4A-22 until cup is
removed. Remove cup seal by prying off with a thin
screwdriver.
5. Repeat steps 3 and 4 for rem aining bearing cup.
6. Once the center yoke cups have been removed,
remove rear yoke h a lf bearing cups. Remove rear
trunnion.
7. Gently pull rear yoke h a lf from prop shaft.
Remove all loose needle bearings. Remove spring seal.
8. Remove front trunnion from center and front
yoke in same m a n n e r as described in Steps 2, 3 and 4.
N OTE: Before front trunnion can be removed all
four (4) bearing caps must be removed.
Assembly
Fig 4A-19-.Alignm ent Kev
*' Clean and inSPeCt al1 n e e d le b e a r in 8 ^ cups,
seals, fittings, trunnions and yokes. Assemble all needle
bearings in caps (27 p e r cap); assemble needle bearings
REAR PROP SHAFT
HORIZONTAL
HANGER WITH
SLOTTED HOLES
FRONT PROP SHAFT
FRONT YOKE OF
REAR PROP SHAFT
VERTICAL
After assembly to hanger,
front face of Bearing Support Asm
must be perpendicular to CenterLine of Prop Shaft as shown.
PROP SHAFT SPLINE SETTING
K300(00) WITH 2 PIECE PROP SHAFT
2-Piece prop shaft must be
assembled as follows to prevent
excessive drive line excitation:
1. Transmission yoke must first
be placed in vertical position.
2. Front yoke of Rear Prop
shaft is set horizontal as shown.
Fig. 4A -2 0 -A lig n m e n t for Phasing
REAR T R U N N IO N
REAR YO K E HALF
F R O N T YO K E
in front yoke (28 total). Retain bearings with a heavy
grease. Assemble seals to bearing cups.
2. Place front trunnion in drive shaft. Place center
yoke on front trunnion. Install one bearing cup and seal
assembly in front yoke. Drive in to a depth that the snap
ring can be installed. Install snap ring. Install rem aining
cup and seal in front yoke. Install snap ring.
3. Install fro nt trunnion bearing cups in center
yoke in same m anner.
4. W ith front trunnion completely installed, install
seal on prop shaft (large face first). G ently slip rear yoke
half on prop shaft using care not to upset rollers. Insert
re a r tru nnion in center yoke. Install rear yoke h alf
bearing caps on re a r trunnion. Install one rear trunnion
b e a rin g cap in center yoke and press into yoke until snap
ring can be installed. Install rem aining cap and snap
ring.
5. G rease universal as outlined in Section 0 at all
three (3) fittings (2 conventional type an d one in rear
yoke half) tha t requires a needle nose grease gun
adapter.
6. Install propeller shaft with constant velocity
jo in t next to tr a n sfe r case. T o rq ue U-bolts to
specifications. The lubrication fitting at this location is
shown in figure 4A-23.
Fig. 4A-24 -Bearing Cap Removal Sequence
M ark the flange yoke and coupling yoke for reassembly
in the same position, as shown in figure 4A-25.
that the ball socket is part o f the flange yoke assembly,
while the centering ball is pressed onto a stud an d is p art
o f the ball stud yoke. See figure 4A-26. Pry the seal from
the ball socket and remove washers, spring and the three
ball seats as illustrated in figure 4A-27.
1. Clean and inspect ball seat insert bushing for
wear. If bushing is worn, replace flange yoke and cross
assembly.
2. Clean and inspect seal and ball seats along with
spring and washers. If any parts show indication o f
excessive wear or are broken, replace the entire set with
a service kit.
N O T E: To service the trunnion caps, use the
a pp ro priate procedures given in the beginning of
this Section.
W h e n both bearing cups are free, disengage the
flange yoke and trunnion from the centering ball. Note
NOTE: W henever the seal is removed to inspect
ball seat parts, it should be discarded and replaced
with a new seal.
3. Remove all plastic from groove o f coupling
yoke.
DOUBLE C A R DAN TYPE-CV J O IN T
Inspection
A n inspection kit including two bearing caps and
two sn a p rings is available to allow the removal of the
two tru nn io n caps shown at location 1, in figure 4A-24.
BALL SUPPORT
TUBE YOKE
A L IG N M E N T P U N C H M A R K S
Fig. 4A -28--lnstalling Tool J-23996 Over Ball
Fig. 4A-26--Cross Sectional View of CV Joint
Fig. 4 A 29 -Installing Outer Cylinder of Tool J-23996
Over Ball
Fig. 4A-27--Exploded View of Centering Ball
M echanism
4.
Inspect the centering ball surface. If it shows
signs of w ear beyond smooth polish, replace it.
Centering Ball Replacement
1. Place fingers o f inner part o f Tool J-23996
u nd e r ball as shown in figure 4A-28.
2. Place outer cylinder o f Tool J-23996 over
outside o f ball as shown in figure 4A-29.
3. T h read nut on Tool j-23996 and draw ball off
stud, using wrench as shown in figure 4A-30.
4. Place the replacem ent ball on stud.
5. Using Tool J-23996, drive ball onto stud as in
figure 4A-31, until the ball can be seen to seat firmly
against the shoulder at the base o f the stud. This is
im p o rta n t as the center o f the double C a rd a n joint is
determ ined by the ball seating tightly in the proper
location.
6. Using grease provided in the ball seat kit,
lubricate all parts and insert them into the clean ball seat
cavity in the following order: spring, washer (smallest
OD), three ball seats (with largest opening outward to
receive ball), washer (largest OD) and seal.
7. Lubricate seal lip and press seal flush with Tool
J-23694, as shown in figure 4A-32. Sealing lip should tip
inward.
8.
Fill cavity with grease provided in kit.
9. Install flange yoke to centering ball as shown in
figure 4A-33, making sure alignm ent marks are correctly
positioned. Install tru n n io n a n d b e a rin g caps as
previously outlined.
Fig. 4A 30 Removing C entering Ball
Fig. 4A-32 In sta llin g Centering Ball Seal
Fig. 4 A -3 1 -In s ta llin g C entering Ball
Fig. 4A-33-Reassem bling Flange Yoke
LU B R IC A T IO N
T he front axle p rop sh aft found on all four-wheel
drive trucks requires special lubrication procedures at
two locations: The C /V joint, and the slip yoke.
All Constant Velocity Joints (C /V )
The constant velocity (C /V ) joint, located at the
transfer case end o f the front propshaft. must be
lubricated periodically with special lubricant, 1050679,
or equivalent. If the fitting cannot be seen from beneath
the vehicle Figure 4A-34 shows how the fitting may be
lubricated from above the C /V joint, with a special
adapter J-25512-2 on the end of a flex hose.
Slip Spline
•
Dana Style Propshaft- First loosen the screw-on
grease cap. shown in Figure 4A-35 and slide the collar
back to reveal the sealing area. Apply chassis lubricant
at the fitting until grease begins to leave through the
vent hole. Cover the vent hole with your finger and
continue applying lubricant until it can be seen leaving
at the slip yoke seal. Reinstall the grease cap.
NOTE: If the slip spline is dry or corroded, it may
be necessary to disconnect the propshaft from the
truck, remove the slip yoke, and wire brush the
affected areas. Wipe clean before reinstallation.
W hen installing the propshaft to transfer case
attaching bolts, torque to specification (20-30 ft.
lbs.).
•
GM Style Propshaft- Apply chassis lubricant at
the fitting until grease begins to leave through the vent
hole.
NOTE: If the slip spline is dry or corroded, it may
be necessary to disconnect the propshaft from the
Slip Yoke Lubrication
truck, remove the slip yoke, and wire brush the
affected areas.
W ipe clean before reinstallation. W hen installing
the propshaft to transfer case front output flange
attaching bolts, torque to specification (70-80 ft.
lbs.).
SPECIFICATIONS
PROPELLER SHAFT
CK
G
P
1 2 -1 7
1 8 -2 2
1 2 -1 7
2 0 -3 0
4 0 -5 0
2 0 -3 0
1 2 -1 7
1 8 -2 2
2 0 -3 0
—
—
P ro p e lle r S h a ft
To Rear A x le (S tra p )
To R ear A x le (" U " Bolt)
B e a rin g S u p p o rt-to -H a n g e r
H a n g e r-to -F ra m e
To T ra n s fe r C ase
D a n a Style
G M Style
2 0 -3 0
7 0 -8 0
—
Torqu e S p ecificatio ns (Ft.-Lbs.)
U NIVERSAL J O IN T A T TA C H M E N T
TO R Q U E S P E C IF IC A TIO N S
S tra p Attachm ents ...............................................15 Ft.-Lbs.
" U " Bolt A ttach m ent ..........................................2 0 Ft.-Lbs.
SECTION 4B
REAR AXLE
The following caution applies to one or more steps in the assembly
procedure o f components in this portion o f the m anual as indicated at
ap pro priate locations by the terminology "See Caution on Page 1 o f this
Section".
C A U TIO N : T H I S F A S T E N E R I S A N I M P O R T A N T A T T A C H I N G
P A R T I N T H A T I T C O U LD A F F E C T T H E P E R F O R M A N C E OF
V IT A L C O M P O N E N T S A N D S Y S T E M S , A N D / O R C O U L D R E S U L T
IN M A JO R R E P A IR E X P E N SE . I T M U S T BE R E P L A C E D W ITH
O N E OF T H E S A M E P A R T N U M B E R OR W IT H A N E Q U I V A L E N T
P A R T I F R E P L A C E M E N T B E C O M E S N E C E S S A R Y. D O N O T U S E A
R E P L A C E M E N T P A R T OF L E S S E R Q U A L I T Y OR S U B S T I T U T E
D E S IG N . T O R Q U E V A L U E S M U S T B E U S E D A S S P E C IF IE D
D U R I N G R E A S S E M B L Y TO A S S U R E P R O P E R R E T E N T I O N OF
T H IS PART.
CONTENTS
G en eral D escriptio n......................................................................... 4B-1
Differential D iagnosis.......................................................................4B-7
G e n e ra l Diagnostic P ro c e d u re .................................................. 4B-10
Differential and Rear Axle Bearing D iagnosis.................. 4B-11
On-Vehicle Service............................................................................... 4 B -13
8 -1 /2 " and 8 -7 /8 " Ring G e a r ................................................. 4B-13
Chevrolet 10-1/2" Ring G e a r ................................................... 4B-18
D a n a 10-1/2" Ring G e a r ........................................................... 4B-21
D an a 9 -3 /4 "R in g G e a r ............................................................... 4B-21
Chevrolet 12-1/4" Ring G e a r ................................................... .4B-21
Specifications....................................................................................... 4B-24
Special T ools........................................................................................4B-25
GENERAL DESCRIPTION
A differential is an a rra n ge m ent o f gears that
divides the torque between the axle shafts and allows
them to rotate at different speeds. A basic differential
consists o f a set o f four gears. Two o f these gears are
called differential side gears, an d the other two are
differential p inion gears. Some differentials have more
than two pinion gears. Each side gear is splined to an
axle shaft. Consequently, each axle shaft must turn w hen
its side gear rotates.
T h e differential pinion gears are mounted on a
differential p inion shaft, and the gears are free to rotate
on this shaft. T he pinion shaft is fitted into a bore in the
differential case and is at right angles to the axle shafts.
Power flow through the differential is as follows:
The drive p inion roates the ring gear. The ring gear,
being bolted to the differential case, rotates the case. The
differential pinion, as it rotates w ith the case, forces the
pinion gears against the side gears. W hen both wheels
have equal traction, the pinion gears do not rotate on the
pinion shaft because the input force on the pinion gear
is equally divided between the two side gears. See figure
4B-1. Consequently, the pinion gears revolve with the
pinion shaft, but do not rotate around the shaft itself.
The side gears, being splined to the axle shafts and in
mesh with the pinion gears, rotate the axle shafts.
If a vehicle were always driven in a straight line, the
ring and pinion gears would be sufficient. The axle shaft
could then be solidly attached to the ring gear and both
driving wheels would turn at equal speeds.
However, if it became necessary to turn a corner, the
tires would scuff and slide because the outer wheel would
travel further than the inner wheel, as in figure 4B-2. To
prevent tire scuffing an d sliding, the differential becomes
effective and allows the axle shafts to rotate at different
speeds.
As the inner wheel slows down, the side gear splined
to that axle shaft also slows down. At this point, the
pinion gears act as balancing levers by m aintaining
equal speeds o f rotation o f the axle shafts.See figure4B-3.
If the vehicle speed rem ains constant and the inner
E Q U A L T R A C T IO N IN
S T R A IG H T A H E A D
D R IV IN G
B A LA N C E D FO RCES M A KE
D IF F E R E N T IA L S E E M L O C K E D
Fig. 4B-3--D ifferential Action on Turns
Fig. 4B-1--D ifferential Inactive
tube is puddle welded to the carrier. Welded-on brackets
provide attachm ent points for suspension componenets
such as shock absorbers and leaf springs. A welded
flange is provided for brake flange plate attachment.
An overhung hypoid drive pinion is supported by
two preloaded tapered roller bearings. The pinion shaft
is sealed by means o f a molded, spring loaded, rubber
seal. The seal is mounted on the pinion flange which is
splined and bolted to the hypoid pinion shaft.
The hypoid ring gear is bolted to a one-piece
differential case which is supported by two preloaded
tapered roller bearings.
OUTSIDE WHEEL
HAS FARTHER,*
TO TRAVEL
BOTH WHEELS
TURN AT SAME
SPEED WHEN
TRAVELING
STRAIGHT
Chevrolet 1 0 - 1 / 2 " Ring Gear Axle
n
Vi
)]
ix
Fig. 4B-2-N eed for D iffe re n tia l Action
wheel slows to 90% o f vehicle speed, the outer wheel
speeds up to 110%. If the inner wheel slows to 75%, the
outer wheel would turn 125%. If one wheel stopped, the
other wheel would turn 200%.
Six distinct axles compromise the truck line-up.
These six, categorized by ring gear diameter, are a) 8-1/
2" and b) 8 -7 /8 " Ring G ear, c) Chevrolet 10-1/2" Ring
G ear, d) D a n a 10-1/2" Ring G ear, e) D a n a 9 -3 /4 " Ring
G e a r and f)Chevrolet 12-1/4" Ring Gear.
8 - 1 / 2 " and 8 - 7 / 8 " Ring Gear Axle
The axle shown in figure 4B-4 is a semifloating,
fabricated constructed type consisting o f a cast carrier
with large bosses on each end into which two welded
steel tubes are fitted. The carrier contains an overhung
hypoid pinion an d ring gear. The differential is a two
pinion a rrangem ent.
The axle housing is m ade up of two steel welded
tubes pressed into the crossbore o f the cast carrier. Each
The axle shown in figure 4B-5 is of the full floating
type with hypoid ring gear and drive pinion. The full
floating construction enables easy removal o f axle shafts
without removing truck load and without jacking up the
axle. The differential carrier is heavily ribbed to provide
rigid support for the differential assembly.
The straddle-mounted drive pinion is supported at
the front by two opposed tapered roller bearings. The
pinion straddle bearing is a roller bearing assembly
consisting o f an outer race and roller assembly. A
precision ground d iam eter on the pinion pilot functions
as an inner race.
Side bearing preload and ring gear-to-pinion
backlash are controlled by side bearing adjusting nuts
threaded into the carrier near the axle tubes. Pinion
depth is controlled by a shim located between the pinion
bearing retainer assembly and the differential carrier.
Dana 1 0 - 1 / 2 " Ring Gear Axle
The D ana axle shown in figure 4B-6 is a Salisburytype similar in design to the 8 -7 /8 " ring gear axle in
figure 4B-4. It does differ in several points, however. The
axle shafts are full floating; the carrier must be spread to
remove the differential; and the drive pinion incorpo
rates two shim packs. The inner pack controls pinion
1.
C o m p a n io n F la n g e
7.
D if f e r e n t ia l Case
13. C o v e r
19. T h ru st W a sh e r
2.
D e fle c to r
8.
Shim
14.
2 0 . D if f e r e n t ia l P in io n
3.
P in io n O i l Seal
9.
G asket
15.
R ing G e a r
21 . Shim
4.
P in io n F ro n t B e a rin g
10.
D if f e r e n t ia l B e a rin g
16.
S id e G e a r
2 2 . P in io n Rear B e aring
5.
P in io n B e a rin g S p acer
11.
" C " Lock
17.
B e a rin g C a p
2 3 . D r iv e P in io n
6.
D if f e r e n t ia l C a r r ie r
12.
P in io n S h a ft L o c k
18.
A x le S h a ft
Sere
P in io n S h a ft
Fig. 4 B -4 -8 -1 /2 " and 8 -7 /8 " Ring Gear Axle Cross-Section Typical
depth, while the outer pack controls pinion hearing
preload.
Dana 9 - 3 / 4 " Ring Gear Axle
T he D a n a axle shown in figure 4B-7 is similar to the
unit shown in 4B-6; however, the differential side
bearing shims are located between the case and the side
bearings.
C hevrolet 1 2 - 1 / 4 " Ring Gear Axle
(1 1 ,0 0 0 Pound Capacity)
T he 11,000 lb. capacity, single-speed hypoid axle,
illustrated in figure 4B-8, has a straddle mounted drive
pinion which is supported at the re a r by a straight roller
bearing. The pinion front bearing consists o f a double
row ball bearing.
The differential is a conventional four-pinion type.
Thrust washers are used between the side gears and case
and also between differential pinions and the differential
case.
A thrust pad mounted on the end o f an adjusting
screw threaded into the carrier housing limits deflection
o f the ring gear under high torque conditions.
Involute splines are incorporated in the axle shaft
flange and in the wheel hubs. This design provides for
the driving torque to be transmitted from the axle shaft
to the hub through the m ating splines.
1.
2.
3.
4.
5.
6.
7.
8.
9.
C o m p a n io n Flange
Oil D e fle c t o r
Oil Seal
Bearing Retainer
Shim
P in io n F r o n t Bearing
C o lla psible Spacer
P in io n Rear Bearing
D rive P in io n
10.
11.
12.
13.
14.
15.
16.
17.
18.
S trad dle Bearing
Ring Gear
D i ff e r e n t ia l Spider
D iff e r e n t ia l Case
D i ff e r e n t ia l P in io n
D iff e r e n t ia l Side Gear
Side Bearing
Side Bearing A d j u s t in g N u t
A d j u s t in g N u t Reta in er
19.
20.
21.
22.
23.
24.
25.
Reta in er Screw
Bearing Cap
Case-to Ring Gear B o lt
D iff e r e n t ia l Cover
Bearing Cap B o lt
Cover Screw
A x l e S ha ft
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
P in io n N u t
W asher
C o m p a n io n Flange
O il Seal
O il S lin g e r
P in io n F r o n t B e aring
F r o n t B e a rin g C u p
P reload S h im Pack
P in io n D e p th S h im Pack
R ear B e a rin g C u p
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
P in io n R ear B e aring
D riv e P in io n
R in g G ear
D iffe r e n tia l Case
R in g G ear B o lt
D iffe r e n tia l Side B earing
S ide B e a rin g C u p
S ide B e a rin g A d ju s tin g S h im s
B e a rin g Cap
B e aring C a p B o lt
Fig. 4B-6--Dana 1 0 -1 /2 " Ring Gear Axle Exploded View
21.
22.
23.
24.
25
26.
27.
28.
29.
D iffe r e n tia l S p id e r
D iffe r e n tia l S id e G ear
W asher
P im o n G ear
W asher
G asket
Cover
C o ver S crew
D ra in P lug
1. Nut
2. Washer
3. Companion Flange
4. Pinion Oil Seal
5. Gasket
6. Outer Pinion Oil Slinger
7 and 8. Cone and Roller
(Outer Pinion Bearing)
9. Shims (Outer Pinion
Bearing)
0. Inner Pinion Oil Slinger
11.
12.
13.
14.
15.
16.
Shims (Inner Pinion
Bearing)
Cup (Inner Pinion
Bearing)
Cone and Roller
(Inner Pinion)
Ring and Pinion
Gasket (Housing
Cover)
Screw and Washer
(Cover)
17.
18.
19.
20.
21.
22.
23.
Cover and Plug
Lock Pin (Pinion
Shaft)
D ifferential Case
Shims (Differential
Adjusting)
Cone and Roller
(Differential Bearing)
Cup (Differential
Bearing)
Cap (Differential
Bearing)
Fig. 4B -7 -D a n a 9 -3 /4 " Ring Gear Axle Exploded View
24.
25.
26.
27.
28.
29.
30.
B o lt (Differential
Bearing Cap)
Bolt (Ring Gear)
Pinion Shaft
Thrust Washer
(Pinion)
Pinion
Side Gear
Thrust Washer (Side
Gear)
1.
2
3
4.
5.
6
7.
U n iv e rs a l J o in t Y o ke
P in io n B e a rin g O il
S e al and R e ta in e r
O il Seal
O il S e al G a s k e t
F ro n t P in io n B e a rin g
D riv e P in io n
R e ar P in io n B e a rin g
8.
9.
10.
11.
12.
13.
R in g G e a r T h ru s t Pad
R in g G ear
D iffe r e n tia l S p id e r
D iffe r e n tia l P in io n
(S p id e r) G ear
D iffe r e n tia l S id e G ear
14.
A x le S h a ft
15.
16
D iffe r e n tia l B e a rin g
D iffe r e n tia l B e a rin g
A d ju s tin g N u t
17.
A d ju s tin g N u t L o c k
18
D iffe r e n tia l
C a s e -R ig h t H a lf
D iffe r e n tia l C a s e -L e ft
H a lf
Fig. 4B-8 Chevrolet 1 2 -1 /4 " Ring Gear Axle—1 1 ,0 0 0 # Capacity
DIFFERENTIAL DIAGNOSIS
S T A N D A R D DIFFERENTIAL
Noise
T he most essential p a rt o f re a r axle service, as with
any mechanical repair, is pro per diagnosis o f the
problem, and, in axle work one o f the most difficult areas
to diagnosis is noise. Locating a broken axle shaft, or
broken differential gear, presents little or no problem,
but, locating and isolating axle noise can be an entirely
different matter.
Degree of Noise
Any gear driven unit, and especially an automotive
drive axle where engine torque multiplication occurs at a
90° turn in the drive line, produces a certain am ount o f
noise. Therefore, an interpretation must be m ade for
each vehicle to determ ine w hether the noise is normal or
if a problem actually exists. A norm al am ount o f noise
must be expected and cann ot be eliminated by
conventional repairs or adjustment. See figure 4B-9.
Acceptable noise can be defined as a slight noise
heard only at a certain speed or under unusual or remote
conditions. For example, this noise tends to reach a
" p e a k " at speeds from 40 to 60 miles per hour
depend in g on road and load conditions, or on gear ratio
and tire size. This slight noise is in no way indicative of
trouble in the axle assembly.
Drive line noises m ay baffle even the best
d ia g n o stic ia n . Vehicle noises co m ing from tires,
transmission, propeller shaft, universal joints, and front
or rear wheel bearings, are often mistaken for axle noise.
Such practices as: raising tire pressure to eliminate tire
noise (although this will not silence tread noise o f mud
and snow tires), listening for the noise at varying speeds
and road surfaces, on drive, float, and coast conditions
will aid in locating the source o f alleged axle noises.
Thus, every effort should be m ade to isolate the noise to
a specific drive line com ponent instead o f making a
r a n d o m guess that could be a costly waste o f time.
Elimination of External Noises
W h e n a rear axle is suspected of being noisy, it is
advisable to m ake a thorough test to determ ine whether
the noise originates in the tires, road surface, front wheel
bearings, engine, transmission, or rear axle assembly.
N oise which originates in other places cannot be
corrected by adjustm ent or replacement o f parts in the
rear axle assembly.
Road N o ise -S o m e road surfaces, such as brick or
rough-surfaced concrete, cause noise which may be
mistaken for tire or rear axle noise. Driving on a
different type o f road, such as smooth asphalt or dirt,
will quickly show w hether the road surface is the cause
o f noise. R oad noise usually is the same on drive or
coast.
Tire Noise- Tire noise may easily be mistaken for
rear axle noise, even though the noisy tires m ay be
located on the front wheels. Tires worn unevenly, or
SOME t/O/SE/S
ACCEPTABLE
having surfaces on non-skid divisions worn in saw-tooth
fashion, are usually noisy and m ay produce vibrations
which seem to originate elsewhere in the vehicle. This is
particularly true with low tire pressure.
Test for Tire N oise-T ire noise changes with
different road surfaces, but rear axle noise does not.
T emporarily inflating all tires to approximately 50
pounds pressure, for test purposes only will materially
alter noise caused by tires but will not affect noise caused
by the rear axle. R ear axle noise usually ceases when
coasting at speeds under 30 miles p e r hour; however, tire
noise continues but with lower tone as vehicle speed is
reduced. R e a r axle noise usually ch ang es when
com paring "p ull" and "coast" but tire noise remains
about the same.
Engine and Transmission N oises-Som etim es a
noise which seems to originate in the rear axle is actually
caused by the engine or transmission. To determine
which unit is actually causing the noise, observe
approximate car speeds and conditions un der which the
noise is most pronounced; then stop vehicle in a quiet
place to avoid interfering noises. W ith transmission in
neutral, run engine slowly up and down through engine
speeds corresponding to vehicle speed at which the noise
was most pronounced. If a similar noise is produced with
vehicle standing, it is caused by the engine or
transmission and not the rear axle.
Front Wheel Bearing N o ise- Loose or rough front
wheel bearings will cause noise which m ay be confused
with rear axle noises; however, front wheel bearing noise
does not change w hen com paring "pu ll" and "coast".
Light application o f brake, while holding vehicle speed
steady, will often cause wheel bearing noise to diminish,
as this takes some weight off the bearing. Front wheel
bearings may be easily checked for noise by jacking up
the wheels and spinning them, and also be shaking
wheels to determ ine if bearings are excessively loose.
Body Boom Noise or Vibration
Objectional "bo dy boo m " noise or vibration at 5565 mph can be caused by an unbalanced propeller shaft.
Excessive looseness at the spline can contribute to this
unbalance.
Other items that may also contribute to the noise
problem are as follows:
1. U ndercoating or mud on the shaft, causing
unbalance.
2. S haft or com panion flange balance weights
missing.
3. S haft dam age, such as bending, dents, or nicks.
4. Tire-type roughness. Switch tires from a known
good car to determ ine tire fault.
If, after m aking a comprehensive check of the
vehicle, all indications point to the rear axle, further
diagnostic steps are necessary to determ ine the axle
com ponents at fault. True axle noises generally fall into
two categories: gear noise and bearing noise.
Rear Axle Noises
If a careful test of vehicle shows that noise is not
caused by external items it is then reasonable to assume
that noise is caused by rear axle assembly. The rear axle
should be tested on a smooth level road to avoid road
noise. It is not advisable to test rear axle for noise by
r u n n in g with rear wheels jacked up.
Noises in rear axle assembly may be caused by a
faulty propeller shaft, faulty rear wheel bearings, faulty
differential or pinion shaft bearings, misalignment
between two U-joints, or worn differential side gears and
pinions; noises may also be caused by mismatched,
im properly adjusted, or scored ring and pinion gear set.
Rear Wheel Bearing Noise- A rough rear wheel
bearing produces a vibration or growl which continues
with vehicle coasting and transmission in neutral. A
brinelled rear wheel bearing causes a knock or click
approxim ately every two revolutions of rear wheel, since
the bearing rollers do not travel at the same speed as the
re a r axle and wheel. With rear wheels jacked up, spin
re a r wheels by hand while listening at hubs for evidence
o f rough or brinelled wheel bearing.
Differential Side Gear and Pinion Noise^Differential side gears and pinions seldom cause noise since their
m ovem ent is relatively slight on straight ahead driving.
Noise produced by these gears will be most pronounced
on turns.
Pinion Bearing failures can be distinguished
because they rotate at higher speeds than differential
side bearings and axle shaft bearings. Rough or
brinelled pinion bearings produce a continuous low
pitched w h irrin g or scraping noise starting at relatively
low speed.
Side Bearings produce a constant rough noise o f a
lower pitch th a n pinion bearings. Side bearing noise may
also fluctuate in the above wheel bearing test.
N O TE : Bearing Diagnosis Charts appe a r later in
this section.
Gear Noise
There are two basic types o f gear noise. The first
type is produced by broken, bent, or forcibly dam aged
gear teeth and is usually quite audible over the entire
speed range and presents no particular problem in
diagnosis.
F or example, hypoid gear tooth scoring as seen in
figure 4B-10 generally results from the following:
insufficient lu b ric a n t im p ro p e r breakin, im p ro p e r
lubricant, insufficient gear backlash, im proper ring and
Fig. 4B-10--Two Causes of Gear Noise
pinion gear alignment, or loss of drive pinion nut torque.
The scoring will progressively lead to complete erosion
o f the gear tooth, or gear tooth pitting and eventual
fracture if the initial scoring condition is not corrected.
A nother cause o f hypoid tooth fracture is extended
overloading o f the gear set which will produce fatigue
fracture, or shock loading which will result in sudden
failure.
Differential pinion and side gears rarely give
trouble. C om m on causes o f differential failure are shock
loading, extended overloading, and seizure of the
differential pinions to the cross shaft resulting from
excessive wheel spin and con seq uen t lubrication
breakdown.
The second type o f gear noise pertains to the mesh
pattern o f the gear teeth. This form o f a bnorm al gear
noise can be recognized as it produces a cycling pitch
(whine) and will be very pronounced in the speed range
at which it occurs, a ppearing under either "drive",
"float" or "coast" conditions. "D riv e " is acceleration or
heavy pull. "C o ast" is with a closed throttle and vehicle
in gear and "float" is using just enough throttle to keep
the car from driving the engine—the vehicle slows down
gradually but engine still pulls slightly. G e a r noise tends
to peak in a narrow speed range or ranges, and will tend
to rem ain constant in pitch. Bearing noise will vary in
pitch with vehicle speeds. See figure 4B-11.
A GENERAL DIAGNOSTIC PROCEDURE FOR
IS OLATIN G REAR A XLE NOISE PROBLEMS
Problem
Cause
1.
Noise is the same in drive or coast
1. a)
b)
c)
Road noise
Tire noise
Front wheel bearing noise
2.
Noise changes on a different type of road
2. a)
b)
Road noise
Tire noise
3.
Noise tone lowers as car speed is lowered
3. Tire noise
4.
Similar noise is produced with car standing
and driving
4. a)
b)
Engine noise
Transmission noise
5.
Vibration
5. a)
b)
c)
d)
e)
Rough rear wheel bearing
Unbalanced or damaged propeller shaft
Tire unbalance
Worn universal joint in propeller shaft
Mis-indexed propeller shaft at companion
flange
Companion flange runout too great
f)
6.
A knock or click approximately every two
revolutions of rear wheel
6. A brinelled rear wheel bearing
7.
Noise most pronounced on turns
7. Differential side gear and pinion
8.
A continuous low pitch whirring or scraping
noise starting at relatively low speed
8. Pinion bearing
9.
Drive noise, coast noise or float noise
9. Ring and pinion gear
10.
Clunk on acceleration or deceleration
10. Worn differential cross shaft in case
11.
Grunt on stops
11. No grease in propeller shaft slip yoke
12.
Groan in Forward or Reverse
12. Wrong lube in differential
13.
Chatter on turns
13. a)
b)
14.
Clunk or knock on rough road operation
14. Excessive end play of axle shafts to differential
cross shaft
Wrong lube in differential
Clutch plates worn
DIFFERENTIAL A N D REAR AXLE BEARING DIAGNOSIS
CO NSIDER THE FO LLOW ING FACTORS W HEN DIA G N O SIN G BEARIN G C O N D ITIO N :
1.
G ENERA L C O N D IT IO N OF A L L PARTS D U R IN G DISASSEMBLY A N D INSPECTION.
2. CLASSIFY THE FA IL U R E W ITH THE A ID OF THE ILLU S TR A TIO N S .
ABRASIVE
ROLLER
3.
DE TE R M IN E THE CAUSE.
4.
MAKE A L L REPAIRS FO LLOW IN G RECOM M END ED PROCEDURES.
WEAR
GALLING
BENT
CAG E
P A TTE R N ON RACES A N D RO LLERS CAUSED BY
F IN E ABRASIVES.
M ETAL SMEARS ON R OLLER ENDS DUE TO O VE R H E A T,
LU B R IC A N T F A ILU R E OR O V E R LO A D (WAGON'S)
CAGE DAM AGE DUE TO IMPROPER H A N D L IN G
OR TOOL USAGE.
C LE A N ALL PARTS A N D H OUSINGS. CHECK SEALS
A N D BEA R IN G S A N D REPLACE IF LE A K IN G , ROUGH
OR N O ISY.
REPLACE BEARING
CHECK SEALS A ND CHECK
FOR PROPER L U B R IC A TIO N .
REPLACE BEARIN G .
ABRASIVE
STEP
WEAR
P A TTER N ON R O LLER ENDS C AUSED BY
FIN E A B R A SIVES.
C LE A N ALL PARTS A N D HOUSINGS. CHECK SEALS
A N D B E ARING S A N D REPLACE IF LE A K IN G , ROUGH
OR N O ISY.
INDENTATIONS
SURFACE DEPRESSIONS ON RACE A N D ROLLERS
C AUSED BY H A R D PARTICLES OF FO R E IG N M A T E R IA L .
C L E A N A LL PARTS AND H OUSINGS. CHECK SEALS
A N D REPLACE BEARINGS IF ROUGH OR NOISY.
ETCHING
BEARING SURFACES APPEAR G R A Y OR GRA YISH
BLACK IN COLOR W ITH R E LA TE D ETCHING AW AY
OF M A T E R IA L U SU A LLY A T RO LLER SPACING.
BENT
CAGE
CAGE DA M AG E DU E TO IMPROPER H A N D L IN G
OR TO O L USAGE.
REPLACE BEARIN G.
REPLACE BEARINGS CHECK SEALS A ND CHECK
FOR PROPER L U B R IC A TIO N .
CAGE
WEAR
WEAR A R O U N D O UTSIDE D IA M E TE R OF CAGE A N D
ROLLER POCKETS CAUSED BY ABRA SIVE M A TE R IA L
AND IN E F F IC IE N T L U B R IC A TIO N .
CLEAN R ELA TE D PARTS AND HOUSINGS.
CHECK SEALS AND REPLACE BEARINGS.
M ISALIGNMENT
O U TER RACE M IS A LIG N M E N T DUE TO FO REIGN
OBJECT.
C LEAN R ELA TE D PARTS A N D REPLACE B EA R IN G .
M AKE SURE RACES ARE PROPERLY SEATED.
DIFFERENTIAL A N D REAR AXLE BEARING DIAGNOSIS
(C O N T ’D)
CRACKED INNER
RACE
FATIGUE
SPALLI
G
R ACE C R A C K E D D U E TO IM PR O PER F IT ,
C O C K IN G , OR POOR B E A R IN G SEATS.
F L A K IN G OF S U R FA C E M E T A L R E S U L T IN G FRO M
F A T IG U E .
R EPLA C E B E A R IN G A N D C O R R E C T B E A R IN G
S EATS.
REPLA CE B E A R IN G
FRETTAGE
C O R R O S IO N SET UP BY S M A L L R E L A T IV E
M O V E M E N T O F PA R TS W IT H NO L U B R IC A T IO N .
REPLACE B E A R IN G . C L E A N R E L A T E D PARTS.
C H EC K S EA LS A N D C H E C K F O R PR O PER L U B R IC A T IO N .
BRINELLING
S U R F A C E IN D E N T A T IO N S IN R A C E W A Y C A U S E D BY
R O LL E R S E IT H E R U N D E R IM P A C T L O A D IN G OR
V IB R A T IO N W H IL E TH E B E A R IN G IS N O T R O T A T IN G .
C L E A N A L L R E L A T E D PA R TS.
REPLAC E B E A R IN G IF R O U G H OR N O IS Y .
STAIN
DISCOLORATION
HEAT
DISCOLORATION
D IS C O L O R A T IO N C A N R A N G E FRO M L IG H T BROW N
TO B LACK C A U S E D B Y IN C O R R E C T L U B R IC A N T OR
M O IS T U R E .
H E A T D IS C O L O R A T IO N C A N R A N G E FR O M F A IN T
Y E L L O W TO D A R K B LU E R E S U L T IN G FRO M O V E R
LO A D (W A G O N 'S ) OR IN C O R R E C T L U B R IC A N T .
RE-USE B E A R IN G S IF S T A IN S CAN BE R E M O V E D BY
L IG H T P O L IS H IN G O R IF NO E V ID E N C E O F O V E R
H E A T IN G IS O B S E R V E D .
OR R O LLE R S .
C H ECK S E A LS A N D R E L A T E D PA R TS FOR D A M A G E .
E X C ESSIVE H E A T C A N CAUSE S O F T E N IN G OF RACES
T O CH ECK FO R LOSS O F TE M P E R O N RACES OR
R O LLE R S A SIM PLE F IL E T E S T M A Y BE M A D E . A
F IL E D R A W N O V E R A TE M P E R E D P A R T W IL L G R A B
A N D C U T M E T A L , W H E R E A S , A F IL E D R A W N O V E R A
H A R D P A R T W IL L G L ID E R E A D IL Y W IT H NO M E T A L
C U T T IN G .
REPLA CE B E A R IN G S IF O V E R H E A T IN G D A M A G E IS
IN D IC A T E D . CHECK SEA LS A N D O T H E R PAR TS.
SMEARS
S M E A R IN G O F M E T A L D U E T O SLIP P A G E .
SLIPPAG E C A N BE C A U S E D BY POOR F IT S .
L U B R IC A T IO N , O V E R H E A T IN G . O V E R L O A D S
O R H A N D L IN G D A M A G E .
R EPLA C E B E A R IN G S , C L E A N R E L A T E D PA RTS
A N D C H EC K FO R PRO PER F IT S A N D
L U B R IC A T IO N .
ON-VEHICLE SERVICE
8 - 1 / 2 and 8 - 7 / 8 RING
GEAR AXLE
AXLE ASSEMBLY
Construction o f the axle assembly is such that
service operations may be p erform ed with the housing
installed in the vehicle or with the housing installed in a
holding fixture. The following removal and installation
procedure is necessary only when the housing requires
replacement.
CAUTION: See C A U T IO N on page 1 o f this
section, regarding A x le Assembly fasteners.
Removal
1. Raise vehicle on hoist.
2. Support rear axle assembly with suitable lifting
device, so that tension is relieved in springs and shock
absorbers.
3. Remove trunnion bearing " U " bolts from the
axle com panion flange, separate trunnion from flange,
position propeller sh aft to one side and tie it to fram e
side rail.
N O TE : Secure trunnion bearing caps to trunnion,
using masking tape or a large ru b b e r band, to
prevent loss o f bearings.
4. Disconnect shock absorbers at lower attachm ent
points and position out of the way.
5. Disconnect axle vent hose from vent connector
an d position vent hose to one side.
6. Disconnect hydraulic brake hose at connector on
axle housing. Remove brake drum , disconnect parking
brake cable at actuating levers and at flange plate. Refer
to Section 5 for cable removal and brake details. Remove
axle " U " bolt nuts, " U " bolts, spacers and clamp plates.
7. Lower axle assembly and remove from vehicle.
Installation
1. Position axle assembly under vehicle and align
w ith springs.
2. Install spacer, clamp plate and " U " bolts to axle
assembly, loosely install retaining nuts to " U " bolts.
3. Position shock absorbers in lower attachm ent
brackets and loosely install nut to retain shock.
4. Connect axle vent hose to vent connector at
carrier.
5. Connect hydraulic brake hose to connector on
axle housing, connect parking brake cable to actuating
levers. Install brake drum and wheel and tire a s s e m b ly bleed brakes and adjust park in g brake as outlined in
applicable portion o f Section 5.
6. Reassemble the propeller shaft to com panion
flange, m aking sure that b earing caps are indexed in
flange seat. Torque b earing cap retaining nuts to
specifications.
7. Position vehicle so that weight is placed on
suspension com ponents and torque affected parts to
specifications.
8. Lower vehicle and remove from hoist.
AXLE SHAFT
Removal
1. Raise vehicle on hoist. Remove wheel and tire
assembly and brake drums.
2. Clean all dirt from area o f carrier cover.
3. D ra in lubricant from carrier by removing cover.
4. Remove the differential pinion shaft lock screw
and the differential pinion shaft as shown in figure 4B14.
5. Push flanged end o f axle shaft toward center o f
vehicle and remove " C " lock from button end o f shaft.
6. Remove axle shaft from housing, being careful
not to dam age oil seal.
N OTE: Axles equipped with 8 -7 /8 " ring gears and
Eaton Locking differentials use a thrust block on
the pinion shaft which affects the removal of axle
shafts as noted below.
1. Raise the vehicle on a hoist. Remove both rear
wheel and tire assemblies and both rear brake drums.
2. Remove the rear cover and drain the lubricant.
3. Rotate the case to the position shown in figure
4B-15. Support the pinion shaft so that it cannot fall
into the case, then remove the lock screw.
4. Carefully withdraw the pinion shaft part-way
out, as shown in figure 4B-16. Rotate the case until the
shaft touches the housing.
5. Reach into the case with a screwdriver or
sim ilar tool, and rotate the C-lock until its open end
points directly inward, as shown in figure 4B-17. The axle
shaft cannot be pushed inward until the C-lock is
properly positioned.
Fig. 4B -15-R em oving Lock Screw
Fig. 4B 17--Correct C-Lock Position
Fig. 4 B -1 6 -P osition in g Case For Best Clearance
Do not force or hammer the axle shaft in an
attem pt to gain clearance.
6. W h e n the C-lock is positioned to pass through
the end o f the thrust block, push the axle shaft inward as
shown in figure 4B-18, and remove the C-lock. Remove
the axle shaft and repeat steps 5 and 6 for the opposite
axle shaft.
7. W h e n installing C-locks keep the pinion shaft
partially w ithdrawn. Place the C-lock in the same
position shown in figure 4B-17. Carefully withdraw the
axle shaft until the C-lock is clear o f the thrust block.
W hen both locks are installed, install the pinion shaft
and lock screw.
Oil Seal/B earing—Replacement Fig. 4B-19
1.
Remove oil seal by using button end o f
shaft. Insert button end behind the steel case o f the oil
seal, then pry seal out of bore being careful not to
Fig. 4B-18--Push Axle Shaft Inward
d am age seal. If both seal and bearing are being replaced
proceed to step 2.
2. Using J-23689, insert into bore so that tool
grasps behind the bearing. See figure 4B-20. Slide washer
against outside o f seal (or bearing) and turn nut finger
tight against washer. Attach Slide H a m m e r J-2619 and
remove bearing and seal.
3. Back off nut and remove bearing an d seal from
tool.
4. Lubricate cavity between seal lips with wheel
bearing lubricant and also lubricate new b earing with
wheel bearing lubricant.
5. To reinstall bearing, use J-23690 Installer. Install
bearing until tool bottoms against tube as illustrated in
axle figure 4B-21.
6. To install oil seal, place seal on J-21128 and
drive into bore until tool bottoms against end o f tube.
Fig. 4B-21-W heel Bearing Installation
Fig. 4B-20- Wheel Bearing Removal
Fig. 4B-22-S eal Installation
See figure 4B-22. This tool installs the seal flush with the
end of the tube.
shaft do not damage oil seal and that they
engage with splines o f differential side gear.
2. Install axle sh aft " C " lock on button end of axle
shaft and push shaft outward so that shaft lock seats in
counterbore o f differential side gear.
3. Position differential pinion shaft through case
and pinions, aligning hole in shaft with lock screw hole.
Install lock screw.
4. Using a new gasket, install carrier cover.
Brake Backing Plate—Replacement
1. Remove brake line at wheel cylinder inlet and
disassemble brake com ponents from flange plate. Refer
to Section 5 for brake disassembly procedure.
2. Remove bolts retaining flange plate to axle, and
remove flange plate.
3. Install new flange plate to axle housing and
torque nuts to specifications.
4. Install brake com ponents on flange and connect
hydraulic line to wheel cylinder inlet. See Section 5 for
brake assembly, bleeding and adjustment procedures.
Axle Shaft—Installation
1.
Slide axle shaft into place.
CAUTION: Exercise care that splines on end o f
CAUTION: M ake sure both gasket surfaces on
carrier a n d cover are clean before installing
new gasket. Torque carrier cover bolts in a
crosswise pattern to ensure uniform draw on
cover gasket.
5. Fill axle with lubricant as specified in Section 0
o f this manual to a level even with the bottom o f filler
hole.
6. Install brake d rum an d wheel and tire assembly.
7.
Lower vehicle and remove from hoist.
Wheel Bolt—Replacement
1. Raise vehicle on hoist allowing axle to hang
freely.
2. Remove wheel and tire an d brake drum.
3. Using Tool J-5504 or J-6627 press out stud as
shown in figure 4B-23.
4. Place new stud in axle flange hole. Slightly start
stud serrations in hole by firmly pressing back o f stud
with your hand.
5. Install a lug nut w ith flat side first (tapered face
outboard). Tighten on lug nut draw ing stud into flange
until stud head is bottom ed on back side o f flange.
6. Remove lug nut.
7. Reinstall brake d ru m an d wheel and tire.
8. Lower vehicle and remove from hoist.
P IN IO N FLANGE, D U S T DEFLECTOR
Fig. 4B-24--M easuring Pinion R otating Torque
A N D /O R OIL SEAL
Removal
1. Raise vehicle on hoist.
2. Disconnect propeller shaft from axle.
3. Position propeller shaft to one side and tie it to
f ra m e side rail.
4. M easure the torque required to rotate the
pinion, as shown in figure 4B-24. Record the torque for
later reference.
5. Scribe a line down pinion stem, pinion nut, and
flange to aid on reinstallation. Make sure lines show the
r e la tio n sh ip o f c o m p o n e n ts accurately. C o un t the
n u m b e r o f exposed threads on pinion stem, and record
for later reference. See figure 4B-25.
6. Install Tool J-86 14-11 on pinion flange and
remove pinion flange self-locking washer faced nut as
shown in figure 4B-26. (Position J-8614-11 on flange so
tha t the four notches are toward flange.) Save scribed
nut for reinstallation.
TO O L J -6 6 2 7
or J - 5 5 0 4
7. T hread pilot end o f Tool J-8614-3 into small
O.D. end o f J-8614-2. Then with J-8 614-11 installed as in
Step 6, insert J-8614-2 into J-86 14-11 and turn it 45
degrees to locked position. Remove flange by turning
J-8614-3 while holding J-8614-11 as shown in figure 4B27.
8. Pry old seal out o f bore, using a screw driver or
a h a m m e r and chisel.
Inspection
1. Inspect pinion flange for smooth oil seal surface,
worn drive splines, dam aged ears, and for smoothness of
bearing contact surface. Replace if necessary.
2. If deflector requires replacement, remove by
tapping from flange, clean up stake points; install new
deflector, and stake deflector at three new equally spaced
positions.
NOTE: Staking operation must be perform ed in
J-22804-l
J-21057
Fig. 4B-26~Rem oving Nut from Drive Pinion
Fig. 4B-28--Pinion Oil Seal Installation
5. Using J-8614-11 as shown in figure 4B-29. install
flange onto pinion. Install washer and nut, and tighten
nut to original position. Refer to scribe marks and
num ber o f exposed threads, recorded earlier.
NOTE: Do not attempt to h a m m e r the flange onto
pinion shaft. To do so may dam age the ring gear
and pinion.
6. Measure rotating torque o f pinion and compare
with torque recorded before removal. Tighten pinion nut
in additional small increments until the torque necessary
to rotate the pinion exceeds the original figure by 1 to 5
inch pounds. Do not exceed the original torque by more
than 5 inch pounds.
7. Reattach propeller shaft and torque to specifi
cations. Reinstall brake drums and wheels.
Fig. 4B-27~Drive Pinion Flange Removal
such a m a n n e r that the seal operating surface is
not dam aged.
Installation
1. Lubricate cavity between the seal lips of the
pinion flange oil seal with a lithium-base extreme
pressure lubricant.
2. Position seal in bore and place gauge plate
J-22804-1 over seal an d against seal flange. The gauge
plate assures p rop er seating o f seal in carrier bore.
3. Use J-21057, as shown in figure 4B-28, to press
seal into carrier bore until gauge plate is flush with the
carrier shoulder and seal flange. Turn gauge plate 180°
from installed position; seal must be square in carrier
bore to seal properly against pinion flange.
4. Pack the cavity between end of pinion splines
and pinion flange with a non-hard en in g sealer (such as
P erm atex Type A or equivalent) prior to installing
w asher and nut on pinion.
CAUTION: See C A U T IO N on page 1 o f this
section regarding the fasteners referred to in
step 7.
8. Lower vehicle and remove from hoist.
CHEVROLET 10-1/2 RING GEAR
AXLES
AXLE ASSEMBLY
Service operations on these axle assemblies may be
perform ed with the housing installed in the vehicle or
with the housing installed in a holding fixture. There
m ay be occasions, however, when it will be necessary to
remove the complete housing assembly. The following
axle assembly removal and installation procedure,
therefore, is necessary only when housing replacement is
required.
C A U T IO N :/!// axle attachm ents are important
attaching parts. See CA U TIO N on page 1 o f
this section.
Removal
1. Raise vehicle, place stand jacks under fram e
side rails, and remove rear wheels.
2. Remove two trunnion bearing " U " bolts from
the re a r yoke, split rear universal joint, position propeller
shaft to one side, and tie it to the frame side rail.
N O T E: The bearings can be left on the trunnion
and held in place with tape.
3. Remove hub and drum assembly and disconnect
p ark in g brake cable at lever and at flange plate. See
Section 5 for cable removal.
4. Disconnect hydraulic brake hose at connector on
rear axle housing. Refer to Section 5.
5. Disconnect shock absorbers at axle brackets.
6. Support axle assembly with hydraulic jack,
remove spring " U " bolts, and lower axle assembly to the
floor.
Installation
1. Place axle assembly under vehicle, raise into
position, install spring " U " bolts, anchor plates and nuts,
and tighten securely.
2. Connect and secure shock absorbers to axle
brackets.
3. Connect brake hose at connector on rear axle
housing.
4. Connect parking brake cable at lever and flange
plate. Install hub and d ru m assembly. Bleed brake
hydraulic system and adjust p ark in g brake.
N O T E: Before reinstalling wheel hub and drum
assembly replace hub oil seal.
5. Reassemble the re a r universal joint, making
sure that " U " bolts are draw n up tight and locked
properly. Caution should be taken not to overtighten
" U " bolt nuts and cause bearing cups to become
distorted.
6. Install rear wheels, remove stand jacks, and
lower vehicle.
7. Test operation o f brakes and rear axle.
AXLE SHAFT
Replacement
1. Remove bolts that attach the axle shaft flange to
the wheel hub. See figure 4B-30.
2. Rap on flange with a soft-faced h a m m e r to
loosen shaft. G rip the rib on end o f flange with a p a ir of
locking pliers and twist to start shaft removal. Remove
shaft from axle tube.
3. Thoroughly clean both the axle shaft flange and
the end of the wheel hub.
NOTE: Any lubricant on these surfaces tends to
loosen axle shaft flange bolts.
4. Place a new gasket over the axle shaft and
position the axle shaft in the housing so that the shaft
splines enter the differential side gear. Position gasket so
that holes are in alignment and install flange-to-hub
attaching bolts. Torque bolts to specifications.
HUB AND D R U M ASSEMBLY—FIG. 4B-31
Removal
1. Remove axle shaft as outlined earlier.
2. Disengage tang o f retainer from slot or flat of
locknut, then remove locknut from housing tube, using
J-2222, as shown in figure 4B-32.
3. Disengage tang o f retainer from slot or flat of
adjusting nut and remove retainer from housing tube.
4. Use appropriate tool as specified in Step 2 to
remove adjusting nut from housing tube.
N OTE: Remove thrust washer from housing tube.
5. Pull hub and drum assembly straight off axle
housing.
6. Remove oil seal, and discard.
Bearing/Cup—Removal
I.
Use a h a m m e r and long drift to knock the inner
bearing, cup and oil seal from the hub assembly.
REAR AXLE
4 B -19
Fig. 4B 3 3 - Removing Outer Bearing and Cup
Inspection and Cleaning o f Bearings
1.
2.
3.
4.
5.
6.
7.
Axle Shaft
Shaft-to-Hub Bolt
Locknut
Locknut Retainer
Adjusting Nut
Thrust Washer
Hub Outer Bearing
8,
9.
10.
11.
12.
13.
14.
Snap Ring
Hub Inner Bearing
Oil Seal
Wheel Bolt
Hub Assembly
Drum Assembly
Gasket
Fig. 4B-31- Hub and Drum Assem bly—1 0 -1 /2 " Axles
1. Inspect bearing rollers for excessive wear,
chipped edges, and other damage. Slowly move rollers
around cone to detect any flat or rough spots on rollers
or cone.
2. Exam ine bearing cups in hub for pits, cracks,
and other damage.
3. Examine axle shaft flange studs, wheel studs,
hub splines, hub bore, and tapped holes for evidence of
dam age. Clean up threads or replace parts where
required.
4. Examine oil seal sleeve for evidence o f wear or
roughness, check axle housing oil deflector and brake
drum oil deflector for evidence o f damage. Replace parts
where required.
5. Examine brake drum for excessive scoring and
other damage. To replace brake drum refer to "Brake
D rum Replacement."
6. Immerse bearing cone and roller assemblies in
cleaning solvent. Clean with stiff brush to remove old
lubricant. Blow bearings dry with compressed air,
directing air stream across bearing. Do not spin bearings
while blowing them dry.
7. Thoroughly remove all lubricant from axle
housing tube and from inside the hub, wipe dry. Make
sure all particles o f gasket are removed from outer end
of hub, axle shaft, and hub cap.
8. Scrape old sealing com pound out of oil seal bore
in the hub.
Bearing/Cup—Installation
Fig. 4B-32--Removing Lock N u t—Typical
2.
pliers.
Remove outer bearing snap ring with a pair o f
3. W ith J-24426 on Handle J-8092, as shown in
figure 4B-33, drive outer bearing and cup from the hub
assembly.
1. Place outer bearing into hub.
2. Install cup o f outer bearing into hub by using
Handle J-8092 and J-8608, installed upside-down Be sure
J-8608 is upside down on driver handle, so that ch am fer
does not contact bearing cup.
3. Drive cup beyond the snap ring groove.
4. Using a pair o f pliers, install snap ring into its
groove.
5. Drive cup back against snap ring by using
J-24426, as shown in figure 4B-33.
6. To install inner bearing cup, use J-24427 on
Handle J-8092. Drive cup into place until it seats against
shoulder o f hub bore.
7. Install new oil seal with J-24428.
2. Make sure inner bearing, oil seal, axle housing
oil deflector, and in n er bearing race and oil seal are
properly positioned.
D rum —Non-Dem ountable-Type—Fig. 4B-31
4. Install thrust washer so that tang on l.D. of
washer is in keyway on axle housing.
Replacement
Construction of the nondem ountable-type hub and
drum assembly is such that replacement cannot be
accomplished with the hub assembly installed on the
vehicle.
1. Separate the drum and hub by removing the
drum -to-hub retaining bolts, hub stud nuts, or by
pressing out the wheel studs, as applicable.
2. Position brake drum to hub assembly, making
certain that all drain holes are in alignment.
3. Apply a light, even coating o f sealing compound
to the hub oil deflector contact surface, and position
deflector to drum.
4. Install drum -to-hub retaining bolts, hub stud
nuts, or press wheel studs into drum, as applicable.
W heel Bolt
Replacement
W heel bolts are serrated and may also be swaged in
place; however, replacem ent procedure rem ains the same
for both types o f installation.
Press bolts out o f hub flange and press new bolts
into place, m aking sure they are a tight fit. If all bolts
are removed, be sure that hub oil deflector is in position
u nder bolt heads. See figure 4B-34.
Installation of Hub and Drum Assembly
3. Install hub and drum assembly on axle housing,
exercising care so as not to dam age oil seal or dislocate
other internal components.
5. Install adjusting nut and complete the installa
tion as directed under "B earing Adjustm ent."
BEARING A D J U S T M E N T
Before checking bearing adjustment,
brakes are fully released and do not drag.
make
sure
Check bearing play by grasping tire at top and
pulling back and forth, or by using a pry b a r under tire.
If bearings are properly adjusted, movem ent of brake
drum in relation to brake flange plate will be barely
noticeable and wheel will turn freely. If movement is
excessive, adjust bearing as follows:
1. Remove axle shaft and raise vehicle until wheel
is free to rotate.
2. Disengage tang of retainer from locknut and
remove both locknut and retainer from axle housing
tube.
3. Using .1-2222, tighten in n e r adjusting nut to
specified torque at the same time rotating hub to make
sure all bearing surfaces are in contact. T h en back off
inner nut to specified am ount o f turn-back.
See figure 4B-35, and refer to Specifications Section
for torque values.
4. Install tanged re ta in e r against the in n e r
adjusting
nut. Align inner adjusting nut so short tang of
1.
U sin g a high m eltin g p oint F.P b ea rin g
retainer
will
engage nearest slot on inner adjusting nut.
lubricant, liberally pack bearings and apply a light coat
on l.D. o f hub bearin g contact surface and O.D. o f axle
5. Install outer locknut and tighten to correct
housing tube.
specified torque. Then bend long tang o f retainer into
REM OVAI
IN S T A L L A T IO N
slot o f outer nut. This method o f adjustment will result
in the pro per hearing adjustment.
VENT ASSEM BLY
DRIVE P IN IO N OIL SEAL
Replacement
N OTE: The pinion oil seal may he replaced with
the carrier assembly installed in the vehicle.
1. Disconnect propeller shaft.
2. Scribe a line down the pinion stem, pinion nut
and co m panion flange.
3. Use J-8614-11 to remove the pinion nut and the
c o m pa n io n flange.
4. Pry the oil seal from the bore, using care not to
d a m ag e the m achined surfaces. Thoroughly clean all
foreign m aterial from contact area.
5. Lubricate the cavity between the seal lips with a
high melting point bearing lubricant.
6. Install a new pinion oii seal into the bore, using
J-24434.
7. Reinstall the com panion flange, pinion nut and
propeller shaft.
T O B E IN S T A L L E D W IT H
F L A T S U R F A C E FA C IN G
C E N T E R L IN E O F REAR
A X LE D IF F E R E N T IA L
H O U S IN G .
CAUTION: See C A U T IO N on page 1 o f this
section, regarding the above fasteners.
DANA
1 0 -1 /2
DANA
R IN G
9 - 3 / 4 R IN G
AXLE
GEAR
Procedures for service to axle assembly, axle shafts,
hub and drum components and bearing adjustments are
identical to those listed for "C hevrolet 10-1/2 Ring G e a r
Axle".
Drive pinion oil seal replacem ent requires different
special tools for the D a n a axles. Follow the same
procedure listed for "C hevrolet 10-1/2" Ring G e a r
Axle"; use J-24384 for seal replacem ent on D ana 101/2" R ing G e a r Axles, and use J-22281 for pinion oil
seal replacem ent on D a n a 9 -3 /4 " Ring G e a r Axles.
12-1/4
R IN G
Fig. 4B-36--Typical Axle Vent Installation
G E A R AXLE
G EA R AXLE
AXLE SHAFT
Replacement
1. Remove hub cap, and install Tool J-8117 in
tapped hole on shaft flange.
2. Install slide ham m er, Tool J-2619, and remove
axle shaft.
3. Thoroughly remove old gasket material from
hub and hub cap. Clean shaft flange and mating
surfaces in the wheel hub.
4. Install axle shaft so that the flange splines index
into hub splines. T a p shaft into position, using J-8117
and J-2619.
5. Install new gasket, position flange to hub and
install attaching bolts. Torque bolts to specifications.
AXLE ASSEMBLY
H UB AND D R U M ASSEMBLY
T he axle assembly removal and installation is
identical to the procedure given earlier for "Chevrolet
10-1/2" Ring G e a r Axle".
Removal
AXLE V E N T
Use the procedure given for "Chevrolet 10-1/2"
Ring G e a r Axle", and use J-0870 to remove the adjusting
nut.
Replacement
Bearing Cup—Removal
Service replacem ent axle housing assemblies are not
equipped with an axle vent; therefore, always make sure
that a new vent assembly is installed when replacing the
housing. If axle vent requires replacement, pry old vent
from housing being sure th a t entire vent is removed.
Prick punch arou nd carrier hole to insure fit o f
replacem ent vent. T a p new vent into housing using a
soft-faced ham m er. Vent should be positioned in housing
so that flat surface is toward centerline o f differential
carrier. See figure 4B-36.
1. Cut a suitable length of 1/2 inch steel bar stock
for press-out tool.
2. Place bar stock tool behind inner bearing cup,
index tool in provided notches, and press out cup with an
a rbor press.
3. Use J-22380, as shown in figure 4B-37, to
remove outer bearing retainer ring.
4. Remove the outer bearing by driving on the
axle shaft spacer, using the splined flange cut from an
old axle shaft, as shown in figure 4B-38.
Inspection and Cleaning o f Bearings
Refer to procedures listed for "Chevrolet 10-1/2"
Ring G ear Axle.
Bearing Cup—Installation
1. To install outer bearing, place axle shaft spacer
in hub, followed by the outer bearing. The larger O.D. of
the bearing goes toward the outer end of the hub.
2. Position outer bearing cup in hub with the thin
edge o f the cup toward the outer end o f the hub.
3. Press the cup into the hub, using J-8114 and
Handle J-8092.
4. W ithdraw cup installer, then install retainer
ring, using J-22380 as shown in figure 4B-37. Press the
cup into contact with the retainer ring as shown in figure
4B-38.
NOTE: The bearing cup-to-retainer ring seating
procedure is essential to assure that an accurate
wheel bearing adjustment will be obtained, and
that the adjustment will not loosen during vehicle
operation.
5. To install inner bearing, use J-8093 with Handle
J-8092 to drive cup into hub bore, as shown in figure 4B39.
6. Install new oil seal, using J-22354 as shown in
figure 4B-40.
D R U M -D E M O U N T A B L E -T Y P E
Replacement
Fig. 4B -37-R em oving Hub Outer Bearing Retainer
Ring
The demountable-type drum m ay be separated from
the hub and removed from the vehicle without
disturbing the axle shaft and hub. The drum is held to
the hub by countersunk, slotted screws, which are easily
removed with a screw driver.
WHEEL BOLT REPLACEM ENT
Refer to figure 4B-34 and to procedure listed under
"Chevrolet 10-1/2" Ring G e a r Axle.
.....
___
Fig. 4B-41 Pinion Oil Seal—1 2 -1 /4 " Axle
Fig. 4B 4 0 --ln sta llin g Hub Oil Seal
IN S TA LLA TIO N OF HUB AND DRUM
ASSEMBLY
1. U sin g a high m elting po int EP bea rin g
lubricant, liberally pack bearings and apply a light coat
on I.D. o f hub bearing contact surface and O.D. of axle
housing tube.
2. M ake sure inner bearing, oil seal, axle housing
oil deflector, and inner bearing race and oil seal are
properly positioned.
3. Install hub and drum assembly on axle housing,
exercising care so as not to da m a g e oil seal or dislocate
other internal components.
4. Place outer bearing cone and roller assembly on
axle housing and press firmly into hub with hand.
5. Install adjusting nut and complete the installa
tion as directed under "B earing A djustment".
BEARING A D J U S T M E N T
Before checking bearing adjustment,
brakes are fully released and do not drag.
make
sure
Check bearing play by grasping tire at top and
pulling back an d forth, or by using a pry bar under tire.
If bearings are properly adjusted, movem ent o f brake
dru m in relation to brake flange plate will be barely
noticeable and wheel will turn freely. If movem ent is
excessive, adjust bearing as follows:
1. Remove axle shaft and raise vehicle until wheel
is free to rotate.
2. Disengage tang o f retainer from locknut and
remove both locknut and retainer from axle housing
tube.
3.
Use J-0870 to tighten inner adjusting nut at the
sam e time rotating hub to m ake sure all bearing surfaces
are in contact. Then back off in ner nut to specified
am ount o f turn-back Fig. 4B-35.
4. Install tan g e d r e ta in e r a ga inst the in n e r
adjusting nut. Align inner adjusting nut so short tang of
retainer will engage nearest slot on inner adjusting nut.
5. Install outer locknut and tighten to correct
specified torque. Then bend long tang o f retainer into
slot of outer nut. This method of adjustment will result
in the proper bearing adjustment.
DRIVE P IN IO N OIL SEAL
Replacement
NOTE: The pinion oil seal m ay be replaced with
the carrier assembly installed in the vehicle.
1. Disconnect propeller shaft.
2. Scribe a line down the pinion stem, pinion nut
and companion flange.
3. Use J - 8 6 14-11 to remove the pinion nut and the
com panion flange.
4. Remove the bolts retaining the oil seal retainer
to the carrier, and remove the retainer. See figure 4B-41.
5. Pry the oil seal from the bore, using care not to
dam ag e the m achined surfaces. Thoroughly clean all
foreign material from contact area.
6. Lubricate the cavity between the seal lips with a
high melting point bearing lubricant.
7. Install a new pinion oil seal into the bore, using
J-22281. Be sure seal bottoms against shoulder in bore.
8. Install the bearing retainer to the carrier.
9. Reinstall the com panion flange, pinion nut and
propeller shaft.
CAUTION: See C A U T IO N on page 1 o f this
section, regarding the above fasteners.
SPECIFICATIONS
c
>
S'
G e a r Backlash
P re fe rre d
00
.0 0 5 " .0 0 8 "
.0 0 5 " .0 0 8 "
.0 0 3 " .0 1 0 "
M in . a n d M a x .
Pinion B e a rin g
P re lo a d (In .-L b s.)
— N ew
—
00
Used
.0 0 3 " .0 1 0 "
O
— o>
.0 0 4 " .0 0 9 "
.0 0 4 " .0 0 9 "
O
c
□
a
IO V 2 "
0
O
.0 0 3 " .0 1 2 "
BOLT TO R Q U ES
(F T .-L B S .)A
.0 0 5 " .0 0 8 "
F ille r Plugs
.0 0 3 " .0 1 2 "
D iffe r e n tia l Pinion
Lock
5
00
1 5 -3 0
1 5 -3 0
2 0 -4 0
2 5 -3 5
5 -1 0
5 -1 0
1 0 -2 0
5 -1 5
18
20"#
20"#
2 05
A x le S h a ft To
H u b Bolts
D iffe r e n tia l
B e a rin g C aps
55
55
85
A E x c e p t w h e re n o te d o th e rw is e .
R in g G e a r S ize
k
CO
Dana
Dana
L u b ric a n t C a p a c ity
4 .2 Pints
2"
3 .5 Pints
C h e v ro le t
1O V
1O V
2"
9 3A
‘"
12V 4"
220
85
35
—
----
—
135
35
105
105
155
115
115
15
* T o r q u e as n e c e s s a ry to o b t a in c o rre c t p r e lo a d .
S V
*
165
135
110
*
65
Brack Backing P late
50
—
2"
CN
Pinion B e a rin g C a g e
To C a rrie r
105
80
10
O'
15
120
Ring G e a r
18
;
sS
rt'
20
Thrust Pad Lock N u t
30
10
O
—
D iffe r e n tia l B e a rin g
A d justin g Lock
—
35
00
>•
D iffe r e n tia l C a rrie r
to A x le Housing
BOLT T O R Q U ES (F T .-L B S .)A
20
*5
(Vs
25
Drive Pinion N u t
20
£
> i
CN
.0 0 5 " .0 0 8 "
C a rr ie r Cover
IO V 2 "
0
C h e v ro le t
C h e v ro le t
DIFFERENTIAL S P E C IF IC A TIO N S
5 .4 Pints
7 .2 Pints
6 .0 Pints
1 4 .0 Pints
SPECIAL TOOLS
£
U
1 i ^n A
—
II
J
‘“ i r * 5
ty g jv .
it
J ll
3
o
2
87/a"
4
7
8
R. G. A X L E O N L Y
9
«
10
k
{]
12
1i
IT
i f
15
16
22
O ,
0
19
20
«■
17
21
23
24
IO '/ j " R .G . AXLE O N L Y
i.
J- 21 5 48
T ru n n io n Seal In sta ller
16. J- 2 4430
2. J- 23 6 90
A x le S h a f t B e a rin g In sta lle r
17. J-23 3 22
P in io n S tra d d le B e arin g In staller
3.
J- 23 6 89
A x le S h a f t B e arin g R e m o v e r
18.
O u te r W h e el B e arin g C u p T o o l
4.
J-21 1 28
A x le S h a f t Se al In sta ller
19. J- 24 4 32
5.
J-21 0 57
P in io n O il Seal In sta ller
20.
6.
J-22804-1
P in io n Se a l G a u g e P late
21. J-86 0 8
J- 24 4 26
J-24427
D iffe re n tia l S id e B e a rin g In sta ller
P in io n R e a r B e a rin g C u p In s ta lle r
In n e r W h e e l B e arin g C u p In s ta lle r
O u te r W h e el Be arin g C u p In sta lle r
7.
J-5748
P o s itra c tio n T o r q u e M easuring A d a p te r
22.
J- 24 3 84
P in io n O il Se al In sta lle r - D ana
8.
J-6627
W h e e l B o lt R e m o v e r
23.
J-24 4 28
W h e e l H u b O il Seal In s ta lle r
9.
J-8092
D riv e r H a n d le
24.
J- 24 4 34
P in io n O il Se a l In sta lle r - C h e v ro le t
10.
J-58 5 3
T o rq u e W re n c h - In ch /P o u n d
25.
J-870
W h e e l Be aring N u t W re n c h
11.
J-8614-II
C o m p a n io n F la n g e H o ld e r
26.
J- 22 3 80
T ru - A rc Plie rs
12.
J-26 1 9
S lid e H a m m er
27.
J- 22 3 54
W h e e l O il Seal In staller
13.
J-22 2 2
W h e el Be arin g N u t W re n ch
28.
J-22281
P in io n O il Se a l In sta ller
14.
J- 24 4 29
A d ju stin g N u t W re n c h
29.
J-8114
W h e e l Be arin g O u te r C u p In sta lle r
15.
J- 24 4 33
P in io n R e a r B e arin g In sta lle r
30.
J-8093
W h e e l Be arin g In n e r C u p In sta lle r
SECTION 4C
FRONT WHEEL DRIVE
The following caution applies to one or more steps in the assembly
procedure o f components in this portion of the m anual as indicated at
a ppropriate locations by the terminology "See Caution on page 1 o f this
Section".
CAUTION: T H IS F A S T E N E R IS A N IM P O R T A N T A T T A C H IN G
P A R T IN T H A T I T C O U LD A F F E C T T H E P E R F O R M A N C E OF
V IT A L C O M P O N E N T S A N D S Y S T E M S , A N D /O R C O U LD R E S U L T
IN M A JO R R E P A IR E X P E N S E , I T M U S T B E R E P L A C E D W IT H
O N E O F T H E S A M E P A R T N U M B E R OR W IT H A N E Q U IV A L E N T
PA R T I F R E P LA C E M E N T B E C O M E S N E C E S S A R Y. DO N O T U SE A
R E P L A C E M E N T P A R T OF L E S S E R Q U A L IT Y OR S U B S T IT U T E
D I SIG N . T O R Q U E V A L U E S M U S T BE U SED A S SP E C IF IE D
D U R IN G R E A S S E M B L Y TO A S S U R E P R O P E R R E T E N T IO N OF
T H IS P A R T .
CONTENTS
G en eral Description......................................................................... .4C-1
D ia g n o s is ............................................................................................. .4C-2
F ro nt Axle A sse m b ly .......................................................................4C-5
R e m o v a l............................................................................................. .4C-5
Installation..........................................................................................4C-5
R epair Axle Joint C o m p o n e n ts .................................................. .4C-6
Specifications........................................................................................4C-6
GENERAL DESCRIPTION
T he front axle is a hypoid gear axle unit equipped
with steering knuckles. Axle assembly num ber and
production date are stam ped on left tube of assembly.
Conventional truck service brakes are provided on all
4-wheel drive units.
K 10-20 Models use the D a n a (44 Series) which
incorporates a 8 -1/2" ring gear. A new 4500 lb. capacity
unit is used on the K-30 Model. The K-30 axle assembly
is a D a n a (60 Series) which incorporates a 9 -3 /4 " ring
gear.
DIAGNOSIS
BEARINGS AND RACES
F R O N T W HEEL, P IN IO N , DIFFERENTIAL SIDE A N D
REAR W HEEL ROLLER B E A R IN G S
DIAGNOSIS
EXCESS NOISE C O M P L A IN T
D IA G N O S T IC PRO CEDURE
1.
2.
Road Test
3.
4.
5.
1.
2.
Tire Noises
Engine or
Exhaust
Noises
Test for
Wheel Bearing
Noise
Test for
Differential
Bearing Noise
3.
4.
5.
1.
2.
3.
4.
1.
2.
3.
4.
1.
2.
3.
4.
1.
2.
Test for
Pinion Bearing
Noise
3.
4.
5.
6.
7.
Check tires for irregular wear
Check tire pressure
Check lubricant level
Drive to warm-up rear axle
Test at various speeds in drive, float, coast and cornering
Change tire pressure to minimize noises
Drive over different road surfaces
Smooth black-top minimizes tire noise
Cross switch tires, if necessary
Snow tire treads and studs caused added noises
Drive slightly above speed where noise occurs, place transmission in neutral
Let engine speed drop to idle
Stop car
Run engine at various speeds
Drive car at low speed on a smooth road
Turn car to develop left and right motions, traffic permitting
Noise should change due to cornering loads
Jack-up wheels to verify roughness at wheels
Drive car at low speed on a smooth road
Constant low pitch bearing noise may be heard
Noise should not change in reversing turns
Noise pattern should vary with wheel speed
Roughness or whine noise should increase with speed
Noise pitch should be higher than differentials
Test on smooth road to minimize tire noises
Test at various speeds in drive, float, and coast
Rear pinion bearing noise may be louder on acceleration
Front pinion bearing noise may be louder on deceleration
Gear noises tend to peak in a narrow speed range
FRONT WHEEL BEARING DIAGNOSIS
CONSIDER THE FOLLOWING FACTORS WHEN DIAGNOSING BEARING CO NDITION
1. GENERAL CO ND ITIO N OF ALL PARTS DURIN G DISASSEMBLY AND INSPECTION
2
CLASSIFY THE FAILURE WITH THE A ID OF THE ILLUSTRATIONS
3
DETERM INE THE CAUSE
4
MAKE ALL REPAIRS FOLLOW ING RECOMMENDED PROCEDURES
M il *
iiy t
A B RAS I VE
ROLLER
WE A R
%—ft
ill 'fI- \\
mm
_______
=
3
GALLING
BENT
CAGE
PATTERN ON RACES AN D ROLLERS CAUSED BY
FINE ABRASIVES.
METAL SMEARS ON ROLLER ENDS DUE TO O VERHEAT,
LUBRICANT FAILU R E OR O VERLO AD (WAGON S)
CAGE DAMAGE DUE TO IMPROPER HA N D LIN G
OR TOOL USAGE.
CLEAN ALL PARTS AN D HOUSINGS. CHECK SEALS
REPLACE BEARING
REPLACE BEARING
CHECK SEALS AND CHECK
OR NOISY.
'} <
—
ABRASI VE
I
£ = 3
STEP W E A R
PATTERN ON ROLLER ENDS CAUSED BY
FINE ABRASIVES.
CLEAN ALL PARTS AND HOUSINGS. CHECK SEALS
AND BEARINGS AND REPLACE IF LEA K IN G . ROUGH
OR NOISY
m i i
d iiifa
INDENTATIONS
SURFACE DEPRESSIONS ON RACE AND ROLLERS
CAUSED BY HARD PARTICLES OF FOREIGN M A TER IAL.
m
i
ETCHING
BEARING SURFACES APPEAR GRAY OR GRAYISH
BLACK IN COLOR W ITH R ELATED ETCHING AWAY
OF M ATERIAL USUALLY AT ROLLER SPACING
l
—
BENT
y.
.—
■
CAGE
CAGE DAMAGE DUE TO IMPROPER HA N DLING
OR TOOL USAGE
REPLACE BEARING
REPLACE BEARINGS CHECK SEALS AND CHECK
FOR PROPER LUBRIC ATION.
Mi I fe
CAGE
WEAR
WEAR A ROUND OUTSIDE DIAM ETER OF CAGE AND
ROLLER POCKETS CAUSED BY ABRASIVE M ATERIAL
AND IN E F F IC IE N T LUB RICATIO N
CLEAN ALL PARTS A ND HOUSINGS. CHECK SEALS
n il a
M im
M ISALIG NM ENT
OUTER RACE M ISALIG N M ENT DUE TO FOREIGN
OBJECT.
CLEAN RELATED PARTS AND REPLACE BEARING
CHECK SEALS AND REPLACE BEARINGS.
FRONT W HEEL BEA RIN G D IA G N O S IS
(C O N T’D)
H ll A
CRACKED INNER
RACE
F AT I GUE
SPALLING
RACE CRAC K ED DUE TO IMPROPER F IT ,
C OCKING. OR POOR B E A RING SEATS.
F L A K IN G OF SURFACE M ETA L R ESULTING FROM
FA TIG U E.
REPLACE BEA R IN G A N D CORRECT BEARING
SEATS.
REPLACE B EA R IN G
BRI NELLI NG
SURFACE IN D E N TA T IO N S IN RACEW AY CAUSED BY
ROLLERS EITH ER UNDER IM PACT LO A D IN G OR
V IB R A T IO N W HILE THE B EARING IS NOT R O TA TIN G .
C LEAN ALL R E L A T E D PARTS.
REPLACE BEARING IF ROUGH OR NOISY.
HUM
m a tk \
mm
FRETTAGE
CORROSION SET UP BY SM ALL R E L A T IV E
M O V E M E N T OF PARTS W ITH NO LU B R IC A TIO N .
REPLACE B E A R IN G . C L E A N R ELA TE D PARTS.
CHECK SEALS AN D CHECK FOR PROPER LU B R IC A TIO N .
ST AI N
D I SC O L O R A T I O N
Iflllfi
HEAT
D I SCO L ORAT I O N
D ISC O LO R A TIO N CAN RANGE FROM L IG H T BROWN
TO BLACK CAUSED BY IN CORRECT LU B R IC A N T OR
MOISTURE.
HEAT D ISCO LO RATIO N CAN RANGE FROM FA IN T
YELLO W TO DAR K BLUE R ESU LTING FROM OVER
LOAD (WAGON'S) OR IN CORR ECT LUBR ICANT.
RE USE B EAR ING S IF STAINS CAN BE R EM O VED BY
LIG H T PO LISH IN G OR IF NO EVIDENCE OF OVER
H E A TIN G IS OBSERVED.
EXCESSIVE HEAT CAN CAUSE SO FTENING OF RACES
OR ROLLERS.
CHECK SEALS A ND R ELA TE D PARTS FOR DAM AGE.
TO CHECK FOR LOSS OF TEMPER ON RACES OR
ROLLERS A SIMPLE FILE TEST M A Y BE M ADE. A
FILE DRAWN OVER A TEM PERED PART W ILL GRAB
AMn P
IIT1 IVtt
U C T1A
A C
AUUM rt\/C
A
AIMU
i_U
A IL, lAfUCDC
W M tn tAAC
o, A
MIIL C
t HQ
UrlAWIM
U V t nD A
H A R D PART W IL L G LID E R E A D IL Y W ITH NO M ETA L
C U TTIN G .
REPLACE BEAR INGS IF O VER H E A TIN G DAMAGE IS
IN D IC A T E D . CHECK SEALS A N D OTHER PARTS.
SMEARS
SM EARING OF M E T A L DUE TO SLIPPAGE.
SLIPPAGE CA N BE C A U SED BY POOR FITS.
L U B R IC A T IO N , O V E R H E A T IN G , O VER LO A D S
OR H A N D L IN G D A M A G E.
REPLACE B EA R IN GS, C LE A N R E L A T E D PARTS
AND CHECK FOR PROPER FITS AND
LU B R IC A TIO N
Fig. 4C -4-F ront Drive Axle Typical
F R O N T AXLE ASSEMBLY (Refer to Fig. 4C4)
Removal
1. Disconnect propeller shaft from front axle
differential.
2. Raise front o f vehicle on hoist until weight is
removed from front springs. Support truck with jack
stands behind front springs.
3. Disconnect connecting rod from steering arm.
4. Disconnect brake hoses from fram e fittings and
cap al! fitting ends or cover with a rag to prevent
contam ination.
5. Disconnect shock absorbers from axle brackets.
6. Disconnect axle vent tube clip at the differential
housing (see fig. 4C-5).
7. D ism ount " U " bolts from axle to separate axle
from truck springs.
8. Raise truck to clear axle assembly and roll front
axle out from under the truck.
Installation
CAUTION: See C A U T IO N on page I o f this
section regarding the fasteners referred to in
steps 3, 5, 6 and 8.
1. Truck should be on jack stands as in Step 2 o f
removal instructions.
2. Place axle in position under truck.
3. Install " U " bolts attaching axle to front springs.
4. Attach shock absorbers to axle brackets.
5. Connect brake hoses to fram e fittings bleed the
brake system (see Section 5).
6. Attach connecting rod to steering arm.
7. Remove jack stands and lower front o f truck.
8. Assemble pro peller s h a ft to fro n t axle
differential.
9. Lower vehicle to floor.
Disassembly
Refer to Seection 3B for hub, spindle and knuckle
removal and installation procedures.
2. If the vehicle is not equipped with RPO F76
freewheeling hubs, remove the hub cap and snap ring.
3. Remove the drive gear and pressure spring.
Place a hand over the drive gear and use a screwdriver to
pry the gear out.
4. Remove the wheel bearing outer lock nut, lock
ring, and wheel bearing inner adjusting as outlined in
Section 3B.
5. Remove the disc assembly outer wheel bearing
and the spring retainer plate.
NOTE: If the disc or other brake components
require repairs or replacement, refer to Section 5.
Repair The Axle Joint Components:
1. Remove the lock rings after removing pressure
from the trunnion bearings by squeezing the ends o f the
bearing in a vise.
2. Support the shaft yoke in a bench vise or on a
short length o f pipe.
3. Using a brass drift and a soft h am m er, drive on
end o f one trunnion bearing just far enough to drive
opposite bearing from yoke.
4. Support the other side o f the yoke in the vise
and drive the other bearing out by tapping on the end of
the trunnion using a brass drift.
5. Remove trunnion.
6. Clean and inspect bearings. Lubricate with a
high melting point type wheel bearing grease.
7. Replace trunnion and press new or relubricated
bearings
into yoke and over trunnion hubs fa r enough to
Fig. 4C-5--Axle Vent Hose Routing Typical
install lock rings.
8. Hold trunnion in one hand and tap yoke lightly
1.
Securely m ount the axle assembly in a suitable
to seat bearings against lock rings.
holding fixture.
Assembly
Reverse disassembly procedure.
SPECIFICATIONS
FOUR W HEEL DRIVE
Bolt Torques
(Ft.-Lbs.)
A x le
G e a r Backlash P re fe rre d
M in . a n d M a x .
N e w Pinion B e a rin g P re lo a d
Used Pinion B e a rin g P re lo a d
. 0 0 4 " -. 0 0 9 "
.0 0 4 " -. 0 0 9 "
2 0 -4 0 in .-lb s .
1 0 -2 0 in .-lb s .
C a rrie r Cover
Ring G e a r
D iffe r e n tia l B e a rin g Caps
F ille r Plugs
Drive Pinion N u t
B rake — Backing P la te —
B rake — Backing P la te —
A x le S h a ft to H u b Bolts —
A x le S h a ft to H u b Bolts —
K 10, K20
K30
K 10, K20
K30
35
110
85
10
255
35
105
60
90
SECTION 5
BRAKES
The following w arning and caution notes apply to one or more steps in
the assembly procedure o f components in this portion o f the m anual as
indicated at appropriate locations by the terminology "See W a r n in g /
Caution on page l o f this section".
Warning: When servicing wheel brake parts, do not create dust by
grinding or sanding brake linings or by cleaning wheel brake parts with
a dry brush or with compressed air. (A water dampened cloth should be
used.) Many wheel brake parts contain asbestos fibers which can
become airborne if dust is created during servicing. Breathing dust
containing asbestos fibers may cause serious bodily harm."
CAUTION: T H IS F A S T E N E R I S A N IM P O R T A N T A T T A C H IN G
P A R T IN T H A T I T C O U L D A F F E C T T H E P E R F O R M A N C E O F
V IT A L C O M P O N E N T S A N D S Y S T E M S A N D / O R C O U L D R E S U L T
IN M A JO R R E P A IR E X P E N S E . I T M U S T B E R E P L A C E D W IT H
O N E O F T H E S A M E P A R T N U M B E R OR W IT H A N E Q U IV A L E N T
P A R T I F R E P L A C E M E N T B E C O M E S N E C E S S A R Y. D O N O T U S E A
R E P L A C E M E N T P A R T O F L E S S E R Q U A L IT Y O R S U B S T IT U T E
D E S IG N . T O R Q U E V A L U E S M U S T B E U S E D A S S P E C I F I E D
D U R IN G R E A S S E M B L Y TO A S S U R E P R O P E R R E T E N T IO N O F
T H IS PA RT.
CONTENTS
G eneral D e s c rip tio n ..............................................................5 _]
D ia g n o s is ................................................................................. ..S-2
On-Vehicle Service................................................................... ..5 _l 0
Pedal T r a v e l .........................................................................5 _l 0
Stop Light Sw itch..............................................................5-10
Bleeding and Flushing B r a k e s ................................... ..5-]0
Brake P ipes...........................................................................5-10
Brake Hoses..........................................................................5 - 14
Bleeding Hydro-Boost Power Steering S ystem ..... ..5 - 15
Parking Brake Pedal or H a n d l e ................................ ..5 - 15
Parking Brake A d ju s tm e n t.............................................5-15
Parking Brake (Propshaft) Internal Expanding... 5-22
Parking Brake C a b le .........................................................5-22
C om bination V alue............................................................5-22
Brake P e d a l ....................................................................... ..5-23
Brake Pedal R o d .............................................................. ..5-24
M aster C ylinder................................................................ ..5-24
Delco Disc Brake Shoe and L in i n g ..................... 5-26
Bendix Disc Brake Shoe and L in in g ................... 5 -3 1
Caliper O verh au l...........................................................5-33
Rotor Servicing.............................................................. 5-36
Brake D rum Shoe and L in in g ................................ 5-37
Standard Drum B ra k e ............................................5-37
Propeller S haft B ra k e.............................................5-40
RPO H22 R ear D rum Brakes.............................5 -4 1
Brake D r u m s .................................................................. 5-43
Wheel C y lin d e r ............................................................. 5-44
Power Brake U n i t .........................................................5-44
Vacuum Booster........................................................ 5-44
Hydro-Boost U n i t ..................................................... 5-45
Specifications...................................................................... 5-47
Brake System D escription..........................................5-47
Brake System Application..........................................5-48
Torque Specifications................................................. 5-52
Special T o o ls...................................................................... 5-53
GENERAL DESCRIPTION
All vehicles are equipped with a dual hydraulic
brake system.
The split system consists basically o f two separate
brake systems. W hen a failure is encountered on either,
the other is adequate to stop the vehicle. If one system is
not functioning, it is normal for the brake pedal lash
and pedal effort to substantially increase. This occurs
because o f the design o f the master cylinder which
incorporates an actuating piston for each system. W hen
the rear system loses fluid, its piston will bottom against
the front piston. W hen the front system loses fluid, its
piston will bottom on the end o f the master cylinder
body. The pressure differential in one o f the systems
causes an uneven hydraulic pressure balance between the
front and rear systems. The combination valve (near the
master cylinder) detects the loss o f pressure and
illuminates the brake alarm indicator light on the
instrument panel. The pressure loss is felt at the brake
pedal by an ap parent lack o f brakes for most of the
brake travel and then, w hen failed ch am b er is bottomed,
the pedal will harden.
If a vehicle displays these symptoms, it is a good
indication that one o f the systems contains air or has
failed, an d it is necessary to bleed or repair the brakes.
M A S TE R CYLINDER
The system is designed with a separate hydraulic
system for the front and rear brakes using a dual master
cylinder. The cylinder has two separate reservoirs and
outlets in a co m m o n body casting.
if a failure should occur, and turns " o n " a red light in
the dash to w arn the operator of the failure.
DISC BRAKES FRO NT
All models have disc brakes on the front. The one
piece caliper mounts on the steering knuckle/steering
arm, which is also a one piece casting, an d astride the
brake disc. The caliper is the single piston design which
is said to be a sliding caliper sliding piston. N o front
brake adjustment is necessary once the system is in
operation and the pedal has been stroked to "s ea t" the
shoes to the caliper.
DISC BRAKES REAR (JF9)
C O M B IN A T IO N VALVE
All models have a com bination valve. The front and
rear hydraulic lines are routed through this com bination
" m e te rin g " and "b ra k e failure w arning switch" to their
a pp rop riate wheel cylinders or caliper.
The m etering portion of the com bination valve
tends to "hold off" front hydraulic pressure until the rear
brake system overcomes the pull back springs; then
pressure is allowed to flow with the result being a good
distribution of braking effort.
T he brake failure w arning switch portion o f the
c o m bination valve "senses" a loss o f hydraulic pressure,
R ear disc brakes operate in the same m an ner as
front disc brakes except the caliper is mounted to a
support attached to the axle flange.
D RU M BRAKES REAR
The rear brakes are duo servo and self adjusting.
Brake adjustment takes place w hen the brakes are
applied with a firm pedal effort while the vehicle is
backing up. Applying the brakes moves the actuator
which turns the star wheel and lengthens the adjuster
screw assembly. This action moves the shoes outward
until clearance between the lining and drum is within
proper limits.
DIAGNOSIS
IN S P E C T IO N AND TE S TIN G BRAKES
Testing Brakes
CAUTION: New linings m ust be protected fro m
severe use f o r several hundred miles.
Brakes should be tested on dry, clean, reasonably
smooth and level roadway. A true test o f brake
perform an ce cann ot be m ade if roadway is wet, greasy
o r covered with loose dirt so that all tires do not grip the
road equally. Testing will also be adversely affected if
roadw ay is crowned so as to throw weight o f vehicle
toward wheels on one side or if roadway is so rough that
wheels tend to bounce.
Test brakes at different vehicle speeds with both
light and heavy pedal pressure; however, avoid locking
the wheels and sliding the tires on roadway. Locked
wheels and sliding tires do not indicate brake efficiency
since heavily braked but turning wheels will stop vehicle
in less distance than locked wheels. More tire-to-road
friction is present with a heavily braked turning tire than
with a sliding tire.
External Conditions that Affect Brake Performance
1. Tires--Tires having unequal contact and grip on
road will cause unequal braking. Tires must be equally
inflated and tread p attern o f right and left tires must be
approximately equal.
2. Vehicle Loading--When vehicle has unequal
loading, the most heavily loaded wheels require more
braking power than others. A heavily loaded vehicle
requires more braking effort.
3. Front Wheel Bearings-A loose front wheel
bearing permits the drum to tilt and have spotty contact
with the brake shoe linings causing erratic action.
4. Front End A lignment-M isalignm ent o f the front
end, particularly in regard to limits on cam ber and
theoretical king pin inclination, will cause the brakes to
pull to one side.
C O N D IT IO N
Pulls
POSSIBLE CAUSE
1. Incorrect tire pressures.
CO R R E C TIO N
1. In fla te evenly on both sides to
the recom m ended pressures.
2.
Front e n d out o f lin e .
2. C heck a n d a lig n to m an ufactu rer's
sp ecification s.
3. U n m atch ed tires on same
3 . Tires with a p p ro x im a te ly the
a x le .
same am o un t of tre a d should
For r a d ia l tire le a d
b e used on the same a x le .
re fe r to Section 3E.
4.
Restricted b ra k e pipes
4 . C heck fo r solf hoses and
or hoses.
d a m a g e d lines. R eplace w ith
new hoses a n d new d o u b le
w a lle d steel b ra k e tu b in g .
5. M a lfu n c tio n in g c a lip e r
5 . Check fo r stuck or sluggish
pistons, p ro p e r lu b ric a tio n .
assem bly.
Remove a n d re b u ild c a lip e r.
6.
D efective or d a m a g e d
shoe a n d lin in g (g rea s e
6.
Install new shoe a n d linin g
in com plete a x le sets.
or b ra k e flu id on
lin in g or b en t shoe).
7. M a lfu n c tio n in g re a r
b rakes.
7 . Check fo r in o p e ra tiv e auto
a d ju s tin g m echanism , d efe c tiv e
lin in g (g rea s e or b ra k e
flu id on lin in g ) or
d efe c tiv e w h eel cylinders.
R e p a ir as necessary.
8.
Loose suspension parts.
8. Check a n d to rq u e a ll
suspension mountings to
specifications.
9.
Loose c a lip e rs .
9 . Check a n d to rq u e bolts to
sp ecification s.
N o ise (h ig h p itched squ eak
1. Front linin gs w orn out.
1. R eplace linin gs.
1. Excessive la te r a l runout.
1. Check p e r instructions a n d
w ith o u t b ra k e a p p lie d ) .
B rake roughness o r c h a tte r
(P e d a l Pulsates)
re p la c e or m achine rotor,
if not w ith in specifications.
2.
P a ra lle lis m not w ithin
specifications.
2 . Check p er instructions a n d
re p la c e or m ach ine the rotor,
if not w ith in specifications.
3. W h e e l B earin gs not
a d ju s te d .
4.
R ear drums out o f ro und.
3 . A djust w h e e l b e a rin g s to
correct specifications.
4 . C heck runout a n d , if not
w ith in specification s, turn
the drums (no t over
maxim um o f 0 .0 6 0 on the
d ia m e te r).
C O N D IT IO N
B rake roughness o r c h a tte r
(P e d a l Pulsates) —
POSSIBLE CAUSE
5. Shoe reversed (steel
C o n tin u e d
CO R R E C TIO N
5 . R eplace shoe a n d lin in g a n d
a g a in s t iro n).
m achine ro tor w ith in
s p ecification s.
Excessive P e d a l E ffort
1. M a lfu n c tio n in g pow er
1. Check p ow er b ra k e a n d r e p a ir
b ra ke.
2.
P a rtia l system f a ilu r e .
if necessary.
2. C heck fro n t a n d re a r b ra k e
system a n d re p a ir, if
necessary. A lso, check
a n d re p a ir b ra k e w a rn in g
lig h t circuit if a f a ile d
system is fo u n d a n d lig h t
d id not fun ctio n.
3. Excessively worn shoe
3 . C heck a n d re p la c e in a x le
a n d lin in g .
4.
Piston in c a lip e r stuck
sets.
4.
Remove c a lip e r a n d re b u ild .
o r sluggish.
5. F a d in g b ra k e s d u e to
incorrect lin in g .
5 . Remove a n d re p la c e with
o rig in a l e q u ip m e n t lin in g
(or e q u iv a le n t).
Excessive P e d a l Travel
1. P a rtia l b ra k e system
f a ilu r e .
1. C heck both fro n t a n d re a r
system fo r a fa ilu r e a n d
re p a ir. Also check a n d
r e p a ir w a rn in g lig h t circuit.
It should h ave in d ic a te d
a fa ilu r e .
2. In s u ffic ie n t flu id in
m aster c y lin d e r.
2 . Fill reservoirs with
a p p ro v e d b ra k e flu id . Check
fo r leaks. Check w a rn in g
lig h t.
3. A ir tra p p e d in system.
3 . B leed system.
4.
4 . A djust re a r b rakes a n d
R e a r b ra k e not a d ju s tin g .
r e p a ir auto adjusters.
5.
B ent shoe a n d lin in g .
5 . R eplace a x le set o f shoe
a n d lin in g .
D ra g g in g Brakes
1. M a s te r c y lin d e r pistons
1. W ith reservoir cover o ff,
(A very lig h t d ra g is
not re tu rn in g
check fo r flu id spurt
p resent in a ll disc
correctly.
a t bypass holes as p e d a l
b rakes im m e d ia te ly a fte r
is dep ressed. Adjust push
p e d a l is re le a s e d .)
ro d , if necessary, or
re b u ild m aster c y lin d er.
2.
Restricted b ra k e pipes
or hoses.
2. C heck fo r soft hoses or
d a m a g e d pipes a n d re p la c e
w ith new hoses a n d new
d o u b le -w a lle d steel
b ra k e tu b in g .
C O N D IT IO N
POSSIBLE CAUSE
3.
D ra g g in g Brakes
(A very lig h t d ra y is
p resent in a ll disc
b rakes im m e d ia te ly a fte r
p e d a l is re le a s e d .) —
G ra b b in g or Uneven
Incorrect p a rk in g b ra k e
a d ju s tm e n t on re a r b rakes.
4 . Check va lve in s ta lle d in
C o n tin u e d
3 . Check a n d re a d ju s t to
correct specifications.
4 . C heck m aster c y lin d e r o u tlet
o u tle t to fro n t disc
a n d rem ove check valve if
b rakes.
present.
1. A ll conditions listed
B rak in g Action
CO R R E C TIO N
u n d er "PULLS".
2. M a lfu n c tio n of com bin atio n
1. A ll corrections listed
u n d e r "PULLS".
2. R eplace a n d b le e d system.
v alve.
3 . M a lfu n c tio n o f pow er
b ra k e unit.
4.
B in d in g b ra k e p e d a l
mechanism.
3 . Check o p e ra tio n a n d
r e p a ir, if necessary.
4 . C heck a n d lu b ric a te , if
necessary. Possibly re p la c e
p e d a l bushing a n d /o r
spacer.
Pulsation (roughness)
1. Uneven p a d w e a r caused
Felt d u rin g norm al
by c a lip e r not slidin g
b ra k e a p p lic a tio n .
d u e to im p ro p e r c le a r
1. Remove c a lip e r a n d correct
as necessary.
ance or d irt.
2.
Uneven rotor w e a r
causing a thickness
2 . M a c h in e rotors as follow s:
a . M a c h in e rotors to o b ta in a
v a ria tio n b etw e e n the
c irc u m fe re n tia l thickness v a ria tio n no
two b ra k in g surfaces.
g re a te r th a n .0 0 0 5 " in 3 6 0 ° a n d a
la te r a l runout no g re a te r th a n .0 0 4 "
(m ax. ra te o f c h a n g e not exceed .0 0 1 "
in 3 0 °).
b. C heck c a lip e r freeness. W ith rotor
rem oved, install c a lip e r a n d m ounting
bolts (pins). C heck f o r
.0 0 5 " -.0 1 2 "
c le a ra n c e a t both top a n d bottom o f
c a lip e r. If less than .0 0 5 " is fo u n d , f ile
w ith a f l a t f ile until a t least .0 0 5 " is
o b ta in e d . DO N O T EXCEED A
M A X IM U M of .0 1 2 " p e r end or .0 2 4 "
to ta l c le a ra n c e . C a lip e r c le a ra n c e to
in b o a rd a n d o u tb o a rd reactio n pads
must b e e q u a l w ithin .0 0 4 " both a t the
top a n d bottom o f the c a lip e r. This is to
ensure correct a lig n m e n t of c a lip e r to
knuckle d u rin g a b ra k e a p p lic a tio n .
c. Remove c a lip e r a fte r freeness check.
C le a n pins a n d sleeves, re p la c e " O "
rings, a n d a p p ly o lig h t c o a tin g o f
silicone g re a s e or e q u iv a le n t to a ll
contact points a n d " O " rings.
\
\
\
\
\
•% \
\■ y \
L e a k in g B ra ke L in e o r C o n n e c tio n
X
XX
L e a kin g W h e el C y lin d e r o r P is to n Seal
X
XX
L e a kin g M a s te r C y lin d e r
X
XX
A ir
In B ra ke S ystem
o
\
\
\
\
\
\
\
\
\
\
\
tfc
\
\
J
s.
\
\
\
%
\
%
\
s, \
% \
\
v
X
X
XX
X
X
X
XX
X
X
C o n ta m in a te d o r Im p ro p e r B ra ke F lu id
XX
L e a k in g V a c u u m S ystem
X
XX
X
X
X
R e s tric te d A ir Passage
in P ow er Head
X
XX
X
Damaged P ow er Head
X
X
X
X
X
I m p ro p e rly A ssem bled
P ow er Head V a lv in c
X
X
X
X
XX
W o rn O u t B ra ke L in in g - Replace
X
X
X
X
X
X
X
X
X
X
X
X
X
XX
X
X
X
U n e v e n B ra ke L in in g W e a r Replace a n d C o rre c t
X
XX
G lazed B ra ke L in in g
In c o r r e c t L in in g M a te r ia l - Replace
X
X
X
X
X
X
X
XX
XX
XX
X
X
X
XX
X
X
X
X
XX
XX
XX
X
X
X
C o n ta m in a te d B rake L in in g - Replace
L in in g s Damaged by
A b u s iv e Use - Replace
Fxce ssive R^ake L in in g D u s t
Heat S potted o r S cored
B ra ke D ru m s o r R o tors
O u t-o f-R o u n d o r V ib r a tin g
B ra ke D ru m s
X
X
X
X
X
X
X
X
XX
X
X
X
XX
X
XX
O u t - o f - P a r a lle l B ra ke R o tors
X
X
X
X
X
XX
X
X
X
X
X
X
X
X
X
X
XX
X
X
X
X
X
X
X
X
X
X
G u id e L u b r ic a n t
R e s tric te d B ra ke F lu id Passage o r
S tic k in q W h e el C v lin d e r P is to n
F a u lty M e te r in g V alve
X
X
X
X
B ra ke Pedal Linka g e
X
X
X
In te r fe r e n c e o r B in d in q
X
X
X
X
XX
XX
X
X
X
X
XX
X
X
X
lo o s e F ro n t S u s p e n s io n A tta c h m e n ts
X
O u t-o f-B a la n c e W h e el A sse m b lie s
X
X
XX
X
X
XX
X
X
X
X
X
X
_ p s l l i i , , '# P l i K . i ! '
F a u lty P ro p o rtio n in g V a lv e
In d ic a te s m o re p ro b a b le c a u s e (s )
XX
XX
In c o r r e c t T ire P re s s u re
XX -
X
XX
In c o r r e c t F ro n t End A lig n m e n t
Im p ro p e rly A d ju s te d M aster
C v lin d e r Push R od
S tic k in g W h eel C y lin d e r or
XX
X
D ru m s Tapered o r Threaded
O p e ra to r R id in g B ra ke Pedal
X
X
Im p ro p e rly A d ju s te d P a r k in g B ra ke
In c o r r e c t W h e e l B e a rin g A d ju s tm e n t
X
X
I n c o r r e c t W h e el C y lin d e r S ize s
Weak o r I n c o r r e c t Brake
S h o e R e te n tio n S o rin a s
B ra ke A s se m b ly A tta c h m e n ts M is s in g o r Loose
I n s u f f ic ie n t B ra ke Shoe
X
XX
Excessive R o to r R u n - O u t
F a u lty A u to m a tic A d ju s te rs
\
X
X -
In d ic a te s ca use s
X
X
XX
X
X
X
X
X
X
X
X
X
DIAGNOSIS - HYDRO - BOOST SYSTEM
N O TE: B efore checking the hydraulic p o w e r booster for the source o f trouble, refer
to the trouble diagnosis procedures fo r Standard Brakes. A fte r these possible causes have
been elim inated, ch eck fo r the probable cause and rem edy as o u tlin ed below:
Norm al O p erating Characteristics
Brake pedal application o f the H ydro-boost system
differs in som e respects from a vacuum type pow er
brake system in th e follow ing m anner:
1. On pedal application u n til b o o ster run-out,
slight pow er steering pum p noise m ay be
heard.
2. Pedal application through run-out will n o t
necessarily be sm ooth due to th e internal
ratio change, i t is possible to push the pedal
past run-out because o f th e higher pedal ratio.
A t run-out o f the vacuum booster the pedal
ju st becom es hard.
N O BOOST -
3. On the first full application o f th e brake pedal,
a slight hissing sound m ay be heard. T he hiss
is the accum ulator charging and the noise should
go away in a sh o rt period o f time.
4. On a spike brake application, a slight pedal
kick-back may be felt.
5. If the vehicle is started w ith the pedal de
pressed, the pedal will fall away slightly then
return back to approxim ately the original
position.
H ARD PEDAL
P relim inary Check
W ith the engine stopped, depress the brake pedal several times to eliminate all accumulator reserve
from the system.
Hold the brake pedal depressed with medium pressure (25 to 35 lbs.), start the engine. If the unit is
operating correctly, the brake pedal will fall slightly and then push back against the driver's foot,
remaining at about the same position. If the booster is not operating correctly, the trouble may be one
of the following causes:
P ro b a b le C ause
R em ed y
1.
Lo o se o r b r o k e n power s t e e r i n g
pump bel t .
1.
T ig h te n o r re p la c e
2.
No f l u i d
2.
F i l l r e s e r v o i r and c h e c k f o r
external le a k s.
3.
L e a k s i n power s t e e r i n g ,
a ccu m u lator h o se s.
3.
Rep lace d e f e c t i v e p a r t s .
4.
L e a k s a t t u b e f i t t i n g s , power s t e e r i n g ,
b o o ste r or accu m u la to r c o n n e c tio n s .
4.
T ig h te n f i t t i n g s o r r e p la c e
s e a ts , i f d e fe c tiv e .
5.
Exte rn al
5.
Rep lace
6.
F a u lt y b o o ste r p is t o n s e a l ca u sin g
le a k a g e a t b o o ste r f la n g e v e n t .
6.
R e p la ce a l l
booster s e a ls .
7.
F a u l t y b o o s t e r i n p u t rod s e a l w i t h
l e a k a g e a t i n p u t ro d en d.
7.
R e p la ce a l l
booster s e a ls .
8.
F a u lty booster cover seal w ith
be tw e en h o u s in g and c o v e r .
8.
Rep lace a l l
booster s e a ls .
9.
F a u lt y b o o ste r spool
9.
Re p la ce a l l
booster s e a ls .
i n power s t e e r i n g
re se rv o ir.
bo o ste r or
le aka g e a t a ccu m u la to r.
leakage
plu g s e a l .
10.
In te rn a l
11 .
C o n t a m i n a t i o n i n power s t e e r i n g
12.
H y d ra u lic l in e s
le ak a g e in b o o s te r.
flu id .
routed i n c o r r e c t l y .
the b e l t .
tub e
bo o ste r.
10.
Rep lace b o o s te r.
11 .
F l u s h power s t e e r i n g s y s t e m and
r e p l a c e w i t h new f l u i d .
12.
Re-route l i n e s .
DIAGNOSIS - HYDRO - BOOST SYSTEM
SLO W BRAKE PEDAL RETURN
R e m ed y
P ro b a b le Cause
1.
Ex c e ssiv e seal
2.
F a u l t y sp o o l
fric tio n
in b o o ster.
a c tio n .
1.
Rep lace a l l
booster s e a l s .
2.
C l e a n sp o o l
and r e p l a c e a l l
booster s e a ls .
3.
B ro k e n p i s t o n r e t u r n s p r i n g .
3.
Rep lace s p r in g .
4.
R e s t r ic t io n in re tu r n l i n e
b o o s t e r to pump r e s e r v o i r .
4.
Rep lace l i n e .
5.
Broken spool
5.
Rep la ce s p r in g .
6.
E x c e s s i v e pe da l
6.
L u b r i c a t e p i v o t b u s h i n g s w i t h D e lc o B r a k e
Lube # 54 500 32 ( o r e q u i v a l e n t ) o r r e p l a c e
b u shin g s.
from
re tu rn sp rin g .
p iv o t f r i c t i o n .
GRABBY BRAKES
R e m ed y
P ro b a b le Cause
1.
Broken spool
1.
Re p lace s p r in g .
2.
F a u l t y s p o o l a c t i o n c a u s e d by
co n ta m in a tio n in syste m .
2.
I n s p e c t , c l e a n and r e p l a c e a l l
booster s e a ls .
3.
No c a r g o body on c h a s s i s .
3.
Normal
re tu rn sp rin g .
c o n d itio n .
BOOSTER CHATTERS - PEDAL VIBRATES
P ro b a b le Cause
R em ed y
1.
T i g h t e n bel t .
2.
F i l l r e s e r v o i r and c h e c k f o r
external le a k s .
F a u l t y s p o o l o p e r a t i o n c a u s e d by
co n ta m in a tio n in system .
3.
I n s p e c t , c l e a n and r e p l a c e a l l
booster s e a ls .
4.
E x c e s s iv e co n tam in atio n
ste e rin g f l u i d .
4.
F l u s h power s t e e r i n g f l u i d fr o m
s y s t e m and r e p l a c e w i t h new
power s t e e r i n g f l u i d .
5.
A ir
5.
A l l o w v e h i c l e to s t a n d f o r
a p p r o x i m a t e l y one h o u r ; the n
b le e d power s t e e r i n g h y d r a u l i c
syste m as d e s c r ib e d e a r l i e r in
th is se ctio n .
1.
Power s t e e r i n g
2.
Low f l u i d l e v e l
pump r e s e r v o i r .
3.
pump b e l t s l i p s .
i n power s t e e r i n g
in
power
i n power s t e e r i n g f l u i d .
DIAGNOSIS - HYDRO-BOOST SYSTEM
POWER STEERING PUMP NOISE O N BRAKE APPLY
Rem edy
P ro b a b le C ause
1.
In s u ffic ie n t flu id
reservoi r.
in
1.
pump
F lu id le v e l decre ases ap p ro xim ately
1 / 2 " on b r a k e a p p l j / - r e f i l 1 to
proper l e v e l .
I f f l u i d i s fo a m y ,
l e t v e h ic le stand f o r ap p ro xim ately
one h o u r ; t he n b l e e d power s t e e r i n g
h y d r a u l i c system as o u t l i n e d e a r l i e r
in th is se c tio n .
BRAKE PEDAL PULLS D O W N SLIGHTLY O N EN G IN E START
P ro b a b le Cause
1.
R em edy
R e s t r ic t io n in gear or booster
re tu rn lin e s .
1.
Rep lace l i n e s o r r e p o s it io n
l i n e s to e li m i n a t e r e s t r i c t i o n .
AC C U M U L A TO R L E A K D O W N - SYSTEM DOES N O T HOLD CHARGE
P relim inary Check
Start engine and turn the steering wheel until the wheels contact the wheel stops lightly. Hold fo ra
maximum of five seconds. Then release the steering wheel and turn off the engine.
Depress and release the brake pedal. There should be a minimum of three power assisted brake
applications before a hard pedal is obtained.
Re-start the engine and turn the steering wheel until the wheels contact the wheel stops lightly. There
should be a light hissing sound as the accumulator is charged. Hold steering wheel lightly against stop for
a maximum of five seconds. Then release the steering wheel, and turn off the engine.
Wait one hour and apply brake pedal (do not re-start the engine). There should still be a minimum of
three power assisted brake applications before obtaining a hard pedal.
If either of these preliminary checks shows that the accumulator is not holding its charge, the trouble
may be one of the following causes.
P r o b a b le Cause
Remedy
1.
Extern al
le a k a g e a t a ccu m ula tor.
1.
R e p la ce b o o ste r a sse m b ly .
2.
In te rn al
le akag e in a ccu m u lator.
2.
Rep la ce b o o ste r.
3.
3.
In t e r n a l le aka g e a t b o o ste r accu m ulator
v a lv e ( i f a ccu m u lator i s not le a k in g
e x te rn a lly or in t e r n a lly ) .
R e p l a c e a l l b o o s t e r s e a l s and
accu m ula tor v a l v e s .
ON-VEHICLE SERVICE
PEDAL TRAVEL
At reasonably frequent intervals, the brakes should
be inspected for pedal travel, which is the distance the
pedal moves toward the floor from a fully-released
position. Inspection should be m ade with the brake pedal
firmly depressed (approxim ately 90 lbs.) while the brakes
are cold.
C-K-G M a n u a l .........4.5"
C-K-G P o w e r.........3.5"
P (Except J F 9 ) ...... 3.5"
P ( J F 9 ) .............. 6.0"
O n power brake-equipped vehicles, p u m p the pedal
a m inim um o f 3 times with the engine off before making
pedal travel checks. This exhausts all vacuum from the
power booster.
STOP LIGHT SWITCH
Adjustm ent
The stop light switch is mounted on a flange
pro truding from the brake pedal support.
1. Release the brake pedal to its normal position.
2. Adjust switch by turning in or out as necessary.
Electrical contact should be made when the brake
pedal is depressed 1.0-1.24" (C-K models), .70" (G-P
models) from its fully released position.
3. Tighten switch locknut, if so equipped, and
connect electrical harness.
BLEEDING AND FLUSHING BRAKE SYSTEM
Bleeding Brake Hydraulic System
A bleeding operation is necessary to remove air
w henever it is introduced into the hydraulic brake
system.
It m ay be necessary to bleed the hydraulic system at
all four wheel cylinders if air has been introduced
through low fluid level or by disconnecting brake pipes
at master cylinder. If brake pipe is disconnected at any
wheel cylinder, then that wheel cylinder only need be
bled. If pipes are disconnected at any fitting located
between m aster cylinder and wheel cylinders, then all
wheel cylinders served by the disconnected pipe must be
bled.
M anual Bleed
If the vehicle is equipped with power brakes, deplete
the vacuum reserve by applying the brakes several times.
1. Fill m aster cylinder with brake fluid and keep at
least on e-half full o f fluid du rin g bleeding operation.
Bleed right rear brake, left rear brake, right front
brake and left front brake.
2. W ith the proper size box end wrench or Tool
J-21472 over bleeder valve, attach bleeder tube to valve
and allow tube to hang subm erged in brake fluid in a
clean glass j a r (fig. 5-1).
3. Open the bleeder valve and fully depress the
brake pedal.
4. Close bleeder valve and release brake pedal.
5. Repeat steps 3 and 4 until all air is evacuated.
Check and refill master cylinder reservoir as
required to prevent air from being drawn through
master cylinder.
6. Repeat the bleeding procedure at all wheels if
the entire system is to be bled.
7. Check the brake pedal, feel for "sponginess"
and repeat entire bleeding procedure if necessary.
Flushing Brake Hydraulic System
It is recom m ended that the entire hydraulic system
be thoroughly flushed with clean brake fluid whenever
new parts are installed in the hydraulic system.
Flushing is also recom m ended if there is any doubt
as to the grade of fluid in the system. If fluid has been
used which contains the slightest trace of mineral oil, all
ru bber parts that have been subjected to the contam i
nated fluid should be replaced.
BRAKE PIPES
Replacement (Figs. 5-2 thru 5-4)
W A R N IN G : NEVER USE COPPER T U B IN G
BECAUSE COPPER IS SUBJECT TO
FATIGUE
CRACKING A N D C O RRO SION W H IC H
COULD RESULT IN BRAKE FAILURE.
Fig. 5-2-Front
Brake
Pipes
and
Hoses--C-K
Models
Fig. 5-4--Front
Pipes
BRAKES
Brake
and
Hoses- P Models
5 -1 3
*
inspection. If any o f the above conditions are observed
on the brake hose, it will be necessary to replace it.
Front Brake Hose
R em o val (fig s . 5 -2 th ru 5 -4 )
1. Raise vehicle on hoist.
2. Clean dirt and foreign material from both hose
end fittings.
3. Disconnect brake pipe from hose fitting using a
back-up wrench on fitting. Be careful not to bend frame
bracket or brake pipe. It may be necessary to soak the
connections with p enetrating oil.
4. Remove " U " clip from female fitting at bracket
and remove hose from bracket.
5. Remove bolt from caliper end o f hose. Remove
hose from caliper, and discard the two copper gaskets on
either side of fitting block.
In s ta lla tio n
Fig. 5-5--Typical Rear Hose Fittings
1. Procure the recom m ended tubing and steel
fitting nuts o f the correct size. (Outside diam eter of
tubing is used to specify size.)
2. Cut tubing to length. Correct length may be
determ ined by measuring old pipe using a cord and
ad ding 1 /8 " for each double flare.
3. D ouble flare tubing ends using a suitable flaring
tool such as J-23530. Follow instructions included in tool
set.
M ake sure fittings are
second flare.
installed
before
starting
W A R N IN G : DOUBLE FLARING TOOL M U S T
BE
USED
AS
SIN G LE
CANNOT
PRODUCE
ENOUGH
TO
HOLD
A
FLARING
FLARE
THE
TOOLS
STRONG
NECESSARY
PRESSURE.
1. Use new copper gaskets on both sides o f fitting
block, wet bolt threads with brake fluid, then with fitting
orientation flange engaged with the caliper orientation
ledge on JB8 and JF9 (hose located in caliper gate on all
except JB8 and JF9), fasten hose to caliper; torque to
specifications.
2. With weight o f vehicle on suspension, pass
female fitting through frame or fram e bracket. Fitting
fits the bracket in only one position. With least am ount
of twist in hose, install fitting in this position. There
should be no kinks in hose.
3. Install " U " clip to female fitting at frame
bracket.
4. Attach brake pipe to hose fitting using a backup
w'rench on fitting; torque to specifications.
5. Inspect to see that hose doesn’t make contact
with any p art of suspension. Check in extreme right
hand and extreme left h and turn conditions. If hose
makes any contact, remove and correct.
6. Bleed brake system.
7. Lower vehicle from hoist.
Rear Brake Hose
R em o val
4.
Bend pipe assembly to match old pipe using a
tubing bender. Clearance o f .75" must be m aintained to
all moving or vibrating parts.
BRAKE HOSES
Inspection
The flexible hydraulic brake hose which transmits
hydraulic pressure from the steel brake pipe on the
fram e to the rear axle and to the calipers should be
inspected every 4 months or 6,000 miles (heavy duty
emission vehicles), every 12 m onths or 7,500 miles (light
duty emission vehicles). The brake hose assembly should
be checked for road hazard dam age, for cracks and
chafing o f the outer cover, and for leaks and blisters. A
light and m irror may be needed for an adequate
1. Raise vehicle on hoist.
2. Remove all three brake pipes from hose, two at
junction block and, with the use o f a back-up wrench,
one on the female fitting at bracket. Be careful not to
bend bracket or pipes; use penetrating oil if necessary.
3. Remove " U " clip and take female fitting out of
bracket (fig. 5-5).
4. Observe position at w'hich junction block is
mounted to the axle. W hen installing new hose be sure
this junction block is in the same position.
5. Remove bolt attaching junction block to axle.
In s ta lla tio n
1. T hread both rear axle pipes into junction block.
2. Bolt junction block to axle and then torque rear
pipes into block.
3. Pass female end o f hose through bracket;
female fitting will fit bracket in only 1 position (except G
models), 2 positions (G models). W ithout twisting hose,
position female end in bracket.
4. Install " U " clip.
5. Attach pipe to female fitting using a back-up
wrench on fitting; torque to specification, again be
careful not to bend bracket or pipe. Check to see that
hose installation did not loosen fram e bracket, re-torque
bracket if necessary.
6. Bleed system.
7. Lower vehicle from hoist.
2.
Remove nuts from the engine com partm ent on
C, K and G models or bolts from m ounting bracket on P
models.
N OTE: Take notice o f the spacers on P models for
reinstallation.
3. Disconnect the release handle rod at the parking
brake assembly end (C-K models).
4. Remove the bolts from the underside o f the
dash and lower the brake assembly (C-K-G Models).
5. C-K-G Models-Disconnect the cable ball from
the parking brake clevis and remove the assembly.
P Models^Remove the clevis pin and disconnect the
cable from the brake assembly; remove the
assembly.
BLEEDING HYDRO-BOOST/POWER
STEERING HYDRAULIC SYSTEM
In s ta lla tio n
T he following procedure should be used to bleed the
power steering hydraulic system on hydro-boost vehicles.
N O T E : If the power steering fluid has foam ed due
to low fluid level, it will be necessary to park the
vehicle for approximately one hour (reservoir cap
loose) so that the foam can dissipate.
1. Raise the front o f the vehicle on a hoist so that
the tires are clear o f the floor.
2. Check reservoir and fill with G M Power
Steering Fluid (or equivalent).
N O T E : Leave the reservoir cap off- during entire
bleed procedure.
3. Install a remote control starter switch so that
engine can be cranked but not started.
C A U T IO N : Whenever the engine is cranked
remotely at the starter, with a special ju m p er or
other means, the distributor prim ary lead must
be disconnected fr o m the negative post on the
coil.
4. Crank engine for 4 to 5 second intervals while
pouring fluid into the reservoir.
5. Fill reservoir and crank as in step 4 until system
will no longer accept fluid. It is norm al that fluid may
spill w hen cranking stops (it is the result o f air in the
system trying to escape). To prevent spilling, crank
engine.
6. Remove remote control starter switch. Reinstall
distributor p rim a ry lead.
7. Start engine and allow to run 2 seconds.
8. Check and refill fluid reservoir if necessary.
9. Start engine and depress the brake pedal several
times while rotating the steering wheel from stop to stop.
10. Turn engine off and then p u m p brake pedal
4-5 times to deplete accumulator pressure.
11. Check and refill fluid reservoir if necessary.
12. Repeat Steps 9, 10 and 11. Install pu m p
reservoir cap.
13. Remove vehicle from hoist.
PARKING BRAKE PEDAL OR HANDLE
Removal (Fig. 5-9)
Reverse the removal procedure. Torque all bolts and
nuts. A fter installing the clevis-pin, use a new cotter pin
to secure the clevis pin. Adjust the cable if necessary as
outlined below.
C A U TIO N : See "C aution" on Page 1 o f this
section.
PARKING BRAKE ADJUSTMENT
A djustment o f park in g brake cable is necessary
w henever holding ability is not adequate or whenever
the center brake cables have been disconnected.
NOTE: The service brake must be properly
adjusted as a base for parking brake adjustment;
conversely the park in g brake must be properly
adjusted for the service brake to function as
intended.
Inspection
If complete release o f the parking brake is not
obtained, unless it is forcibly returned to its released
position, or if application effort is high, check parking
brake assembly for free operation. If operation is sticky
or a bind is experienced, correct as follows:
1. Clean and lubricate brake cables and equalizer
with Delco Brake Lube (or equivalent).
2. Inspect brake assembly for straightness and
alignment (replace if necessary).
3. Clean and lubricate parking brake assembly
with Delco Brake Lube (or equivalent).
4. Checking routing o f cables for kinks or binding.
A djustm ent-Foot Pedal Type
NOTE: Before adjusting parking brake, check
service brake condition and adjustment.
1. Raise vehicle on hoist.
2.
Loosen the equalizer adjusting nut.
3. Apply p a rking brake 4 notches from fully
released position.
4. Tighten the equalizer nut until a m oderate drag
is felt when the rear wheels are rotated forward.
1.
Place parking brake pedal or handle in the
released position.
C A U TIO N : See " Caution" on Page 1 o f this
section.
L-6 & N 4 0
/
V -8 & N 4 0
fryI vtcwfA]
C-K M O D ELS
POOO ( 4 2 ) M O D ELS
G M O D ELS
P 3 0 0 ( 3 2 ) M O D ELS
Fig. 5-9 -Parking Brake Assem bly-Typical
lVIEW
P300 (42) & M40 & JB9
5. Fully release park in g brake and rotate the rear
wheels. N o drag should be present.
6. Remove vehicle from hoist.
A djustm ent-O rscheln Lever Type
1. T urn adjusting knob on parking brake lever
counterclockwise to stop.
2. Apply parking brake.
3. Raise vehicle on a hoist.
4. Loosen nut at interm ediate cable equalizer and
then adjust nut to give light drag at rear wheels.
C A U TIO N : See "C aution" on Page I o f this
section.
5. Readjust parking brake lever knob to give a
definite snap-over-center feel.
PARKING BRAKE (PROPELLER SHAFT)INTERNAL EXPANDING
Adjustm ent-Drum On
1. Jack up at least one rear wheel. Block wheels
and release h a n d brake.
2. Remove cotter pin and clevis p in connecting
pull rod and relay lever. This will assure freedom for full
shoe release.
C A U TIO N : It m ay be necessary to knock out
lanced area in brake drum with p unch and
ham m er to gain entry into adjusting screw
through brake drum. Be sure all m etal has been
removed fr o m p arking brake com partm ent.
3. Rotate brake drum to bring one o f access holes
into line with adjusting screw at bottom o f shoes
( m a n u a l transm ission), top o f shoes (autom atic
transmission).
4. Expand shoes by rotating adjusting screws with
screwdriver inserted through hole in drum. Move outer
end o f screwdriver away from drive shaft. Continue
adjustm ent until shoes are tight against dru m and drum
can not be rotated by hand. Back off adjustm ent ten
notches and check drum for free rotation.
5. Place p a rk in g brake lever in fully released
position. Take up slack in brake linkage by pulling back
on cable just enough to overcome spring tension. Adjust
clevis of pull rod or front cable to line up with hole in
relay levers.
a. Insert clevis pin and cotter pin, then tighten
clevis locknut.
b. Install a new metal hole cover in drum to
prevent contam inatio n of brake.
c. Lower rear wheels. Remove jack and wheel
blocks.
C A U T IO N : See " Caution" on Page I o f this
section.
Adjustm ent -Drum Off
1.
J-21177
G auge,
2.
W ith park in g brake d ru m off, use special Tool
or J-22364, D rum to Brake Shoe Clearance
to check d iam eter o f drum clearance surface.
T urn the tool to the opposite side and fit over
brake shoes by turning the star wheel until the gauge just
slides over the linings.
3. Rotate the gauge around the brake shoe lining
surface to insure pro per clearance.
4. Install propeller shaft flange at m ainshaft as
outlined in transmission section.
5. Lower rear wheels. Remove jack and wheel
blocks.
PARKING BRAKE CABLES
Front Parking Brake Cable Replacement
1. Raise vehicle on hoist.
2. Remove adjusting nut from equalizer.
3. Remove retainer clip from rear portion o f front
cable at fram e and from lever arm.
4. Disconnect front brake cable from parking
brake pedal or lever assemblies. Remove front brake
cable. On some models it may assist installation o f new
cable if a heavy cord is tied to o ther end of cable in
order to guide new cable through pro per routing.
5. Install cable by reversing removal procedure.
6. Adjust parking brake.
Center Parking Brake Cable Replacement
1. Raise vehicle on hoist.
2. Remove adjusting nut from
3. Unhook connector at each
hooks and guides.
4. Install new cable by
procedure.
5. Adjust parking brake.
6. Apply parking brake 3
pressure and repeat adjustment.
equalizer.
end and disengage
reversing
times
rem oval
with
heavy
Rear Parking Brake Cable Replacement
1. Raise vehicle on hoist.
2. Remove rear wheel and brake drum.
3. Loosen adjusting nut at equalizer.
4. Disengage re a r cable at connector.
5. Bend retainer fingers.
6. Disengage cable at brake shoe operating lever.
7. Install new cable by reversing removal
procedure.
8. Adjust parking brake.
COMBINATION VALVE
Testing Electrical Circuit of Com bination Valve
1. Disconnect wire from switch terminal and use a
ju m p e r to connect wire to a good ground.
2. Turn ignition key on " O n " - w arning lamp
should light. If lamp does not light, bulb is burned out or
electrical circuit is defective. Replace bulb or repair
electrical circuit as necessary.
3. W hen w arning lamp lights, turn ignition switch
off. Disconnect ju m p e r and reconnect wire to switch
terminal.
Testing W arning Light Switch Portion of
Com bination Valve
1.
Raise vehicle on hoist. Attach a bleeder hose to
a rear brake bleed screw and im merse the other end o f
the hose in a container partially filled with clean brake
fluid. Be sure m aster cylinder reservoir is full.
2. Turn ignition switch to " O n " ; open bleeder
screw while a helper applies m oderate pressure to the
brake pedal; w a rn in g lamp should light. Close bleeder
screw' before helper releases brake pedal. Reapply brake
pedal with m oderate-to-heavy pressure; light should go
out.
3. Attach the bleeder hose to a front brake bleeder
screw and repeat above test. W a rn in g lamp action should
be the same as in Step No. 2. T urn ignition switch off.
4. If w arn in g lamp does not light during Steps 2
and 3 but does light when a ju m p e r is connected to
ground, the w arning light switch portion o f the
com bination valve is defective. Do not attempt to
disassemble the com bination valve. If any portion of the
com bination valve is defective, it must be replaced with
a new c om bination valve.
5. Lower vehicle to floor. Check an d refill master
cylinder to pro per level.
Replacem ent
The com bination valve is not repairable and must
be serviced as a complete assembly.
1. Disconnect hydraulic lines at com bination valve.
Plug lines to prevent loss o f fluid and entrance o f dirt.
Disconnect w arn in g switch wiring harness from valve
switch terminal.
2. Remove com bination valve.
3. Install com bination valve by reversing removal
steps.
4. Bleed entire brake system. Do not move vehicle
until a firm brake pedal is obtained.
BRAKE PEDAL
N O T E: The brake pedal mounting is an integral
design w ith the cluth pedal (except automatic
transmission), necessitating the removal o f the
clutch pedal before removing the brake pedal.
Removal (Fig. 5 -1 2 )
1. Remove the pull back spring from the body or
brake pedal support bracket.
2. M anual Transm ission Vehicles-Rem ove the
clutch pedal as outlined under "Clutch Pedal" in Section
1C.
A utom atic Transm ission Vehicles-Rem ove pedal
pivot bolt nut or pivot pin retainer and remove bolts
or pin an d bushings.
3. P M odels-R em ove the sleeve assembly screw
a ttachm ent and remove sleeve.
4. Disengage the push rod from the master
cylinder and remove the pedal.
Inspection
Clean all parts and inspect for wear, cracks or any
other da m a ge that m ight im p air operation; replace if
required.
Installation
Reverse the above procedure and m ake certain the
brake pedal is secure and adjusted properly before
op erating the vehicle. Lubricate pedal pivot bushings
and pivot pin, bolt or sleeve with Delco Brake Lube (or
equivalent). Adjust stoplam p switch.
C A U TIO N : See "C aution" on Page 1 o f this
section.
11. Fasten the boot to the floorpan and compress
the boot to 2.54" installed height; tighten the boot to
2.54" installed height; tighten the boot screws to 13-18
in. lbs. (Refer to Figure 5-13).
12. Adjust brake pedal and stoplamp switch as
outlined previously.
BRAKE PEDAL ROD
P30(42) and G Models
P30(32) Models
Replacement
R eplacem ent (Fig. 5-13)
1. G Models-Remove the brake pedal striker screw
and remove the striker. Remove the cotter pin and
w asher and disconnect the pedal rod from the brake
pedal.
2. P 3 0 (4 2 ) Models-Remove the cotter pin nut and
bolt to disconnect the pedal rod from the brake pedal.
3. Remove the pedal rod retainer bolt (at the rod
pivot) and remove the retainer.
4. Remove the cotter pin and washer and remove
the pedal rod.
5. To install a new rod, reverse Steps 1-4 above.
1. Remove the cotter pin, nut, special washers and
bolt at the brake pedal lever end of rod; discard the
cotter pin.
2. Remove the boot to floorpan screws.
3. Raise the vehicle on a hoist.
4. Remove the cotter pin, nut, special washers and
bolt at the lower end o f the rod and remove the pedal
rod assembly. Discard the cotter pin.
5. To install a new rod, adjust the rod length to
31.00" (center o f upper attachm ent to center o f lower
attachment).
6. Lubricate the pedal rod bolts and special
washers with Delco Brake Lube (or equivalent).
7. Install the rod up through the floorpan opening
and install the lower pivot bolt, special washers and nut.
Tighten the nut to 22-30 ft. lbs. and install a N E W cotter
pin.
8. Push the boot up to the floorpan.
9. Lower the vehicle from the hoist.
10. Install the rod upper pivot bolt, special washers
an d nut. Tighten the nut to 22-30 ft. lbs. and install a
N E W cotter pin.
Fig. 5-13--Brake Pedal and Stop Lamp A djustm ent
P30(32) Model
NOTE: Lubricate pivot points with Delco Brake
Lube (or equivalent).
C A U TIO N : See "C aution" on Page 1 o f this
section.
6. Check b ra k e pedal a n d sto plam p switch
adjustments as outlined previously.
MASTER CYLINDER
Filling Brake M aster Cylinder
The master cylinder must be kept properly filled to
Fig. 5-15-D elco Secondary Piston - Exploded View
insure adequate reserve and to prevent air from entering
the hydraulic system. However, because o f expansion due
to heat absorbed from brakes and from engine, master
cylinder must not be overfilled.
T he brake fluid reservoir is on the master cylinder
which is located und er the hood on the left side of the
dash.
T horoughly clean reservoir cover before removal to
avoid getting dirt into reservoir. Remove cover and
diap hragm . A dd fluid as required to bring level to 1 /4 "
(plus o r minus 1/8") from the lowest portion o f the top
o f each reservoir. Use Delco Supreme No. 11 Hydraulic
Brake Fluid or equivalent.
D o not use shock absorber fluid or any other fluid
which contains m ineral oil. Do not use a container which
has been used for mineral oil or a container which is wet
from water. M ineral oil will cause swelling and distortion
o f ru b b e r parts in the hydraulic brake system and water
will mix with brake fluid, lowering the fluid boiling
point. Keep all fluid containers capped to prevent water
contam ination.
Except Bendix Mini-Master Cylinder
Removal
1. Disconnect brake pipes from master cylinder
and tape end o f pipes to prevent entrance o f dirt.
2. M anual brake only-Disconnect brake pedal
from m aster cylinder push rod.
3. Remove two nuts holding m aster cylinder to
dash or power cylinder and remove master cylinder from
vehicle. Be careful not to drip brake fluid on exterior
paint.
Disassembly (Figs. 5-14 and 5 -1 5 )
1. Clean outside o f m aster cylinder thoroughly.
Remove reservoir cover and diap hragm . T urn cylinder
over an d p u m p push rod by h a n d to drain all brake
fluid. Always discard used fluid.
2. M anual brake only-Pull boot away from master
cylinder to uncover push rod retainer. The retainer has a
small, depressed tab in the side. This tab must be pried
up to release retainer.
3. Depress piston and remove secondary piston
stop bolt from bottom o f front fluid reservoir (if so
equipped).
4. Place m aster cylinder in a vise so that lock ring
can be removed from groove in the inside diam eter o f
bore. Remove lock ring and prim ary piston assembly.
Remove secondary piston, secondary piston spring and
retainer by blowing air through the outlet port.
5. Place m aster cylinder in vise, so that outlet holes
are up. Enlarge hole in tube fitting insert using a 13/64"
drill. Place a heavy washer over outlet on m aster cylinder
and thread a 1/4-20 x 3 / 4 " screw into the insert. Tighten
screw until insert is unseated. Remove insert, screw, and
washer.
6. Remove p rim a ry seal, and secondary seal from
secondary piston.
7. Use clean brake fluid to clean all metal brake
parts thoroughly. A ir dry and place cleaned parts on
clean p a p e r or lint free clean cloth.
Do not use anti-freeze alcohol, gasoline, kerosene,
or any other cleaning fluid that might contain even
a trace o f mineral oil.
Inspection
Inspect cylinder bore for scoring or corrosion. It is
best to replace a corroded cylinder. Corrosion can be
identified as pits or excessive roughness.
Polish any discolored or stained area with crocus
cloth by revolving cylinder on cloth supported by finger.
Rinse cylinder in clean brake fluid. Shake excess
rinsing fluid from cylinder. Do not use a rag to dry
cylinder, as lint from rag cannot be kept from cylinder
bore surfaces.
Make certain that com pensating port in cylinder is
clear.
If scratches or corroded spots are too deep to be
polished satisfactorily, the cylinder should be replaced.
Assembly
1. Place brass tube fitting insert (new parts) in
outlet holes so that it is in a position to be pressed into
outlet hole. The recom m ended method o f inserting tube
fitting insert is to thread a spare brake line tube nut into
outlet hole and turn nut down until tube fitting insert
bottoms. Remove tube nut and check outlet hole for
loose burrs, which m ight have been turned up when tube
fitting insert was pressed down.
2. Put new secondary seal in groove in end o f
secondary piston (fig. 5-15).
3. Assemble a new prim ary seal over end o f
secondary piston, so that flat side o f the seal seats
against flange o f piston (fig. 5-15).
4. Assemble new secondary seal into groove on end
o f the secondary piston.
5. In o rder to insure correct assembly of the
prim ary assembly, a complete prim ary piston assembly is
included in the repair kits.
6. Coat bore o f m aster cylinder with clean brake
fluid. Coat p rim a ry an d secondary seals on secondary
piston w ith clean brake fluid. Insert the secondary piston
spring retainer into secondary piston spring. Place
retainer an d spring over end o f secondary piston, so that
retain er locates inside lip o f p rim a ry cup.
7. Hold master cylinder with open end o f bore
down, push secondary piston into bore, so that spring
will seat against closed end o f bore.
8. Place master cylinder in a vise with open end o f
bore up. Coat prim ary and secondary seal on prim ary
piston with clean brake fluid. Push prim ary piston
assembly, spring end first, into bore o f master cylinder.
Hold the piston down and snap lock ring into position in
groove in inside diam eter o f bore.
9. Install a new reservoir d ia p h ra g m in reservoir
cover w here needed, and install cover on master cylinder.
Beaded side faces master cylinder casting to insure
positive sealing. The bail wire is now pushed into
position to hold reservoir cover.
10. M anual brake only-Assemble push rod through
push rod retainer, if it has been disassembled. Push
retainer over end o f master cylinder. Assemble new boot
over push rod an d press it down over the push rod
retainer.
Installation
C A U TIO N : Refer to "Caution" on Page 1 o f
this section regarding fasteners referred to in
Steps 1 and 2 below.
1.
M anual brake only-Connect push rod to brake
pedal pin and install retainer while holding master
cylinder in place.
2. Install m aster cylinder on dash or power
cylinder; torque nuts to specifications.
3. Connect brake pipes to m aster cylinder.
4. Bleed hydraulic system.
5. R oad test vehicle for pro per brake performance.
Bendix Mini-Master Cylinder
N O T E : Rem oval, Inspection an d Installation
procedures are the same as described for "Except
Bendix M ini-M aster Cylinder".
Disassembly
1. Remove the reservoir cover and d iaph ragm , and
dra in the fluid from the reservoir.
2. Remove the four bolts that secure the body to
the reservoir using Socket J-25085.
3. Remove the small " O " ring and the two
com pensating valve seals from the recessed areas on the
bottom side o f the reservoir.
N O T E: Do not remove the two small filters from
the inside o f the reservoir unless they are dam aged
and are to be replaced.
4. D epress the prim ary piston using a tool with a
sm ooth rounded end. T hen remove the com pensating
valve poppets an d the com pensating valve springs from
the com pensating valve ports in the master cylinder
body.
5.
Using a small screwdriver, remove the snap ring
at the end o f the master cylinder bore. Then release the
piston and remove the p rim ary and secondary piston
assemblies from the cylinder bore. It may be necessary to
plug the front outlet port and to apply low air pressure to
the front compensating valve port to remove the
secondary piston assembly.
Assembly
1. Lubricate the secondary piston assembly and the
master cylinder bore with clean brake fluid.
2. Assemble the secondary spring (shorter o f the
two springs) in the open end o f the secondary piston
actuator, and assemble the piston return spring (longer
spring) on the projection at the rear o f the secondary
piston.
3. Insert the secondary piston assembly, actuator
end first, into the master cylinder bore, and press
assembly to the bottom o f the bore.
4. Lubricate the prim ary piston assembly with
clean brake fluid. Insert the p rim a ry piston assembly,
actuator end first, into the bore.
5. Place the snap ring over a smooth round ended
tool and depress the pistons in the bore.
6. Assemble the retaining ring in the groove in the
cylinder bore.
7. Assemble the com pensating valve seals and the
small " O " ring seal in the recesses on the bottom o f the
reservoir. Be sure that all seals are fully seated.
8. W hile holding the pistons depressed, assemble
the compensating valve springs and the compensating
valve poppets in the compensating valve ports.
9. Holding the pistons compressed, position the
reservoir on the master cylinder body and secure with
the four m ounting bolts. Tighten the bolts to 12-15 ft.
lbs.
DELCO DISC BRAKE SHOE AND LINING
Lining Inspection
Inspect the brake linings every 7,500 miles and any
time that the wheels are removed (tire rotation, etc.).
Check both ends o f the outboard shoe by looking in at
each end o f the caliper (fig. 5-18). These are the points at
which the highest rate o f w ear normally occurs. However,
at the same time, check the lining thickness on the
inboard shoe to make sure that it has not worn
prematurely. Look down through the inspection hole in
the top o f the caliper to view the inboard shoe.
W henever the thickness o f any lining is w orn to within
.030" of rivet at either end o f the shoe, all disc brake
shoe and lining assemblies should be replaced at the
same time (fig. 5-19).
Caliper Removal
W A R N IN G : See " W a rn in g " on Page 5-1
of this section.
Fig. 5-16--Bendix M ini-M aster Cylinder- Exploded View
1. Remove two thirds o f the total fluid capacity
from the front master cylinder reservoir. Removal of the
fluid is necessary to prevent reservoir overflow when the
caliper piston is pushed back in its bore to remove the
caliper. This may be done by breaking the front line
connection at the m aster cylinder and bleeding down the
fluid level. D o not remove the brake line or completely
empty the reservoir or it will be necessary to bleed the
hydraulic system. Discard — do not attem pt to reuse —
the brake fluid removed.
2. Raise the vehicle on a hoist an d remove the
wheel covers and wheel assemblies. Position a 7 inch " C "
clam p on the caliper so that solid side o f the clamp rests
against the metal p art o f the outboard shoe (fig. 5-20).
Tighten the " C " clamp until the caliper moves away
from the vehicle far enough to push the piston to the
bottom o f the piston bore. This will allow the shoes to
back off from the rotor surfaces. Remove the " C " clamp.
3. It is not necessary to disconnect the brake hose
for shoe and lining replacement. Remove the two
m ounting bolts which attach the caliper to the support
bracket (tig. 5-21). Lift the caliper off the rotor and
remove the inboard shoe. Dislodge the outboard shoe and
position the caliper on the fro n t suspension arm so that the
brake hose will not support the weight o f the caliper.
Remove the shoe support spring fro m the cavity in the
piston.
4. Using Tool J-22835, remove the sleeves from the
inboard ears o f the caliper (fig. 5-22). Next, remove the
ru bber bushings from the grooves in each o f the four
caliper ears.
Cleaning and Inspection
1.
Thoroughly clean the holes and the bushing
N E W SHOE & L IN IN G
READY
FOR REPLACEMENT
Fig. 5-19 -New and Worn Linings
Fig. 5 -1 7 -Delco Single Piston Disc Brake
Fig. 5-20--Use of " C ” Clamp
this will dam age the plating. If the bolts are corroded, or
dam aged, they should be replaced.
2. Examine the inside of the caliper for evidence
o f fluid leakage. If leakage is noted, the caliper should
be overhauled. W ipe the inside o f the caliper clean,
including the exterior o f the dust boot. Check the boot
for cuts, cracks or other damage. M ake sure that the boot
is properly, engaged in the groove in the piston and also
in the caliper counter-bore (fig. 5-24).
C A U TIO N : Do not use compressed air to clean
the inside o f the caliper since this m ay cause
the dust hoot to become unseated.
3. If the vehicle has a brake problem and
diagnosis points to the rotor, it should be inspected and
checked for runout at this time.
grooves in the caliper ears. W ipe all dirt from the
m ounting bolts. D o not use abrasives on the bolts since
Caliper Installation
1.
Install ru b b e r bushings in all four caliper ears.
THE D IM ENSIO N BETWEEN EACH C A LIPER STOP
A N D THE C A LIPER S H O U LD BE , 0 0 5 " - .0 l2 ''
Fig. 5-21 Removing M ou n tin g Bolts
Fig. 5-23--Caliper to Stop Clearance
BOOT
Fig. 5-22- Removing Sleeves
C A U T IO N : It is essential that the new sleeves
a n d rubber bushings be used in order to insure
the proper fu n ctio n in g o f the sliding caliper
design.
2. Use Tool, J-22835, to install the sleeves (fig.
5-25). Position the sleeves so that the end toward the
shoe and lining assemblies is flush with the machined
surface o f the ear.
3. Install the shoe support spring by replacing the
single tang end of the spring over the notch in the center
o f the edge o f the shoe. Then press the two tangs at the
spring end o f the inboard shoe spring over the bottom
edge o F the shoe so that they engage the shoe securely,
as shown in Figure 5-26.
4. Position the inboard shoe and lining assembly
(with spring attached) in the caliper so that the ear end
P ISTO N
Fig. 5-28-Installing Outboard Shoe
o f the shoe and lining is down and the bottom end up at
an angle with the spring resting on the piston I.D. (fig.
5-27). Press down on both ends o f the shoe until the shoe
is in a flat position, resting on the piston. The spring end
o f the inboard shoe support spring should be resting on
the I.D. of the piston.
CAUTION: On inboard shoes there is a specific
left hand an d right hand shoe. When properly
installed the wear sensor will be toward rear o f
caliper.
5.
Position the outboard shoe in the caliper, with
the ears at the top o f the shoe over the caliper ears and
the tab at the bottom of the shoe engaged in the caliper
cut-out (see fig. 5-28). Be sure to note right and left brake
shoes. 6. Postion the caliper over the rotor, lining up
the holes in the caliper ears with the holes in the
mounting bracket.
CAUTION: When reinstalling caliper be sure
you haven't turned it over, end over end. This
would cause a severe twist in the brake hose.
A fter positioning caliper on disc, observe brake
hose being sure it is not twisted.
Start the bolts through the sleeves in the inboard
caliper ears and through the m ounting bracket,
making sure that the ends o f the bolts pass under
the retaining ears on the inboard shoe (fig. 5-29).
Push bolts on through to engage the holes in the
outboard shoes and the outboard caliper ears at the
same time, threading the bolts into the m ounting
bracket. Torque the bolts to 35 ft. lbs.
CAUTION: See " Caution" on Page 1 o f this
section.
7. Add fresh approved brake fluid to the master
cylinder reservoirs to bring the level up to within 1/8
inch o f the top.
8. Pum p brake pedal to seat linings against rotor.
9. Clinch u p p e r ears o f o u tb o a rd shoe by
positioning channel lock pliers with one jaw on top of
CALIPER
INBOARD SHOE
AND LINING
OUTBOARD SHOE
AND LINING
SCREW
SUPPORT
KEY
SPLASH SHIELD
Fig. 5 -31-B endix Disc Brake Caliper Assembly
Fig. 5-29--lnstalling M ou n tin g Bolts
CAUTION: See "C aution" on Page 1 o f this
section.
2.
W henever the front wheel disc brakes
relined, the rear drum brakes should be checked also.
are
BENDIX DISC BRAKE SHOE AND LINING
The brake linings should be inspected any time the
wheels are removed. Check both ends o f the outboard
shoe by looking in at each end o f the caliper (fig. 5-31).
This is the point at which the highest rate o f w ear
normally occurs. At the same time, check the lining
thickness on the inboard shoe by looking down through
the inspection hole in the top o f the caliper; see "Brake
Inspection" portion o f this section. The in board shoe is
installed with the ends o f the shoe resting in the steering
knuckle. The large tab at the bottom o f the outboard
shoe is bent over at the right angle and fits in the cutout
in the outboard section o f the caliper.
Fig. 5 -3 0 -Clinching O utboard Shoe
up per ear an d one jaw in notch on bottom o f shoe
opposite upp er ear (fig. 5-30).
10. A fter clinching, ears are to be flat against
caliper housing with no radial clearance.
11. If radial clearance exists, repeat clinching
procedure.
N OTE: The inboard shoe does not incorporate a
lining w ear sensor as with standard disc brakes.
Removal
WARNING: See " W a r n in g " on page 1 of
this section.
Completion
1.
Replace the shoe and linings on the other front
1.
Remove m aster cylinder cover and observe
wheel disc brake in exactly the same m a n n e r as just
brake fuuid level in front reservoir is more than 1/3 full,
described. Relining is to be done in full axle sets only.
siphon the necessary am ount out to bring the level to 1/3
W hen completed, reinstall the wheel and tire assemblies.
full. This step is taken to avoid reservoir overflow when
T orque wheel nuts to specifications. Install wheel covers
the caliper piston is pushed back into its bore. Discard
and lower the vehicle to the floor.
the brake fluid removed. N ever reuse brake fluid.
HEAVY WIRE
CALIPER
OUTBOARD
SHOE
INBOARD
SHOE
Fig. 5-32--Pushing Piston in to Bore Using a "C"
Clamp
2. Raise the front o f the vehicle on a hoist and
remove the front wheels.
3. Push the piston back into its bore. This can be
accomplished by using a " C " clamp as shown in Figure
5-32.
4. Remove the bolt at the caliper support key.
U sing a brass punch, remove the key and spring (fig.
5-33).
5. Lift the caliper off the disc and support in a
raised position with a heavy wire (fig. 5-34).
C A U T IO N : Do not support the weight o f the
caliper on the brake hose.
6. Remove the inb oard shoe from the steering
SUPPORT
KEY
Fig. 5-34--Removing Caliper from the Disc
knuckle. Remove and discard the inboard shoe clip.
Remove the outboard shoe from the caliper. It m ay be
necessary to tap the shoe to loosen it in the caliper
housing.
C A U TIO N : M ark disc p a d positions i f pads are
to be reinstalled.
Cleaning and Inspection
NOTE: The shoes should be replaced when the
lining is w orn to approximately 1/32" thickness
over the rivet heads. Replace shoes in axle sets.
1. E xamine the inside of the caliper for evidence
o f fluid leakage. If leakage is noted, the caliper should
be overhauled.
2. Wipe the inside o f the caliper clean, including
the exterior of the dust boot. Check the boot for cuts,
cracks or other damage.
C A U TIO N : Do not use compressed air to clean
the inside o f the caliper.
3. Use a wire brush to remove any rust or
corrosion from the machined surfaces o f the steering
knuckle and caliper. It is im portant to clean those areas
o f the caliper and spindle assembly that are in contact
during the sliding action o f the caliper.
Installation
BRASS ROD
C A U TIO N : I f original disc pads are being
reinstalled, they must be installed in original
positions (as m arked at removal).
1. Lubricate the caliper and steering knuckle
sliding surfaces and the support spring with Delco
Silicone Lube (or equivalent).
2. Install a N E W inboard shoe clip in the steering
knuckle. Be sure the tabs are positioned correctly and the
loop-type spring positioned away from the rotor. Install
the lower end o f the inb oard shoe into the groove
provided in the steering knuckle (against the spring clip).
Slide the u p p e r end o f the shoe into position. Be sure the
clip rem ains in position.
3. Postion the outboard shoe in the caliper with the
ears at the top o f the shoe over the caliper ears and the
tab at the bottom o f the shoe engaged in the caliper
cutout. If assembly is difficult, a " C " clam p m ay be used.
Be careful not to m a r the lining.
4. With both shoes installed, lift up the caliper and
rest the bottom edge o f the outboard lining on the outer
edge o f the brake disc to make sure there is no clearance
between the tab at the bottom o f the outboard shoe and
the caliper abutm ent. The outboard shoe should fit
tightly in the caliper and should not rattle.
5. Position the caliper over the brake disc, guiding
the upp er caliper groove onto the m ating surface o f the
steering knuckle. Position the caliper to the lower
steering knuckle sliding surface.
N OTE: Make sure that the brake hose is not
twisted or kinked.
6. Place the spring over the caliper support key,
install the assembly between the steering knuckle and
lower caliper grooove. T a p into place (until the key
retain in g screw can be installed) using a brass punch and
a light h a m m e r (fig. 5-35).
7. Install the screw and torque to 12 to 18 ft. lbs.
CAUTION: The bolt boss m ust fit fu lly into the
circular cutout in the key.
See "C aution" on Page 1 o f this section.
8. Reinstall the front wheel and tire assembly.
9. Add brake fluid to the m aster cylinder reservoir
to bring the fluid level up to within 1/4 inch o f the top.
N O T E: Before moving the vehicle, pum p the brake
pedal several times to make sure that it is firm. Do
not move vehicle until a firm pedal is obtained.
Check m aster cylinder fluid level again after
pum ping the brake pedal.
CALIPER OVERHAUL
Delco
Removal
1. Removal o f the caliper for overhaul is the same
as for shoe and lining replacem ent except that it will be
necessary to disconnect the brake hose; (R efer to front
brake hose replacement).
2. First, disconnect the hose from the steel brake
pipe and cap the fittings to prevent dirt from entering
the pipe or the hose. Then, remove the U-shaped
retainer from the hose fitting. W ithdraw the hose from
the fram e support bracket and remove the caliper — with
hose attached — to a work bench for overhaul.
Disassembly
1. Before beginning disassembly, thoroughly clean
the exterior o f the caliper using brake cleaner. Place the
caliper on a clean work surface.
2. Remove the brake hose from the caliper,
discarding the copper gasket. Check the hose for worn
spots, cracks o r other signs of deterioration, discard the
hose, if damaged, to be replaced with a new hose at
reassembly. D rain brake fluid from the caliper.
3. Use clean shop towels to pad the interior o f the
caliper.
WARNING: DO NOT PLACE THE FINGERS
IN FRONT OF THE PISTON IN AN AT
TEMPT TO CATCH OR PROTECT IT WHEN
APPLYING COMPRESSED AIR. THIS COULD
RESULT IN SERIOUS INJURY.
BRAKE FLUID
INLET HOLE
AIR HOSE
SHOP
TOWELS
Remove the piston by directing compressed air into
the caliper inlet hole (fig. 5-36).
CAUTION: Use ju s t enough air pressure to ease
the piston out o f the bore. I f the piston is blown
out, even with padding provided' it m ay become
damaged.
4. Use a screwdriver to pry the boot out o f the
caliper. Extend the screwdriver across the caliper bore,
under the boot, an d pry up. Be careful not to scratch the
caliper bore.
5. Use a piece of wood or plastic — a plastic
toothpick is ideal — to remove the piston seal from its
groove in the caliper bore. D O N O T USE A M ETAL
T O O L O F A N Y TYPE F O R THIS O PERA TIO N .
6. Remove the bleeder valve from the cliper.
Cleaning and Inspection
1. T he boot, piston seal, rubber bushings and
sleeves are to be replaced each time the caliper is
overhauled. Discard, do not bother to clean and inspect,
these parts.
2. Clean all other parts in clean denatured alcohol
or brake cleaner. Use dry, filtered compressed air to dry
parts and blow out all passages in the caliper and
bleeder valves.
The use of lubricated shop air will leave a film of
m ineral oil on the metal parts. This may dam age
ru b b e r parts w hen they come in contact after
reassembly.
3. Check the m ounting for corrosion, breaks in the
plating or other dam age. Do not use abrasives in an
attem pt to clean the pins -- replace them.
4. Carefully examine the piston outside diam eter
for scoring, nicks, corrosion an d worn or dam aged
chrom e plating. If any surface defects are detected,
replace the piston.
5. Check the bore in the caliper for the same
defects as the piston with the exception of plating
dam age. T he piston bore is not plated and stains or
m inor corrosion can be polished with crocus cloth. Do
not use em ery cloth. Thoroughly clean the caliper after
the use o f crocus cloth. If the bore cannot be cleaned up
in this m anner, replace the caliper.
Reassembly
1. Lubricate the bore in the caliper and the new
piston seal with clean brake fluid. Position the seal in the
caliper bore groove. Lubricate the piston with clean
brake fluid and assemble a new boot into the groove in
the piston so that the fold faces the open end o f the
piston. Insert the piston into the caliper bore, using care
not to unseat the seal and force down to the bottom in
the bore. This will require a force o f 50 to 100 pounds.
Position the outside d iam eter o f the boot in the caliper
counterbore and seat with Tool J-22904 (fig. 5-37).
2. Check the boot installation to make sure that
the retaining ring molded into the boot is not bent and
that the boot is installed fully, below the caliper face,
and evenly all around. Otherwise dirt or moisture may
enter the bore and cause d am age or corrosion.
Fig. 5-37-Seating Boot
3.
Install the brake hose in the caliper inlet using a
new copper gasket.
Installation
1.
Installation o f the caliper and m ounting parts
(rubber bushing, sleeves, shoe and lining assemblies and
pins) is the same as for lining replacement except for the
following:
a. The brake hose must be connected to the
brake pipe at the fram e or frame bracket.
Use extreme care to orient the hose so that the
keyed hose end fitting aligns with the slot in the
bracket without twisting or kinking the hose.
b. A fter overhaul — or any time that the brake
hose or line is disconnected — the calipers must be bled.
Bendix
Removal
CAUTION: Clean dirt fro m hose to caliper
connection before proceeding with removal.
1. Remove the hose to caliper bolt and cap or tape
the open connections to prevent dirt from entering the
hose or caliper. Discard the copper gaskets.
2. Remove the caliper assembly as described under
"Shoe and Linings-Removal".
Disassembly (Fig. 5-38)
1.
Clean the exterior o f the caliper using clean
brake fluid and place on a clean work surface.
NOTE: An alternate method o f removing the
piston is to stroke the brake pedal (gently) while
the hydraulic lines are still connected. This will
push the piston out o f the caliper bore.
4. Remove the boot from the piston bore.
5. Using a small piece o f wood or plastic, remove
the square ring seal from the piston bore.
CAUTION: Do not use a m etal tool o f any kind
fo r this operation as it m ay dam age the bore.
6. Remove the bleeder valve from the caliper.
Cleaning and Inspection
Fig. 5-38--Bendix Brake Caliper Assembly
CAUTION: The use o f lubricated shop air will
leave a film o f mineral oil on the m etal parts.
This m ay damage rubber parts when they come
in contact after reassembly.
2. Check the sliding surfaces o f the caliper,
steering knuckle and support spring for rust or corrosion.
Clean up any surface defects with crocus cloth.
3. Carefully exam ine the outside surface o f the
piston for scoring, nicks, corrosion and worn or dam aged
plating. If any surface defects are detected, replace the
piston.
CALIPER H O U S IN G
Fig. 5-39-R em oving
2.
CAUTION: The dust boot and piston seal are to
be replaced whenever the caliper is overhauled.
Discard these parts.
1. Clean all parts (other than those mentioned
above in clean brake fluid. Use dry, filtered, compressor
air to blow out all passages in the caliper and bleeder
valve.
the
Caliper Piston
D ra in the brake fluid from the caliper.
WARNING: Do not place th e fingers in front
of th e piston in a n a tte m p t to catch or
protect it when applying co m pressed air.
CAUTION: The piston outside diameter is the
prim ary sealing surface in the caliper assembly.
It is m anufactured and pla ted to close
tolerances. Refinishing by any means or the use
o f any abrasive is not acceptable practice.
4. Check the bore in the caliper for the same
defects as the piston. The piston bore, however, is not
plated and stains or m inor corrosion can be polished
with crocus cloth.
CAUTION: Do not use emery cloth or any other
fo rm o f abrasive. Thoroughly clean the caliper
after the use o f crocus cloth. I f the bore cannot
be cleaned up in this manner, replace the
caliper.
Assembly
1. Lubricate the caliper piston bore and the N E W
3.
Using clean shop cloths, pad the interior o f the
piston seal with the clean brake fluid. Position the square
caliper and remove the piston by directing compressed
ring seal in the caliper bore groove.
air into the caliper inlet hole (fig. 5-39).
2. Lubricate both sealing lips o f the dust boot and
the piston with a light film o f clean brake fluid. Place the
CAUTION: Use ju s t ju s t enough air pressure to
new boot over Piston Installer Tool J-24548. This is most
ease the piston out o f the bore. Do not blow
easily accomplished by placing the boot large diam eter
piston out o f the bore. I f the piston is seized or
over the tool first, then riding the smaller diam eter onto
cocked or does not come out readily, release the
the tool. The large diam eter lip must then be slid off" the
air pressure a n d use a soft (brass) hamm er to
tool to make ready for installation into the bore groove.
rap sharply on a nd around the end o f the
Install the boot (large bead) into the piston bore groove
piston. Reapply air pressure to remove the
by reaching inside o f Tool J-24548 and pressing the boot
piston.
bead into the groove (fig. 5-40).
1. Connect the brake hose to the caliper using
N E W copper gaskets.
Inner lip o f b o o t
must be fu lly
seated in caliper
housing.
CAUTION: Hose must be properly positioned to
prevent hose twist or misalignment.
2. Bleed the caliper assemblies as outlined earlier
in this section.
ROTOR SERVICING
J-24548
Checking Lateral Runout
PISTON SEAL
Fig. 5 -4 0 -Insta llin g Caliper Piston Boot
CAUTION: Be sure boot is fu lly seated in the
groove before proceeding.
3.
Place the piston inside o f Tool J-24548, force
piston halfway into the piston bore using a wood
h a m m e r handle or " C " clam p (fig. 5-41); remove Tool
J-24548. Check to be sure the boot was not unseated at
piston installation. Make sure the outer bead o f the boot
is seated in the piston outer groove.
Installation
N O T E: Installation o f the caliper and m ounting
parts is the same for: "Shoe and Lining-Disc
Brake" except for steps given below:
1. Lateral runout is the m ovem ent o f the rotor
from side to side as it rotates on the steering knuckle
spindle. This could be described as "rotor wobble".
2. The movem ent of the rotor from side to side in
the lateral plane causes the brake shoe and lining and
pistons to be knocked back into their bores. This results
in additional pedal travel required and a vibration
during the braking action.
3. To check lateral runout, first tighten the wheel
bearings until all o f the play is out o f the bearings.
Fasten a dial indicator to some portion of the suspension
the
so that the point o f the stylus contacts the rotor face
approximately one inch from the rotor edge (fig. 5-42).
Set the dial at zero. Move the rotor one complete
rotation, checking the indicator as the rotor moves.
4. Lateral runout should not be over .004" total
indicator reading.
Parallelism Check
1. Parallelism is the m easurem ent o f the thickness
of the rotor at four or more points around the
circumference of the rotor. All m easurem ents must be
made at the same distance in from the edge o f the rotor.
2. A rotor that varies over .0005" causes pedal
vibration, as well as front end vibration during brake
applications. A ro to r that does not m eet these
specifications m ay be refinished
precision equipm en t is available.
to specifications
if
DRUM BRAKE SHOE AND LINING
Rotor T olerance and Surface Finish
Service Brake
In m anu facturin g the brake rotor, tolerances o f the
ru b b in g surfaces for flatness, for parallelism and for
lateral runout are held very closely. The m aintenance o f
these close controls on the shape o f the rubbing surfaces
is necessary to prevent brake roughness.
In addition to these tolerences. the surface finish
must be held to a specified range. The control of the
r u b b in g surface finish is necessary to avoid pulls and
erratic perform ance and to extend lining life.
Light scoring o f the rotor surfaces not exceeding
.015" in depth, which may result from normal use, is not
detrim ental to brake operation.
Adjustment
M achining
Since accurate control o f the rotor tolerances is
necessary for pro p e r perform ance of the disc brakes,
m achining o f the rotor should be done only with
precision equipment.
WARNING: ALL BRAKE ROTORS HAVE A
MINIMUM THICKNESS DIMENSION CAST
INTO THEM. THIS DIMENSION IS THE
MINIMUM WEAR DIMENSION AND NOT A
REFINISH DIMENSION. DO NOT USE A
BRAKE ROTOR THAT WILL NOT MEET THE
SPECIFICATIONS, AS SHOWN BELOW,
AFTER REFINISHING. REPLACE WITH NEW
BRAKE ROTOR.
ROTOR THICKNESS
MINIMUM
REPLACEMENT
AFTER REFINISHING
(DISCARD)
1.480
1.230
.980
1.465
1.215
.965
Wheel Bolt Replacement (Disc Brakes)
1. Remove hub and rotor assembly from vehicle.
2. M ark rotor to hub location and remove bolts
attaching hub to rotor.
3. The wheel bolts on disc brakes can be pressed
out fro m the outside o f the hub an d installed from inside
the rotor by pressing into place. N o drilling or cutting is
required.
4. Reinstall assembly and adjust wheel bearings.
1. Using a punch, knock out lanced area in brake
drum. If this is done with the drum installed on the
vehicle, the drum must be removed and all metal cleaned
out of the brake com partm ent. Be sure to procure a new
metal hole cover and install it in the d rum after
adjustment to prevent dirt and w ater from getting into
the brakes. Use J-6166 to turn brake adjusting screw;
expand brake shoes at each wheel until the wheel can
just be turned by hand. The drag should be equal at all
wheels.
2. Back off' brake adjusting screw at each wheel 30
notches. If shoes still drag lightly on drum, back off
adjusting screw one or two additional notches. Brakes
should be free of drag when screw has been backed off
approximately 12 notches. Heavy drag at this point
indicates tight parking brake cables.
3. Install metal adjusting hole cover in brake
drum.
4. Check parking brake adjustment.
Removal and Inspecting
WARNING: See " W a rn in g ” on Page 1 of
this section.
1. Raise vehicle on hoist. Remove wheel and brake
drum. It may be necessary to back off the brake shoe
adjustment before the brake drums can be removed. To
back off' shoe adjustment, rotate shoe adjusting screw
downward.
NOTE: On JB6, JB7 and JB8 equipped vehicles, it
is necessary to remove the axle shafts to remove
the hub and d ru m assembly; refer to Section 4B o f
this manual.
2. Unhook the p rim a ry and secondary shoe return
springs using large pliers.
3. Remove shoe hold down springs.
4. Lift up on actuator, unhook actuating link from
anchor pin, then remove.
5. Spread shoes to clear wheel cylinder connecting
links, remove parking brake strut and spring, disconnect
cable from parking brake lever, remove shoes from the
backing plate.
6. Separate the brake shoes by removing adjustingscrew and lock spring. Remove park in g brake lever and
secondary brake shoe.
7. Clean all dirt out of brake drum . Inspect drums
and replace or recondition if required.
8. Clean all dirt from brake assemblies and inspect
for any unusual condition.
9. Wheel cylinders having torn, cut, or heatcracked boots should be completely overhauled.
Inspection for leakage may be accomplished at the
boot center hole after removal o f link pin. Fluid
W HEEL C Y LIN D E R L IN K "
W HEEL CYLIN D E R SCRr , , , r
S E C O N D A R Y SHO E & L IN IN G
SHOE G U ID E
P A R K IN G BRAKE STRUT
STRUT S P R IN G
AD JU STE R LEVER
A C T U A T IN G L IN K
H O LD D O W N P IN -
A R K IN G BR AKE LEVER
HEEL CYLIN D E R
P R IM A R Y SHOE A N D L IN IN G
..O L D D O W N SPRING
S P R IN G & CUP
-A D J U S T IN G SCREW SPRING
L— A D J U S T IN G SCREW
BR AKE SHO E RETURN SPRING
-EVER RETURN SPRING S
Fig. 5-43--Typical Drum Brake Assembly
coatings on piston within cylinder and on end of
link pin removed from boot are normal, as cylinder
contains a porous PISTON W H ICH IS I M P R E G
N A T E D W ITH A C O R R O S IO N IN H IBITIN G
F L U ID . Fluid spilling from boot center hole, after
link pin is removed, indicates cup leakage and
necessity for completely over-hauling cylinder.
10. Inspect backing plate for oil leakage past wheel
bearin g oil seals. Correct any leak by installation o f new
seals (See Section 4B).
11. Check all backing plate attaching bolts to make
sure they are tight. Using fine em ery cloth, clean all rust
and dirt from shoe contact surfaces on plate.
rivet extending through the shoe rim, but no farther.
Keep hands clean while handling brake lining.
3. Start riveting at center o f shoe an d lining and
work toward the ends. Use a roll set for riveting; a star
set might split the tubular end and then the rivet would
not fill the hole. The p rim ary lining is shorter than
secondary lining; therefore, the rivet holes at each end
of the shoe rim are not used.
4. A fter riveting is completed, lining must seat
snugly against shoe with no more than .005" separation
midway between rivets. Check with a .004" (go) and a
.006" (No Go) feeler gage.
Relining Brake Shoes
1. Lubricate fulcrum end o f parking brake lever
with Delco Brake L ubricant or equivalent, then attach
lever to secondary shoe. Make sure that lever is free
moving.
2. Connect brake shoes together with adjusting
screw spring, then place adjusting screw in position.
W hen installing the adjusting screw spring an d adjusting
screw, make sure the spring does not touch the starwheel
portion o f the adjusting screw; and, also, w hen installing
adjusting screw, make sure right hand thread adjusting
screw is on left side of vehicle an d left hand thread
adjusting screw is on right side o f vehicle. Make certain
starwheel lines up with adjusting hole in backing plate.
If old brake shoes are to be relined, inspect shoes
for distortion and for looseness between the rim and
web; these are the causes for discarding any shoe. If
shoes are serviceable, be governed by the following
points in installing new linings:
1. Remove old linings by drilling out rivets.
Punching rivets out will distort shoe rim. Thoroughly
clean surface o f shoe rim and file off any burrs or high
spots.
2. Use G M brake lining (or equivalent) and the
rivets included in lining package which are o f the correct
size. The rivets must fit the holes with the solid body of
Installation and Adjustment
8. M easure brake drum I.D. using inside caliper
portion o f Tool J-2 1 177 (fig. 5-44). Adjust brake shoes to
dimension obtained on outside caliper portion o f Tool
J-2 1 177 (fig. 5-45).
9. Install brake drum s and wheels.
10. If any hydraulic connections were disturbed,
bleed hydraulic system.
11. Adjust parking brake.
12. Inspect all brake pipes, hoses and connections
for evidence of fluid leakage. Tighten any leaking
connection. Then apply heavy pedal pressure to brake
pedal and recheck connections.
13. Check fluid level in master cylinder and add
fluid if necessary.
14. Check brake pedal for proper feel and for
proper return.
15. Remove vehicle from hoist and road test for
proper brake action. Brakes must not be severely applied
immediately after installation o f new brake shoes or
linings. Severe application m ay perm anently dam age
new linings and m ay score brake drums. W hen linings
are new, they must be given moderate use for several
hundred miles of burnishing.
Repair Brake Lining
This procedure is to be used when brake action is
unequal, severe, hard, noisy or otherwise unsatisfactory
and when brake linings have had little wear.
1. Check fluid in master cylinder and add fluid if
necessary.
2. Check brake pedal for proper feel and for
proper return.
3. Raise vehicle on hoist and remove all wheels.
4. Remove all brake drums. Brake pedal must not
be operated while drum s are removed.
WARNING: See " W a r n in g " on page 1 of this
section.
3. Lubricate shoe contact surfaces on backing plate
with a thin coating o f Delco Brake Lubricant or
equivalent. Sparingly apply same lubricant where brake
cable contacts backing plate.
4. Place brake shoes on backing plate, at the same
time engaging shoes with wheel cylinder links. The
p rim a ry shoe (short lining) goes toward front o f vehicle.
Connect cable to parking brake lever and install strut
and spring between lever and prim ary shoe.
5. Install acutator. actuator return spring and
actuating link. If old brake shoe return springs are
nicked, distorted or of doubtful strength (discolored
from heat), it is advisable to install new parts.
6. Install shoe hold down springs.
7. Install the prim ary and secondary shoe return
springs using large pliers. Be careful not to distort
springs.
5. Clean all dirt out o f brake drums. Inspect drums
and replace or recondition if required.
6. Clean all dirt from brake assemblies, then
inspect brake linings for uneven wear, oil soaking, loose
rivets o r im bedded foreign particles. If linings are oil
soaked, replacement is required.
7. If linings are otherwise serviceable, tighten or
replace loose rivets and thoroughly clean all steel or
other im bedded particles from surfaces and rivet
counterbores o f linings.
8. Check all backing plate bolts to make sure they
are tight. (R efer to Section 4B for wheel stud
replacement procedure.)
9. Measure brake drum I.D. using inside caliper
portion o f Tool J-2 1 177. Adjust brake shoes to dimension
obtained on outside caliper portion of Tool J-2 1 177 (figs.
5-44 and 5-45).
10. Install dru m and wheel and tire assemblies.
11. Remove vehicle from hoist and road test for
proper brake action. Brakes must not be severely applied
im mediately after installation. Severe application may
perm an ently da m ag e new linings and m ay score brake
drums. W h e n linings are new, they must be given
moderate use for several hund red miles o f burnishing.
Propeller Shaft Brake
Removal (Fig. 5 -4 6 )
1.
2.
Remove the propeller shaft; see Section 4A.
Remove the brake drum.
N O TE : It may be necessary to back off the shoe
adjustm ent before rem oving the drum.
On autom atic transmission models, the exhaust
crossover pipe may be in the way. If so, loosen the
transmission rear m ounting bolts and jack the
transmission sufficiently for brake dru m to clear the
pipe.
3. Remove the two pull back springs.
4. Remove the guide plate from anchor pin.
5. Remove shoe hold down cups, springs, and
w ashers from hold down pins—remove pins.
6. Pull brake shoe an d lining assemblies away
from anchor pin and remove the strut and spring.
7. Lift the brake shoes and linings with the
adjusting nut and bolt and connecting spring off the
flange plate.
8. Move the shoes toward each other until the
adjusting bolt and connecting spring drop off.
9. Remove the clip holding the brake lever to the
prim ary shoe (shoe with short lining).
10. Compress the spring on the brake cable and
remove the cable from the lever.
11. If necessary to remove the anchor pin,
straighten the washer from pin hex and reinforcement.
Remove reinforcem ent and washer with anchor pin.
12. If necessary to remove the cable, compress
tangs on cable and pull assembly out of the hole in the
flange plate.
13. If necessary to remove the flange plate, remove
the transmission flange nut and transmission output
flange. Remove bolts holding the flange plate to bearing
retainer and remove the flange plate.
Inspection
Replace any worn or broken parts.
Installation
CAUTION: Refer to "C aution" on Page 1 o f
this section when installing fasteners in steps 1,
2 and 4 below.
1. Place the flange plate in position on the rear
bearing retainer and fasten with four bolts. Torque bolts
to 24 foot pounds.
2. Install transmission output flange on spline of
m ainsh aft and fasten with flange nut. Torque nut to 100
ft. lbs.
3. Install cable assembly from back o f flange plate.
RETURN
S P R IN G S
W AVE
W ASHER
BRAKE
LEVER
HO LD
DOW N
NUT
P IN
DRUM
HO LD
DOW N
W A S H E R , S P R IN G , C U P
B A C K IN G
BRAKE
PLATE
CABLE
Push retainer through hole in flange plate until tangs
securely grip the in n e r side o f the plate.
4. Place washer and reinforcem ent over the
threaded end o f anchor pin. Hold anchor pin nut (flat
side against flange on flange plate) in position behind
flange plate and insert threaded end o f anchor pin from
front side. T h re a d the anchor pin into nut and tighten
securely (l 40 foot pounds torque). Bend tang o f washer
over re inforcem ent and side o f washer over hex of
anchor pin.
5. Install lever on cable by compressing spring and
inserting cable in channel o f lever. Release spring.
6. Install prim ary shoe (short lining) to lever as
follows: Place pin in lever, place washer on pin and push
p in through hole in prim ary shoe. Fasten parts together
by installing the clip in groove o f pin.
7. Fasten two brake shoes and linings together by
installing connecting spring. Move the shoes toward each
other and install adjusting screw.
8. Lubricate the flange plate contact surfaces with
a very light coat of Delco Brake Lube (or equivalent).
9. Place shoe and linings in position on flange
plate.
A C T U A T IN G
ANCHOR
SU PPO R T
LEVER
CAM
A C T U A T IN G
F R IC T IO N
LEVER
S P R IN G
L IN K
O V E R RIDE
LEVER
O V E R RIDE
S P R IN G
RETURN
S P R IN G
HO LD D O W N
PIN
STAR
W HEEL
A C T U A T IN G
LEv e r
Fig. 5-47--Rear Brake Used w ith RPO H-22
N OTE: W hen facing the brake assembly, the shoe
with the short lining should be to the left with the
lever assembled to it (automatic transmission), to
the right (m anual transmission).
10. Pull brake shoes a p art and install strut lever
and spring between them. The loop on the strut spring
should be in the " u p " position.
11. Install hold down pins, washers, springs and
cups from flange plate to shoes.
12. Place guide plate on anchor pin.
13. Install pull back springs.
14. Remove the "knock o u t" plug (if necessary)
and install a new metal plug in the brake drum adjusting
hole.
15. Install the brake drum.
16. Install the propeller shaft.
RPO H22 Rear Drum Brakes
Removal (Fig. 5-47)
WARNING: See " W a r n in g " on Page 1 of
th is section.
Fig. 5-48- Removing Pull Pack Spring w ith Tool
J-22348
1. Raise the vehicle on a hoist.
2. Retract self adjusters if necessary and remove
brake drums.
3. Using Tool J-22348, remove the brake shoe pull
back springs (fig. 5-48).
4. Loosen the actuating lever cam cap screw and
while holding the star wheel end o f the actuating lever
past the star wheel, remove the cap screw and cam.
5. Remove the brake shoe hold down springs and
pins by compressing the spring with Tool J-22348 and, at
the same time, pushing the pin back through the flange
plate toward the tool. Then, keeping the spring
compressed, remove the lock from the pin with a magnet
(fig. 5-49).
6. Lift off the brake shoe and self adjuster as an
assembly.
7. The self adjuster can now be removed from the
brake shoe by rem oving the hold down spring and pin.
NOTE: The actuating lever, override lever and
spring are an assembly. It is recom m ended that
they not be disassembled for service purposes unles
Fig. 5-49- Removing Hold Down Pins Using J 22348
they are broken. It is much easier to assemble and
disassemble the brakes leaving them intact,
o
-T-i
j
,
j • •
n ,
i
8. Ih re a d the adjusting screw out o f the anchor
support and remove and discard the friction spring.
9. Clean all dirt out o f brake drum. Inspect drums
for roughness, scoring or out-of-round. Replace or
recondition drum s as necessary.
Fig. 5-50- Brake Shoe and Self A djuster Assembly
N O TE: See Section on "B R A K E D R U M S ".
10.
Carefully pull lower edges of wheel cylinder
boots away from cylinders. If brake fluid flows out,
overhaul o f the wheel cylinders is necessary.
N O T E: A slight am oun t o f fluid is nearly always
present and acts as a lubricant for the piston.
11. Inspect flange plate for oil leakage past axle
shaft oil seals. Install seals if necessary.
12. Check all flange plate attaching bolts to make
sure they are tight (150 ft. lbs. torque). Clean all dirt and
rust from shoe contact faces on flange plate using emery
cloth.
13. Thoroughly clean adjusting screws and threads
in the anchor brackets.
Installation
1. Put a light film o f Delco Brake Lube (or
equivalent) on shoe bearing surfaces o f brake flange
plate and on threads o f adjusting screw.
2. T h re a d adjusting screw completely into anchor
bracket without friction spring to be sure threads are
clean and screw turns easily. Then remove screw,
position a new friction spring on screw and reinstall in
anchor bracket.
CAUTION: See "C aution" on Page I o f this
section.
Fig. 5-51-M easuring Points for Shoe Centering
3. Assemble self adjuster assembly to brake shoe
and position actuating lever link on override lever.
4.
Position hold down pins in flange plate.
5. Install brake shoe and self adjuster assemblies
onto hold down pins, indexing ends o f shoes with wheel
cylinder push rods and legs o f friction springs.
NOTE: Make sure the toe of the shoe is against the
adjusting screw (fig.5-50).
6.
Install cup, spring and retainer on end o f hold
A C T U A T IN G LEVER
Fig. 5 -5 2 -P o sitio n in g A ctu a to r Lever
down pin. Using Tool J-22348, compress the spring. With
spring compressed, push the hold down p in back through
the flange plate toward the tool and install the lock on
the pin.
7. Using Tool J-22348, install brake shoe return
springs.
8. Holding the star wheel end o f the actuating
lever as far as possible past the star wheel, position the
adjusting lever cam into the actuating lever link and
assemble with cap screw.
9. Check the brake shoes for being centered by
m easuring the distance from the lining surface to the
edge o f the flange plate at the points shown in Figure
5-51. To center the shoes, tap the upper or lower end of
the shoes with a plastic mallet until the distances at each
end become equal.
10. Locate the adjusting lever .020" to .039" above
the outside d iam eter of the adjusting screw thread by
loosening the cap screw and turning the adjusting cam.
N O T E : To determ ine .020" to .039", turn the
adjusting screw 2 full turns out from the fully
retracted position. Hold a .060" plug gage (from
J-9789-01 Universal C a rb u re to r G age Set) at a 90°
angle with the star wheel edge o f the actuating
lever. T urn the adjusting cam until the actuating
lever and threaded area on the adjusting screw just
touch the gage (figs. 5-52 and 5-53).
11. Secure the adjusting cam cap screw and retract
the adjusting screw.
12. Install brake drums and wheels and remove
vehicle from jack stands.
13. Adjust the brakes by m aking several forward
Fig. 5 -5 3 -P u ll Gage Positioning for Correct A ctuator
Lever A d justm ent
and reverse stops until a satisfactory brake pedal height
results.
BRAKE DRUMS
Inspection and Reconditioning
W A R N IN G : See " W a rn in g " on Page 1 of
this section.
W henever brake drums are removed, they should be
thoroughly cleaned and inspected for cracks, scores, deep
grooves and out-of-round.
Cracked, Scored, or Grooved Drum
A cracked d rum is unsafe for further service and
must be replaced. D o not attempt to weld a cracked
drum.
Smooth up any slight scores. Heavy or extensive
scoring will cause excessive brake lining wear, an d it will
probably be necessary to rebore in order to true up the
braking surface.
If the brake linings are slightly worn and the drum
is grooved, the d rum should be polished with fine emery
cloth but should not be turned. At this stage, eliminating
the grooves in drum would necessitate removal o f too
much metal, while if left alone, the grooves and lining
ridges match and satisfactory service can be obtained.
If brake linings are to be replaced, a grooved drum
should be turned for use w ith new linings. A grooved
drum, if used with new lining, will not only w ear the
lining, but will make it difficult, if not impossible to
obtain efficient brake perform ance.
Out-Of-Round or Tapered Drum
An out-of-round drum makes accurate brake shoe
adjustm ent impossible and is likely to cause excessive
wear o f other parts of brake mechanism due to its
eccentric action. An out-of-round drum can also cause
severe and irregular tire tread w ear as well as pulsating
brake pedal. W hen the braking surface o f a brake drum
exceeds the factory specification limits in tap er (a n d /o r)
being out-of-round, the dru m should be turned to true
up the braking surface. Out-of-round as well as taper
and w ear can be accurately measured with an inside
m icrom eter fitted with proper extension rods.
W hen measuring a d ru m for out-of-round, taper
and wear, take m easurem ents at the open and closed
edges o f m achined surface and at right angles to each
other.
Turning Brake Drums
If a dru m is to be turned, only enough metal should
be removed to obtain a true, smooth braking surface. If
a dru m does not clean-up when turned to a maximum
d iam eter as shown in the general specification, it must be
replaced. Removal o f more metal will affect dissipation
of heat and m ay cause distortion o f the drum.
All brake drum s have a m aximum d iam eter cast
into them. This diam eter is the m aximum wear diam eter
and not a refinish diam eter. Do not refinish a brake
drum that will not meet the specifications, as shown
below, after refinishing.
DRUM DIAMETERS
O R IG IN A L
M A X IM U M R E F IN IS H
REPLACEM ENT
(D IS C A R D )
11.000
11 .0 6 0
12.060
13.060
11 .0 9 0
12.0 90
13 .0 9 0
12.000
13.000
Brake Drum Balance
D uring m anufacture, brake drums are balanced
within three ounce inches. These weights must not be
removed.
WHEEL CYLINDER
Removal
1. Remove wheel, drum and brake shoes.
careful not to get grease or dirt on brake lining.
2. Remove wheel cylinder from backing plate.
Be
Disassembly
1. Inspect cylinder bore for scoring or corrosion. It
is best to replace a corroded cylinder.
2. Polish any discolored or stained area with crocus
cloth by revolving cylinder on cloth supported by a
finger.
3. Rinse cylinder in clean brake fluid.
4. Shake excessive rinsing fluid from cylinder. Do
not use a rag to dry cylinder, as lint from the rag cannot
be kept from cylinder bore surfaces.
Assembly
1. Lubricate cylinder bore and counterbore with
clean brake fluid and insert spring-expander assembly.
2. Install new cups. (Be sure cups are lint and dirt
free.) Do not lubricate cups prior to assembly.
3. Install new pistons.
4. Press new boots into cylinder counterbores by
hand. Do not lubricate boots prior to assembly.
Installation
1. Install wheel cylinder on brake backing plate
and connect brake pipe to hose. Torque rear wheel brake
pipe to wheel cylinder to specifications.
2. Install brake shoes, drum and wheel; then flush
and bleed hydraulic system.
POWER BRAKE UNIT
Vacuum Booster
Replacement (Fig. 5 -54)
C A U TIO N : See "C aution" on page 1 o f this
section when installing fasteners referred to in
steps 6, 7 and 9 below.
1. Remove two nuts holding master cylinder to
power cylinder and position it away from power
cylinder.
C A U TIO N : Do not disconnect hydraulic brake
lines; be careful not to bend or kin k pipes.
2. Disconnect the vacuum hose from the vacuum
check valve on the front housing o f the power head. Plug
vacuum hose to prevent dust and dirt from entering
hose.
3. Disconnect the power brake push rod from the
brake pedal.
4. Remove the four nuts from the mounting studs
which hold the power brake to the cowl.
2.
P30(32) Models-Raise the vehicle on a hoist.
3. Clean all dirt from the booster at the hydraulic
line connections and m aster cylinder.
4. Remove the nuts and lockwashers that secure
the master cylinder to the booster and the support
bracket. Support the master cylinder, being careful to
avoid kinking or bending the hydraulic lines attached to
the master cylinder. Cover the end of the master cylinder
with a clean cloth.
NOTE: It should not be necessary to disconnect the
hydraulic lines from the master cylinder.
5. Disconnect the hydraulic lines from the booster
ports. Plug all lines and the booster ports to prevent loss
o f fluid and to keep out foreign material.
6.
P 3 0 (4 2 ) and C-K-G Models-
a. Remove booster pedal push rod cotter pin and
washer and disconnect the push rod from the brake
pedal (C and K models) or booster bracket pivot lever
(G and P models).
b. Remove the booster support bracket on C and
K models, support braces on G and P30(42) models.
c. Remove the booster bracket to dash panel or
support bracket nuts and remove the booster assembly.
7.
P 3 0 (3 2 ) Models-
a. Remove the cotter pin, nut, bolt and washers
that secure the operating lever to the vertical brake rod.
b. Remove the six nuts, lock washer and bolts
that secure the booster linkage bracket to the front and
rear support brackets, and remove the booster from the
vehicle by sliding the booster off the rear support studs.
Fig. 5-54--Vacuum Booster Installation
5. C arry the power brake to a clean work area and
clean the exterior of the power brake prior to
disassembly.
6. M ount power brake assembly to cowl and torque
nuts to specified torque.
7. Connect power brake push rod to brake pedal.
8. Connect vacuum hose to vacuum check valve.
9. Connect master cylinder to power cylinder and
torque nuts to specifications.
Hydro-Boost Unit
R eplacem ent (fig. 5 -55)
c. Remove the cotter pin, nut, washer and bolt
that secures the operating lever to the pedal rod.
d. Remove the brake pedal rod lever nut and
bolt and then remove the lever, sleeve and bushings.
8. To install, reverse Steps 1-7 above. T orque all
hydraullic lines and attaching bolts to specifications.
NOTE: Lubricate pedal rod and linkage pivot
bolts, pins, sleeves and bushings with Delco Brake
Lube (or equivalent).
C A U TIO N : See "C aution" on Page 1 o f this
section.
9. Bleed the booster/pow er steering hydraulic
1.
Depress and release the brake pedal several
system as described earlier in this section.
times (engine not running) to be sure that all pressure is
10. Check brake pedal and stoplamp switch
discharged from the accumulator prior to disconnectiong
the hoses from the booster.
adjustment.
G M ODELS
M O T O R H O M E C H A S S IS M O D E L S
P M O D E L S (E X C E P T M O T O R H O M E )
Fig. 5-55--Booster Insta lla tion (Hydroboost)
SPECIFICATIONS
BRAKESYSTEM DESCRIPTION
SYSTEM
FRONT BRAKES
REAR BRAKES
B R A K E A S S IS T
JB1
D isc 1 1 .8 6 x 1 .2 8
D ru m 1 1 .0 0 x 2 .0 0
N one (M a n u a l Brakes)
JB 3
D isc 1 1 .8 6 x 1 .2 8
D ru m 1 1 .0 0 x 2 .0 0
V a c u u m - S ingle D ia p h ra g m
JB 5
D isc 1 1 .8 6 x 1 .28
D ru m 1 1 .1 5 x 2 .7 5
V a c u u m - D ual D ia p h ra g m
JB 6
D isc 1 2 .5 0 x 1 .2 8
D ru m 1 1 .1 5 x 2 .7 5
V a c u u m - D ual D ia ph ra gm
JB 7
D isc 1 2 .5 0 x 1 .2 8
D ru m 1 3 .0 0 x 2 .5 0
V a c u u m - D u al D ia p h ra g m
JB 8
D isc 1 2 .5 0 x 1 .5 3
D ru m 1 3 .0 0 x 3 .5 0
H y d ra u lic - H y d ro b o o s t
JF9
D isc 1 4 .2 5 x 1 .5 3
D isc 1 3 .7 5 x 1 .5 3
H y d ra u lic - H y d ro b o o s t
BRAKE SYSTEM APPLICATION
MODEL
T O N R A T IN G
C 10516
1 /2
C 10703
W HEELBASE
1 0 6 .5
1 1 7 .5
C 10903
1 3 1 .5
M E R C H A N D IZ IN G
BRAKE
G V W R A T IN G
O P T IO N
SYSTEM
6050
Base
JB 5
4900
Base
JB1
5 3 0 0 -5 6 0 0
J50
JB 3
5 3 0 0 -5 6 0 0
J55*
JB 5*
6 0 5 0 -6 2 0 0
J55
JB 5
4900
5 3 0 0 -5 6 0 0
C 10906
C 20903
3 /4
C 20906
J55*
JB 5*
J55
JB 5
1 2 9 .5
6 0 5 0 -7 0 0 0
Base
JB 5
1 3 1 .5
6 4 0 0 -7 1 0 0
Base
JB6
6 4 0 0 -7 1 0 0
J55*
JB 7*
7 5 0 0 -8 2 0 0
J55
JB7
Base
JB 6
1 6 4 .5
C 20963
1
JB 3
5 3 0 0 -5 6 0 0
7100
7100
C 30903
JB1
6 0 5 0 -6 2 0 0
1 2 9 .5
C 20943
Base
J50
1 3 1 .5
J55*
JB7*
7 5 0 0 -8 2 0 0
J55
JB7
7 5 0 0 -8 2 0 0
Base
JB7
8200
Base
JB7
6 6 0 0 -8 2 0 0
Base
JB7
6 6 0 0 -8 2 0 0
J55*
JB 8*
9 0 0 0 -1 0 0 0 0
J55
JB 8
C 30943
1 6 4 .5
9 0 0 0 -1 0 0 0 0
Base
JB 8
C 31003
1 3 5 .5
6 6 0 0 -8 2 0 0
Base
JB 7
C 31403
* O p tio n a l H eavy D u ty Brakes.
1 5 9 .5
6 6 0 0 -8 2 0 0
J55*
JB 8*
9 0 0 0 -1 0 0 0 0
J55
JB 8
6 6 0 0 -8 2 0 0
Base
JB 7
6 6 0 0 -8 2 0 0
J55*
JB 8*
9 0 0 0 -1 0 0 0 0
J55
JB 8
BRAKE SYSTEM APPLICATION (continued)
M E R C H A N D IZ IN G
MODEL
K 10516
TON
R A T IN G
W HEELBASE
GVW
R A T IN G
BRAKE
O P T IO N
SYSTEM
1 0 6 .5
6200
Base
JB5
K 10703
1 1 7 .5
6200
Base
JB 5
K 10903
1 3 1 .5
6200
Base
JB 5
K 10906
1 2 9 .5
6 2 0 0 -7 3 0 0
Base
JB5
1 3 1 .5
6800
6800
Base
J55*
JB6
JB 7*
7 5 0 0 -8 4 0 0
J55
JB 7
Base
J55*
JB 6
JB 7*
7 5 0 0 -8 4 0 0
J55
JB 7
1 3 1 .5
8 6 0 0 -1 0 0 0 0
Base
JB8
K 30943
1 6 4 .5
9 2 0 0 -1 0 0 0 0
Base
JB 8
K 31003
1 3 5 .5
8 6 0 0 -1 0 0 0 0
Base
JB 8
K 31403
1 5 9 .5
8 6 0 0 -1 0 0 0 0
Base
JB 8
K 20903
1 /2
3 /4
K 20906
1 2 9 .5
6800
6800
K 30903
1
^ O p tio n a l H eavy D u ty Brakes.
BRAKE SYSTEM APPLICATION (continued)
M E R C H A N D IZ IN G
MODEL
G 11005
TON
R A T IN G
1 /2
W HEELBASE
110
G 11006
G 11305
125
GVW
R A T IN G
G 21005
3 /4
110
G 21006
G 21305
125
G 21306
G 31005
1
G 31305
110
125
G 31306
G 31303
4800
Base
JB1
J50*
J50
JB 3*
JB 3
5 4 0 0 -5 6 0 0
Base
JB 3
4900
4900
Base
J50*
JB1
JB 3*
J50
JB 3
5600
Base
JB 3
6400
Base
JB 5
6400
Base
JB 5
6400
Base
JB 5
6400
Base
JB 5
6 4 0 0 -7 1 0 0
6 4 0 0 -7 1 0 0
Base
J55*
JB 6
JB 7*
7 7 0 0 -8 1 0 0
J55
JB 7
6 6 0 0 -7 4 0 0
6 6 0 0 -7 4 0 0
Base
J55*
JB 6
JB 7*
7 9 0 0 -8 4 0 0
J55
JB 7
6 6 0 0 -7 4 0 0
6 6 0 0 -7 4 0 0
Base
J55*
JB 6
JB 7*
7 9 0 0 -8 4 0 0
J55
JB 7
7 4 0 0 -8 4 0 0
Base
JB 7
R 05
JB 8
Base
JB 8
8900
G 31603
^ O p tio n a l H eavy D u t y Brakes.
146
BRAKE
SYSTEM
4800
5 4 0 0 -5 6 0 0
5 4 0 0 -5 6 0 0
G 11306
O P T IO N
8 9 0 0 -1 0 5 0 0
BRAKE SYSTEM APPLICATION (continued)
M E R C H A N D IZ IN G
BRAKE
MODEL
T O N R A T IN G
W HEELBASE
G V W R A T IN G
P10542
1 /2
102
6200
Base
JB 5
P20842
3 /4
125
6800
Base
JB 6
6800
7 5 0 0 -8 0 0 0
J55*
JB 7*
J55
JB7
6800
Base
6800
J55*
JB 6
JB 7*
7 5 0 0 -8 0 0 0
J55
JB 7
7 6 0 0 -8 2 0 0
Base
JB7
7 6 0 0 -8 2 0 0
9 0 0 0 -1 0 0 0 0
J55*
J55
JB 8*
JB 8
P21042
P30842
133
1
125
P 30832
P31042
133
O P T IO N
SYSTEM
1 2 0 0 0 -1 4 0 0 0
H 2 2 or H 2 3
JF9
1 0 5 0 0 -1 2 5 0 0
Base
JB 8
7 6 0 0 -8 2 0 0
Base
JB 7
7 6 0 0 -8 2 0 0
9000 10000
J55*
J55
JB 8*
JB 8
1 2 0 0 0 -1 4 0 0 0
H 22 or H 23
JF9
P31132
137
1 0 5 0 0 -1 2 5 0 0
Base
JB 8
P31432
1 5 8 .5
1 0 5 0 0 -1 2 5 0 0
Base
JB 8
H F 7 or H F 8
JF9
14500
P31442
157
7 6 0 0 -8 2 0 0
Base
JB 7
7 6 0 0 -8 2 0 0
J55*
JB 8*
9000 10000
1 2 0 0 0 -1 4 0 0 0
P31832
^ O p tio n a l H eavy D u ty Brakes.
I7 8
14500
J55
JB 8
H 2 2 or H 2 3
JF9
Base
JF9
K
C
M aster C ylinder - to Dash or Booster
**25 ft. lbs.
Booster to Dash or Frame
**25 ft. lbs.
Com bination Valve
- Mountinq Bolts
- Bracket
C aliper
150 in.
-
**25 ft. lbs.
" 2 5 ft. lbs.
lbs.
150 in. lbs.
-
- Mountinq Bolt
- Support Plate to Knuckle
Brake Pedal
- Bracket to Dash
**r Bracket to 1. P .
- Pivot Bolt Nut
- Sleeve to Bracket
- Stoplamp Switch Bracket
- Push Rod to Pedal
- Push Rod Adiustinq Nut
Parkinq Brake
35 ft.
lbs.
140 in.
lbs.
25 ft.
lbs.
25 ft.
lbs.
25 in.
lbs.
25 in.
lbs.
25 ft. lbs
-
25 ft.
-
lbs.
25 ft, lbs.
-
25 ft. lbs.
-
-
-
100 in lbs.
100 in.
lbs.
- to I P , Kick Panel
or Floorpan
- C able C lips - Screw s
150 in .
lbs.
lbs.
150 in.
-
lbs.
150 in.
150 in. lbs.
p
25 ft lbs.
25 ft. lbs.
25 ft. lbs
17 ft.
lbs.
17 ft.
lbs.
25 ft.
lbs.
25 ft.
lbs.
150 in.
-
lbs.
25 ft. lbs.
_
-
45 ft.
25 ft.
-
lbs.
-
- to Dash
- B o lts
G
25 ft. lbs.
100 in.
lbs.
-
25 ft.
lbs.
22 ft.
-
lbs.
100 in.
lbs.
18 ft.
lbs.
100 in.
lbs.
_
18 ft.
lbs.
150 in.
55 in.
lbs.
lbs.
30 ft.
-
-
20 ft.
lbs.
lbs.
lbs.
Propshaft Parking Brake
- Adiustinq Nut
- Bracket to Trans.
lbs.
100 in. lbs.
-
- Cable Clip to Frame
_
_
-
150 in.
- Cable Clip to Dash
_
_
-
55 in.
lbs.
_
-
-
-
-
-
20 ft.
30 ft.
80 ft.
lbs.
lbs.
- Cable Clip to Trans.
- Flanqe Plate
- Drum
Brkt,
50 in. lbs.
Wheel C ylinder to Flanqe Plate Bolt
140 ft. lbs.
Rear Brake Anchor Pin
Front Brake Hose
(230 ft . lbs. JB7 and JB8)
22 ft. lbs.
58 in. lbs.
- to Caliper
- to Frame Nut
- Bracket Bolt
Rear Brake Hose
- to Axle Bracket
- Bracket to Axle
Brake Line
- Attachinq Nuts
- R e ta in in g C lip s - Screw s
- B olts
lbs.
(180 in. lbs. on JB5, JB6, JB7 and JB8)
150 in.
lbs.
_
150 in.
150 in.
lbs.
150 in.
lbs.
lb s *
150 in.
lb s .'
lbs.
150 in. lbs.
150 in. lbs. | 100 in.
| 150 in.
150 in.
-
60 in.
Brake Bleeder Valves
150 in.
lbs.
150 in.
lbs.
90 in.
-
lbs.
150 in.
lbs.
150 in.
lb s *
150 in.
lbs.
lbs.
lbs.
18 ft. lbs.
lbs.
H ydro-B oost - Pedal Rod - P30(32) M odels
25 ft.
lbs.
- Pedal Rod Boot - P30(32)M odels
_
_
_
15 in.
lbs.
- Pivot Lever Rod Retainer
_
-
_
25 ft.
lbs.
- Pivot Lever Bolt
_
-
-
45 ft.
lbs.
- Booster Brackets
_
_
-
25 ft.
lbs.
150 in.
lbs.
- Booster Brace at Dash or
Rad. Supt.
- Power Steering Pump to
Booster Line
- Booster to Gear Line
- R eturn Line at B o o ste r & Gear
- Return Lin e Clamp Screw
-
Line Clamp to Bracket Screw
-
Hose C la m p to S kirt Screw
- Line C lam p to Frame B o lt
*20 ft. lbs. (C K P20-30)
25 ft.
lbs.
25 ft.
25 ft.
lbs.
lbs.
15 in,
lbs.
150 in.
lbs.
40 in.
lbs.
-
-
150 in.
lbs.
-
-
**32 ft lbs. — Master Cylinder to Booster
Master Cylinder or Booster to Dash Reinforcement
-
18 ft.
lbs.
SPECIAL TOOLS
1.
2.
3.
4.
5.
6.
J-253 10 Tubing Bender
J-2 3 5 3 0 Flaring Tool
J-2 3533 Tubing C utter
J-2 5 0 8 5 Socket
J-8 0 4 9 or J-2 2 3 4 8 Spring Remover
J -2 1 177 or J-2 2 3 6 4 D rum /Shoe Gauge
7.
8.
9.
10.
11.
J -2 1 472
J-22904
J-23518
J-23709
J-24548
or J-2 2 3 6 4 Bleeder Wrench
Dust B oot Installer
Bleeder Adapter
C om bination Valve Pin Retainer
Dust Boot Installer
SECTION 6A
ENGINE MECHANICAL
CONTENTS OF THIS SECTION
Engine Identification....................................................................... 6A-1
D ia g n o sis............................................................................................. 6A-3
6 Cylinder E n g i n e ........................................................................... 6A-7
8 Cylinder E n g i n e ......................................................................... 6A-43
ENGINE INDENTIFICATION
All engines have a portion of the V1N num ber and a
build date code stam ped on the cylinder case.
The 6-cylinder stam ping is on the right hand side on
the distributor pad. An optional code location is at the
left rear of the cylinder and case on the bellhousing/
converter housing m ounting surface (Fig. 6A-1).
Small block 8-cylinder engines have the stamping on
top front of right hand bank o f cylinder and case. The
optional location is re ar o f the oil filter on the left side
o f the engine (Fig. 6A-1).
The Mark IV 8-cylinder engines (big block) have the
same stam ping locations as the small blocks with the
addition o f a stam ping location in front o f the engine,
above the timing chain cover (Fig. 6A-2).
DIAGNOSIS
ENGINE FAILS TO START
a. Check for sufficient fuel to operate engine.
b. C a r b u r e to r flooded a n d / o r fuel level in
carbu reto r bowl not correct.
c. Dirt and w ater in gas line or carburetor.
d. Sticking choke.
e. Faulty fuel pump.
f. Corroded or loose battery term inal connections
a n d / o r weak battery.
g. Broken or loose ignition wires a n d / o r faulty
ignition switch.
h. Excessive moisture on plugs, caps or ignition
system.
i.
D am aged distributor rotor or cracked distributor
j.
Fouled spark plugs a n d / o r im proper spark plug
k.
Weak or faulty coil.
I.
Faulty solenoid or starting motor,
cap.
g aP-
m.
Park or neutral switch inoperative.
ENGINE LOPES WHILE IDLING
a. Check
and head.
b. Check
c. Check
d. Check
for air leaks between intake manifold
for blown head gasket.
for worn timing gears, chain or sprockets.
f o r w o r n cam shaft lobes.
e.
f.
g.
h.
Check
Check
Check
Check
for overheated engine.
for plugged crankcase vent valve.
for faulty fuel pump.
for leaky E G R valve.
ENGINE MISSES WHILE IDLING
a. Check, inspect and regap spark plugs. Replace
as necessary.
b. Remove moisture from spark plug wires a n d /o r
distributor cap.
c. Check for broken or loose ignition wires. Repair
or replace as necessary.
d. Check co nd itio n o f cylinders for uneven
compression. Repair as necessary.
e. Check for weak or faulty HEI system coil as
outlined in Section 6D o f this manual.
f. Inspect condition o f distributor cap and rotor.
Replace if dam aged or cracked.
g. Check carburetor for internal obstructions,
incorrect idle speed, faulty altitude compensator, sticking
choke or enrichm ent system and adjust, rep air or replace
as necessary.
E N G IN E
E N G IN E
I D. C O D E
D IS T R IB U T O R
V IE W
B
O P T IO N A L
PAD
V IE W
V IE W
[ z ] — V . I. N . L O C A T IO N
A
A
O P T IO N A L
V IE W C
ENGINE
V IE W A
a
V .I.N .
OPTIONAL
LOCATION
Fig. 6A-2--VIN Locations (M K IV V-8)
h. Inspect carburetor fuel filter for presence o f
w ater a n d / o r impurities an d correct as necessary.
i. Check carburetor m ounting gasket for air leaks.
Repair as necessary.
j. Check distributor spark advance mechanism for
proper operation. Repair or replace as necessary.
k. Inspect valve train components. Adjust, repair
a n d / o r replace as necessary.
1. Check engine for low compression. Repair as
necessary.
m. Check operation o f exhaust gas recirculation
valve. Repair or replace as necessary.
n. Check ignition timing, and condition o f ignition
system as outlined in Section 6D o f this m anual. Correct
as necessary.
0.
Check for vacuum leaks. Correct as necessary.
p. Check operation o f EFE valve as outlined in
Section 6E o f this manual. Repair or replace as
necessary.
ENGINE MISSES AT VARIOUS SPEEDS
a. Inspect carburetor fuel filter fo r presence of
w ater a n d / o r impurities. Correct as necessary.
b. Check fuel system fo r leaks, plugged fuel lines,
incorrect fuel pu m p pressure a n d / o r plugged carburetor
jets. Correct as necessary.
c. Check ignition timing. Correct as necessary.
d. Check for excessive play in distributor shaft.
Rep air or replace as necessary.
e. Check for weak or faulty H.E.I. system coil as
outlined in Section 6D o f this manual.
f. Check, inspect and regap spark plugs. Replace
as necessary.
g. D etonation an d pre-ignition may be caused by
using sub-stan dard fuel. Correct as necessary.
h.
Check for weak valve springs and condition of
cam shaft lobes. R epair or replace as necessary.
1. Check engine operating temperature. Correct as
necessary.
j. Check operation o f exhaust gas recirculation
valve. Repair or replace as necessary.
k. Inspect distributor cap for evidence o f carbon
tracking. Replace if necessary.
1. Check for faulty altitude compensator and
incorrect carburetor adjustments. Correct as necessary.
m. Check for vacuum leaks. Correct as necessary.
n. Check operation EFE valve as outlined in
Section 6E o f this manual. Repair or replace as
necessary.
ENGINE STALLS
a.
Check carburetor for incorrect a n d / o r misadb. Inspect carburetor fuel filter for presence of
justed idle speed, float level, leaking needle and seat, air
w ater a n d / o r impurities. Correct as necessary.
valve, sticking choke or e n ric h m e n t system and
secondary vacuum break operation. Adjust, repair or
c. Check H.E.I. system as outlined in Section 6D o f
replace as necessary.
this manual.
d. Check, inspect and regap spark plugs. Replace
as necessary.
e. Check distributor spark advance m echanism for
proper operation. R epair or replace as necessary.
f. Inspect exhaust system for restrictions. Correct
as necessary.
g. Check carburetor m ounting gasket for air leaks.
Repair as necessary.
h. Check and adjust valve lash.
i. Check for burned, warped or sticking valves.
Repair or replace as necessary.
j. Check engine for low compression. Repair as
necessary.
k. Check engine operating temperature. Correct as
necessary.
1. Check for loose, corroded or leaking wiring
connections (hulk-head connectors, etc.). Repair as
necessary.
m. Check operation of exhaust gas recirculation
system. R ep air or replace as necessary.
n. Check fuel system for leaks a n d / o r obstructions.
R epair as necessary.
o.
Check for vacuum leaks. Correct as necessary,
p. Check operation o f EFE valve as outlined in
Section 6E of this manual. R epair or replace as
necessary.
ENGINE HAS LOW POWER
a. Check for weak or faulty H.E.I. system coil as
outlined in Section 6D o f this manual.
b.
Check ignition timing. Correct as necessary.
c. Check for excessive play in distributor shaft.
R epair or replace as necessary.
d. Check, inspect and regap spark plugs. Replace
as necessary.
e. Check carb uretor for incorrect a n d / o r misadjusted idle speed, float level, leaking needle and seat, air
valve and sticking choke or enrichm ent system. Adjust,
re p a ir or replace as necessary.
f. Inspect c arburetor fuel filter for presence of
w ater a n d / o r impurities. Correct as necessary.
g. Check fuel p u m p fo r leaks an d p ro p e r
operation. Correct as necessary.
h. Check for sticking valves, weak valve springs,
incorrect valve timing, lifter noise and worn camshaft
lobes. Adjust, re p a ir or replace as necessary.
i. Check for excessive piston to bore clearance.
Correct as necessary.
j. Check c o n d itio n of cylinders for uneven
compression a n d / o r blown head gasket. Repair as
necessary.
k. Check power steering flow control
operation. R epair or replace as necessary.
valve
1. Check for clutch slippage (vehicles with m anual
transmissions) and adjust or replace as necessary.
m. Check hydraulic brake
operation. Correct as necessary.
system
for
proper
n. Check engine operating tem perature. Correct as
necessary.
o.
Check pressure re g u la to r valve (au to m atic
transmission) for proper operation. R epair as necessary.
p. Check transmission fluid level. Correct as
necessary.
q. Loss o f power may be caused by using sub
standard fuel. Correct as necessary.
r. Check operation o f EFE valve as outlined in
Section 6F. of this manual. R epair or replace as
necessary.
s. Check o p e ra tio n o f div erter valve (A.I.R.
system). Repair or replace as necessary.
t. Check for engine vacuum leaks. Correct as
necessary.
ENGINE DIESELING ON SHUT OFF
a. Check base idle speed for im proper adjustment
an d correct as necessary.
b. Check ignition timing and reset to specifications
if required.
c. Check idle mixture setting an d correct as
necessary.
d. Check accelerator and choke linkage operation
and correct as necessary.
e. Check engine operating tem perature and correct
as necessary.
f. Check thermae valve for sticking and correct as
necessary.
ENGINE DETONATION
a. Check fo r overadvanced ignition timing a n d /o r
faulty ignition system and correct as necessary.
b. Check for loose or im proper application of
spark plugs, or spark plugs with cracked or broken
ceramic cores a n d replace as necessary.
c. Check for the use o f sub-standard fuel and
correct as necessary.
d. Check for foreign material in fuel lines a n d /o r
carb uretor and correct as necessary.
e. Check for restricted fuel delivery to carburetor
(pinched lines, faulty fuel tank cap or pick-up) and
correct as necessary.
f. Check fuel pu m p operation and replace if
necessary.
g. Check EFE system operation and repair or
replace as necessary.
h. Check E G R system operation and correct as
necessary.
1. Check engine operating tem perature and correct
i.
Check thermostatically controlled air cleaner
operation and correct as necessary.
as necessary.
m. Check fo r excessive com b ustion c h a m b e r
j. Check P.C.V. system operation and correct as
deposits
and correct as necessary.
necessary.
n. Check for leaking, sticking, or broken valves
k. Check for vacuum leaks and repair or replace as
and repair or replace as necessary.
necessary.
EXTERNAL OIL LEAKAGE
a. Check for im properly seated or fuel pum p
gasket. Replace as necessary.
b. Check for im properly seated or broken push rod
cover gasket. Replace as necessary.
c. Check for im properly seated or broken oil filter
gasket. Replace as necessary.
d. Check for broken or improperly seated oil pan
gasket. Replace as necessary.
e. Inspect gasket surface o f oil p a n to be bent or
distorted. R ep air or replace as necessary.
f. Check for im properly seated or broken timing
chain cover gasket. Replace as necessary.
g. Inspect timing cover oil seal. Replace if
necessary.
h. Check for worn or im properly seated rear main
bearing oil seal. Replace if necessary.
i. Inspect for loose oil line plugs. Repair or replace
if necessary.
j. Check for engine oil pan drain plug im properly
seated. Correct as necessary.
k. Inspect cam shaft rear bearing drain hole for
obstructions. Correct as necessary.
1.
Check for loose rocker arm cover. Broken or
distorted cover correct as necessary.
m. Check EFE valve switch for leakage. Replace if
necessary.
n. Check oil pressure switch for leakage. Replace if
necessary.
EXCESSIVE OIL CONSUMPTION DUE TO OIL ENTERING COMBUSTION CHAMBER
THROUGH HEAD AREA
a. Check for intake valve seats to be dam aged,
missing or loose. Repair or replace as necessary.
b. Check for w orn valve stems or guides. Repair as
necessary.
c. Inspect for plugged oil dra in back holes in head,
Correct as necessary.
d. Inspect PCV system operation. Correct as
necessary.
EXCESSIVE OIL CONSUMPTION DUE TO OIL ENTERING COMBUSTION CHAMBER BY
PASSING PISTON RINGS
a. Check engine oil level too high. Correct as
necessary.
b. Check for piston ring gaps not staggered and
correct as necessary.
c. Check for incorrect size rings installed and
correct as necessary.
d. Check for piston rings out of round, broken or
scored and replace as necessary.
e. Inspect insufficient piston ring tension due to
engine overheating and replace as necessary.
f. Check for ring grooves or oil return slots
clogged and corrected as necessary.
g. Inspect rings sticking in ring grooves o f piston
and correct as necessary.
h. Inspect ring grooves worn excessively in piston
and correct as necessary.
i. Inspect compression rings installed upside down
and correct as necessary.
j. Check for excessively worn or scored cylinder
walls and correct as necessary.
k. Inspect oil too thin and replace if necessary.
1.
Inspect mis-match o f oil ring expand er and rail
and correct as necessary.
NO OIL PRESSURE WHILE IDLING
a.
Check faulty oil gauge sending unit, and correct
as necessary.
b.
Check for oil pu m p not functioning properly.
(Regulator ball stuck in position by foreign material)
and correct as necessary.
c. Inspect for excessive clearance at main and
connecting rod bearings and correct as necessary.
d. Inspect for loose cam shaft bearings and correct
as necessary.
e. Inspect leakage at internal oil passages and
correct as necessary.
NO OIL PRESSURE WHILE ACCELERATING
a. Check low oil level in oil pan and correct as
necessary.
b. Inspect leakage at internal oil passages and
correct as necessary.
c. Check oil p u m p suction screen loose or fallen off
and correct as necessary.
BURNED, STICKING OR BROKEN VALVES
a. Check
necessary.
for
weak
springs
and
replace
as
b. Check for im p rop er valve lifter clearance and
adjust as necessary.
c. Check for im prop er valve guide clearance a n d /
or worn valve guides and correct as necessary.
d. Check for out-of-round valve seats or incorrect
valve seat width and correct as necessary.
e. Check for deposits on valve seats a n d / o r gum
form ation on stems or guides and correct as necessary.
f. Check for warped valves or faulty valve forgings
and correct as necessary.
g. Check for exhaust back pressure and correct as
necessary.
h. Check im pro per spark timing and correct as
necessary.
i. Check excessive idling and correct as necessary.
NOISY VALVES
a. Check and adjust valve lash if necessary.
b. Check for excessively worn, dirty or faulty valve
lifters. Replace if necessary.
c. Check for worn valve guides. Repair as
necessary.
d. Check for excessive run-out o f valve seat or
valve face. R epair as necessary.
e. Check for w orn c a m s h a ft lobes. Replace
cam shaft if necessary.
f. Inspect for pulled or loose rocker arm studs.
Repair or replace as necessary.
g. Check for bent push rods. Replace if necessary.
h. Inspect for broken valve spring. Replace if
necessary.
NOISY PISTONS AND RINGS
a.
Check for excessive piston to bore clearance.
Correct as necessary.
b. Inspect for im prop e r fit o f piston pin. Correct as
necessary.
c. Inspect for excessive accumulation of carbon in
combustion cham ber or on piston tops. Clean a n d /o r
repair as necessary.
d. Check for connecting rods alignment. Correct as
necessary.
e. Inspect for excessive clearance between rings
and grooves. Repair or replace as necessary.
f. Check for broken piston rings. Replace as
necessary.
BROKEN PISTONS AND/OR RINGS
a. Check for u ndersize pistons. Replace if
necessary.
b. Check for w rong type a n d / o r size rings
installed. Replace if necessary.
c. Check for tapered or eccentric cylinder bores.
Correct as necessary.
d. Check connecting rod alignment. Replace if
necessary.
e. Check for excessively w orn ring grooves.
Replace if necessary.
f. Check for im properly assembled piston pins.
Replace as necessary.
g. Check for insufficient
Correct as necessary.
h. Inspect
necessary.
i. Check
necessary.
j.
for
for
engine
ring
gap
overheating.
su b -sta n d a rd
fuel.
clearance.
Correct
as
Correct
as
Check ignition timing. Correct as necessary.
NOISY CONNECTING RODS
a. Check connecting rods for im proper alignment
and correct as necessary.
b. Check for excessive bearing clearance and
correct as necessary.
c. Check for eccentric or out-of-round crankshaft
jo urna ls and correct as necessary.
d. Check for insufficient oil supply and correct as
necessary.
e. Check for low oil pressure and correct as
necessary.
f. Check for connecting rod bolts not tightened
correctly and correct as necessary.
NOISY MAIN BEARINGS
a. Check low oil pressure a n d / o r insufficient oil
supply and correct as necessary.
b. Check for excessive bearing clearance and
correct as necessary.
c. Check for excessive crankshaft end play and
correct as necessary.
d. Check for eccentric or out-of-round crankshaft
jou rnals and correct as necessary.
e. Check for sprung crankshaft and replace if
necessary.
f. Check for excessive belt tension and adjust as
necessary.
g. Check for loose torsional d a m p e r and replace as
necessary.
NOISY VALVE LIFTERS
a. Check for broken valve springs and replace as
necessary.
b. Check for worn or sticking rocker arms and
rep air or replace as necessary.
c. Check for worn or bent push rods and replace as
necessary.
d. Check for valve lifters incorrectly fitted to bore
size and correct as necessary.
e. Check faulty valve lifter plunger or push rod
seat and replace lifters as necessary.
f. Check for plungers excessively w orn causing fast
leakdown under pressure and replace as necessary.
g. Check for excessively w orn cam shaft lobes and
replace if necessary.
h.
Check valve lifter oil feed holes plugged causing
internal breakdown and correct as necessary.
i. Check faulty valve lifter check ball, (nicked, flat
spot, or out o f round) and replace as necessary.
j.
Check rocker arm retaining nut to be installed
upside dow'n and correct as necessary.
k. Check for end o f push rod excessively worn or
flaked and replace as necessary.
6 C ylinder Engine
Contents
G en eral D e s c rip tio n .......................................................
Engine L u b ric a tio n .........................................................
O n Vehicle S erv ic e.........................................................
E ngine M o u n t s ..............................................................
M anifold A ssembly-Non-Integrated H e a d ...........
Exhaust M anifold-Integrated H e a d ........................
Rocker Arm C o v e r.......................................................
Valve M e c h a n ism ..........................................................
Valve Stem Oil Seal a n d / o r Valve S p rin g ........
Valve L i f t e r s ...................................................................
Cylinder H e a d ...............................................................
Rocker Arm S tu d s ........................................................
Valve G u id e s ...................................................................
Valve S e a t s ......................................................................
6A-7
6A-8
6A-15
6A-15
6A-16
6A-16
6A-17
6A-17
6A-17
6A-18
6A-20
6A-22
6A-23
6A-23
Valves................................................................................ .6A-24
Torsional D a m p e r ......................................................... .6A-24
Crankcase Front C o v e r .............................................. .6A-25
Oil Seal (Front C o v er)............................................... .6A-26
C a m s h a f t .......................................................................... .6A-27
C am sh aft Bearings.........................................................6A-29
Oil P a n ............................................................................. .6A-30
Oil P u m p ........................................................................... 6A-30
Connecting Rod B earings...........................................6A-31
Crankshaft Main B e a rin g s.........................................6A-32
Oil Seal (R ear M a i n ) ................................................. .6A-35
Piston and Connecting Rod Assemblies.............. .6A-36
Engine A ssem bly........................................................... .6A-40
C r a n k s h a f t .........................................................................6A-41
GENERAL DESCRIPTION
CYLINDER BLOCK
The cylinder block is m ade o f cast iron and has 6
cylinders arranged "In-Line". Seven main bearings
support the crankshaft which is retained by recessed
bearing caps that are machined with the block for
proper alignm ent and clearances. Cylinders are com
pletely encircled by coolant jackets.
CYLINDER HEAD
The cast iron cylinder head provides a compression
ratio o f 8.3:1. It is cast with individual intake and
exhaust ports for each cylinder. Valve guides are integral
and rocker arm s are retained on individual threaded
studs pressed into head. Most 250 heads have integrated
inlet manifold
manifolds.
while
the
292
uses
separate
inlet
CRANKSHAFT AND BEARINGS
The crankshaft is cast nodular iron and is supported
by seven main bearings. N u m b e r seven bearing is the
end thrust bearing. M ain bearings are lubricated from
oil holes which intersect the main oil gallery located on
the right side o f the block. The cam bearings are also fed
oil by intersecting holes with main oil gallery. The lifters
are located in the main oil gallery.
A d am p er assembly, on the forward end o f the
crakshaft, dam pens any engine torsional vibrations. The
outer ring o f the d a m p e r is grooved for the accessory
drive belts.
CAMSHAFT AND DRIVE
The cast iron cam shaft is supported by four
bearings and is gear driven. A cast iron crankshaft gear
drives the alum inum cam sh aft gear. Cam lobes are
ground, h a rd e n e d and tapered w ith the high side toward
the rear. This, coupled with a spherical face on the
lifters, causes the valve lifters to rotate.
PISTONS AND CONNECTING RODS
The pistons are m ade o f a cast alum inum alloy
using two compression rings an d one oil control ring.
Piston pins are offset .060" toward the thrust side
(right h an d side) to provide a gradual change in thrust
pressure against the cylinder wall as the piston travels its
path. Pins are chrom ium steel an d have a floating fit in
the pistons. They are retained in the connecting rods by
a press fit.
Connecting rods are m ade o f forged steel. Full
pressure lubrication is directed to the connecting rods by
drilled oil passages from the adjacent m ain bearing
journal. Oil holes at the connecting rod journals are
located so that oil is supplied to give maxiumu
lubrication just p rio r to full bearing load.
VALVE TRAIN
A very simple ball pivot-type train is used. Motion
is transm itted from the cam sh aft through the hydraulic
lifters and push rods to the rocker arms. The rocker arm
pivots on its ball and transmits the cam shaft motion to
the valve. The rocker arm ball is retained by a self
locking nut.
HYDRAULIC VALVE LIFTERS
H ydraulic Valve Lifters are used to keep all parts of
the valve train in constant contact for quiet operation.
The hydraulic lifter assembly consists of: the lifter
body, which rides in the cylinder block boss, a plunger, a
push rod seat, a m etering valve, a plunger spring, a
check ball and spring, a check ball retainer and a push
rod seat retainer.
W h en the lifter is riding on the low point (base
circle) o f the cam, the plunger spring keeps the plunger
and push rod seat in contact with the push rod.
W h e n the lifter body begins to ride up the cam lobe,
the check ball cust off the transfer o f oil from the
reservoir below the plunger. The plunger and lifter body
then rise as a unit, pushing up the push rod and opening
the valve. A very small am ount o f oil will leak out
between the plunger and the body.
As the lifter body rides down the other side o f the
cam, the plunger follows with it until the valve closes.
The lifter body continues to follow the cam to its low
point, but the plunger spring keeps the plunger in
contact with the push rod. The ball check valve will then
move off its seat and the lifter reservoir will be refilled
with oil.
INTAKE MANIFOLD
The intake manifold is o f cast iron, single level
design for efficient fuel distribution. The 250 manifold is
an integral unit with the head, except KIO and CIO with
F44, while the 292 uses a separate component. The
carburetor pad is centrally located with a passage
running underneath the pad (E.F.E.), through which
exhaust gases are forced, to prom ote faster fuel
vaporization when the engine is cold. An E G R port is
also cast into the manifold for the induction of a
metered am ount o f exhaust gases into the air and fuel
mixture which has entered through the carburetor.
EXHAUST MANIFOLD
A single four port, underslung, center take down
manifold o f cast iron is used to direct exhaust gases from
the combustion chambers. A heat shield is mounted to
the m anifold that is used to route heated air to the air
cleaner for better fuel vaporization.
ENGINE SERVICE
NOTE: The following inform ation is im portant in
preventing engine d am age and in providing
reliable engine performance.
W hen raising or supporting the engine for any
reason, do not use a jack under the oil pan, any sheet
metal or crankshaft pulley. Due to the small clearance
between the oil pan and the oil pu m p screen, jacking
against the oil p an may cause it to be bent against the
pu m p screen, resulting in a dam aged oil pickup unit.
It should be kept in mind, while working on the
engine, that the 12-volt electrical system is capable o f
violent and d a m aging short circuits. W hen perform ing
any work where electrical terminals could possibly be
grounded, the ground cable o f the battery should be
disconnected at the battery.
Any time the carburetor or air cleaner is removed,
the intake opening should be covered. This will protect
against accidental entrance of foreign material which
could follow the intake passage into the cylinder and
cause extensive dam age w hen the engine is started.
Engine Lubrication
Full pressure lubrication, through a full flow oil
filter is furnished by a gear-type oil pump. The
distributor, driven by a helical gear on the camshaft,
drives the oil pump. The m ain oil gallery feeds oil,
through drilled passages, to the cam shaft and crankshaft
to lubricate the bearings. The m ain oil gallery also feeds
the valve lifters; which, through hollow push rods, feed
the individually mounted rocker arms (Fig. 6A-3).
OIL PRESSURE
SENDING UNIT
DISTRIBUTOR SHAFT
O ILING
zzzzzzzzzzz
T IM IN G GEAR
OIL NOZZLE
SPLASH R
OILING ;:
FULL FLOW OIL FILTER
FILTER BY-PASS
SYSTEM
Fig. 6 A -4 -P Series Engine Rear M ount
4 l
2 5 0 CU. IN . ENGINE
LEFT & RIGHT M O U N T
& FRAME BRACKET
2 9 2 CU. IN . ENGINE
LEFT M O U N T &
FRAME BRACKEET
0
^
ENGINE BRACKET
ALL P SERIES
W IT H L-6 ENGINE
2 5 0 CU. IN . ENGINE
LEFT & RIGHT M O U N T
& FRAME BRACKET
2 9 2 CU. IN . ENGINE
LEFT M O U N T & FRAME
BRACKET
VIEW
ENGINE BRACKET
ALL C SERIES
W ITH L-6 ENGINE
2 9 2 CU. IN . ENGINE
RIGHT FRAME
BRACKET & M O U N T
VIEW
Fig. 6A-8--K Series Engine Rear M ount
6A14
LIGHT
TRUCK
SERVICE
ENG IN E M O U N T & BRACKET
ALL K SERIES W IT H L-6 EN G IN E
MANUAL
FRONT M O U N T
REAR M O U N T
Fig. 6A-10-G Series Engine M ounts
ON VEHICLE SERVICE
ENGINE MOUNTS
C hecking Engine Mounts
b. R u bb er separated from a metal plate o f the
mount; or
c. R ubber split through center,
Replace the mount. If there is relative movement
between a metal plate o f the mount and its attaching
points, lower the engine on the mounts and tighten the
screws or nuts attaching the m ount to the engine, frame,
or bracket.
Front M ou nt
Rear M ount
Raise the engine to remove weight from the mounts
and to place a slight tension in the rubber. Observe both
mounts while raising engine. If an engine mount
exhibits:
a. H ard ru b b e r surface covered with heat check
cracks;
Raise the vehicle on a hoist. Push up and pull down
on the transmission tailshaft while observing the
transmission mount. If the ru bb er separates from the
metal plate of the mount or if the tailsahft moves up but
not down (mount bottomed out) replace the mount. If
there is relative movement between a metal plate of the
Engine mounts (Fig. 6A-4 - 6A-10) are the nonadjustable type and seldom require service. Broken or
deteriorated mounts should be replaced immediately,
because o f the . added strain placed on other mounts and
drive line components.
m o un t and its attaching point, tighten the screws or nuts
attaching the m ount to the transmission or crossmember.
Front Mount Replacement
1. Remove engine m ount through bolt.
2. Raise engine and remove m ount
bracket attaching bolts. Remove mount.
to
fram e
CAUTION: Raise engine only enough fo r
sufficient clearance. Check fo r interference
between rear o f engine a n d cowl panel.
3. Install new engine m ount to fram e bracket and
torque attaching bolts to specifications.
4. Install engine m ount through bolt and torque to
specification.
Rear Mount Replacement
1. Support engine weight to relieve rear mounts.
2. Remove crossmember-to-mount bolts.
3. On P Series with m anual transmission and
propeller shaft prak in g brake, remove m ount attaching
bolts from fra m e outrigger and clutch housing and
remove re a r m ounting cushions.
4. R em ove m ou nt-to -tra n sm issio n bolts, then
remove mount.
5. On P Series with m anual transmission and
propeller shaft park in g brake, install new m ounting
cushions and bolts.
6. Install new m ount on transmission.
7. W hile lowering transmission, align and start
crossm em ber-to-m ount bolts.
8. Torque bolts to specifications then bend lock
tabs to bolt head as applicable.
M A N IF O L D ASSEMBLY - N O N -IN T E G R A T E D
HEAD
Removal
1. Remove air cleaner.
2. Disconnect both throttle controls at bellcrank
and remove throttle return spring.
3. Disconnect fuel and vacuum lines at carburetor.
4. Disconnect crankcase ventilation hose at rocker
arm cover.
5. Disconnect vapor hose at canister.
6. Disconnect exhaust pipe at m anifold flange and
discard packing.
7. Remove m anifold attaching bolts and clamps
then remove m anifold assembly and discard gaskets.
8. Check for cracks in manifold castings.
9. Separate m anifold by removing one bolt and
two nuts at center o f assembly.
Installation
1. Clean gasket surfaces on cylinder head and
manifolds.
2. Lay a straight edge along the full length o f the
exhaust port faces and measure any gaps between the
straight edge and the port faces. If at any point a gap of
.030 or m ore exists, it is likely that the manifold has
distorted to a point where it will not seat properly. If a
good exhaust seal is to be expected, the exhaust manifold
must be replaced.
3. Reinstall the one bolt and two nuts at the center
o f the manifold to finger tight.
4. Position a new gasket over m anifold end studs
on the cylinder head.
5. Install manifold assembly bolts and clamps
while holding manifold assembly in place by hand.
6. Clean, oil and torque all m anifold assembly to
cylinder head bolts and nuts to 35 lbs. ft.
7. Complete torquing the inlet to exhaust manifold
bolt and two nuts at the center o f the manifold to 30 lb.
ft.
8. Connect exhaust pipe to m anifold using a new
packing.
9. Connect crankcase ventilation hose at rocker
arm cover.
10. Connect vapor hoses at canister.
11. Connect fuel and vacuum lines a carburetor.
12. Connect throttle controls at bellcrank and
install throttle return spring.
13. Install air cleaner, start engine, check for leaks
and adjust carburetor idle speed.
EXH AUST M A N IF O LD ASSEMBLY IN TE G RATE D HEAD
Removal
1. Disconnect negative battery cable.
2. Remove air cleaner.
3. Remove power steering pum p a n d / o r A.I.R.
pum p brackets, if so equipped.
4. Raise vehicle on hoist and disconnect exhaust
pipe at manifold and converter bracket at transmission
mount. If equipped with manifold converter, disconnect
exhaust pipe from converter, remove converter.
5. Lower vehicle.
6. Remove rear heat shield and accelerator cable
bracket.
7. Remove exhaust manifold bolts.
8. Remove exhaust m anifold, check EFE Valve to
see if free and check manifold for cracks.
Installation
NOTE: If a new exhaust manifold is being
installed, the E.F.E. valve and actuator and rod
assembly must be transferred from the old
component.
1. Clean gasket surface and position new gasket on
exhaust manifold.
2. Install manifold bolts, while holding manifold
assembly in place.
3. Torque all cylinder head to manifold bolts to
specifications (Fig. 6A -11).
4. Install rear heat shield and accelerator cable
bracket.
5. Raise vehicle on hoist.
6. Connect exhaust pipe at manifold flange and
converter bracket at transmission mount. If equipped
with m anifold converter, loosely install M a n ifo ld
18/23
LBS F T
©
^ © © „ r,T©
©
\ /
©
»T © - S ’, - © fBfFT
©
®
®
©
Fig. 6A 11 -Cylinder Head To Exhaust M anifold
Tightening Sequence
Converter, attach exhaust pipe and align exhaust system.
T orque attaching bolts to specification.
7. Lower vehicle.
8. Install power steering p u m p a n d / o r A.I.R. pu m p
and brackets, if so equipped. Tighten drive belt using
strand tension gauge.
9. Install air cleaner.
10. Connect negative battery cable.
11. Start engine and check for leaks.
ROCKER ARM COVER
Removal
1. Disconnect crankcase ventilation hose(s) at
rocker arm cover.
2. Remove air cleaner.
3. Disconnect all wires, fuel and vacuum pipes
from rocker arm cover clips.
4. Disconnect air injection hose from check valve
o f AIR pipe (where so equipped).
5. Remove rocker arm cover by rotating out from
under air pipe.
CAUTION: Do not p ry rocker arm cover loose.
Gaskets adhering to cyllinder head and rocker
arm cover m ay be sheared by bum ping fro n t
end o f rocker arm cover rearward with palm o f
hand or rubber mallet.
Installation
1. Clean gasket surfaces on cylinder head with
degreaser. Using RTV, install rocker arm cover and
torque bolts to specification.
N O TE : All loose RTV sealer, or pieces causing
installation interference must be removed from
both cylinder head an d cover seal surfaces prior to
applying new sealer.
A 1/8" bead o f RTV sealer should be placed all
aro un d the rocker cover sealing surface of the
cylinder head. (W hen going around attaching bolt
holes, always go around the inboard side of the
holes). Install cover and torque bolts to specifica
tion while RTV is wet (within 10 min.).
2. Connect wires, fuel and vacuum pipes at rocker
arm cover clips.
3. Install air cleaner.
4.
hoses.
Connect crankcase ventilation hoses and AIR
VALVE M E C H A N IS M
Removal
1. Remove rocker arm cover as outlined.
2. Remove rocker arm nuts, rocker arm
rocker arms and push rods.
balls,
NOTE: Place rocker arms, rocker arm balls and
push rods in a rack so that they may be reinstalled
in the same location.
Installation and Adjustment
NOTE: W henever new rocker arms a n d / o r rocker
arm balls are being installed, coat bearing surfaces
o f rocker arms and rocker arm balls with
"M olykote" or its equivalent.
1. Install push rods. Be sure push rods seat in lifter
socket.
2. Install rocker arms, rocker arm balls an d rocker
arm nuts. Tighten rocker arm nuts until all lash is
eliminated.
3. Adjust valves w hen lifter is on base circle o f
cam shaft lobe as follows:
a. M ark distributor housing, with chalk, at
num ber one and n u m b e r six positions (plug wire) then
disconnect plug wires at spark plugs and coil and remove
distributor cap and plug wire assembly (if not previously
done).
b. Crank engine until distributor rotor points to
num ber one cylinder position. The following valves can
be adjusted with engine in num ber one firing position:
N u m b e r one cylinder-Exhuast and Intake.
N u m b e r two cylinder-Intake
N u m b e r three cylinder-Exhaust
N u m b e r four cylinder-Intake
N u m b e r five cylinder-Exhaust
c. Back out adjusting nut until lash is felt at the
push rod then turn in adjusting nut until all lash is
removed. Theis can be determ ined by checking push rod
end play while turning adjusting nut (Fig. 6A-12). W hen
play has been removed, turn adjusting nut in one full
additional turn (to center lifter plunger).
d. Crank engine until distributor rotor points to
num ber six position. The following valves can be
adjusted with engine in nu m b er six firing position:
N u m b e r two cylinder-Exhaust
N u m b e r three cylinder-Intake
N u m b e r four cylinder-Exhuast
N u m b e r five cylinder -Intake
N u m b e r six cylinder-Intake and Exhuast
4. Install distributor cap and spark plug wire
assembly.
5. Install rocker arm cover as outlined.
6. Adjust carburetor idle speed.
VALVE STEM OIL SEAL A N D /O R VALVE
SPRING
Replacement
6. To replace, set the valve spring, valve shield and
valve can in place. Compress the spring with Tool J-5892
and install oil seal in the lower groove o f the stem,
m aking sure the seal is flat and not twisted.
N OTE: A light coat o f oil on the seal will help
prevent twisting.
7. Install the valve locks and release the compres
sor tool, making sure the locks seat properly in the upper
groove of the valve stem.
NOTE: Grease may be used to hold the locks in
place while releasing the compressor tool.
8. Install spark plug, and torque to 15 lb. ft.
9. Install and adjust valve mechanism as previously
outlined.
VALVE LIFTERS
Hydraulic valve lifters very seldom require atten
tion. The lifters are extremely simple in design.
Readjustments are not necessary, and servicing o f the
lifters requires only that care and cleanliness be
exercised in the handling o f parts.
Locating Noisy Lifters
Fig. 6A-12--Valve A djustm ent
J -5 8 9 2
L___
J -2 3 5 9 0
Fig. 6A-13-C om pressing Valve Spring
1. Rem ove rocker arm cover as previously
outlined.
2. Remove spark plug, rocker arm and push rod on
the cylinder(s) to be serviced.
3. Install air line ad ap ter Tool J-23590 to spark
plug port and apply compressed air to hold the valves in
place.
4. Using Tool J-5892 to compress the valve spring,
remove the valve locks, valve cap, valve shield and valve
spring and d a m p e r (fig. 6A-13).
5. Remove the valve stem oil seal.
Locate a noisy valve lifter by using a piece of
garden hose approxim ately four feet in length. Place one
end o f the hose near the end o f each intake and exhaust
valve with the other end o f the hose to the ear. In this
m a n n e r the sound is localized, m aking it easy to
determ ine which lifter is at fault.
A nother method is to place a finger on the face of
the valve spring retainer. If the lifter is not functioning
properly, a distinct shock will be felt w hen the valve
returns to its seat.
T he general types o f valve lifter noise are as
follows:
1. Hard R apping Noise - Usually caused by the
plunger becoming tight in the bore o f the lifter body to
such an extent t h a l j h e return spring can no longer push
the plunger back up to working position. Probable causes
are:
a. Excessive varnish or c arbon deposit causing
abnorm al stickiness.
b. G alling or "pickup" between plunger and
bore o f lifter body, usually caused by an abrasive piece
of dirt or metal wedging between plunger and lifter
body.
2. M oderate Rapping Noise - Probable causes are:
a. Excessively high leakdown rate.
b. Leaky check valve seat.
c. Im proper adjustment.
3. G eneral Noise T hroughout the Valve T rain This will, in most cases, be caused by either insufficient
oil supply or im pro per adjustment.
4. Intermittent Clicking Probable causes are:
a. A microscopic piece o f dirt momentarily
caught between ball seat and check valve ball.
b. In rare cases, the ball itself m ay be out-of
round or have a flat spot.
c. Im proper adjustment.
In most cases where noise exists in one or more
lifters, all lifter units should be removed, disassembled,
cleaned in a solvent, reassembled, and reinstalled in the
engine. If dirt, varnish, carbon, etc., is shown to exist in
one unit, it more than likely exists in all the units, thus it
would only be a matter o f time before all lifters caused
trouble.
R e m o va l
1. Remove rocker arm cover and loosen rocker
arm s sufficiently to remove the push rods. Place push
rods in a rack so that they m ay be returned to their
original location.
2. M ark distributor housing, with chalk, at nu m b er
one an d nu m b e r six position (plug wire) then disconnect
plug wires at spark plugs and coil and remove distributor
cap an d plug wire assembly.
3. Crank engine until distributor rotor points to
n u m b e r one position, then disconnect d istrib u to r
p rim a ry lead at coil and remove distributor.
4. R E M O V E PU SH R O D COVERS (discard
gaskets).
5. Remove valve lifters.
N O T E : Place valve lifters in a rack so that they
m ay be installed in the same location.
D isassem b ly
Fig. 6A-15-R em oving Ball Check Valve
4.
Remove the ball check valve and spring by
prying the ball retainer loose from the plunger with the
blade o f a small screw driver (fig. 6A-15).
C le a n in g an d In sp ectio n
1. Hold the plunger down with a push rod, and
using the blade o f a small screw driver, remove the push
rod seat retainer.
2. Remove the push rod seat and metering valve
(fig. 6A-14).
3. Remove the plunger, ball check valve assembly
and the plunger spring.
Thoroughly clean all parts in cleaning solvent, and
inspect them carefully. If any parts are d am aged or
worn, the entire lifter assembly should be replaced. If the
lifter body wall is scuffed or worn, inspect the cylinder
block lifter bore, if the bottom o f the lifter is scuffed or
worn inspect the cam shaft lobe, if the push rod seat is
scuffed or worn inspect the push rod.
An additive containing EP lube, such as EOS,
or equivalent, should always be added to crankcase oil for
run-in when any new camshaft or lifters are installed. All
damaged or worn lifters should be replaced.
A ssem bly
1. Place the check ball on small hole in bottom o f
the plunger.
2. Insert check ball spring on seat in ball retainer
and place retainer over ball so that spring rests on the
ball. Carefully press the retainer into position in plunger
with the blade o f a small screw driver (fig. 6A-16).
1
L ifte r B o d y
2
Push Rod S eat
3. M e te rin g V a lv e
4
C h e ck B a ll
5. C h e ck B a ll R e ta in e r
6
7
Push Rod Seat
R e ta in e r
P lu n g e r
8
9.
C h eck B a ll S p rin g
P lu n g e r S p rin g
3. Place the plunger spring over the ball retainer
and slide the lifter body over the spring and plunger,
being careful to line up the oil feed holes in the lifter
body and plunger.
4. Fill the assembly with SAE 10 oil, then insert
the end of a 1/8" d rift pin into the plunger and press
down solid. At this point oil holes in the lifter body and
plunger assembly will be aligned (fig. 6A-17).
the oil holes. The lifter is now completely assembled,
filled with oil and ready for installation.
NOTE: Before installing lifters, coat the bottom of
the lifter with "M olykote" or its equivalent.
In s ta lla tio n
1.
Install valve lifters.
N OTE: W henever new valve lifters are being
installed, coat foot of valve lifters with "M olykote"
or its equivalent.
2. Install push rod covers, using new gaskets, and
torque bolts to specifications.
3. Install distributor, positioning rotor to num ber
one cylinder position, then connect p rim a ry lead at
distributor.
4. Install push rods and adjust valve mechanism as
outlined.
5. Adjust ignition timing and carburetor idle
speed.
CYLINDER HEAD ASSEMBLY
R em o val
Fig. 6A 16- In sta llin g Ball Check Valve
1. Remove m a n ifo ld assem bly as previosuly
outlined.
2. Remove rocker arm cover and valve mechanism
as previously outlined.
3. D rain cooling system (block).
4. Remove fuel and vacuum line from retaining
clip at w ater outlet, then disconnect wires from
temperature sending units.
5. Disconnect air injection hose at check valve (if
so equipped).
6. Disconnect rad iato r upper hose at water outlet
housing and battery ground strap at cylinder head.
7. Remove cylinder head bolts, cylinder head and
gasket. Place cylinder head on two blocks o f wood to
prevent damage.
Disassem bly
Fig. 6A-17--Assem bling Hydraulic Lifter
C A U T IO N : Do not attem pt to force or pum p
the plunger.
5. Insert a 1 /1 6" drift pin through both oil holes to
hold the plunger down against the lifter spring tension
(fig. 6A-17).
6. Remove the 1/8 " drift pin, refill assembly with
SAE 10 oil.
7. Install the m etering valve and push rod seat (fig.
6A-14).
8. Install the push rod seat retainer, press down on
the push rod seat and remove the 1/16" drift pin from
1. With the cylinder head removed, use tool J-8062
to compress the valve springs and remove the valve keys
(fig. 6A-18). Release the compressor tool and remove
rotators or spring caps, spring shields (if so equipped)
springs and spring dam per, then remove oil seals and
valve spring shims.
2. Remove valves from cylinder head and place
them in a rack in their proper sequence so that they can
be assembled in their original positions.
C lea n in g
1. Clean all deposits from combustion chambers
and valve ports using Tool J-8089 (fig. 6A-19).
2. Thoroughly clean the valve guides using Tool
J-8101 (fig. 6A-20).
3. Clean all carbon and sludge from push rods,
rocker arms and push rod guides.
Fig. 6A-20-C leaning Valve Guides (Typical)
Fig. 6A- 18- Com pressing Valve Spring (Typical)
Fig. 6A-19-C leaning Com bustion Chambers (Typical)
4.
Clean valve stems and heads on a buffing wheel.
5. Clean carbon deposits from head gasket m ating
surface.
Fig. 6A-21--Measuring Valve Stem Clearance (Typical)
In s p e ctio n
1. Inspect the cylinder head for cracks in the
exhaust ports, combustion cham bers, or external cracks
to the w ater cham ber.
2. Inspect the valves for burned heads, cracked
faces or d am aged stems.
N O T E: Excessive valve stem to bore clearance will
cause excessive oil consumption and may cause
valve breakage. Insufficient clearance will result in
noisy and sticky functioning of the valve and
disturb engine smoothness.
3.
Measure valve stem clearance (fig. 6A-21) as
follows: Clam p a dial indicator on one side o f the
cylinder head rocker arm cover gasket rail, locating the
indicator so that movem ent o f the valve stem from side
to side (crosswise to the head) will cause a direct
movem ent of the indicator stem. The indicator stem
must contact the side o f the valve stem just above the
valve guide. With the valve head dropped about 1/16"
off the valve seat; move the stem o f the valve from side
to side using light pressure to obtain a clearance reading.
5.
Inspect rocker arm studs for wear or damage.
Assembly
1. Insert valves in the proper ports.
2. Set the valve spring shim, valve spring (with
damper, if used) valve shield and valve cap or rotator in
place (fig. 6A-23).
3. Compress the spring with Tool J-8062.
4. Install oil seal in the lower groove o f the stem,
making sure that the seal is flat and not twisted.
5. Install the valve locks and release the compres
sor tool, making sure that the locks seat properly in the
upper groove o f the valve stem.
Installation
CAUTiON: The gasket surfaces on both the
head and the block m ust be clean o f any
foreign m atter and free o f nicks or heavy
scratches. Cylinder bolt threads in the block
and threads on the cylinder head bolt m ust be
cleaned. (Dirt will affect bolt torque.) Do not
use gasket sealer or composition steel asbestos
gasket.
1. Place the gasket in position over the dowel pins
with the bead up.
2. Carefully guide cylinder head into place over
Fig. 6A-22--Checking Valve Spring Tension
dowel pins and gasket.
3. Coat threads o f cylinder head bolts with sealing
If clearance exceeds specifications it will be necessary to
com
pound
and install finger tight.
ream valve guides for oversize valves as outlined.
4. Tighten cylinder head bolts a little at a time in
4.
Check valve spring tension with Tool J-8056
the sequence shown on the torque sequence chart until
spring tester (fig. 6A-22).
the specified torque is reached.
N O T E: Springs should be compressed to the
5. Connect rad iato r upper hose and engine ground
specified height and checked against the specifica
strap.
tions chart. Springs should be replaced if not
6. Connect tem perature sending unit wires and
within 10 lbs. of the specified load (without
install fuel and vacuum lines in clip at water outlet.
dampers).
7. Fill cooling system.
8. Install m a n ifo ld
assembly as previously
outlined.
9. Install and adjust valve mechanism as previously
outlined.
10. Install an d torque rocker arm cover.
•cap
11. Connect AIR pipe (if so equipped).
SEAL
S HIELD
* DAMPER
ROCKER ARM STUDS
Replacement
Rocker arm studs that have dam aged threads or are
loose in cylinder heads should be replaced with new
studs available in .003" and .013" oversize. Studs may be
installed after ream ing the holes as follows:
1. Remove old stud by placing Tool J-5802-A over
the stud, installing n ut and flat washer and removing
stud by turning nut (fig. 6A-24).
2. Ream hole for oversize stud using Tool J-5715
for .003" oversize or Tool J-6036 for .013" oversize (fig.
6A-25).
CAUTION: Do not attempt to install an
oversize stud without reaming stud hole.
3. Coat press-fit area o f stud with hypoid axle
Fig. 6A 24 Removing Rocker Arm Stud (Typical)
Fig. 6A-26--lnstalling Rocker Arm Stud (Typical)
Fig. 6A-25- Reaming Rocker Arm Stud Bore (Typical)
lubricant. Install new stud, using Tool J-6880 as a guide.
G au ge should bottom on head (fig. 6A-26).
Fig. 6A -27-R eam ing Valve Guide (Typical)
VALVE G U ID E BORES
Valves with oversize stems are available (see
specifications). To ream the valve guide bores for
oversize valves, use Tool Set J-5830 (fig. 6A-27).
VALVE SEATS
Reconditioning the valve seats is very important,
because the seating o f the valves must be perfect for the
engine to deliver the power and perform ance built into
it.
A nother im portant factor is the cooling o f the valve
heads. G ood contact between each valve and its seat in
the head is imperative to insure that the heat in the valve
head will be properly carried away.
Several different types of equipm ent are available
for reseating valves seats. The recom m endations o f the
m anufacturer of the equipm ent being used should be
carefully followed to attain proper results.
Regardless o f w hat type o f equipm ent is used,
however, it is essential that valve guide bores be free
from carbon or dirt to ensure proper centering of pilot
in the guide.
R e c o n d itio n in g
1.
Install expanding pilot in the valve guide bore
and expand pilot.
2. Place ro ughing stone or form ing stone over pilot
and just clean up the valve seat. Use a stone cut to
specifications.
3. Remove roughing stone or fo rm ing stone from
pilot, place finishing stone, cut to specifications, over
pilot an d cut just e nough m etal from the seat to provide
a smooth finish. Refer to specifications.
4. N a rro w down the valve seat to the specified
width.
N O TE : This operation is done by grinding the port
side with a 30 degree stone to lower seat and a 60
degree stone to raise seat.
5. Remove expanding pilot and clean cylinder
head carefully to remove all chips and grindings from
above operations.
6. M easure valve seat concentricity (fig. 6A-28).
VALVES
Valves that are pitted can be refaced to the proper
angle, insuring correct relation between the head and
stem on a valve refacing mechanism. Valve stems which
show excessive wear, or valves that are w arped
excessively should be replaced. W hen a valve head which
is w arped excessively is refaced, a knife edge will be
ground on p a rt or all of the valve head due to the
a m o un t of metal that must be removed to completely
reface. K nife edges lead to breakage, bu rning or p re
ignition due to heat localizing on this knife edge. If the
edge o f the valve head is less than 1/32" thick after
grinding, replace the valve.
Several different types o f equipm ent are available
for refacing valves. The recom m endations o f the
m anu fa c tu rer o f the equ ip m ent being used should be
carefully followed to attain p rop er results.
grinding wheel to make sure it is smooth and true. Set
check at angle specified for valve. Refer to specifications.
2. Clam p the valve stem in the chuck o f the
machine.
3. Start the grinder and move the valve head in
line with the grinder wheel.
4. Turn the feed screw until the valve head just
contacts wheel. Move valve back and forth across the
wheel and regulate the feed screw to provide light valve
contact.
5. Continue grinding until the valve face is true
and smooth all around the valve. If this makes the valve
head thin (1 /3 2 " min.) the valve must be replaced as the
valve will overheat and burn.
6. Remove valve from chuck and place stem in
"V " block. Feed valve squarely against g rinding wheel to
grind any pit from rocker arm end o f stem.
N OTE: Only the extreme end o f the valve stem is
hardened to resist wear. Do not grind end of stem
excessively.
7. After cleaning valve face and cylinder head
valve seat of grinding particles, make pencil marks about
1/4" apart across the valve face, place the valve in
cylinder head and give the valve 1/2 turn in each
direction while exerting firm pressure on head o f valve.
8. Remove valve and check face carefully. If all
pencil marks have not been removed at the point of
contact with the valve seat, it will be necessary to repeat
the refacing operating and again recheck for proper
seating.
9. G rin d and check the rem aining valves in the
same manner.
TO R S IO N A L DAM PER
R em oval
R e c o n d itio n in g
1.
If necessary, dress the valve refacing machine
1. D rain radiator and remove as outlined in
Section 6B.
2. Remove fan belt and (if so equipped) accessory
drive pulley and belt.
3. Install Tool J-23523 to d a m p e r and turn puller
screw to remove d a m p e r (fig. 6A-29). Remove tool.
In s ta lla tio n
1. Coat front cover oil seal contact area o f d a m p e r
with engine oil.
C A U T IO N : It is necessary to use installer Tool
J -22197 to prevent the inertia weight section
from walking o ff the hub during installation o f
damper.
Fig. 6A-28--M easuring Valve Seat Concentricity
(Typical)
NOTE: The d a m p e r on the 292 L-6 should be
pulled on by using special tool J-23523 or
equivalent.
2. Attach d a m p e r installer Tool J-22197 to dam per.
Tighten fingers of tool to prevent weight from moving
(fig. 6A-30).
3. Position d a m p e r on cranksahft and drive into
Fig. 6A -29-R em oving Torsional Damper
position, using J-5590 until it bottoms against crankshaft
gear (fig. 6A-30). Remove installer tool.
4. Install fan belt an d adjust using strand tension
gauge.
5. If so equipped, install accessory drive pulley and
belt.
6. Install radiator core as outlined in Section 6B.
7. Fill cooling system and check for leaks.
C R A N K C A S E F R O N T COVER (T IM IN G GEAR
COVER)
R e m o v a l (w ith o u t re m o v in g oil p an )
1. Remove torsional d a m p e r as outlined.
2. Remove the two, oil pan-to-front cover attach
ing screws.
Fig. 6A-31--Cutting Tabs on Oil Pan Front Seal
3.
screws.
Remove
the
front
cover-to-block
attaching
4. Pull the cover slightly forward only enough to
permit cutting of oil p a n front seal.
5. Using a sharp knife or other suitable cutting
tool, cut oil pan fron t seal flush with cylinder block at
both sides of cover (fig. 6A-31).
6. Remove front cover and attached portion o f oil
pan front seal. Remove front cover gasket.
In s ta lla tio n
1.
front cover.
Clean gasket surfaces on block and crankcase
OIL SEAL (F R O N T COVER)
R ep lacem en t
W ith Cover Installed
1. With torsional d a m p e r removed, pry old seal
out o f cover from the front with a screw driver, being
carefull not to dam age the seal surface on the cover.
2. Install new seal so that open end is toward the
inside o f the cover and drive it into position with tool
J-23042 (fig. 6A-35).
W ith Cover Removed
1. With cover removed, pry old seal out o f cover
from the front with screw driver, being careful not to
distort cover.
2. Install new seal so that open end o f the seal is
Fig. 6A -33-A pplying Front Cover Sealant
J- 23042
J -2 3 0 4 2
Fig. 6A 34--J-23042 C entering Tool In Cover
2. Cut tabs from the new oil pan front seal (fig.
6A-32) use a sharp instrum ent to ensure a clean cut.
3. Install seal to front cover, pressing tips into
holes provided in cover.
4. Coat the gasket with gasket sealer and place in
position on cover.
5. Apply a 1/8 inch bead o f silicone ru b b e r sealer
part 1 0 5 1 4 3 5 (o r e q u iv a le n t) to th e jo in t fo rm e d a t th e
oil pan and c y lin d e r block (fig . 6 A -3 3 ).
6. Install centering Tool J-23042 in crankcase front
cover seal (fig. 6A-34).
N O T E : It is im po rtan t that centering tool be used
to align crankcase front cover so that torsional
d a m p e r installation will not dam age seal and so
that seal is positioned evenly around balancer.
7. Install crankcase fro nt cover to block. Install and
partially tighten the two, oil pan-to-front cover screws.
8.
Install the front cover-to-block attaching screws.
9. Remove centering Tool J-23042 and torque all
cover attaching screws to specifications.
10. Install torsional d am per as outlined.
Fig. 6A-35--Installing Oil Seal (Cover Installed)
(Typical)
toward the inside o f cover an d drive it into position with
Tool J-23042 (fig. 6A-36).
CAUTION: Support cover at sealing area.
(Tool J-971 m ay be used as support.)
CAMSHAFT
Measuring Lobe Lift
N O T E: This procedure is similar to that used for
checking valve timing. If im pro pe r valve operation
is indicated, measure the lift of each push rod in
consecutive order and record the readings.
1. Remove valve mechanism as outlined.
2. Position indicator with ball socket adapter (Tool
J-8520) on push rod (fig. 6A-37).
3. Rotate the cranksahft slowly in the direction o f
rotation until the lifter is on the heel o f the cam lobe. At
this point, the push rod will be in its lowest position.
4. Set dial indicator on zero, then rotate the
ca rn ksha ft slowly, or attach an auxiliary starter switch
and " b u m p " the engine over, until the push rod is in the
fully raised position.
CAUTION: Whenever the engine is cranked
remotely at the starter, with a special jum per
cable or other means, the " BA T T ' positive lead
m ust be disconnected fro m the coil.
5. C om pare the total lift recorded from the dial
indicator with specifications.
6. Continue to rotate the crankshaft until the
indicator reads zero. This will be a check on the accuracy
o f the original indicator reading.
7. If cam shaft readings for all lobes are within
specifications, remove dial indicator assembly.
8. Install and adjust valve mechanism as outlined.
Removal
1.
Remove engine, following procedure on page
o f this section.
2. Remove lifters as previously outlined.
3. Remove crankcase front cover as previously
outlined.
4. Remove fuel pump.
5. Align timing gear marks then remove the two
cam sahft thrust plate bolts by working through holes in
cam shaft gear (fig. 6A-38).
6. Remove the cam shaft and g ear assembly by
pulling it out through the front o f the block.
6A
NOTE: Support cam shaft carefully when removing
so as not to dam ag e the cam shaft bearings.
Inspection
The cam shaft bearing journals should be measured
with a m icrometer for an out-of-round condition. If the
journals exceed .001" out-of-round, the cam shaft should
be replaced.
The cam shaft should also be checked for alingment.
The best method is by use of "V " blocks and a dial
indicator (fig. 6A-39). The dial indicator will indicate the
exact am ount the cam sh aft is out of true. If it is out
more than .0015" dial indicator reading, the cam shaft
should be replaced.
Inspect the cam shaft gear and thrust plate for w ear
or damage. M easure the cam shaft end play. This should
be .001" to .005" (fig. 6A-40).
Gear Replacement
1.
If the inspection indicated that the camshaft,
gear or thrust plate should be replaced, the gear must be
T IM IN G
MARKS
TH R U S T
PLATE
SCREW S
Fig. 6A-41 -Removing Cam shaft Gear
removed from the camshaft. This operation requires the
use o f cam shaft gear removed J-971.
2. Place the cam shaft through the gear remover,
place end o f rem over on table o f a press and press shaft
out o f gear (fig. 6A-41).
C A U T IO N : Thrust plate m ust he positioned so
that w oodruff key in shaft does not dam age it
when the sh a ft is pressed out o f gear. Also
support the huh o f the gear or the gear will be
seriously damaged.
3. To assemble cam shaft gear thrust plate and gear
spacer ring to cam shaft firmly support cam shaft at back
o f front jo urna l in an a rb o r press.
4. Place g ear spacer ring and thrust plate over end
o f shaft, and install woodruff key in shaft keyway. Install
cam sh aft gear and press it onto the shaft until it bottoms
against the gear spacer ring. The end clearance o f the
thrust plate should be .001" to .005" (fig. 6A-40).
In s ta lla tio n
1. Install the cam shaft and gear assembly in the
engine block, being careful not to d am age cam shaft
bearings or camshaft.
2. Turn crankshaft and cam shaft so that the valve
timing marks on the gear teeth will line up (fig. 6A-38).
Push cam shaft into position. Install cam shaft thrust
plate-to-block bolts and torque to specifications.
3. Check cam shaft and crankshaft gear run out
with a dial indicator (fig. 6A-42). The cam shaft gear run
out should not exceed .004" and the crankshaft gear run
out should not exceed .003".
4. If gear run out is excessive, the gear will have to
be removed and any burrs cleaned from the shaft or the
gear will have to be replaced.
5. Check the backlash between the timing gear
teeth with a dial indicator (fig. 6A-43). The backlash
should be not less than .004" nor more than .006".
6. Install fuel pump.
7. Install crankcase front cover.
8. Install lifters.
Fig. 6A-44-R eplacing Cam shaft Center Bearing
Fig. 6A 42--Checking C am shaft Gear Runout
Fig. 6A-45-R eplacing Cam shaft Front Bearing
2. Remove oil p an and oil pu m p as described on
page 6A-30 o f this section.
3. Drive cam shaft rear plug from cylinder block.
Fig. 6A-43--Checking T im in g Gear Backlash
9.
Install engine in vehicle.
C A M S H A F T BEARINGS
R e m o va l
1.
Remove cam shaft as previously outlined.
NOTE: This procedure is based on removal o f the
bearings nearest center of the engine first. With
this method a m inim um am ount o f turns are
necessary to remove all bearings.
4. Using Tool Set J-6098, with nut and thrust
washer installed to end o f threads, index pilot in
cam shaft front bearing and install puller screw through
pilot.
5. Install remover and installer tool with shoulder
toward bearing, m aking sure a sufficient amount o f
threads are engaged.
6. Using two wrenches, hold puller screw while
turning nut. W hen bearing has been pulled from bore,
remove remover and installer tool and bearing from
puller screw (fig. 6A-44).
7. Remove rem ain in g bearings (except front and
rear) in the same manner. It will be necessary to index
pilot in cam shaft rear bearing to remove the rear
interm ediate bearing.
8. Assemble remover and installer tool on driver
handle an d r e m o te cam shaft front and rear bearings by
driving towards center o f cylinder block (fig. 6A-45).
Installation
N O T E : The cam shaft fro nt and rear bearings
should be installed first. These bearings will act as
guides for the pilot and center the rem aining
bearings being pulled into place.
1. Assemble remover and installer tool on driver
han dle and install cam shaft front and re a r bearings by
driving towards center o f cylinder block (fig. 6A-45).
2. Using Tool Set J-6098, with nut and thrust
w ash er installed to end o f threads, index pilot in
ca m sha ft fro nt bearings an d install puller screw through
pilot.
3. Index cam shaft bearing in bore, then install
rem over and installer tool on puller screw with shoulder
toward bearing.
CAUTION: A ll cam bearing oil holes m ust be
aligned with oil holes in cam bore.
4. U sing two wrenches, hold puller screw while
tu rning nut. A fter bearing has been pulled into bore,
remove the rem over and installer tool from puller screw
an d check alignm ent o f oil hole in cam shaft bearing.
5. Install rem aining bearings in the same manner.
It will be necessary to index pilot in the cam shaft rear
bearin g to install the rear interm ediate bearing.
6. Install a new cam shaft rear plug.
N OTE: Plug should be installed flush to 1/32"
deep and be parallel with rear surface of cylinder
block.
OIL PAN
Removal
1. Disconnect battery negative cable.
2. Raise vehicle on hoist and drain engine oil.
3. Remove starter.
4. Remove flywheel splash shield or converter
housing u nd erpan, as applicable.
5. Remove " th ro u g h " bolts from engine front
mounts.
6. Raise front of engine, reinstall m ount through
bolts and lower engine.
7. Remove oil p a n bolts.
8. Remove oil pan.
Fig. 6A-46--Pan Gaskets and Seals
4. Install side gaskets to engine block, using a
gasket sealer with sufficient body to act as a retainer.
5. Install oil pan, torquing the retaining bolts to
specifications.
6. Raise engine sufficiently to allow removal of
"th ro u g h " bolts - lower engine and install mount
"th ro u g h " bolts. Torque bolts to specifications.
7. Install flywheel splash shield or converter
housing underpan, as applicable.
8. Install starter.
9. Lower vehicle and fill crankcase with oil.
10. Connect battery negative cable, start engine
and check for leaks.
OIL PUMP
Removal
1. Remove oil pan as outlined.
2. Remove two flange mounting bolts, pickup pipe
bolt, then remove pum p and screen as an assembly.
Disassembly
Installation
1. Remove the pum p cover attaching screws, the
pum p cover and the pum p cover gasket (fig. 6A-47).
1. Thoroughly clean all gasket sealing surfaces.
2. Using a new gasket, install rear seal in rear
m ain bearing cap.
3. Install front seal on crankcase front cover,
pressing tips into holes provided in cover (fig. 6A-46).
N O TE : M ark gear teeth so they m ay be
reassembled with the same teeth indexing.
2. Remove the idler gear and the drive gear and
shaft from the pum p body.
3. Remove the pressure regulator valve retaining
pin, pressure regulator valve and related parts.
7.
Check the pressure regulator valve for fit.
NOTE: The pu m p gears and body are not serviced
separately. If the pum p gears or body are dam aged
or worn, replacement o f the entire oil pum p
assembly is necessary.
Assembly
1. If the pickup screen and pipe assembly was
removed, it should be replaced with a new part. Loss of
press fit condition could result in an air leak and loss of
oil pressure. M ount the pum p in a soft-jawed vice, apply
sealer to the end o f pipe and tap the pipe in place with a
plastic ha m m e r using Tool J-8369.
CAUTION: Be careful o f twisting, shearing or
collapsing pipe while installing in pum p.
Pickup screen m ust be parallel to bottom o f oil
pan when oil pum p is installed.
2. Install the pressure regulator valve and related
parts.
3. Install the drive gear and shaft in the pum p
body.
4. Install the idler gear in the pum p body with the
smooth side of gear towards pum p cover opening.
5. Install the pum p, with new gasket, and torque
attaching screws to specifications.
6. Turn drive shaft by hand to check for smooth
operation.
C O N N E C T IN G ROD BEARINGS
1.
2.
3.
4.
5.
Pressure Regulator
Valve
Pressure Regulator
Spring
Retaining Pin
Screws
Pump Cover
6.
7.
8.
9.
10.
Cover Gasket
Idler Gear
Drive Gear and Shaft
Pump Body
Pickup Screen and
Pipe
Connecting rod bearings are o f the precision insert
type and do not utilize shims for adjustment. DO N O T
FILE RODS OR R O D CAPS. If clearances are found to
be excessive a new bearing will be required. Bearings are
available in standard size and .001" and .002" undersize
for use with new and used standard size crankshafts, and
in .010" and .020" undersize for use with reconditioned
crankshafts.
Inspection and Replacement
Fig. 6A-47--0il Pump (L6 Exploded)
4.
If the pickup screen and pipe assembly need
replacing, m ount the pu m p in a soft-jawed vise and
extract pipe from pump.
CAUTION: Do not disturb the pickup screen on
the pipe. This is serviced as an assembly.
Cleaning and Inspection
1. W ash all parts in cleaning solvent and dry with
compressed air.
2. Inspect the pum p body and cover for cracks or
excessive wear.
3. Inspect p u m p gears for dam age or excessive
wear.
4. Check the drive gear shaft for looseness in the
pum p body.
5. Inspect inside o f pum p cover for wear that
would perm it oil to leak past the ends o f the gears.
6. Inspect the pickup screen and pipe assembly for
da m a ge to screen, pipe or relief grommet.
1. With oil p a n and oil p u m p removed, remove the
connecting rod cap and bearing.
2. Inspect the bearings for evidence o f wear or
damage. (Bearings showing the above should not be
installed.)
3. Wipe the bearings and crankpin clean o f oil.
4. Measure the crankpin for out-of-round or taper
with a micrometer. If not within specifications replace or
recondition the cranksahft. If within specifications and a
new bearing is to be installed, measure the maximum
diam eter of the crankpin to determine new bearing size
required.
5. If within specifications measure new or used
bearing clearances with Plastigage or its equivalent.
NOTE: If a bearing is being fitted to an out-ofround crankpin, be sure to fit to the maximum
diam eter o f the crankpin. If the bearing is fitted to
Fig. 6A-50--Measuring Connecting Rod Side
Clearance
c. Install the bearing cap and evenly torque nuts
to specifications.
Fig. 6A-48-Gauging Plastic on Crankpin
CAUTION: Do not turn the crankshaft with the
gauging plastic installed.
d. Remove the bearing cap and using the scale
on the gauging plastic envelope, measure the gauging
plastic width at the widest point (fig. 6A-49).
6. If the clearance exceeds specifications, select a
new, correct size, bearing and remeasure the clearance.
7. Coat the bearing surface with oil, install the rod
cap and torque nuts to specifications.
8. W hen all connecting rod bearings have been
installed, tap each rod lightly (parallel to the crankpin)
to make sure they have clearance.
9. Measure all connecting rod side clearances
between the connecting rod cap and side o f crankpin
(fig. 6A-50).
C R A N K S H A FT M A IN BEARINGS
Fig. 6A 49 Measuring Gauging Plastic
the m inim um diam eter and the crankpin is out-of
round .001" interference between the bearing and
crankpin will result in rapid bearing failure.
a. Place a piece o f gauging plastic the full width
of the crankpin as contacted by the bearing (parallel to
the crankshaft)(fig. 6A-48).
b. Install the bearing in the connecting rod and
cap.
M ain bearings are of the precision insert type and
do not utilize shim for adjustment. If clearances are
found to be excessive, a new bearing, both upper and
lower halves, will be required. Bearings are available in
standard size and .001", .002", .009", .010" and .020"
undersize.
Selective fitting o f both rod and m ain bearing
inserts is necessary in production in order to obtain close
tolerances. For this reason you may find one half o f a
standard insert with one half of a .001" undersize insert
which will decrease the clearance .0005" from using a
full standard bearing.
W hen a production cranksahft cannot be prescision
fitted by this method, it is then ground .009" undersize
on main journals only. A .009" undersize bearing and
.010" undersize bearing may be used for precision fitting
in the same m a n n e r as previously described. Any engine
fitted with a .009" undersize crankshaft will be identified
by the following markings.
•
".009" will be stamped on the crankshaft
counterweight forward o f the center main journal.
•
A figure " 9 " will be stamped on the block at
the left front oil pan rail.
I
N OTE: If, for any reason, main bearings caps are
replaced, shim m ing may be necessary. Lam inated
shims for each cap are available for service. Shim
re q u ir e m e n t will be d e te rm in e d by bea rin g
clearance.
Inspection
In general, the lower h a lf o f the bearing (except
N o.l bearing) shows a greater w ear and the most distress
from fatigue. If upon inspection the lower half is
suitable for use, it can be assumed that the upper half is
also satisfactory. If the lower h a lf shows evidence of
w ear or dam age, both upper an d lower halves should be
replaced. Never replace one h a lf without replacing the
other half.
Checking Clearance
To obtain the most accurate results with "Plastigage", (or its equivalent) a wax-like plastic material
which will compress evenly between the bearing and
journ al surfaces w ithout da m a g in g either surface, certain
precautions should be observed. If the engine is out o f
the vehicle an d upside down, the crankshaft will rest on
the u pp er bearings and the total clearance can be
m easured between the lower b earing and journal. If the
engine is to rem ain in the vehicle, the crankshaft should
be supported both front and rear (dam per and flywheel)
to remove the clearance from the upper bearing. The
Fig. 6A-52--Measuring Gauging Plastic (Typcial)
Fig. 6A-53 -Measuring Crankshaft End Play (Typical)
total clearance can then be measured between the lower
bearing and journal.
N OTE: To assure the p rop er seating of the
crankshaft all bearing cap bolts should be at their
specified torque. In addition, p rep aratory to
checking fit o f bearings, the surface o f the
crankshaft jo urna l and bearing should be wiped
clean o f oil.
1. With the oil pan an d oil pu m p removed, and
staring with the rear m ain bearing, remove bearing cap
and wipe oil from jo u rn al and bearing cap.
2. Place a piece of gauging plastic the full w idth of
the bearing (parallel to the crankshaft) on the journal
(fig. 6A-51).
CAUTION: Do not rotate the crankshaft while
the gauging plastic is between the bearing and
journal.
3. Install the bearing cap and evenly torque the
retaining bolts to specifications.
4. Remove bearing cap. The flattened gauging
plastic will be found a dhering to either the bearing shell
or journal.
5. On the edge of gauging plastic envelope there is
a graduated scale which is correlated in thousandths of
an inch. W ithout rem oving the gauging plastic, measure
its compressed w idth (at the widest point) with the
graduations on the gauging plastic envelope (fig. 6A-52).
N O TE: Normally, m ain bearing journals wear
evenly and are not out-of-round. However, if a
bearing is being fitted to an out-of-round jou rnal
(.001" max.), be sure to fit to the maximum
d ia m e te r of the journal.
If the b earing is fitted to the m inim um diam eter
and the jou rn a l is out-of-round .001", interference
between the bearing and journ al will result in
rapid bearing failure. If the flattened gauging
plastic tapers toward the middle or ends, there is a
difference in clearance indicating taper, low spot or
other irregularity o f the bearing or journal. Be sure
to measure the jou rna l with a micrometer if the
flattened gauging plastic indicates more than .001"
difference.
6. If the b earing clearance is within specifications,
the bearing insert is satisfactory. If the clearance is not
within specifications, replace the insert. Always replace
both upper and lower insert as a unit.
N O T E: If a new bearing cap is being installed and
clearance is less tha .001", inspect for burrs or
nicks; if none are found then install shims as
required.
7. A standard, .001" or .002" undersize bearing
may produce the proper clearance. If not, it will be
necessary to regrind the cran ksh aft journ al for use with
the next undersize bearing.
8. Proceed to the next bearing. A fter all bearings
have been checked, rotate the crankshaft to see that
there is no excessive drag.
9. M easure crankshaft end play (see specifications)
by forcing the crankshaft to the extreme front position.
M easure at the front end o f the rear main bearing with
a feeler gauge (fig. 6A-53).
10.
Install a new rear main bearing oil seal in the
cylinder block and main bearing cap.
Replacement
N OTE: Main bearings may be replaced with or
without removing the crankshaft.
W ith C rankshaft Removed
1. Remove and inspect the crankshaft.
2. Remove the main bearings from the cylinder
block and main bearing caps.
3. Coat bearing surfaces of new, correct size, main
bearings with oil and install in the cylinder block and
main bearing caps.
4. Install the crankshaft.
W ithout C rankshaft Removal
1. With oil pan, oil p u m p and spark plugs
removed, remove cap on m ain bearing requiring
replacement and remove bearing from cap.
2. The rear main journal has no oil hole. Replace
the rear main bearing upper half as follows:
a. Use a small drift punch and h a m m e r to start
the upper bearing h a lf rotating out o f block.
b. Use a pair of pliers (with taped jaws) to hold
the bearing thrust surface to the oil slinger and rotate
the crankshaft to remove bearing (fig. 6A-54).
c. Oil new selected size upper bearing and insert
plain (unnotched) end between crankshaft and indented
or notched side of block.
d. Use pliers as in removing to rotate bearing
into place. The last 1/4 movement may be done by
holding just the slinger with the pliers or tap in place
with a drift punch.
3. All other cran ksh aft journals have oil holes.
Replace the main bearing upper h a lf as follows:
a. Install a main bearing removing and install
ing tool in oil hole in crankshaft journal.
N O TE : If such a tool is not available, a cotter pin
m ay be bent as required to do the job.
b. Rotate the crankshaft clockwise as viewed
from the front o f engine. This will roll upper bearing out
o f block.
c. Oil new selected size upper bearing and insert
plain (unnotched) end between crankshaft and indented
or notched side of block. Rotate the bearing into place
and remove tool from oil hole in crankshaft journal.
4.
Oil new lower bearing and install in bearing
Fig. 6A 57--Rmoving Oil Seal Upper Half (Typical)
cap.
5. Install main bearing cap with arrows pointing
toward front o f engine.
6.
Torque main b earing cap bolts to specifications.
OIL SEAL (REAR M A IN )
Replacement
Fig. 6A-58--Crankshaft Oil Seal (Rear Main)
APPLY
SE ALAN T
TO SHAD ED
AREAS O N L Y
Fig. 6A-59-Sealing Bearing Cap (Typical)
NOTE: Always replace the upper and lower seal as
a unit. Install seal with lip facing front o f engine.
The rear m ain bearing oil seal can be replaced (both
halves) without removal o f the crankshaft. Extreme care
should be exercised when installing this seal to protect
the sealing bead located in the channel on the outside
d iam eter o f the seal. An installation tool (fig. 6A-55) can
be used to protect the seal bead when positioning seal as
follows:
1. W ith the oil pan and oil pum p removed, remove
the rear m ain b earing cap.
2. Remove oil seal from the bearing cap by prying
from the bottom with a small screw driver (fig. 6A-56).
3. To remove the upper h a lf of the seal, use a
small h a m m e r to tap a brass p in punch on one end o f
seal until it protrudes far enough to be removed with
pliers (fig. 6A-57).
4. Clean all sealant and foreign material from
cylinder case bearing cap and crankshaft, using a
nonabrasive cleaner.
5. Inspect components for nicks, scratches, burrs
a n d m achining defects at all sealing surfaces, case
assembly and crankshaft.
6. Coat seal lips and seal bead with light engine oil
- keep oil off seal m ating ends.
7. Position tip of tool between crankshaft and seal
seat in cylinder case.
8. Position seal between crankshaft and tip o f tool
so that seal bead contacts tip of tool.
N O T E : Make sure that oil-seal lip is positioned
toward front o f engine (fig. 6A-58).
9. Roll seal around crankshaft using tool as a
"s h o e -h o rn " to protect seal bead from sharp corner of
seal seat surface in cylinder case.
C A U T IO N : Installation tool m ust remain in
position until seal is properly positioned with
both ends flu sh with block.
10. Remove tool, being careful not to withdraw
seal.
11. Install seal half in bearing cap, again using
tool as a "s hoe-horn", feeding seal into cap using light
pressure with thum b and finger.
12. Install bearing cap to case with sealant applied
to the cap-to-case interface being careful to keep sealant
off the seal split line (fig. 6A-59).
13. Install the rear m ain bearing cap (with new
seal) and torque to specifications.
P IS TO N A N D C O N N E C T IN G ROD
ASSEMBLIES
Removal
1. W ith oil pan, oil p u m p and cylinder head
removed, use a ridge ream er to remove any ridge a n d / o r
deposits from the upper end of the cylinder bore.
N O T E : Before ridge a n d / o r deposits are removed,
turn cra nk sh a ft until piston is at the bottom o f
stroke and place a cloth on top o f piston to collect
the cuttings. A fter ridge a n d / o r deposits are
removed, turn crankshaft until piston is at top o f
stroke and remove cloth an d cuttings.
2. Inspect connecting rods and connecting rod caps
for cylinder identification. If necessary, mark them.
Fig. 6A-60- Removing Connecting Rod Piston
Assembly
3.
Remove connecting rod cap and install Tool
J-5239 ( 3 /8 " ) or J-6305 (1 1/32") on studs. Push
connecting rod and piston assembly out of top o f
cylinder block (fig. 6A-60).
NOTE: It will be necessary to turn the crankshaft
slightly to disconnect some o f the connecting rod
and piston assemblies and push them out o f the
cylinder.
Disassembly
1. Remove connecting rod bearings from connect
ing rods and caps.
NOTE: If connecting rod bearings are being
reused, place them in a rack so they m ay be
reinstalled in their original rod and cap.
2. Remove piston rings by expanding and sliding
them off the pistons. Tools J-8020 (3-9/16"), J-8021 (37 /8 "), J-8032 (4"), J-22249 (3-15/16"), J-22147 (-3/32").
and J-22250 (4 -1/4") are available for this purpose.
3. Place connecting rod an d piston assembly on
tool J-24086. Using an arbor press and piston pin
remover, J-24086, press the piston pin out o f connecting
rod and piston (fig. 6A-61).
Cleaning and Inspection
Connecting Rods
W ash connecting rods in cleaning solvent and dry
with compressed air.
PRESS
limit, the piston an d piston pin assembly should be
replaced.
ASSEMBLY
PISTON PIN
REMOVER
J - 2 4 0 8 6 -8
1. Lubricate piston pin holes in piston and
connecting rod to facilitate installation o f pin.
2. Place connecting rod in piston and hold in place
with piston pin guide and piston pin. Place connecting
rod and piston assembly on fixture and support assembly
(fig. 6A-62).
N OTE: See figure 6A-63 for correct size o f piston
pin guide.
3. Using piston pin installer, J-24086-9, press the
piston pin into the piston and connecting rod (Fig. 6A64).
FIXTURE &
SUPPORT
ASSEMBLY
J -2 4 0 8 6 -2 0
N OTE: The piston pin installer is a variable
insertion length tool designed to be applicable to
all G M piston assemblies. The insertion length is
varied by rotating the hub on the shaft much like
adjusting a micrometer. An alpha-num eric scale is
used to determ ine the desired length for a given
piston pin assembly. Refer to figure 6A-63 for
correct setting.
CAUTION. A fte r installer hub bottoms on
support assembly, do not exceed 6000 psi
Fig. 6A-61--F?emoving Piston Pin
-PISTON PIN
Check for twisted or bent rods and inspect for nicks
or cracks. Replace connecting rods that are damaged.
I4fI
Pistons
Clean varnish from piston skirts and pins with a
cleaning solvent. DO N O T W IR E BRUSH A N Y PA R T
O F T H E PISTON. Clean the ring grooves with a groove
cleaner and m ake sure oil ring holes and slots are clean.
Inspect the piston for cracked ring lands, skirts or
pin bosses, wavy or worn ring lands, scuffed or dam aged
skirts, eroded areas at top o f the piston. Replace pistons
that are d am aged or show signs o f excessive wear.
Inspect the grooves for nicks or burrs that might
cause the rings to h ang up.
M easure piston skirt (across center line o f piston
pin) and check clearance as outlined under "Piston
Selection".
Piston Pins
T he piston pin clearance is designed to m aintain
a dequate clearance under all engine operating condi
tions. Because of this, the piston and piston pin are a
matched set and not serviced separately.
Inspect piston pin bores and piston pins for wear.
Piston p in bores and piston pins must be free o f varnish
or scuffing w hen being measured. The piston pin should
be measured with a micrometer and the piston pin bore
should be m easured with a dial bore gauge or an inside
micrometer. If clearance is in excess o f the .001" w ear
PISTON
PIN GUIDE
FIXTURE &
SUPPORT
ASSEMBLY
CYL.
D IS P L A C E M E N T
IN S T A L L E R S E T T IN G
PIN S IZE
Gold
J-24086-6
I-6
.905”
110 cu. i n . / l .8 Litre
Blue
J-24086-5
I-7
.866”
140 cu. in ./2 .3 Litre
Violet
J-24086-7
I-7
.9 2 7 "
Violet
J-24086-7
G-8
.927”
Small Block
283, 302, 305,
307, 3 5 0 , 4 0 0
V iolet
J-24086-7
G-8
.927”
Mark IV
366 , 396,
402, 427, 454
Gray
J-24086-3
G-7
.990”
85 cu. i n . / l -4 Litre
PIN G U ID E
97 cu. i n . / l -6 Litre
4
2 50 cu. in./4.1 Litre
6
2 92 cu. in ./4 .8 Litre
8
Fig. 6A-63--Piston Pin Tool Specifications
pressure, as this could cause structural damage
to the tool.
4.
Remove piston and connecting rod assembly
from tool and check piston for freedom o f movement on
piston pin.
PISTON PIN
INSTALLER
J -2 4 0 8 6 -9
PISTON PIN
and (J-22250
purpose.
(4-1/4")
are
available
for
this
a. Install oil ring spacer in groove and insert
anti-rotation tang in oil hole.
b. Hold spacer ends butted and install lower
steel oil ring rail with gap properly located.
c. Install
properly located.
upper steel oil ring rail with gap
d. Flex the oil ring assembly to make sure ring
is free. If binding occurs at any point, the cause should
be determined, and if caused by ring groove, remove by
dressing groove with a fine cut file. If binding is caused
by a distorted ring, check a new ring.
e. Install second compression ring expander then
ring with gaps properly located.
f.
located.
Fig. 6A-66--Checking Ring in Groove
Piston Rings
All compression rings are m arked on the upper side
o f the ring. W hen installing compression rings, make
sure the m arked side is toward the top o f the piston. The
top ring is chrom e faced, or treated with molybdenum
for m axim um life.
The oil control rings are o f three piece type,
consisting of two segments (rails) and spacer.
1. Select rings com parable in size to the piston
being used.
2. Slip the compression ring in the cylinder bore;
then press the ring down into the cylinder bore about
1 /4 " (above ring travel). Be sure ring is square with
cylinder wall.
3. M easure the space or gap between the ends o f
the ring with a feeler gauge (fig. 6A-65).
4. If the gap between the ends o f the ring is below
specifications, remove the ring and try another for fit.
5. Fit each compression ring to the cylinder in
which it is going to be used.
6. If the pistons have not been cleaned and
inspected as previously outlined, do so.
7. Slip the outer surface o f the top and second
compression ring into the respective piston ring groove
an d roll the ring entirely around the groove (Fig. 6A-66)
to m ake sure that the ring is free. If binding occurs at
any point the cause should be determined, and if caused
by ring groove, remove by dressing with a fine cut file. If
the binding is caused by a distorted ring, check a new
ring.
8. Install piston rings as follows (fig. 6A-67).
N O T E: Tools J-8020 (3-9/16"), J-8021 (3-7/8"),
J-8032 (4"), J-22249 (3-15/16"), J-22147 (4-3/32"),
Install top compression ring with gap properly
9.
Proper clearance o f the piston ring in
ring groove is very im p ortan t to provide proper
action and reduce wear. Therefore, when fitting
rings, the clearances between the surfaces o f the
groove should be m easured (fig. 6A-68).
Specifications.)
its piston
ring
new
ring
(See
Fig. 6A 70--lnstalling Connecting Rod and Piston
Assembly
Fig. 6A-68--Measuring Ring Groove Clearance
3. With bearing caps removed, install Tool J-5239
( 3 /8 " ) or J-6305 (11 /3 2 " ) on connecting rod bolts.
CAUTION: Be sure ring gaps are properly
positioned as previously outlined.
4. Install each connecting rod and piston in its
respective bore. Pistons must have notches facing front
o f engine (fig. 6A-69).
Use Tool J-8037 to compress the rings (fig. 6A-70).
G uide the connecting rod into place on the
crankshaft jou rn a l with Tool J-5239 ( 3 /8 " ) or J-6305
(11/32"). Use a ha m m er handle and light blows to
install the piston into the bore. Hold the ring
compressor firmly against the cylinder block until all
piston rings have entered the cylinder bore.
5. Remove Tool J-5239 or J-6305.
6. Install the bearing caps and torque nuts to
specifications.
NOTE: If bearing replacement is required refer to
"Connecting Rod Bearings".
Fig. 6A-69--Pistons - Installed Position
Installation
N O T E: Cylinder bores must be clean before piston
installation. This may be accomplished with a hot
w ater and detergent wash or with a light honing as
necessary. A fter cleaning, the bores should be
swabbed several times with light engine oil and a
clean dry cloth.
1. Lubricate connecting rod bearings and install in
rods and rod caps.
2. Lightly coat pistons, rings and cylinder walls
with light engine oil.
Be sure to install new pistons in the same cylinders
for which they were fitted, and used pistons in the
same cylinder from which they were removed. If a
connecting rod is ever transposed from one block
or cylinder to another, new bearings should be
fitted and the connecting rod should be num bered
to correspond with the new cylinder num ber.
ENG INE ASSEMBLY
Removal
1.
2.
3.
4.
Remove Hood.
Disconnect battery cables at batery.
Remove air cleaner.
D rain radiator and block.
5. Disconnect rad iato r and heater hoses and
remove rad iato r and fan shroud.
6. Disconnect wires at:
• Starter Solenoid
• Delcotron
• T em peratu re switch
• Oil Pressure Switch
• Coil
7. Disconnect:
• Accelerator linkage at inlet manifold.
• Fuel line, from tank, at fuel pump.
• Hoses at fuel vapor storage canister (if
applicable).
• Vacuum line to power brake unit at manifold,
if so equipped.
8. Remove power steering pum p and lay aside, if
so equipped.
9. Raise vehicle on hoist.
10. D rain crankcase.
1 1. Disconnect exhaust pipe at manifold and. if so
equipped, converter bracket at transmission rear mount.
12. Remove starter.
13. Remove flywheel splash shield or converter
housing cover as applicable.
14. On vehicles with autom atic transmissions,
remove converter to flywheel attaching bolt.
15. Remove m ount " th r o u g h " bolts.
16. Remove bell housing bolts.
17. Lower vehicle on hoist.
18. Raise transmission using floor jack.
19. Attach engine lifting devices, raise engine.
20. Remove motor m ount to engine brackets.
21. Remove engine assembly.
Installation
1. Position engine assembly in vheicle.
2. Attach m otor m ount to engine brackets and
lower engine in place.
3. Remove engine lifting device.
4. Remove transmission floor jack.
5. Raise vehicle on hoist.
6. Install m ount "th r o u g h " bolts. Torque to
specification.
7. Install
bell
hou sing
bolts.
To rqu e
to
specifications.
8. On vehicles with automatic transmissions, install
c o n v e rte r to flywheel a tta c h in g bolts. T orque to
specification.
9. Install flywheel splash shield or converter
housing cover as applicable. Torque attaching bolts to
specifications.
10. Install starter.
11. C o nnect exh aust pipe at m a n ifold and
converter bracket at transmission rear mount.
12. Lower vehicle on hoist.
13. Reinstall power steering pump, if so equipped.
14. Connect:
• Accelerator linkage at inlet manifold.
• Fuel line, from tank, at fuel pump.
• Hoses at fuel vapor storage canister.
• Vacuum line to power brake unit at manifold,
if equipped.
15 Connect wires at:
• Starter Solenoid
• Delcotron
• Tem perature Switch
• Oil Pressure Switch
• Coil
16. Install radiator and fan shroud and reconnect
radiator and heater hoses.
17. Fill cooling system.
18. Fill crankcase with oil. See ow ner’s manual for
specifications.
19. Install air cleaner.
20. Install hood.
21. Connect battery cables.
NOTE: To avoid possible arcing o f battery,
connect positive battery cable first.
22. Start engine, check for leaks and check timing.
CRA N K S H A FT
Removal
1. Remove engine as previously outlined. Remove
clutch, if applicable, and flywheel and m ount engine on
stand.
2. Remove the oil dipstick and oil dipstick tube.
3. Remove the spark plugs.
4. Remove c ra n k s h a ft pulley and torsional
damper.
5. Remove oil p a n and oil pump.
6. Remove crankcase front cover.
7. Check the connecting rod caps for cylinder
num ber identification. If necessary, mark them.
8. Remove the connecting rod caps and push the
pistons to the top o f bores.
9. Remove m ain bearing caps and lift cranksahft
out of cylinder block.
10. Remove re a r main bearing oil seal and main
bearings from cylinder block and m ain bearing caps.
Cleaning and Inspection
1. Wash crankshaft in solvent and dry with
compressed air.
2. Measure dimensions o f main bearing journals
and crankpins with a microm eter for out-of-round, taper
or undersize. (See Specifications.)
3. Check crankshaft for run-out o f supporting at
the front and rear m ain bearings journals in "V " blocks
and check at the front and rear interm ediate journals
with a dial indicator. (See Specifications.)
4. Replace or recondition the crankshaft if out o f
specifications.
Gear Replacement
Remove crankshaft gear using Tool J-8105 and
install using Tool J-5590 (fig. 6A-71).
Installation
1.
Install rear m ain bearing oil seal in cylinder
block and rear m ain bearing cap grooves. Install with lip
o f seal toward front o f engine. W here seal has two lips
install lip and helix towards front o f engine.
2. Lubricate lips o f seal with engine oil. Keep oil
off partin g line surface.
3. Install m ain bearings in cylinder block and
m ain bearing caps then lubricate bearing surface with
engine oil.
4. Install crankshaft, being csreful not to dam age
bearing surfaces.
5. Apply a thin coat o f brush-on type oil sealing
com pound to block m ating surface and corresponding
surface o f cap only (fig. 6A-22). D o not allow sealer on
crankshaft or seal.
6. Install m ain bearing caps with arrows pointing
toward front of engine.
7. Torque all except rear m ain bearing cap bolts to
specifications. Torque rear main bearing cap bolts to 1012 ft. lbs. then tap end o f crankshaft, first rearw ard then
forward with a lead ham m er. This will line up rear main
bearing and crankshaft thrust surfaces. Retorque all
main bearing cap bolts to specifications.
8. Measure crankshaft end play with a feeler
gauge. Force crankshaft forward and measure clearance
between the front o f the rear m ain bearing and the
crankshaft thrust surface.
9. Install flywheel and torque to specifications. A
wood block placed between the crankshaft and cylinder
block will prevent crankshaft from rotating.
NOTE: Align dowel hole in flywheel with dowel
hole in crankshaft. On vehicles equipped with
automatic transmissions, install flywheel with the
converter attaching pads towards transmission.
Fig. 6A71-Gear Replacement
APPLY
SEALANT
T O SHADED
AREAS O N L Y
8 C ylinder Engine
Contents
G eneral D e sc rip tio n .......................................................
Engine L u b ric a tio n .........................................................
O n Vehicle S e rv ic e .........................................................
Engine M o u n ts ..............................................................
Intake M a n i f o l d ............................................................
Exhaust M a n i f o l d .........................................................
Rocker Arm C o v e r.......................................................
Valve M e c h a n ism ..........................................................
Valve Stem Oil Seal a n d /o r
Valve S p rin g ......................................................................
Valve L i f t e r s ..................................................................
Cylinder Head A ssem b ly ...........................................
Rocker Arm S tu d s ........................................................
Valve G uide B o re s .......................................................
Valve S e a t s ......................................................................
6A-43
6A-44
6A-44
6A-44
6A-53
6A-53
6A-54
6A-55
6A-56
6A-57
6A-59
6A-62
6A-63
6A-63
Valves................................................................................ 6A-64
Torsional D a m p e r ......................................................... 6A-64
Crankcase Front C o v e r .............................................. 6A-65
Oil Seal (Front Cover) ............................................. 6A-66
C a m s h a f t..........................................................................6A-67
Cam shaft Bearings........................................................6A-68
Oil P a n ............................................................................. 6A-70
Oil P um p.......................................................................... 6A-70
Connecting Rod B earings.......................................... 6A-72
M ain B earin g s............................................................... 6A-72
Oil Seal (Rear M a i n ) ................................................. 6A-75
Connecting Rod Piston A sem blies......................... 6A-76
Engine Assembly........................................................... 6A-80
C r a n k s h a f t....................................................................... 6A-81
Sprocket or G e a r R eplacem ent............................... 6A-81
GENERAL DESCRIPTION
CYLINDER BLOCK
The cylinder block is m ade o f cast iron and has 8
cylinders arranged in a "V " shape with 4 cylinders in
each bank. Five m ain bearings support the crankshaft
which is retained by bearing caps that are machined
with the block for proper alignment and clearnances.
Cylinders are completely encircled by coolant jackets.
CYLINDER HEAD
The
ratio o f
exhaust
integral,
studs.
cast iron cylinder heads provide a compression
8.5:1. They are cast with individual intake and
ports for each cylinder. Valve guides are
and rocker arms are retained on individual
C R A N K S H A FT AND BEARINGS
The crankshaft is cast nodular iron and is supported
by five main bearings. N u m b e r five bearing is the end
thrust bearing.
M ain bearings are lubricated from oil holes which
intersect the cam shaft bearings. The cam shaft bearings
are fed oil by the m ain oil gallery which is rifle drilled
down the center of the block, above the camshaft. Two
additional oil gallerys are on either side o f the main oil
gallery to provide an oil supply for the hydraulic lifters.
A torsional d am p er on the forward end of the
crankshaft d am pens any engine torsional vibrations.
timing chain which in turn drives the cam shaft through
a bakelite fabric composition gear with steel hub.
Cam lobes are ground, hardened and tapered with
the high side toward the rear. This, coupled with a
spherical face on the lifter, causes the valve lifters to
rotate.
Cam shaft bearings are lubricated through oil holes
which intersect the main oil gallery. The main oil gallery
is rifle drilled down the center o f the block, above the
camshaft.
PISTONS AND C O N N E C T IN G RODS
The pistons are m ade o f cast aluminum alloy using
two compression rings and one oil control ring. Piston
pins are offset 1/16" toward the thrust side (right hand
side) to provide a gradual change in thrust pressure
against the cylinder wall as the piston travels its path.
Pins are Chromium steel and have a floating fit in the
pistons They are retained in the connecting rods by a
press fit.
Connecting rods are made of forged steel. Full
pressure lubrication is directed to the connecting rods by
drilled oil passages from the adjacent main bearing
journal. Oil holes at the connecting rod journals are
located so that oil is supplied to give m aximum
lubrication just prior to full bearing load.
VALVE TRAIN
C A M S H A F T AND DRIVE
The cast iron cam shaft is supported by five bearings
and is chain driven. A steel crankshaft gear drives the
A very simple ball pivot-type train is used. Motion
is transmitted from the cam shaft through the hydraulic
lifter and push rod to the rocker arm. The rocker arm
pivots on its ball and transmits the cam shaft motion to
the valve. The rocker-arm ball is retained by a nut.
HYDRA ULIC VALVE LIFTERS
Hydraulic Valve Lifters are used to keep all parts o f
the valve train in constant contact.
The hydraulic lifter assembly consists of: the lifter
body, which rides in the cylinder block boss, a plunger, a
push rod seat, a m etering valve, a plunger spring, a
check ball an d spring, a check ball retainer and a push
rod seat retainer.
W hen the lifter is rid in g on the low point o f the
cam, the plunger spring keeps the plunger and push rod
seat in contact with the push rod.
W h e n the lifter body begins to ride up the cam lobe,
the check ball cuts off the transfer o f oil from the
reservoir below the plunger. The plunger an d lifter body
then rise as a unit, pushing up the push rod and opening
the valve.
As the lifter body rides down the other side o f the
cam, the plunger follows w ith it until the valve closes.
The lifter body continues to follow the cam to its low
point, but the plunger spring keeps the plunger in
contact with the push rod. The ball check valve will then
move off its seat an d the lifter reservoir will rem ain full.
IN T A K E M A N IF O L D
The intake m anifold is of cast iron double level
design for efficient fuel distribution. The carburetor pad
is centrally located with a passage running underneath
the pad (E.F.E.) through which exhaust gases are forced
to prom ote faster fuel vaporization when the engine is
cold. An E G R port is also cast into the manifold for the
mixture of exhaust gases with the fuel air mixture.
E XHUAST M AN IFO LD S
Two cast iron exhaust m anifolds are used to direct
exhaust gases from the combustion chambers to the
exhaust system. The right hand side m anifold receives a
heat shield that is used to route heated air to the air
cleaner for better fuel vaporization.
C O M B U S T IO N CHAMBERS
Combustion Cham bers are cast to insure uniform
shape for all cylinders. Spark plugs are located between
the intake and exhaust valves.
The contoured wedge shape o f the combustion
c h a m b e r m inim izes the possibility o f detonation,
facilitates breathing and provides swirling turbulence for
smooth, complete combustion.
ENGINE LUBRICATION
Full pressure lubrication through a full flow oil
filter, is furnished by a gear-type oil pump. The
distributor, driven by a helical gear on the camshaft,
drives the oil pump. The m ain oil gallery feeds oil,
through drilled passages, to the cam shaft and crankshaft
to lubricate the bearings. The valve lifter oil gallery
feeds the valve lifters which, through hollow push rods,
feed the individually mounted rocker arms (fig. 6A-1V
and 6A-2V).
ON VEHICLE SERVICE
E N G IN E M O U N T S
Engine mounts (fig. 6A-3V - 6A-8V) are the nonadjustable type a n d seldom require service. Broken or
deteriorated mounts should be replaced immediately,
because o f the added strain placed on other mounts and
drive line components.
c.
R ubber split through center
Replace the mount. If there is relative movement
between a metal plate o f the m ount and its attaching
points, lower the engine on the mounts and tighten the
screws or nuts attaching the m ount to the engine, frame,
or bracket.
Checking Engine Mounts
Front M oun t
Rear M ount
Raise the engine to remove weight from the mounts
and to place a slight tension in the rubber. Observe both
mounts while raising engine. If an engine mount
exhibits:
a. Hard ru b b e r surface covered with heat check
cracks:
b. R u b b e r separated from a metal plate o f the
m ount; or
Raise the vehicle on a hoist. Push up and pull down
on the transmission tailshaft while observing the
transmission mount. If the rub ber separates from the
metal plate o f the mount or if the tailshaft moves up but
not down (mount bottomed out) replace the mount. If
there is relative movement between a metal plate o f the
m ount and its attaching point, tighten the screws or nuts
attaching the mount to the transmission or crossmember.
FUEL PUMP PUSH ROD OILING
OIL F)LTER AND
BY-PASS VALVE
FUEL PUMP PUSH ROD OILING
CRANKCASE AND CRANKSHAFT OILING
VALVE MECHANISM OILING
Front Mount Replacement
1. Remove m ount retaining bolt from below fram e
mounting bracket.
2. Raise front of engine and remove mount-toengine bolts and remove mount.
CAUTION: Raise engine only enough fo r
sufficient clearance. Check fo r interference
between rear o f engine and cowl panel.
3. Replace m ount to engine and lower engine into
place.
4. Install retaining bolt and torque all bolts to
specifications.
Rear Mount Replacement
1.
2.
Support engine weight to relieve rear mounts.
Remove crossmember-to-mount bolts.
3. On P Series with m anual transmission and
propeller shaft parking brake, remove m ount attaching
bolts from fram e outrigger and clutch housing and
remove rear m ounting cushions.
Fig. 6A-3V--"P" Series Engine Mount Bracket
(EXCEPT MOBILE HOME CHASSIS)
WITHOUT PROPELLER SHAFT PARKING BRAKE
ALL MANUAL TRANSMISSION
ALL TURBO HYDRA-MATIC 350
ALL MOBILE HOME CHASSIS
WITHOUT PROPELLER SHAFT PARKING BRAKE
AUTOMATIC TRANSMISSION
WITH PROPELLER SHAFT PARKING BRAKE
AU TO M A TIC
TR A N S M IS S IO N
'/ M A N U A L
TR A N S M IS S IO N
VIEW A
FRONT MOUNT
V
4. R em ove m o u n t-to -tra n sm issio n bolts, then
remove mount.
5. On P Series with m anual transmission and
propeller shaft parking brake, install new m ounting
cushions and bolts.
6. Install new m ount on transmission.
7. While lowering transmission, align and start
crossm em ber-to-m ount bolts.
8. Torque bolts to specifications then bend lock
tabs to bolt head as applicable.
IN T A K E M A N IF O L D
Removal
1.
2.
D ra in rad ia to r and remove air cleaner.
Disconnect:
• Battery negative cable at battery.
• R a d ia to r upper hose and heater hose at
manifold.
• W a te r p u m p by-pass at w ater p u m p (Mark IV
only).
• Accelerator linkage at carburetor.
• Fuel line at carburetor.
• Crankcase ventilation lines.
• Spark advance hose at distributor.
3. Remove distributor cap and m ark rotor position
with chalk, then remove distributor.
4. Remove (as required) air cleaner bracket, air
compressor an d bracket, accelerator return spring and
bracket, and accelerator bellcrank.
5. Remove generator upp er m ounting bracket.
6. Remove m anifold attaching bolts, then remove
m an ifo ld and carburetor as an assembly. Discard gaskets
and seals.
7. If m anifold is to be replaced, transfer:
• C a rb u re to r and carbu reto r attaching bolts.
• T em p erature sending unit.
• T herm ostat with housing (use new gasket).
• H eater hose and water p u m p by-pass adapters.
• E G R Valve (use new gasket) (if applicable).
• TVS switch (if applicable).
• Vacuum fitting(s).
• Choke spring assembly (where applicable).
Installation
1. Clean gasket and seal surfaces on manifold,
block, and cylinder heads.
2. Install manifold seals on block and gaskets on
cylinder heads (fig. 6A-9V). Use sealer at w ater passages
and w here seals butt to gaskets.
3. Install m anifold and torque bolts to specifica
tions in the sequence outlined in fig. 6A-10V.
4. Install (if removed) air cleaner bracket, air
compressor a n d bracket, accelerator bellcrank.
5. Install distributor, positioning rotor at chalk
mark, then install distributor cap.
6. Connect:
• Spark advance hose at distributor.
• Crankcase ventilation lines.
Fig. 6A-9V~lntake Manifold Gasket
•
•
•
Seal Location
Fuel line at carburetor.
Accelerator linkage at carburetor.
W ater p u m p by-pass at w ater pu m p (M ark IV
only).
• Battery negative cable at battery.
7. Install air cleaner.
8. Fill with coolant, start engine, adjust ignition
tim ing and c arburetor idle speed and check for leaks.
EXHAUST M A N IF O LD
Removal
1. Remove carbu retor heat stove pipe.
2. On Small V8 engine, remove the spark plug
wiring heatshields.
3. On M ark IV V8 engine, remove spark plugs.
4. Disconnect exhaust pipe from manifold and
hang exhaust pipe from fram e with wire.
5. Remove end bolts then remove center bolts and
remove manifold.
Installation
N OTE: If installing a new right side manifold, the
carburetor heat stove must be transferred from the
old unit (fig. 6A-1IV 6V-12V).
1. Clean m ating surfaces on manifold an d head,
then install m anifold in position and install bolts
(fingertight).
2. Torque m anifold bolts to specifications in the
sequence shown on torque chart at end o f section.
3. Connect exhaust pipe to manifold. Use new
gasket or packing.
Fig. 6 A -1 0 V -In ta ke M anifold Torque Sequence
W IN G NUT
LOWER STOVE
NOTE: Inboard flange
of lower stove must be
installed on top of rib
of exhaust manifold.
CARBURETOR TEE
'
AiR CLEANER
HOSE
350/400 V8 4Bbl
ivnwfiri
UPPER STOVE
LOWER STOVE
Fig. 6 A -1 IV -C a rb u re to r Heat Stove Assem bly—Small
Fig. 6A-12V--Carburetor Heat Stove Assembly—M ark
V-8
IV
4. On M ark IV V8 engines, install spark plugs.
Torque plugs to specifications.
5. Install c arburetor heat stove pipe.
6. On Small V8 engine, install spark plug wiring
heatshields.
7. Start engine and check for leaks.
3. Disconnect electrical wiring harness from rocker
arm clips.
4. Remove carburetor heat stove pipe from right
exhaust manifold.
5. If the vehicle is equipped with air conditioning,
remove the A / C compressor rear brace on small V-8 (fig.
6A-13V) or upper brace on M ark IV (fig. 6A-14V).
6. Remove rocker arm cover to head attaching
bolts and remove rocker arm cover.
ROCKER ARM COVER
Removal (All)
1. Remove air cleaner.
2. Disconnect crankcase ventilation hoses at rocker
arm covers.
CAUTION: Do not pry rocker arm cover loose.
Gaskets adhering to cylinder head and rocker
arm cover may be sheared by bum ping fro n t
4. Connect electrical wiring harness at clips on
rocker arm cover.
5. Connect crankcase ventilation hoses.
6. Install air cleaner, start engine and check for
leaks.
Installation (M ark IV)
1. Clean sealing surface on cylinder head with
degreaser then, using RTV, place rocker arm cover on
the head, install re ta in in g bolts an d torque to
specification.
NOTE: All loose RTV sealer, or pieces causing
installation interference, must be removed from
both cylinder head and cover seal surfaces prior to
applying new sealer.
A 1/8" bead o f RTV sealer should be placed all
around the rocker cover sealing surface of the
cylinder head. (W hen going around the attaching
bolt holes, always flow the RTV on the inboard
side o f the holes). Install cover and torque bolts to
specification while RTV is wet (within 10 min.).
2. On A / C equipped vehicles, install the A /C
com pressor u pp e r brace. A djust pulley belt to
specification.
3. Install carburetor heat stove pipe.
4. Connect electrical wiring harness at clips on
rocker arm cover.
5. Connect crankcase ventilation hoses.
6. Install air cleaner, start engine and check for
leaks.
VALVE M E C H A N IS M
Removal
1. Remove rocker arm covers as previously
outlined.
2. Remove rocker arm nuts, rocker arm balls,
rocker arms and push rods.
NOTE: Place rocker arms, rocker arm balls and
push rods in a rack to they may be reinstalled in
the same locations.
Installation and Adjustment
Fig. 6A-14V--A/C Compressor m o u n tin g —M ark IV
en d o f rocker arm cover rearward with palm o f
hand or a rubber mallet.
Installation (Small V-8)
1. Clean gasket surfaces on cylinder head and
rocker arm cover with degreaser then, using a new
gasket, place rocker arm cover on the head, install
retaining bolts and torque to specifications.
2. On A / C equipped vehicles, install the A / C
co m p resso r
re a r
brace. A dju st pulley belt to
specifications.
3. Install carburetor heat stove pipe.
N OTE: W henever new rocker arms a n d / o r rocker
arm balls are being installed, coat bearing surfaces
o f rocker arm s and rocker arm balls with
"M olykote" or its equivalent.
1. Install push rods. Be sure push rods seat in lifter
socket.
2. Install rocker arms, rocker arm balls and rocker
arm nuts. Tighten rocker arm nuts until all lash is
eliminated.
3. Adjust valves when lifter is on base circle o f
cam shaft lobe as follows:
a.
C rank engine until mark on torsional d a m p e r
lines up with center or " O " m ark on the timing tab
fastened to the crankcase front cover and the engine is
in the n um b e r 1 firing position. This m ay be determined
by placing fingers on the n um b e r 1 valve as the mark on
the d a m p e r comes n ear the " O " mark on the crankcase
front cover. If the valves are not moving, the engine is in
the n u m b e r 1 firing position. If the valves move as the
mark comes up to the timing tab, the engine is in
n u m b e r 6 firing position and should be turned over one
more time to reach the n u m b e r 1 position.
b. W ith the engine in the n um b e r 1 firing
position as determ ined above, the following valves may
be adjusted.
-- E x h a u s t - 1, 3, 4, 8
— In ta k e - 1 , 2, 5, 7
c. Back out adjusting nut until lash is felt at the
push rod then tu rn in adjusting nut until all lash is
removed. This can be determ ined by checking push rod
side play while turning adjusting nut (fig. 6A-15V).
W hen play has been removed, turn adjusting nut in one
full ad ditional turn (to center lifter plunger).
d. Crank the engine one revolution until the
p o in te r"o " m ark and torsional d a m p e r m ark are again
in alignment. This is n um b e r 6 firing position. W ith the
engine in this position the following valves m ay be
adjusted.
— Exhaust—2, 5, 6, 7
— Intake—3, 4, 6, 8
4. Install rocker arm covers as previously outlined.
5. S tart engine and adjust carburetor idle speed.
2. Remove spark plug, rocker arm and push rod on
the cylinder(s) to be serviced.
3. Install air line adap ter Tool J-23590 to spark
plug port and apply compressed air to hold the valves in
place.
4. Using Tool J-5892 to compress the valve spring,
remove the valve locks, valve cap an d valve spring and
d a m p e r (fig. 6A-16V).
5. Remove the valve stem oil seal.
Installation
Sm all V8 Engines
1. Set the valve spring and damper, valve shield
and valve cap in place. Compress the spring with Tool
J-5892 and install oil seal in the lower groove o f the
stem, making sure the seal is flat and not twisted.
NOTE: A light coat o f oil on the seal will help
prevent twisting.
2. Install the valve locks and release the compres
sor tool making sure the locks seat properly in the upper
groove of the valve stem.
NOTE: G rease may be used to hold the locks in
place while releasing the compressor tool.
3. Install spark plug and torque to specification.
4. Install and adjust valve mechanism as previously
outlined.
M a rk IV V8 Engines
VALVE STEM OIL SEAL a n d /o r VALVE
S P R IN G
1.
Install new valve stem oil seal (coated with oil)
in position over valve guide.
Removal
NOTE: Seal installation instructions are supplied
1.
outlined.
R em ove
rocker
arm
cover
as
previously
with each service kit. Install seal following
procedures outlined on the supplied instruction
sheet.
2. Set the valve spring and d a m p e r and valve cap
in place.
3. Compress the spring with Tool J-5892 and
install the valve locks then release the compressor tool,
m aking sure the locks seat properly in the groove o f the
valve stem.
N O TE : Grease may be used to hold the locks in
place while releasing the compressor tool.
4. Install spark plug and torque to specifications.
5. Install and adjust valve mechanism as previously
outlined.
VALVE LIFTERS
H ydraulic valve lifters very seldom require a tten
tion. The lifters are extremely simple in design,
readjustm ents are not necessary, and servicing of the
lifters requires only that care and cleanliness be
exercised in the handling o f parts.
Locating Noisy Lifters
Locate a noisy valve lifter by using a piece o f
garden hose approxim ately four feet in length. Place one
end o f the hose near the end of each intake and exhaust
valve with the other end o f the hose to the ear. In this
m anner, the sound is localized making it easy to
determ ine which lifter is at fault.
A n othe r method is to place a finger on the face o f
the valve spring retainer. If the lifter is not functioning
properly, a distinct shock will be felt when the valve
returns to its seat.
The general types o f valve lifter noise are as
follows:
1. Hard Rapping N o ise -U su a lly caused by the
plunger becoming tight in the bore o f the lifter body to
such an extent that the return spring can no longer push
the plunger back up to working position. Probable causes
are:
a. Excessive varnish or carbon deposit causing
a b n o rm al stickiness.
b. G alling or "pick -u p" between plunger and
bore o f lifter body, usually caused by an abrasive piece
o f dirt or metal wedging between plunger and lifter
body.
2. M oderate R apping N oise-Probable causes are:
a. Excessively high leakdown rate.
b. Leaky check valve seat.
c. Im proper adjustment.
3. G eneral Noise T hro ugh ou t the Valve Train-This
will, in most cases, be caused by either insufficient oil
supply or im p rop er adjustment.
4. Interm ittent Clicking-Probable causes are:
a. A microscopic piece o f dirt m om entarily
caught between ball seat an d check valve ball.
b. In rare cases, the ball itself m ay be out-ofround or have a flat spot.
c. Im pro per adjustment.
In most cases where noise exists in one or more
lifters all lifter units should be removed, disassembled,
cleaned in a solvent, reassembled, and reinstalled in the
engine. If dirt, corrosion, carbon, etc. is shown to exist in
one unit, it more likely exists in all the units, thus it
would only be a matter o f time before all lifters caused
trouble.
Removal
1. Remove intake manifold as previously outlined.
2. Remove valve m echan ism
as previously
outlined.
3. Remove valve lifters.
NOTE: Place valve lifters in a rack so that they
may be reinstalled in the same location.
Installation
1.
Install valve lifters.
NOTE: W henever new valve lifters are being
installed, coat foot o f valve lifters with "M olykote"
or its equivalent.
2. Install intake manifold as previously outlined.
3. Install and adjust valve m echanism as outlined.
Disassembly
1. Hold the plunger down with a push rod, and
using the blade of a small screw driver, remove the push
rod seat retainer.
2. Remove the push rod seat and m etering valve
(fig. 6A-17V).
3. Remove the plunger, ball check valve assembly
and the plunger spring.
4. Remove the ball check valve and spring by
I. L ifte r B o dy
2 Push Rod S e at
3. M e te rin g V a lv e
6
7
Push Rod S eat
R e ta in e r
P lu n g e r
4
C h e c k B a ll
5
C h e c k B a ll R e ta in e r
8
9
C h e c k B a ll S p rin g
P lu n g e r S p rin g
Fig. 6A-18V--Removing Ball Check Valve
Fig. 6 A - 1 9 V - ln s t a llin g B all C h e ck V alve
prying the ball retainer loose from the plunger with the
blade o f a small screw driver (fig. 6A-18V).
Cleaning and Inspection
T horoughly clean all parts in cleaning solvent, and
inspect them carefully. If any parts are dam aged or
worn, the entire lifter assembly should be replaced. If the
lifter body wall is scuffed or worn, inspect the cylinder
block lifter bore. If the bottom o f the lifter is scuffed or
worn, inspect the cam shaft lobe. If the push rod seat is
scuffed or worn, inspect the push rod. An additive
containing EP lube, such as EOS, or equivalent, should always
be added to crankcase oil for run-in when any new camshaft
or lifters are installed. All damaged or worn lifters should be
replaced.
Assembly
1. Place the check ball on small hole in bottom of
the plunger.
2. Insert check ball spring on seat in ball retainer
and place retainer over ball so that spring rests on the
ball. Carefully press the retainer into position in plunger
with the blade o f a small screw driver (fig. 6A-19V).
3. Place the plunger spring over the ball retainer
and slide the lifter body over the spring and plunger,
being careful to line up the oil feed holes in the lifter
body and plunger.
4. Fill the assembly with SAE 10 oil, then insert
the en d o f a 1 /8 " drift pin into the plunger and press
down solid. A t this point, oil holes in the lifter body and
plunger assembly will be aligned (fig. 6A-20V).
CAUTION: Do not attem pt to fo rce or pum p
the plunger.
5. Insert a 1/16" drift pin through both oil holes to
Fig. 6A-20V--Assembly Hydraulic Lifter
hold the plunger down against the lifter spring tension
(fig. 6A-20V).
6. Remove the 1/8" drift pin, refill assembly with
SAE 10 oil.
7. Install the metering valve an d push rod seat (fig.
6A-17V).
8. Install the push rod seat retainer, press down on
the push rod seat and remove the 1/16" drift pin from
the oil holes. The lifter is now completely assembled,
filled with oil and ready for installation.
N O T E : Before installing lifters, coat the bottom o f
the lifter with "M olykote" or its equivalent.
CYLINDER HEAD ASSEMBLY
Removal
spring shields (if so equipped) springs an d spring
damper, then remove oil seals and valve spring shims.
3.
Remove valves from cylinder head and place
them in a rack in their proper sequence so that they can
be assembled in their original positions.
Cleaning
E Remove intake m anifold as previously outlined.
2. Remove generator lower mounting bolt and lay
unit aside.
3. R em ove exhaust m a n ifo ld s as previously
outlined.
4. If vehicle is equipped with A /C , remove A / C
compressor and forward m ounting bracket. Lay unit
aside.
N OTE: On vehicles equipped with A.I.R., discon
nect the ru b b e r hosing at the injection tubing check
valve (fig. 6A-21V). In this m anner, the tubing will
not have to be removed from the exhaust manifold.
5. Rem ove valve m ech anism
as previously
outlined.
6. D rain cylinder block o f coolant.
7. Remove cylinder head bolts, cylinder head and
gasket. Place cylinder head on two blocks o f wood to
prevent damage.
Disassembly
1. With cylinder head removed, remove valve
rocker arm nuts, balls and rocker arms (if not previously
done).
2. Using Tool J-8062, compress the valve springs
(fig. 6A-22V) and remove valve keys. Release the
compressor tool and remove rotators or spring caps.
DISCONNECT
HOSING
'
HERE
SMALL V-8
1. Clean all carbon from combustion cham bers
and valve ports using Tool J-8089 (fig. 6A-23V).
2. Thoroughly clean the valve guides using Tool
J-8101 (fig. 6A-24V).
3. Clean all carbon and sludge from push rods,
rocker arms and push rod guides.
4. Clean valve stems and heads on a buffing wheel.
5. Clean carbon deposits from head gasket mating
surface.
Inspection
1. Inspect the cylinder head for cracks in the
exhaust ports, combustion chambers, or external cracks
to the water chamber.
2. Inspect the valves for burned heads, cracked
faces or dam aged stems.
N OTE: Excessive valve stem to bore clearance will
cause excessive oil consumption and m ay cause
valve breakage. Insufficient clearance will result in
noisy and sticky functioning o f the valve and
disturb engine smoothness.
3. Measure valve stem clearance (fig. 6A-25V) as
follows: Clam p a dial indicator on one side of the
cylinder head rocker arm cover gasket rail, locating the
indicator so that movem ent o f the valve stem from side
DISCONNECT
HOSING
HERE
M A R K IV
Fig. 6A-24V-Cleaning Valve Guides (Typical)
Fig. 6A-22V--Compressing Valve Spring (Typical)
Fig. 6A-23V--Cleaning Com bustion Chambers (Typical)
to side (crosswise to the head) will cause a direct
m ovem ent o f the indicator stem. The indicator stem
must contact the side o f the valve stem just above the
valve guide. With the valve head dropped about 1/16"
off the valve seat; move the stem o f the valve from side
to side using light pressure to obtain a clearance reading.
If clearance exceeds specifications it will be necessary to
ream valve guides for oversize valves as outlined.
4. Check valve spring tension with Tool J-8056
spring tester (fig. 6A-26V).
NO TE: Springs should be compressed to the
specified height and checked against the specifica
tions chart. Springs should be replaced if not
within 10 lbs. o f the specified load (without
dampers).
5. Inspect rocker arm studs for w ear of damage.
Fig. 6A-25V--Measuring Valve Stem Clearances
(Typical)
Inspect push rod guides on M ark IV V8 engines for wear
or damage.
Assembly
1.
Insert a valve in the proper port.
c. Install oil seal in the lower groove o f the stem,
m aking sure that the seal is flat and not twisted.
d. Install the valve locks and release the
compressor tool making sure that the locks seat properly
in the upper groove o f the valve stem.
M a rk IV V8
a. Install valve spring shim on valve spring seat
then install a new valve stem oil seal over valve and
valve guide.
b. Set the valve spring (with damper); and valve
cap in place (fig. 6A-28V).
c. Compress the spring with Tool J-8062.
d. Install the valve locks and release the
Fig. 6A-26V--Checking Valve Spring Tension
2.
follows:
J ts
1
Assemble the valve spring and related parts as
J
S m all V8
CAUTION: On engines using exhaust valve
rotators, m ake sure that the proper (shorter)
springs are used on exhaust valves.
a. Set the valve spring shim, valve spring (with
d a m p e r if used), valve shield and valve cap or rotator in
place (fig. 6A-27V).
b.
Compress the spring with Tool J-8062.
ROTATOR O N EXHAUST VALVE
Fig. 6A-28V-Exhaust Valve Spring In stallation (M ark
IV)
compressor tool, m aking sure the locks seat properly in
the groove o f the valve stem.
N O TE : G rease may be used to hold the locks in
place, while releasing the compressor tool.
3. Install the re m ain in g valves.
4. On Small V8 engines check each valve stem oil
seal by placing Valve Seal Leak Detector (Toool J-23994)
over the end of the valve stem and against the cap.
O perate the vacuum pu m p an d m ake sure no air leaks
past the seal (fig. 6A-29V).
5. Check the installed height o f the valve springs,
using a narrow thin scale. A cutaway scale will help (fig.
6A-30V). M easure from the top of the shim or the spring
seat to the top o f the valve spring or valve spring shield
(fig. 6A-31V). If this is found to exceed the specified
height, install a valve spring seat shim approximately
1/16" thick. At no time should the spring be shim m ed to
give an installed height under the m inim um specified.
Installation
sealer thin and even. One method o f applying the sealer
that will assure the proper coat is with the use o f a paint
roller. Too much sealer may hold the gasket away from
the head or block.
CAUTION: Use no sealer on engines using a
composition S T E E L A S B E S T O S gasket.
2. Place the gasket in position over the dowel pins
with the bead up.
3. Carefully guide the cylinder head into place
over the dowel pins and gasket.
4. Coat threads o f cylinder head bolts with sealing
compound and install bolts finger tight.
5. Tighten each cylinder head bolt a little at a time
in the sequence shown in the torque sequence chart until
the specified torque is reached.
6. Install exhaust manifolds as previously outlined.
7. Install intake manifold as previously outlined.
8. Install and adjust valve mechanism as previously
outlined.
ROCKER ARM STUDS
CAUTION: The gasket surfaces on both the
head a n d the block m ust be clean o f any
Replacement
foreig n m atter a nd fr e e o f nicks or heavy
M ark IV
scratches. Cylinder bolt threads in the block
The push rod guides are related to the cylinder head
a nd threads on the cylinder head bolts must be
by the rocker arm studs (fig. 6A-32V). Replace where
clean. (D irt will affect bolt torque).
1.
On engines using a STEEL gasket, coat both necessary and torque rocker arm studs to specifications.
sides o f a new gasket with a good sealer. Spread the
N OTE: Coat Threads on cylinder head end of
rocker arm studs with sealer before assembly to
cylinder head.
Sm all V8
GR IN D OUT THIS POR TIO N
i | i| II i j
1
1
111j I p 11 1 I ' l ' l ' l ' l " 1
—
2
l ' r~rj
r ........
3
4
5
" I " ’!”
Rocker arm studs that have dam aged threads or are
6
Fig. 6A-30V--Cutaway Scale
SEE SPECIFICATIONS
Fig 6A-32V -Rocker Arm Stud
Push Rod G uide
loose in cylinder heads should be replaced with new
studs available in .003" and .013" oversize. Studs may be
installed after ream ing the holes as follows:
1. Remove old stud by placing Tool J-5802-1 over
the stud, installing nut and flat washer and removing
stud by turning nut (fig. 6A-33V).
2. R eam hole for oversize stud using Tool J-5715
for .003" oversize or Tool J-6036 for .013" oversize (fig.
6A-34V).
CAUTION: Do not attem pt to install an
oversize stu d without ream ing stud hole.
3. Coat press-fit area o f stud with hypoid axle
5802
Fig. 6 A -3 5 V -In sta llin g Rocker Arm Stud (Sm all V8)
lubricant. Install new stud, using Tool J-6880 as a guide.
G auge should bottom on head (fig. 6A-35V).
VALVE G UIDE BORES
Valves with oversize stems are available (see
specifications). To ream the valve guide bores for
oversize valves use Tool Set J-5830 for Small V8 or
J-7049 for Mark IV V8.
VALVE SEATS
Fig. 6A 33V--Removing Rocker Arm Stud (Small V8)
OVERSIZE
Reconditioning the valve seats is very im portant,
because the seating o f the valves must be perfect for the
engine to deliver the power and perform ance built into
it.
A nother im portant factor is the cooling of the valve
heads. Good contact between each valve and its seat in
the head is imperative to insure that the heat in the valve
head will be properly carried away.
Several different types o f equipm ent are available
for reseating valves seats. The recom m endations of the
m anufacturer o f the equipm ent being used should be
carefully followed to attain proper results.
Regardless of w hat type o f equipm ent is used,
however, it is essential that valve guide bores be free
from carbon or dirt to ensure proper centering o f pilot
in the guide.
Reconditioning
1. Install expanding pilot in the valve guide bore
and expand pilot.
2. Place roughing stone or form ing stone over pilot
an d just clean up the valve seat. Use a stone cut to
specifications.
3. Remove roughing stone or form ing stone from
pilot, place finishing stone, cut to specifications, over
pilot and cut just enough metal from the seat to provide
a smooth finish. Refer to specifications.
4. Narrow down the valve seat to the specified width.
NO TE: This operation is done by grinding the port
side with a 30 degree stone to lower seat and a 60
degree stone to raise seat.
5. Remove e x panding pilot and clean cylinder
head carefully to remove all chips and grindings from
above operations.
6. M easure valve seat concentricity (fig. 6A-36V).
N OTE: Valve seats should be concentric to within
.002" total indicator reading.
VALVES
Valves that are pitted can be refaced to the proper
angle, insuring correct relation between the head and
stem on a valve refacing mechanism. Valve stems which
show excessive wear, or valves that are w arped
excessively should be replaced. W hen a valve head which
is warped excessively is refaced, a knife edge will be
ground on p art or all o f the valve head due to the
am o u n t o f metal that must be removed to completely
reface. K nife edges lead to breakage, b urning or p re
ignition due to heat localizing on this knife edge. If the
edge o f the valve head is less than 1/32" thick after
grinding, replace the valve.
Several different types o f e quipm ent are available
for refacing valves. The recom m endation o f the
m a n u fa ctu rer of the e quipm ent being used should be
carefully followed to attain proper results.
wheel and regulate the feed screw to provide light valve
contact.
5. Continue grinding until the valve face is true
and smooth all around the valve. If this makes the valve
head thin ( 1 /3 2 " min.) the valve must be replaced as the
valve will overheat and burn.
6. Remove valve from chuck and place stem in
"V " block. Feed valve squarely against grinding wheel to
grind any pit from rocker arm end o f stem.
N OTE: Only the extreme end o f the valve stem is
h ardened to resist wear. Do not grind end o f stem
excessively.
7. A fter cleaning valve face and cylinder head
valve seat o f grinding particles, make pencil marks about
1/4" apart across the valve face, place the valve in
cylinder head and give the valve 1/2 turn in each
direction while exerting firm pressure on head of valve.
8. Remove valve and check face carefully. If all
pencil marks have not been removed at the point of
contact with the valve seat, it will be necessary to repeat
the refacing operation and again recheck for proper
seating.
9. G rin d and check the rem aining valves in the
same manner.
TO R S IO N A L DAM PER
Removal
Reconditioning
1. If necessary, dress the valve refacing machine
grinding wheel to make sure it is smooth and true. Set
chuck at angle specified for valve. Refer to specifications.
2. C lam p the valve stem in the chuck o f the
machine.
3. Start the grinder and move the valve head in
line with the g rinder wheel.
4. T u rn the feed screw until the valve head just
contacts wheel. Move valve back and forth across the
1. Remove fan belt, fan and pulley.
2. Rem ove the r a d ia to r shroud
outlined in Section 6B.
assembly
as
NOTE: If additional operations (such as camshaft
removal) are not being performed, the radiator
removal will not be necessary.
3. Remove accessory drive pulley then remove
da m p e r retaining bolt.
4. Install Tool J-23523 on d a m p e r then, turning
puller screw, remove d a m p e r (fig. 6A-37V).
N O T E: Tool J-23523 has holes forming two
patterns. A two bolt and a three bolt pattern. The
holes for the two bolt pattern must be elongated
for use on the M ark IV V8 engines.
8.
leaks.
Fill cooling system, start engine and check for
CRANKCASE FR O N T COVER
Removal
Installation
Sm all V8 Engine
CAUTION: The inertial weight section o f the
1. Remove torsional d a m p e r as previously
outlined.
2. Remove w ater pump as outlined in Section 6B.
3. Remove crankcase front cover attaching screws
and remove front cover and gasket, then discard gasket.
torsional damper is assembled to the hub with a
rubber type material. The installation proce
dures (with proper tool) m ust be follow ed or
m ovem ent o f the inertia weight section on the
hub will destroy the turning o f the torsional
damper.
M ark IV V8 Engine
1. Coat front cover seal contact area (on dam per)
with engine oil.
2. Place
crankshaft.
3.
dam per
in
position
over
key
on
Pull d a m p e r onto crankshaft as follows:
a. Install ap pro priate
J-23523 into crankshaft.
threaded
end
o f Tool
CAUTION: Install tool in crankshaft so that at
least 1 /2 " o f thread engagem ent is obtained.
b. Install plate, thrust
complete tool installation.
c.
6A-38V.
bearing
and
nut
to
Pull d a m p e r into position as shown in Figure
d. Remove tool from crankshaft then install
d a m p e r retaining bolt and torque to specifications.
4.
Install accessory drive pulley.
5.
Install rad iato r shroud as outlined in Section 6B.
6. Install fan and pulley to water pum p hub and
tighten securely.
7. Install fan belt and adjust to specifications using
strand tension gauge.
J- 2 3 5 2 3
1. Remove torsional d a m p er and water pum p as
outlined.
2. Remove the two. oil pan-to-front cover attach
ing screws.
3. Remove the front cover-to-block attaching
screws.
4. Pull the cover slightly forward only enough to
perm it cutting o f oil p a n front seal.
5. Using a sharp knife or other suitable cutting
tool, cut oil p a n front seal flush with cylinder block at
both sides o f cover (fig. 6A-39V).
6. Remove front cover and attaching portion o f oil
pan front seal. Remove front cover gasket.
Installation
Sm all V8 Engine
1. Clean gasket surface on block and crankcase
front cover.
2. Use a sharp knife or other suitable cutting tool,
to remove any excess oil p a n gasket material that may be
protruding at the oil to engine block junction.
3. Apply a 1/8 inch bead o f silicone rub ber sealer,
part 1051435 (or equivalent) to the joint formed at the
oil pan and cylinder block.
4. Coat the cover gasket with gasket sealer and
place in position on cover.
5. Install cover-to-oil p a n seal, lightly coat bottom
of seal with engine oil, an d position cover over
crankshaft end.
6. Loosely install the cover-to-block, upper attach
ing screws.
7. Tighten screws alternately and evenly while
pressing downward on cover so that dowels in block are
aligned with corresponding holes in cover.
N O TE: Position cover so that dowels enter holes in
cover without binding. Do not force cover over
dowels so that cover flange or holes are distorted.
8. Install rem aining cover screws and torque to
specifications.
9. Install torsional d a m p e r and w ater pu m p as
previously outlined.
Fig. 6A-41V-Applying Front Cover Sealer
11.
Install torsional da m p e r and w ater p u m p as
previously outlined.
M a rk IV V8 Engine
OIL SEAL (F R O N T COVER)
1. Clean gasket surface on block and crankcase
front cover.
2. Cut tabs from the new oil pan front seal (fig.
6A-40V)., use a sharp instrument to ensure a clean cut.
3. Install seal to fro nt cover, pressing tips into
holes provided in cover.
4. Coat the gasket w ith gasket sealer and place in
position on cover.
5. Apply a 1/8 inch bead o f silicone ru bb er sealer,
p art 1051435 (or equivalent) to the joint formed at the
oil pan and cylinder block (fig. 6A-41V).
6. Position crankcase front cover over crankshaft.
7. Press cover downward against oil p a n until
cover is aligned and installed over dowel pins on block.
8. Install and partially tighten the two, oil pan-tofron t cover attaching screws.
9. Install the front cover-to-block attaching screws.
10. Torque all screws to specifications.
C U T THI S
FROM N E W
SEAL
Replacement
W ith Cover Removed
1. W ith cover removed, pry oil seal out o f cover
from the front with a large screw driver.
2. Install new seal so that open end o f the seal is
toward the inside o f cover and drive it into position with
Tool J-23042 on Small V8 engines or Tool J-22102 on
Mark IV V8 engines (fig. 6A-42V).
CAUTION: Support cover at seal area. (Tool
J-971 m ay be used as support).
W ith Cover Installed
1. W ith torsional d a m p e r removed, pry seal out of
cover from the front with a large screw driver, being
careful not to dam ag e the surface on the crankshaft.
2. Install new seal so that open end of seal is
toward the inside o f cover and drive it into position with
Tool J-23042 on Small V8 engines or Tool J-22102 on
M ark IV V8 engines (fig. 6A-43V).
CAMSHAFT
M easuring Lobe Lift
N OTE: Procedure is sim ilar to that used for
checking valve timing. If im proper valve operation
is indicated, measure the lift o f each push rod in
consecutive order and record the readings.
1. Remove the valve mechanism as previously
outlined.
2. Position indicator with ball socket adapter (Tool
J-8520) on push rod (fig. 6A-44V).
N OTE: Make sure push rod is in the lifter socket.
3. Rotate the crankshaft slowly in the direction of
rotation until the lifter is on the heel o f the cam lobe. At
this point, the push rod will be in its lowest position.
4. Set dial indicator on zero, then rotate the
c rankshaft slowly, or attach an auxiliary starter switch
and " b u m p " the engine over, until the push rod is fully
raised position.
CAUTION: Whenever the engine is cranked
remotely at the started, with a special jum per
cable or other means, the distributor prim ary
lead m ust be disconnected fro m the coil.
J-23042
Fig. 6A 4 4 V -M e a su rin g Cam shaft Lobe Lift
5. Com pare the total lift recorded from the dial
indicator with specifications.
6. If cam shaft readings for all lobes are within
specifications, remove dial indicator assembly.
7. Install and adjust valve mechanism as outlined.
Removal
1. Remove valve lifters as previously outlined.
2. Remove crankcase front cover as previously
outlined.
3. Remove grille as outlined in Section 6B.
4. Remove fuel pu m p push rod as outlined in
Section 6C.
5. Complete cam shaft removal as follows:
N O TE : Sprocket is a light fit on camshaft. If
sprocket does not come off easily a light blow on
the lower edge o f the sprocket (with a plastic
mallet) should dislodge the sprocket.
6. Install two 5 /1 6 " x 18 x 4" bolts in cam shaft
bolt holes then remove cam shaft (fig. 6A-45V).
C A U T IO N :^// cam shaft journals are the same
diam eter a n d care m ust be used in removing
cam shaft to avoid dam age to bearings.
Inspection
The cam shaft b earing jo urna ls should be measured
with a micrometer for an out-of-round condition. If the
journ als exceed .001" out-of-round, the cam shaft should
be replaced.
The ca m sha ft should also be checked for alignment.
The best m ethod is by use of "V " blocks and a dial
indicator (fig. 6A-46V). The dial indicator will indicate
the exact a m o u n t the cam shaft is out of true. If it is out
more than .0015" dial indicator reading, the cam shaft
should be replaced.
Installation
Fig. 6A47V --Tim ing Sprocket A lignm ent M arks
N O TE : W henever a new cam shaft is installed coat
ca m sha ft lobes with "M olykote" or its equivalent.
W henever a new cam shaft is installed, replacement
o f all valve lifters is recom m ended to insure
durability o f the cam shaft lobes and lifter feet.
1. Lubricate cam sh aft journals with engine oil and
install camshaft.
2. Install tim ing chain on cam shaft sprocket. Hold
the sprocket vertically w ith the chain h anging down and
align marks on cam shaft and crankshaft sprockets.
(R efer to fig. 6A-47V 6A-48V).
3. Align dowel in cam sh aft with dowel hole in
cam shaft sprocket then install sprocket on camshaft.
4. D raw the cam shaft sprocket onto cam shaft
using the m ounting bolts. Torque to specifications.
5. Lubricate timing chain with engine oil.
6. Install fuel pum p push rod as outlined in
Section 6C.
7. Install grille as outlined in Section 6B.
8. Install crankcase front cover as previously
outlined.
9. Install valve lifters as previously outlined.
C A M S H A F T BEARINGS
Removal
C am shaft bearings can be replaced while engine is
disassembled for overhaul or without complete disassem
bly o f the engine. To replace bearings w ithout complete
disassembly remove the cam shaft an d crankshaft leaving
cylinder heads attached and pistons in place. Before
removing crankshaft, tape threads of connecting rod
bolts to prevent d am age to crankshaft. Fasten connecting
rods against sides o f engine so they will not be in the
way while replacing cam shaft bearings.
1. With cam shaft and crankshaft removed, drive
cam shaft rear plug from cylinder block.
N OTE: This procedure is based on removal o f the
bearings nearest center of the engine first. With
this method a m inimum am ount o f turns are
necessary to remove all bearings.
2. Using Tool J-6098, with nut and thrust washer
installed to end o f threads, index pilot in cam shaft front
bearing and install puller screw through pilot.
3. Install remover and installer tool with shoulder
toward bearing, making sure a sufficient am ount o f
threads are engaged.
4. Using two wrenches, hold puller screw while
turning nut. W hen bearing has been pulled from bore,
remove remover and installer tool and bearing from
puller screw (fig. 6A-49V).
handle and remove cam shaft front and rear bearings by
driving towards center o f cylinder block (fig. 6A-50V).
Installation
Fig. 6 A -4 8 V -In sta llin g T im ing Chain
Fig. 6A-49V--Removing Cam shaft Bearings
5. Remove rem ain in g bearings (except front and
rear) in the same m anner. It will be necessary to index
pilot in cam sh aft rear bearing to remove the rear
interm ediate bearing.
6. Assemble rem over and installer tool on driver
The cam shaft front and rear bearings should be
installed first. These bearings will act as guides for the
pilot and center the rem aining bearings being pulled
into place.
1. Assemble remover and installer tool on driver
handle and install cam shaft front and rear bearings by
driving towards center o f cylinder block (fig. 6A-50V).
2. Using Tool Set J-6098. with nut then thrust
washer installed to end o f threads, index pilot in
cam shaft front bearing and install puller screw through
pilot.
3. Index cam shaft bearing in bore (with oil hole
aligned as outlined below), then install remover and
installer tool on puller screw with shoulder toward
bearing.
a. Small V8 Engines—N u m b e r one cam bearing
oil hole must be positioned so that oil holes are
equidistant from 6 o ’clock position. N u m b e r two through
num ber four bearing oil holes must be positioned at 5
o ’clock position (toward left side of engine and at a
position even with bottom o f cylinder bore). N u m b e r five
bearing oil hole must be in 12 o ’clock position.
b. M ark IV V8 Engines—N u m b er one through
nu m b e r four cam bearing oil hole must be aligned with
oil holes in cam bearing bore. The nu m b er five bearing
bore is annulus and cam bearing must be positioned at
or near the 6 o ’clock position.
4. Using two wrenches, hold puller screw while
turning nut. A fter bearing has been pulled into bore,
remove the remover and installer tool from puller screw
and check alignm ent o f oil hole in cam shaft bearing (fig.
6A-49V).
5. Install rem ain in g bearings in the same manner.
It will be necessary to index pilot in the cam shaft rear
bearing to install the rear interm ediate bearing.
6. Install a new cam shaft re a r plug.
N O T E : Plug should be installed flush to 1/32"
deep and be parallel with rear surface o f cylinder
block.
OIL PAN
Removal
1. D ra in engine oil.
2. Remove oil dip stick and tube.
3. Remove exhaust crossover pipe.
4. On vehicles equipped with automatic transm is
sion remove converter housing u nder pan.
5. Remove starter brace and inb oard bolt, swing
starter aside.
6. Remove oil pan and discard gaskets and seals.
Installation
1. Thoroughly clean all gasket and seal surfaces on
oil pan, cylinder block, crankcase front cover and rear
m ain bearin g cap.
2. Install new oil pan side gaskets on cylinder
block using gasket sealer as a retainer. Install new oil
pan rear seal in rear main bearing cap groove, with ends
butting side gaskets. Install new oil pan front seal in
groove in crankcase front cover with ends butting side
gaskets (fig. 6A-51V).
3. Install oil pan and torque bolts to specifications.
4. Install starter brace and attaching bolts. Torque
bolts to specifications.
5. Install converter housing under pan.
6. Install exhaust crossover pipe.
7. Install oil dip stick tube and dip stick.
8. Fill with oil, start engine an d check for leaks.
OIL P U M P
Removal
1. Remove oil pan as previously outlined.
2. Remove p u m p to rear m ain bearing cap bolt
and remove pu m p and extension shaft.
Disassembly (Figures 6A-52V and 6A-53V)
1. Remove the pum p cover attaching screws and
the pump cover.
N O T E: M ark g ear teeth so they m ay be
reassembled with the same teeth indexing.
2. Remove the idler gear and the drive gear and
shaft from the pu m p body.
3. Remove the pressure regulator valve retaining
pin, pressure regulator valve and related parts.
4. If the pickup screen and pipe assembly need
replacing, m ount the pum p in a soft-jawed vise and
extract pipe from pump.
l
1.
2.
3.
4
5.
6.
S h a ft Extension
Pum p Body
Drive Gear an d Shaft
Idle r Gear
Pump Cover
Pressure R e g u la tor
Valve
7.
8
9.
10.
Pressure R e g u la tor
S prin g
R e ta in in g Pin
S crew s
P ic k u p Screen and
Pipe
1.
S h a f t E x ten s ion
8.
2.
3.
S h a f t C o u p lin g
Pump Body
9
4.
5.
6.
Drive G e a r an d S h a ft
Id le r G ea r
P ic k u p S c ree n and
Pipe
P u m p C o ver
7.
10
1 1.
12.
Fig. 6A-53V-O il Pump
P ressu re R e g u la t o r
V a lv e
P ressu re R e g u la t o r
S p r in g
W asher
R e ta in in g Pin
Screw s
Fig. 6A-54V -Insta llin g Screen - Small V8
M ark IV
CAUTION: Do not disturb the pickup screen on
the pipe. This is serviced as an assembly.
Cleaning and Inspection
1. W ash all parts in cleaning solvent and dry with
compressed air.
2. Inspect the p u m p body and cover for cracks or
excessive wear.
3. Inspect p u m p gears for dam age or excessive
wear.
4. Check the drive gear shaft for looseness in the
p u m p body.
5. Inspect inside o f p u m p cover for w ear that
would p erm it oil to leak past the ends o f the gears.
6. Inspect the pickup screen and pipe assembly for
d a m a g e to screen, pipe or relief grommet.
7. Check the pressure regulator valve for fit.
N O T E : The p u m p gears an d body are not serviced
separately. If the pu m p gears or body are dam aged
or worn, replacem ent o f the entire oil p u m p
assembly is necessary.
Assembly (Figures 6A-52V and 6A-53V)
Fig. 6 A -5 5 V -In sta llin g Screen - M ark IV
2. Install the pressure regulator valve and related
parts.
3. Install the drive gear and shaft in the pu m p
body.
4. Install the idler gear in the pum p body with the
smooth side o f gear towards pum p cover opening.
5. Install the p u m p cover and torque attaching
screws to specifications.
6. Turn drive shaft by hand to check for smooth
operation.
Installation
1.
If the pickup screen and pipe assembly was
1. Assemble pu m p and extension shaft to rear
removed, it should be replaced with a new part. Loss of
main bearing cap, aligning slot on top end o f extension
press fit condition could result in an air leak and loss of
shaft with drive tang on lower end o f distributor drive
oil pressure. M ount the pu m p in a soft-jawed vise, apply
shaft.
sealer to end o f pipe, and using Tool J-8369 for "Small
V8" (fig. 6A-54V) or Tool J-22144 for " M ark IV V8" (fig.
2. Install pum p to rear bearing cap bolt and torque
6A-55V) tap the pipe in place with a plastic hammer.
to specifications.
CAUTION: Be careful o f twisting, shearing or
collapsing pipe while installing in pum p.
NOTE: Installed position o f oil pum p screen is
with bottom edge parallel to oil pan rails.
3.
Install oil pan previously outlined.
C O N N E C T IN G ROD BEARING S
Connecting rod bearings are o f the precision insert
type and do not utilize shims for adjustment. DO N O T
FILE RO D S OR R O D CAPS. If clearances are found to
be excessive a new bearing will be required. Bearings are
available in stan dard size an d .001" and .002" undersize
for use with new and used sta n d a rd size crankshafts, and
in .010" and .020" undersize for use with reconditioned
crankshafts.
Inspection and Replacement
1. W ith oil pan and oil pu m p removed, remove the
connecting rod cap and bearing.
2. Inspect the bearing for evidence of w ear or
dam age. (Bearings showing the above should not be
installed.)
3. W ipe the bearings and crankpin clean o f oil.
4. M easure the crankpin for out-of-round or taper
with a micrometer. If not w ithin specifications replace or
recondition the crankshaft. If within specifications and a
new bearing is to be installed, measure the m aximum
diam eter o f the c rankpin to determine new bearing size
required.
5. If within specifications measure new or used
bearing clearances with Plastigage or its equivalent.
N O T E: If a bearing is being fitted to an out-of
round crankpin, be sure to fit to the m aximum
d iam eter o f the crankpin. If the bearing is fitted to
the m inim um diam eter and the crankpin is out-ofround .001" interference between the bearing and
crankpin will result in rapid bearing failure.
a. Place a piece o f gauging plastic the full width
of the crankpin as contacted by the bearing (parallel to
the crankshaft) (fig. 6A-56V).
b. Install the bearing in the connecting rod and
cap.
c. Install the bearing cap and evenly torque nuts
to specifications.
CAUTION: Do not turn the crankshaft with the
gauging plastic installed.
d. Remove the bearing cap and using the scale
on the gauging plastic envelope, measure the gauging
plastic width at the widest point (fig.6A-57V).
6. If the clearance exceeds specifications, select a
new, correct size, bearing and rem easure the clearance.
7. Coat the bearing surface with oil, install the rod
cap and torque nuts to specifications.
8. W hen all connecting rod bearings have been
installed tap each rod lightly (parallel to the crankpin) to
make sure they have clearance.
9. Measure all connecting rod side clearances (see
specifications) between connecting rod caps (fig. 6A-58V).
M A IN BEARINGS
M ain bearings are o f the precision insert type and
do not utilize shims for adjustment. If clearances are
found to be excessive, a new bearing, both upper and
lower halves, will be required. Bearings are available in
standard size and .001", .002", .009", .010" and .020"
undersize.
Selective fitting o f both rod and m ain bearing
To obtain the most accurate results with "Plastigage", (or its equivalent) a wax-like plastic material
which will compress evenly between the bearing and
journ al surfaces without dam aging either surface, certain
precautions should be observed.
If the engine is out o f the vehicle and upside down,
the crankshaft will rest on the upper bearings and the
total clearance can be measured between the lower
bearing and journal. If the engine is to rem ain in the
vehicle, the crankshaft should be supported both front
and rear (dam per and flywheel) to remove the clearance
from the upper bearing. The total clearance can then be
measured between the lower bearing and journal.
Fig. 6A-58V--M easuring Connecting Rod Side
Clearance
inserts is necessary in production in order to obtain close
tolerances. F o r this reason you m ay find one half o f a
stan dard insert with one h alf of a .001" undersize insert
which will decrease the clearance .0005" from using a
full stand ard bearing.
W h e n a production crank shaft cannot be precision
fitted by this method, it is then ground .009" undersize
on main journals only. A .0 0 9 " undersize bearing and
.0 1 0 " undersize bearing may be used for precision
fitting in th e sam e m an ner as previously described. Any
en g in e fitted with a .0 0 9 " undersize c ra n ksha ft will be
identified by th e following markings.
• ".009" will be stam ped on the crankshaft
counterweight forward o f the center main journal.
• A figure "9 " will be stamped on the block at
the left front oil pan rail.
N O TE: If, for any
replaced, shim m ing
shims for each cap
r e q u ire m e n t will
clearance.
reason, m ain bearing caps are
m ay be necessary. Lam inated
are available for service. Shim
be d e te rm in e d by be a rin g
Inspection
In general, the lower h a lf of the bearing (except No.
1 bearing) shows a greater w ear and the most distress
from fatigue. If upon inspection the lower half is
suitable for use, it can be assumed that the upper half is
also satisfactory. If the lower h a lf shows evidence o f
w ear or dam age, both upper and lower halves should be
replaced. N ever replace one half without replacing the
other half.
Checking Clearance
NOTE: To assure the proper seating o f the
crankshaft, all bearing cap bolts should be at their
specified torque. In addition, p rep aratory to
checking fit o f bearings, the surface of the
crankshaft jo u rn a l and bearing should be wiped
clean o f oil.
1. With the oil pan and oil pu m p removed, and
starting with the rear m ain bearing, remove bearing cap
and wipe oil from jou rn a l and bearing cap.
2. Place a piece o f gauging plastic the full width of
the bearing (parallel to the crankshaft) on the journal
(fig. 6A-59V).
CAUTION: Do not rotate the crankshaft while
the gauging plastic is between the bearing and
journal.
3. Install the bearing cap and evenly torque the
retaining bolts to specifications.
4. Remove bearing cap. The flattened gauging
plastic will be found adhering to either the bearing shell
or journal.
Fig. 6A -60V -M easuring Gauging Plastic
Fig. 6A-61V Measuring C rankshaft End Play
5. O n the edge of gauging plastic envelope there is
a graduated scale which is correlated in thousandths o f
an inch. W ithout removing the gauging plastic, measure
its compressed width (at the widest point) with the
graduations on the gauging plastic envelope (fig. 6A60V).
have been checked rotate the crankshaft to see that there
is no excessive drag.
9. Measure crankshaft end play (see specifications)
by forcing the crankshaft to the extreme front position.
Measure at the front end o f the re a r main bearing with
a feeler gauge (fig. 6A-61V).
10. Install a new rear main bearing oil seal in the
cylinder block and main bearing cap.
N O T E: Norm ally main bearing journals wear
evenly and are not out-of-round. However, if a
b earing is being fitted to an out-of-round (.001"
max.), be sure to fit to the m aximum diam eter of
the journal: If the bearing is fitted to the minim um
d iam eter and the jou rnal is out-of-round .001",
interference between the bearing and journal will
result in rapid bearing failure. If the flattened
gauging plastic tapers toward the middle or ends,
there is a difference in clearance indicating taper,
low spot or other irregularity o f the bearing or
journal. Be sure to measure the jou rnal with a
m ic ro m e te r if the flattened g a u g in g plastic
indicates more than .001" difference.
6. If the b earing clearance is within specifications,
the bearing insert is satisfactory. If the clearance is not
w ithin specifications, replace the insert. Always replace
both upper and lower inserts as a unit.
N O T E : If a new bearing cap is being installed and
clearance is less than .001", inspect for burrs or
nicks; if none are found then install shims as
required.
7. A standard, .001" or .002" undersize bearing
m ay produce the proper clearance. If not, it will be
necessary to regrind the crankshaft jou rnal for use with
the next undersize bearing.
8. Proceed to the next bearing. A fter all bearings
Replacement
NOTE: Main bearings may be replaced with or
without removing the crankshaft.
W ith Crankshaft Removal
1. Remove and inspect the crankshaft.
2. Remove the main bearings from the cylinder
block and main bearing caps.
3. Coat bearing surfaces of new, correct size, main
bearings with oil and install in the cylinder block and
m ain bearing caps.
4. Install the crankshaft.
W ithout C rankshaft Removal
1. W ith oil pan, oil pu m p and spark plugs
removed, remove cap on m ain bearing requiring
replacement and remove bearing from cap.
2. Install a m ain bearing removing and installing
tool in oil hole in crankshaft journal.
NOTE: If such a tool is not availale, a cotter pin
may be bent as required to do the job.
3. Rotate the crankshaft clockwise as viewed from
the front o f engine. This will roll u pper bearing out of
block.
4. Oil new selected size upper bearing and insert
plain (unnotched) end between crankshaft and indented
or notched side o f block. Rotate the bearing into place
and remove tool from oil hole in crankshaft journal.
5. Oil new lower bearing and install in bearing
cap.
6. Install main bearing cap with arrows pointing
toward front o f engine.
7. Torque m ain bearing cap bolts to specifications.
OIL SEAL (REAR M A IN )
Replacement
N OTE: Always replace the upper and lower seal as
a unit. Install seal w ith lip facing front o f engine.
T he re a r m ain bearing oil seal can be replaced (both
halves) without removal o f the crankshaft. Extreme care
should be exercised when installing this seal to protect
the sealing bead located in the channel on the outside
d iam eter o f the seal. An installation tool (fig. 6A-62V)
can be used to protect the seal bead when positioning
seal as follows:
1. With the oil pan and oil pu m p removed, remove
the re a r main bearing cap.
2. Remove oil seal from the bearing cap by prying
from the bottom with a small screw driver (fig. 6A-63V).
3. To remove the upper half o f the seal, use a
Fig. 6A-64V~Removing Oil Seal • Upper H alf
small ha m m e r to tap a brass pin punch on one end of
seal until it protrudes far enough to be removed with
pliers (fig. 6A-64V).
4. Clean all sealant and foreign material from
cylinder case bearing cap and crankshaft, using a n o n
abrasive cleaner.
5. Inspect com ponents for nicks, scratches, burrs
and machining defects at all sealing surfaces, case
assembly and crankshaft.
6. Coat seal lips an d seal bead with light engine oil
- keep oil off seal m ating ends.
7. Position tip o f tool between crankshaft and seal
seat in cylinder case.
8. Position seal between crankshaft and tip o f tool
so that seal bead contacts tip of tool.
N OTE: Make sure that oil-seal lip is positioned
toward front o f engine (fig. 6A-65V).
9.
Roll seal around crankshaft using tool as a
APPLY
SEALANT
TO SHADED
AREAS O NLY
Fig. 6A-66V--Sealing Bearing Cap
"sh o e -h o rn " to protect seal bead from sh arp corner of
seal seat surface in cylinder case.
CAUTION: Installation tool must remain in
position until seal is properly positioned with
both ends flu sh with block.
10. Remove tool, being careful not to withdraw
Fig. 6A-67V -Removing Connecting Rod
seal.
Piston
Assembly
11. Install Seal half in bearing cap, again using
tool as a "sho e-h orn", feeding seal into cap using light
pressure with thum b and finger.
12. Install bearing cap to case with sealant applied
to the cap-to-case interface being careful to keep sealant
off the seal split line (fig. 6A-66V).
13. Install the rear m ain bearing cap (with new
seal) and torque to specifications.
C O N N E C T IN G ROD AN D PISTON
ASSEMBLIES
Removal
1. W ith oil pan, oil pu m p and cylinder head
removed, use a ridge ream er to remove any ridge a n d /o r
deposits from the upper end o f the cylinder bore.
N O T E : Before ridge a n d / o r deposits are removed,
turn crankshaft until piston is at the bottom of
stroke and place a cloth on top of piston to collect
the cuttings. A fter ridge a n d / o r deposits are
removed, turn crankshaft until piston is at top of
stroke and remove cloth and cuttings.
2. Inspect connecting rods and connecting rod caps
for cylinder identification. If necessary m ark them.
3. Remove connecting rod cap and install Tool
J-5239 ( 3 /8 " ) or J-6305 (11 /32") on studs. Push
connecting rod and piston assembly out of top of
cylinder block (fig. 6A-67V).
N O T E : It will be necessary to turn the crankshaft
slightly to disconnectt some o f the connecting rod
and piston assemblies and push them out of the
cylinder.
Disassembly
1. Remove connecting rod bearings from connect
ing rods and caps.
N OTE: If connecting rod bearings are being
reused, place them in a rack so they may be
reinstalled in their original rod and cap.
2. Remove piston rings by expanding and sliding
them off the pistons. Tools J-8020 (3-9/16"), J-8021 (37 /8 "), J8032 (4"), J-22249 (3-15/16"), J-22147 (4-3/32").
and J-22250 (4-1/4") are available for this purpose.
3. Place connecting rod and piston assembly on
Tool J-24086-20. Using an arbor press and piston pin
remover, J-24086-8, press the piston pin out of
connecting rod and piston (fig. 6A-68V).
Cleaning and Inspection
Connecting Rods
W ash connecting rods in cleaning solvent and dry
with compressed air.
Check for twisted or bent rods and inspect for nicks
or cracks. Replace connecting rods th a t are dam aged.
Pistons
Clean varnish from piston skirts and pins with a
cleaning solvent. DO NOT WIRE BRUSH ANY PART OF
THE PISTON. Clean the ring grooves with a groove
cleaner and make sure oil ring holes and slots are clean.
Inspect the piston for cracked ring lands, skirts or
pin bosses, wavy or worn ring lands, scuffed or dam aged
PRESS
PISTON PIN
REMOVER
J -2 4 0 8 6 -8
FIXTURE &
SUPPORT
ASSEMBLY
J -2 4 0 8 6 - 2 0
Fig. 6A-69V- Piston Pin Ready for Installation
Fig. 6A-68V--Removing Piston Pin
skirts, eroded areas at top o f the piston. Replace pistons
that are dam aged or show signs o f excessive wear.
Inspect the grooves for nicks or burrs that m ight
cause the rings to hang up.
M easure piston skirt (across center line o f piston
pin) an d check clearance as outlined under "Piston
Selection".
Piston Pins
T he piston pin clearance is designed to m aintain
adequate clearance und er all engine operating condi
tions. Because of this, the piston and piston p in are a
m atched set an d not serviced separately.
Inspect piston pin bores and piston pins for wear.
Piston pin bores and piston pins must be free o f varnish
or scuffing when being measured. The piston pin should
be m easured with a micrometer an d the piston pin bore
should be m easured with a dial bore gauge or an inside
micrometer. If clearance is in excess o f the .001" w ear
limit, the piston and piston pin assembly should be
replaced.
Assembly
with piston pin guide and piston pin. Place assembly on
fixture and support assembly (fig. 6A-69V).
NOTE: See figure 6A-70V for correct size o f piston
pin guide.
3. Using piston pin installer, J-24086-9, press the
piston pin into the piston and connecting rod (fig. 6A71V).
NOTE: The piston pin installer is a variable
insertion length tool designed to be applicable to
all G M Piston assemblies.
The insertion length is varied by rotating the hub
on the shaft much like adjusting a micrometer. An
alpha-numeric scale is used to determine the
desired length for a given piston pin assembly.
Refer to figure 6A-70V for correct setting.
C A U TIO N : A fte r installer hub bottoms on
support assembly, do not exceed 6000 psi
pressure, as this could cause structural damage
to the tool.
4. Remove piston and connecting rod assembly
from tool and check piston for freedom o f movement on
piston pin.
Piston Rings
1. Lubricate piston pin holes in piston and
connecting rod to facilitate installation o f pin.
2. Place connecting rod in piston and hold in place
All compression rings are m arked on the upper side
o f the ring. W hen installing compression rings, make
sure the m arked side is toward the top o f the piston. The
C YL.
DISPLACEM ENT
IN S T A L L E R SETTING
PIN SIZE
I-6
.905"
I-7
.866"
I-7
.927"
Violet
J-24086-7
G-8
.927"
Small Block
283, 302, 305,
307, 350, 400
Violet
J-24086-7
G-8
.927"
Mark IV
366, 396,
402, 427, 454
Gray
J-24086-3
G-7
.990"
85 cu. i n . / l .4 Litre
PIN GU ID E
Gold
J-24086-6
PISTON PIN
INSTALLER
J 2 4 0 8 6 -9
97 cu. i n . / l -6 Litre
4
110 cu. in ./l .8 Litre
140 cu. in ./2.3 Litre
250 cu. in./4.1 Litre
6
Blue
J-24086-5
Violet
J-24086-7
292 cu. in ./4.8 Litre
8
PISTON PIN
Fig. 6A-71V--lnstalling Piston Pin
Fig. 6A-70V -Piston Pin Tool Specification
top ring is chrom e faced, or treated with m olybdenum
for m axim um life.
The oil control rings are o f three piece type,
consisting of two segments (rails) and a spacer.
1. Select rings com parable in size to the piston
being used.
2. Slip the compression ring in the cylinder bore;
then press the ring down into the cylinder bore about
1/4 inch (above ring travel). Be sure ring is square with
cylinder wall.
3. Measure the space or gap between the ends of
the ring with a feeler gauge (fig. 6A-72V).
4. If the gap between the ends of the ring is below
specifications, remove the ring and try another for fit.
5. Fit each compression ring to the cylinder in
which it is going to be used.
6. If the pistons have not been cleaned and
inspected as previously outlined, do so.
7. Slip the outer surface o f the top and second
compression ring into the respective piston ring groove
and roll the ring entirely around the groove (fig. 6A-73V)
to make sure that the ring is free. If binding occurs at
any point the cause should be determined, and if caused
by ring groove, remove by dressing with a fine cut file. If
the binding is caused by a distorted ring, check a new
ring.
8. Install piston rings as follows (fig. 6A-74V).
N OTE: Tools J-8020 (3-9/16"), J-8021 (3-7/8"),
r
*
J
Fig. 6A-72V--Measuring Ring Gap
J8032 (4"), J-22249 (3-15/16"), J-22147 (4-3/32"),
and J-22250 (4-1/4") are available for this purpose.
b. Hold spacer ends butted and install lower
steel oil ring rail with gap properly located.
c. Install
properly located.
upper steel oil ring rail with
gap
d. Flex the oil ring assembly to make sure ring
is free. If binding occurs at any point the cause should
be determined, and if caused by ring groove, remove by
dressing groove with a fine cut file. If binding is caused
by a distorted ring, check a new ring.
e. Install second compression ring expander then
ring with gaps properly located.
f. Install top compression ring with gap properly
located.
9.
Proper clearance o f the piston ring in its piston
ring groove is very im portant to provide proper ring
action and reduce wear. Therefore, w hen fitting new
rings, the clearances between the surfaces o f the ring and
groove should be m easured (fig. 6A-75V). (See
Specifications).
Installation
Fig. 6A-73V--Checking Ring in Groove
NOTE: Cylinder bores must be clean before piston
installation. This may be accomplished with a hot
w ater and detergent wash or with a light honing as
necessary. A fter cleaning, the bores should be
swabbed several times with light engine oil and a
clean dry cloth.
1. Lubricate connecting rod bearings and install in
rods and rod caps.
2. Lightly coat pistons, rings and cylinder walls
with light engine oil.
3. With bearing caps removed, install Tool J-5239
(3 /8 ") or J-6305 (11 /32") on connecting rod bolts.
Fig. 6A-74V--Ring Gap Location
a.
Install oil ring spacer in groove and insert
anti-rotation tang in oil hole.
6.
Install the bearing caps and torque nuts to
specifications.
C O N N E C T IN G ROD
BEARING T A N G
SLOTS INSTALLED
OPPOSITE
CAMSHAFT
SLOT
NOTE: If bearing replacement is required refer to
"C onnecting Rod Bearings".
Be sure to install new pistons in the same cylinders
for which they were fitted, and used pistons in the
same cylinder from which they were removed.
Each connecting rod and bearing cap should be
marked, beginning at the front of the engine. On
V8 engines 1,3,5 and 7 in the left bank and, 2 4, 6
and 8 in the right bank. The numbers on the
connecting rod and bearing cap must be on the
same side when installed in the cylinder bore. If a
connecting rod is ever transposed from one block
or cylinder to another, new bearings should be
fitted and the connecting rod should be numbered
to correspond with the new cylinder number.
ENG INE ASSEMBLY
Fig. 6A-76V-C onnecting Rods - Installed Position
Removal
1.
2.
3.
4.
5.
remove
6.
Fig. 6A-77V -ln sta llin g Connecting Rod
Piston
Assembly
C A U TIO N : Be sure ring gaps are property
positioned as previously outlined.
4. Install each connecting rod and piston assembly
in its respective bore. Install with connecting rod bearing
tang slots on side opposite cam shaft (fig. 6A-76V). Use
Tool J-8037 to compress the rings (fig. 6A-77V). Guide
the connecting rod into place on the cranksahft journal
with Tool J-5239 ( 3 /8 ") or J-6305 (11/32"). Use a
h a m m e r handle and light blows to install the piston into
the bore. Hold the ring compressor firmly against the
cylinder block until all piston rings have entered the
cylinder bore.
5.
Remove Tool J-5239 or J-6305.
Remove hood.
Disconnect battery cables at battery.
Remove air cleaner.
D rain radiator and block.
Disconnect radiator and heater hoses and
radiator and fan shroud.
Disconnect wires at:
• Starter Solenoid
• Delcotron
• T em perature switch
• Oil Pressure Switch
• Coil
7. Disconnect:
• Accelerator linkage at inlet manifold.
• Fuel line, from tank, at fuel pump.
• Hoses at fuel vapor storage canister (if
applicable).
• Vacuum line to power brake unit at manifold,
if so equipped.
8. Remove power steering p u m p and lay aside, if
so equipped.
9. Raise vehicle on hoist.
10. D rain crankcase.
11. Disconnect exhaust pipe at m anifold and, if so
equipped, converter bracket at transmission rear mount.
12. Remove starter.
13. Remove flywheel splash shield or converter
housing cover as applicable.
14. O n vehicles with autom atic transm ission,
remove converter to flywheel attaching bolt.
15. Remove m ount "th ro u g h " bolts.
16. Remove bell housing bolts.
17. Lower vehicle on hoist.
18. Raise transmission using floor jack.
19. Attach engine lifting devices, raise engine.
20. Remove motor m ount to engine brackets.
21. Remove engine assembly.
Installation
1. Position engine assembly in vehicle.
2. Attach m otor m ount to engine brackets and
lower engine in place.
3. Remove engine lifting device.
4. Remove transmission floor jack.
5. Raise vehicle on hoist.
6. Install m ount " th r o u g h " bolts. Torque to
specifications.
7. Install
bell
ho using
bolts.
To rqu e
to
specifications.
8. On vehicles with automatic transmissions, install
c on ve rte r to flywheel a tta c h in g bolts. T o rq ue to
specifications.
9. Install flywheel splash shield of converter
housing cover as applicable. Torque attaching bolts to
specifications.
10. Install starter.
11. C on nect exhau st p ip e at m a nifo ld and
converter bracket at transmission rear mount.
12. Lower vehicle on hoist.
13. Reinstall power steering pump, if so equipped.
14. Connect:
• Accelerator linkage at inlet manifold.
• Fuel line, from tank, at fuel pump.
• Hoses at fuel v apor storage canister.
• Vacuum line to power brake unit at manifold,
if equipped.
15. Connect wires at:
• S tarter Solenoid
• Delcotron
• T em perature Switch
• Oil Pressure Switch
• Coil
16. Install radiato r and fanshroud and reconnect
ra d ia to r and heater hoses.
17. Fill cooling system.
18. Fill crankcase with oil. See o w n e r’s m anual for
specifications.
19. Install air cleaner.
20. Install hood.
21. Connect battery cables.
N O T E : To avoid possible arcing o f battery,
connect positive battery cable first.
22. Start engine, check for leaks and check timing.
CRANKSAHFT
The crankshaft can be removed while the engine is
disassembled for overhaul, as previously outlined or
without complete disassembly as outlined below.
R e m o va l
1. With the engine rem oved from the vehicle and
the transm ission a n d / o r clutch housing removed from
the engine, m ount engine in stand and clam p securely.
2. Remove the oil dip stick and oil dip stick tube,
(if applicable).
3. Remove the starting motor, clutch assembly (if
equipped) and flywheel.
4. Remove the spark plugs.
5. Remove c ra n k sh a ft pulley and torsional
damper.
6. Remove oil pan and oil pump.
7. Remove crankcase front cover, and if so
equipped, remove timing chain and cam shaft sprocket.
8. Check the connecting rod caps for cylinder
nu m b e r identification. If necessary m ark them.
9. Remove the connecting rod caps and push the
pistons to top o f bores.
10. Remove main bearing caps and lift crankshaft
out o f cylinder block.
11. Remove re a r m ain bearing oil seal an d main
bearings from cylinder block and m ain bearing caps.
Cleaning and Inspection
1. W ash crankshaft in solvent and dry with
compressed air.
2. Measure dimensions o f main bearing journals
and crankpins with a micrometer for out-of-round, taper
or undersize. (See Specifications.)
3. Check crankshaft for run-out by supporting at
the front and rear m ain bearings journals in " V " blocks
and check at the front an d rear interm ediate journals
with a dial indicator. (See Specifications.)
4. Replace or recondition the crankshaft if out o f
specifications.
SPROCKET OR GEAR R E PLACEM ENT
(REFER TO FIG. 6A-78V)
• On "Small V8" engines, remove crankshaft
sprocket using Tool J-5825, install using Tool J-5590.
• On Mark IV V8 engines, remove crankshaft
sprocket using Tool J 1619, install using Tool J-21058.
Installation
1.
Install rear main bearing oil seal in cylinder
block an d rear main bearing cap grooves. Install with lip
o f seal toward front o f engine. W here seal has two lips
install lip with helix towards front o f engine.
APPLY
SEALANT
TO SHADED
AREAS ONLY
Fig. 6A-79V--Sealing Bearing Cap Block
2. Lubricate lips o f seal with engine oil. Keep oil
off p a rting line surface.
3. Install m ain bearings in cylinder block and
m ain b earing caps then lubricate bearing surface with
engine oil.
4. Install crankshaft, being careful not to dam age
bearing surfaces.
5. Apply a thin coat o f brush-on type oil sealing
compound to block m ating surface and corresponding
surface of cap only (fig. 6A-79V). D o not allow sealer on
crankshaft or seal.
6. Install main bearing caps with arrows pointing
toward front of engine.
7. Torque all except rear m ain bearing cap bolts to
specifications. Torque rear main bearing cap bolts to 1012 ft. lbs. then tap end of crankshaft, first rearw ard then
forward with a lead ham m er. This will line up rear main
bearing and crankshaft thrust surfaces. Retorque all
m ain bearing cap bolts to specifications.
8. M easure crankshaft end play with a feeler
gauge. Force crankshaft forward and measure clearance
between the front of the rear m ain b earing and the
crankshaft thrust surface.
9. Install flywheel and torque to specifications. A
wood block placed between the crankshaft and cylinder
block will prevent crankshaft from rotating.
NOTE: Align dowel hole in flywheel with dowel
hole in crankshaft. On vehicles equipped with
automatic transmissions, install flywheel with the
converter attaching pads towards transmission.
GEN ERAL DATA:
In L ine
T ype
V-8
25 0
Displacem ent (cu. in.)
29 2
3 .8 7 5
Bore
3 .5 3
Stroke
35 0
400
454
3 .7 3 6
4
4 .1 2 5
4 .2 5 0
3 .75
4
4 .1 2 4 6 -4 .1 2 7 4
4 .2 4 9 5 -4 .2 5 2 5
4 .1 2
8 .2 5 :1
Com pression Ratio
305
3 .4 8
8 .0 :1
Firing Order
8.5:1
1-5-3-6-2-4
1-8-4-3-6-5-7-2
CY LIN DER BORE:
D iam eter
O ut o f
R ound
T aper
3 .8 7 4 5 -3 .8 7 7 5
Production
3 .7 3 5 0 -3 .7 3 8 5
3 .9 9 9 5 -4 .0 0 2 5
.0 0 0 5 M ax.
.001 Max.
Service
.0 0 2 M ax.
T hrust Side
P roduc
tion
Relief Side
.0 0 0 5 M ax.
.0 0 0 5 M ax.
C/5
.001 Max.
Service
“U
m
.005 M ax.
O
PISTON:
Production
.0 0 0 5 -.0 0 1 5
.0 0 2 6 -.0 0 3 6
Service
.0 0 2 5 M ax.
.0 0 4 5 M ax.
Clearance
.0 0 0 7 -.0 0 1 7
.0 0 0 7 -.0 0 1 7
.0 0 2 7 M ax.
.0 0 1 4 -.0 0 2 4
.0 0 2 4
.0 0 3 5 M ax.
O
PISTON RING:
C
0
M
P
R
E
S
S
I
0
N
0
I
L
P roduc
tion
Clear
ance
G roove
Top
.0 0 1 2 -.0 0 2 7
2nd
.0 0 1 2 -.0 0 3 2
>
.0 0 2 0 -.0 0 4 0
P roduc
tion
.0 1 0 -.0 2 0
Top
.0 1 0 -.0 2 0
2nd
G roove
Clearance
Gap
P roduction
.0 0 5 M ax.
.0 1 0 -.0 2 0
.0 1 0 -.0 2 5
Hi L im it P ro d u c tio n + .01
Service
.0 0 5 -.0 0 5 5
H
O
Z
Hi L im it P ro d u c tio n + .001
Service
Gap
.0 0 1 7 -.0 0 3 2
.0 0 1 2 -.0 0 3 2
.0 0 2 -.0 0 7
|
C/5
.0 0 0 5 -.0 0 6 5
Hi L im it P ro d u c tio n + .001
Service
P roduction
.0 1 5 -.0 5 5
Service
Hi L im it P ro d u c tio n + .01
PISTON PIN:
D iam eter
Clearance
Service
F it in Rod
,9 8 9 5 -.9 8 9 8
.9 2 7 0 -.9 2 7 3
P roduction
.0 0 0 1 5 -.0 0 0 2 5
.0 0 0 2 5 -.0 0 0 3 5
.0 0 0 2 5 -.0 0 0 3 5
.0 0 0 2 5 -.0 0 0 3 5
.001 M ax.
.0 0 0 8 -.0 0 1 6 In te rfe re n c e
O)
>i
00
Ca)
6A-84
292
250
CRANKSHAFT:
305
|
350
#1
2.4484-2.4493
2.2983-2.2993
Main
Journal
Service
.0008
.0029
.0034
1.999-1.2000
2.099-2.100
Service
Production
Service
Production
.0007-.0027
Service
R od Side Clearance
2.199-2.200
.0013-.0025
#5
.0024-.0040
.006-.010
2.1985-2.1995
.0003 (Max.)
.001 (Max.)
Production
Rod Bearing
Clearance
#5
.0017-.0032
#1 - .002 (M ax.) A ll Others .0035 (Max.)
.002-.006
Service
C rankshaft End Play
O ut of
R ound
#2-3-4
.0 0 1 1 .0 0 2 3
#1-2-3-4
.0006-.0017
.0002 (Max.)
.001 (Max.)
.0013-.0035
.0035 (Max.)
.008-.014
.0009-.0025
.013-.023
MANUAL
.0003
#1
.0008-.0020
SERVICE
A ll
A ll
Production
Crank
pin
#5
2.7478-2.7488
.0002 (Max.)
.001 (Max.)
Production
Diam eter
#5
2.6479-2.6488
TRUCK
Main
Bearing
Clearanc e
#2-3-4
3.7481-2.7490
.001 (Max.)
Service
O ut of
R ound
#1
2.7485-2.7494
.0002 (Max.)
Production
la p e r
2.6484-2.6493
454
LIGHT
#2-3-4
2.4481-2.4490
#5
2.4479-2.4488
A ll
D iam eter
400
#1-2-3-4
250
292
305
Intake
.2 2 1 7
.2 3 1 5
.2 4 8 5
Exhaust
.2 2 1 7
.2 3 1 5
CAMSHAFT:
Lobe
Lift ± .002"
Journal Diameter
Camshaft Runout
Camshaft End Play
1 .8 6 7 7 -1 .8 6 9 7
.2 7 3 3
1 .8 6 8 2 -1 .8 6 9 2
.2 3 4 3
1 .9 4 8 2 -1 .9 4 9 2
.0 0 1 5 Max.
Hydraulic
1 .7 5 :1
1 .5 0 :1
1.70:1
One Turn D ow n From Zero Lash
45°
46 °
.0 0 2 (M ax.)
MECHANICAL
Free Length
Approx. jf of Coils
454
.2 3 4 3
ENGINE
Damper
400
.2 6 0 0
.0 0 1 -.0 0 5
VALVE SYSTEM:
Lifter
Rocker Arm Ratio
Intake
Valve Lash
Exhaust
Face Angle (Int. & Exch.)
Seat Angle (Int. & Exh.)
Seat Runout (Int. & Exh.)
Intake
Seat Width
Exhaust
Produc Int.
Stem
tion
Exh.
Clearance
Service
Free Length
Valve
Pressure Closed
Spring lbs. @ i1 1 .
Open
(Outer)
Installed Height
± 1/32"
350
1 /3 2 -1 /1 6
1 /1 6 -3 /3 2
.0 0 1 0 -.0 0 2 7
.0 0 1 0 -.0 0 2 7
.0 0 1 5 -.0 0 3 2
.0 0 1 2 .0 0 2 9
Hi L im it P ro d u ctio n + .001 In tak e - + .002 Exhaust
2 .0 8
2.12
55-64 @ 1 .6 6
8 5 -9 3 @ 1 .6 9
1 8 0 -1 9 2 @ 1.27
1 7 4 -1 8 4 @ 1.30
2 .0 3
7 6 -8 4 @ 1 .7 0 Intake @ 1.61 Exhaust
1 9 4 -2 0 6 @ 1 .2 5 In tak e @ 1.16 E xhaust
1 -2 1 /3 2
1 -5 /8
1-23/32 In tak e 1-19/32 Exhaust
1-7 /8
1 .9 4
1 .9 4
1 .8 6
1.86
4
4
4
4
74 -8 6 @ 1 .8 8
2 8 8 -3 1 2 @ 1 .3 8
6A-85
S P E C IA L T O O L S
J -4 5 3 6
J -1 2 6 4
J -8 0 5 8
E n g in e L i f t K it
J -5 8 5 3
J -8 0 8 7
J -8 0 0 1
(0 -1 0 0 in lb .)
I n d ic a to r S et ( C y lin d e r B o re )
I n d ic a to r S et (U n iv e rs a l)
B e lt T e n s io n G auge
P is to n R in g C o m p re s s o r
J -2 3 6 0 0
J -8 0 3 7
J -8 0 2 0
J -8 0 2 1
J -8 0 3 2
J -2 2 2 4 9
J -2 2 1 4 7
J -2 2 2 5 0
J -5 2 3 9
J -6 3 0 5
J -8 0 6 2
J -8 1 0 1
J -5 8 3 0
J -7 0 4 9
J -8 0 8 9
J -5 8 6 0
16.
J-5 7 1 5
17.
18.
19.
J-6036
J-6 8 8 0
J -5 8 0 2
J-95 34
20
J -9 5 3 5
21
22
23
24
25
26
27
28.
29.
30
J-22144
J 8369
J-6098
J-09 7 1
J-23523
J -2 2 1 9 7
J-1619
J-5825
J-8105
J-5590
31
J-23042
32
J-22102
( 0 - 2 0 0 F t. L b .) T o r q u e W re n c h
(0 -5 0 F t. L b .)
( 3 - 9 / 1 6 " ) P is to n R in g E x p a n d e r
(3 -7 /8 ” )
(4 ” )
(3 -1 5 /1 6 ” )
( 4 -3 /3 2 ” )
(4 -1 /4 ” )
( 3 / 8 ” ) C o n n e c tin g R o d G u id e S et
( 1 1 /3 2 ” )
V a lv e S p rin g C o m p re s s o r
V a lv e G u id e C le a n e r
( 1 1 / 3 2 ” ) V a lv e G u id e R e a m e r
S et
(3 /8 ” )
C a rb o n R e m o v in g B ru sh
C y lin d e r H ead B o lt W re n c h
( . 0 0 3 ” ) R o c k e r A r m Stud
Reamer
(.013” )
Ro c ke r A r m Stud Installer
R o c ke r A r m Stud Remover
D i s t r i b u t o r L o w e r Bushing
Remover
D istributo r Lower Bushing
Installer
Oil Pick-up Screen Installer
Oil Pick-up Screen Installer
Cam Bearing Tool
Camshaft Gear S upport
Torsional Damper Puller
Torsional Damper Installer
Crankshaft Spro cket Puller
C rankshaft Spro cket Puller
C rankshaft Gear Puller
C rankshaft Spro cket or Gear
Installer
Crankcase Cover Centering
Gauge and Seal Installer
Crankcase Cover Seal Installer
TOOLS NOT I LLUST RAT ED
Valve Seal Leak Detector
J-23994
SECTION 6B
ENGINE COOLING
INDEX
G eneral D escriptio n..........................................................
D ia g n o s is ..............................................................................
M aintenance and A djustm ents.....................................
Coolant L e v e l...................................................................
Coolant System Checks.................................................
Periodic M a in te n a n c e ....................................................
C le a n in g ............................................................................
Reverse F lu s h in g ...........................................................
R a d i a t o r ..........................................................................
Cylinder Block and Cylinder H e a d .....................
6B-1
6B-2
6B-4
6B-4
6B-4
6B-4
6B-5
6B-5
6B-5
6B-5
H e a te r C o r e ..................................................................
Fan Belt A d ju s tm e n t.....................................................
R adiator C a p .....................................................................
T h e rm o sta t..........................................................................
Replacem ent.....................................................................
Thermostatic Fan Clutch R e p la c e m e n t..................
W a te r P u m p ......................................................................
R e m o v a l............................................................................
Installation........................................................................
6B-6
6B-6
6B-6
6B-6
6B-6
6B-6
6B-7
6B-7
6B-8
GENERAL DESCRIPTION
All light duty trucks have pressure type engine cooling
systems with thermostatic control of coolant circulation. The
cooling system is sealed by a pressure type radiator filler
cap.
T he pressure type ra d ia to r filler cap (fig. 6B-1) is
designed to operate the cooling system at higher than
atmospheric pressure. The h igher pressure raises the
boiling point o f the coolant which increases the efficiency
o f the radiator.
The rad iator filler cap contains a pressure relief
valve and a vacuum relief valve. The pressure relief
valve is held against its seat by a spring, which when
compressed, allows excessive pressure to be relieved out
the ra d ia to r overflow.
T he vacuum valve is also held against its seat by a
spring which when compressed, opens the valve relieving
the vacuum created when the system cools.
T he cooling systems w a te r p u m p is o f the
centrifugal vane impeller type (figs. 6B-2 and 6B-3). The
bearings are p erm anently lubricated during m anufacture
and are sealed to prevent the loss o f lubricant or the
entry o f dirt and water. The pum p requires no care other
than to make certain the air vent at the top o f the
housing and the d rain holes in the bottom do not
become plugged with dirt or grease.
I
W ater pum p components are not serviced sepa
rately; therefore, in the event o f water pum p failure, it
will be necessary to replace the complete assembly removal and installation procedures are covered in this
section.
Fig. 6B-3-Water Pump—Typical V8
DIAGNOSIS
If the cooling system requires frequent addition of
coolant in ord er to m ain tain the proper level, check all
units and connections in the cooling system for evidence
o f leakage. Inspection should be m ade with cooling
system cold. Small leaks which m ay show dam pness or
dripping can easily escape detection when the engine is
hot, due to the rapid evaporation o f coolant. Tell-tale
stains o f grayish white or rusty color, or dye stains from
anti-freeze, at joints in cooling system are almost always
sure signs o f small leaks even though there appears to be
no dam age.
A ir m ay be draw n into the cooling system through
leakage at the water pum p seal or through leaks in the
coolant recovery system. G as may be forced into the
cooling system through leakage at the cylinder head
gasket even though the leakage is not sufficient to allow
w ater to enter the combustion chamber.
pressure surge should be felt. Check for a plugged vent
hole in pump.
Test for restriction in the radiator, by w arm ing the
engine up and then turning the engine off and feeling
the radiator. The radiator should be hot along the left
side and w arm along the right side, with an even
temperature rise from right to left. Cold spots in the
radiator indicate clogged sections.
An operational check o f the thermostat can be made
by hanging therm ostat on a hook in a 33% glycol
solution 25° above the tem perature stamped on the
thermostat valve. Submerge the valve completely and
agitate the solution thoroughly. U n d e r this condition the
valve should open. Remove the thermostat and place in a
33% glycol solution 10° below tem perature indicated on
the valve. W ith valve completely subm erged and water
agitated thoroughly, the valve should close completely.
Coolant Loss
COOLING SYSTEM CHECKS
To check for exhaust leaks into the cooling system,
drain the system until the coolant level stands just above
the top o f the cylinder head, then disconnect the radiator
upper hose an d remove the therm ostat and fan belt.
Start the engine and quickly accelerate several times. At
the same time note any appreciable water rise or the
ap pearance o f bubbles which are indicative o f exhaust
gases leaking into the cooling system.
W ater pu m p operation may be checked by running
the engine while squeezing the radiator upper hose. A
1. Check for crack in block. Pull engine oil d ip
stick to check for w ater in crankcase.
2. Remove rocker arm covers and check for
cracked cylinder head.
3. Remove cylinder heads and check gaskets.
W hile heads are off, check for cracks in heads or block.
Overheating
1. Check to see that the radiato r cap seats in
ra d ia to r filler neck and releases at specified pressure (15
lbs.).
2. Check coolant level.
3. Check tem perature sending unit a n d / o r gauge.
4. Check engine thermostat.
5. Check fan belt for excessive looseness.
6. Check for punctures in radiator, ruptured or
disconnected hoses, loose pressure cap or use o f low
boiling point antifreeze. These conditions prevent
cooling system from m aintaining proper pressure.
7. Clean debris from rad ia to r a n d / o r condenser.
8. Check engine operation to make sure tune-up is
not needed. Im p ro per tim ing m ay cause overheating.
9. Check for driving conditions which may cause
overheating. Prolonged idling, start and stop driving in
long lines o f traffic on hot days, climbing steep grades on
hot days, etc. will occasionally cause coolant to boil.
10. Clean cooling system.
11. Remove cylinder heads and check water
passages in heads and block for obstructions.
FAN CLUTCH
1.
NOISE
F a n noise is sometimes evident under the following
norm al conditions: a. when clutch is engaged for
m axim um cooling, and b. du ring first few minutes after
start-up until the clutch can re-distribute the silicone
fluid back to its norm al disengaged operating condition
after overnight settling.
However, fa n noise or an excessive roar will
generally occur continuously u n de r all high engine speed
conditions (2500 r.p.m. and up) if the clutch assembly is
locked up due to an internal failure. If the fan cannot be
rotated by h and or there is a rough grating feel as the
fan is turned, the clutch should be replaced.
2.
LOOSENESS
U n d e r various tem perature conditions, there is a
visible lateral movem ent that can be observed at the tip
o f the fan blade. This is a no rm al condition due to the
type o f bearing used. A pproxim ately 1/4" m axim um
lateral movem ent measured at the fan tip is allowable.
This is not cause for replacement.
3.
SILICONE FLUID LEAK
T he operation o f the unit is generally not affected
by small fluid leaks which m ay occur in the area around
the bearing assembly. However, if the degree o f leakage
appears excessive, proceed to item 4.
B. If the fan and clutch assembly free-wheels with
no drag (revolves over 5 times when spun by hand), the
clutch should be replaced. If clutch perform s properly
with a slight drag go to step C.
N OTE: Testing a fan clutch by holding the small
hub with one hand and rotating the aluminum
housing in a clockwise/counterclockwise motion
will cause the clutch to free-wheel, which is a
normal condition when operated in this manner.
This should not be considered a test by which
replacement is determined.
C. Use dial type thermometer, J6742-01, or similar
type.
NOTE: J6742-01 reads to 180 degrees F, therefore,
allow approxim ately 3 /1 6 " pointer movem ent for
each 10 degrees over 180 degrees.
CAUTION: Check fo r adequate clearance
between fa n blades and thermometer sensor
before starting engine.
Position therm om eter so that the therm om eter
sensor is centered in the space between the fan
blades and radiator. This can be achieved by
inserting the sensor through one o f the existing
holes in the fan shroud or fan guard, or by placing
between the radiator and the shroud. On some
models, it may be necessary to drill a 3 /1 6 " hole in
the fan shroud to insert J6742-01.
D. Cover ra d ia to r grille sufficiently to induce a
high engine temperature. Start engine and turn on air
conditioning if equipped. M aintain a position in front of
the vehicle to observe the therm om eter reading. With a
rod, broom handle, or etc., push on the accelerator
linkage to m ain tain approximately 3000 r.p.m. Use
tachometer if available.
E. Observe therm om eter reading w hen clutch
engages. It will take approximately 5 to 10 minutes for
the temperature to become high enough to allow
engagement o f the fan clutch. This will be indicated by
an increase or roar in fan air noise and by a drop in the
therm om eter reading o f approximately 5-15 degrees F. If
the clutch did not engage by the temperature specified
below, the unit should be replaced.
165c All vehicles except as listed below.
170c Corvette without A /C .
190c Corvette with A /C .
NOTE: Be sure fan clutch was disengaged
beginning o f test.
at
CAUTION: Do not continue test past a
thermometer reading as specified to prevent
engine overheating.
If no sharp increase in fan noise or tem perature
drop was observed and the fan noise level was
constantly high from start o f test to 165 degrees F,
the unit should be replaced.
F. As soon as the clutch engages, remove the
4. ENGINE OVERHEATING
radiator grille cover and turn off the air conditioning to
A.
Start with a cool engine to ensure complete fan assist in engine cooling. The engine should be run at
clutch disengagem ent. Refer to Item b, p a ra g ra p h 1.
approximately 1500 r.p.m.
G.
A fter several minutes the fan clutch should
disengage, as indicated by a reduction in fa n speed and
roar.
MAINTENANCE AND ADJUSTMENTS
C O O LA N T LEVEL
N O T E: With the coolant recovery system, the
coolant level is checked by observing the liquid
level in the reservoir. T he radiator cap need not be
removed. The coolant level should be at the "Cold
Full" m ark w hen cooling system cools and coolant
is at am b ien t tem perature. A fter the vehicle has
been driven sufficiently to obtain norm al operating
temperatures, the level should be at the "H o t Full"
mark.
T he ra d ia to r coolant level should only be checked
w hen the engine is cool, particularly on cars equipped
with air conditioning. If the rad iator cap is removed
from a hot cooling system, serious personal injury may
result.
Coolant level in crossflow radiators without the
coolant recovery system should be m aintained three
inches below the bottom o f the filler neck w hen the
system is cold. W h en a surge radiator supply tank is used
the coolant level should be m aintained at the one-half
full level in the supply tank. It is very im portant that the
correct fluid level be m aintained. The sealing ability of
the ra d ia to r cap is affected w hen the cooling level is too
high.
All passenger car cooling systems are pressurized
with a 15 pound pressure cap which permits safe engine
operation at coolant tem peratures o f up to 258 °F.
W h e n the radiator cap is removed or loosened, the
system pressure drops to atmospheric, an d the heat
which had caused w ater tem perature to be higher than
212°F, will be dissipated by conversion o f w ater to
steam. Inasmuch as the steam may form in the engine
w ater passages, it will blow coolant out o f the radiator
u p p e r hose and tan k top, necessitating coolant
replacement. Engine operating tem peratures higher than
the norm al boiling point o f water are in no way
objectionable so long as the coolant level is satisfactory
when the engine is cool.
Upon repeated coolant loss, the pressure radiator
cap an d seat should be checked for sealing ability. Also,
the cooling system should be checked for loose hose
connections, defective hoses, gasket leaks, etc.
Cooling System Checks
1. Test for restriction in the radiator, by w arm ing
the engine up an d then turning the engine off and
feeling the radiator. The rad ia to r should be hot along
the left side and w arm along the right side, with an even
tem perature rise from right to left. Cold spots in the
ra d iato r indicate clogged sections.
2. W a te r pu m p operation may be checked by
ru n n in g the engine while squeezing the radiator upper
hose. A pressure surge should be felt. Check for a
plugged vent-hole in pump.
NOTE: A defective head gasket may allow exhaust
gases to leak into the cooling system. This is
particularly dam ag in g to the cooling system as the
gases combine with the w ater to form acids which
are harm ful to the radiator and engine.
WARNING: If you siphon coolant from the
radiator, do not use mouth to start siphoning
action. The coolant solution is POISONOUS
and can cause death or serious illness if
swallowed.
3.
To check for exhaust leaks into the cooling
system, drain coolant from the system until the coolant
level stands just above the top o f the cylinder head, then
disconnect the radiator upper hose and remove the
thermostat and fan belt. Start the engine and quickly
accelerate several times. At the same time note any
appreciable water rise or the appearance o f bubbles
which are indicative o f exhaust gases leaking into the
cooling system.
Periodic Maintenance
It is the ow ner’s responsibility to keep the freeze
protection at a level commensurate with the area in
which the vehicle will be operated. Regardless o f
w hether freezing tem peratures are or are not expected,
cooling system protection should be m aintained at least
to -20 °F to provide adequate corrosion protection and
proper tem perature indicating light operation. With
glycol co ntent less th an re q u ire m e n t for -20 °F
protection, coolant boiling point is less than the
temperature indicating light setting. W h en adding
solution due to loss o f coolant for any reason or in areas
where temperatures lower than -20 °F m ay occur, a
sufficient am ount o f an ethylene glycol base coolant that
meets G M Specification 1899-M should be used.
Every two years the cooling system should be
serviced by flushing with plain water, then completely
refilled with a fresh solution o f water and a high-quality,
inhibited (permanent-type) glycol base coolant meeting
G M Specification 1899-M and providing freezing
protection at least to -20 °F At this time, also add G M
Cooling System Inhibitor and Sealer or equivalent. In
addition, such an inhibitor and sealer should be added every
fall thereafter.
NOTE: Alcohol or methanol base coolants or plain
w ater are not recom m ended for your engine at any
time.
Two com m on causes o f corrosion are: (1) air
suction—Air may be drawn into the system due to low
liquid level in the radiator, leaky water pum p or loose
hose connections, defective pressure cap or leaky
overflow hose connection to radiator on recovery bottle;
(2) exhaust gas leakage—Exhaust gas may be blown into
the cooling system past the cylinder head gasket or
through cracks in the cylinder head and block.
Cleaning
A good cleaning solution should be used to loosen
the rust and scale before reverse flushing the cooling
system. There are a num ber o f cleaning solutions
available and the m a n u fa c tu re r’s instructions with the
p articular cleaner being used should always be followed.
An excellent pre pa ra tion to use for this purpose is
G M Cooling System Cleaner or its equivalent. The
following directions for cleaning the system applies only
when this type cleaner is used.
W ARNING: If you siphon coolant from the
radiator, do not use mouth to start siphoning
action. The coolant solution is POISONOUS
and can cause death or serious illness if
swallowed.
1. D rain coolant from the cooling system, includ
ing the cylinder block.
N O TE : The V8 cylinder block drain plugs are
located on both sides o f the block about halfway
back and on the lower edge near the oil pan rail.
T he 6-cylinder block drain is located on the left
side o f the engine at about centerline of the block
a n d adjacent to the flywheel housing.
2. Remove thermostat and replace thermostat
housing.
3. Add the liquid portion (No. 1) o f the cooling
system cleaner.
4. Fill the cooling system with w ater to a level of
about 3 inches below the top o f the overflow pipe.
5. Cover the rad iato r and run the engine at
m oderate speed until engine coolant tem perature reaches
180 degrees.
6. Remove cover from radiator and continue to
run the engine for 20 minutes. Avoid boiling.
7. W hile the engine is still running, add the
powder portion (No. 2) of the cooling system cleaner and
continue to run the engine for 10 minutes.
W ARNING:
hands.
Be careful not to scald your
8.
At the end o f this time, stop the engine, wait a
few minutes and then open the dra in cocks.
NOTE: Dirt and bugs may be cleaned out o f the
radiator air passages by blowing out with air
pressure from the back of the core. Do not bend
radiator fins.
Reverse Flushing
Reverse flushing should always be accomplished
after the system is thoroughly cleaned as outlined above.
Flushing is accomplished through the system in a
direction opposite to the normal flow. This action causes
the water to get behind the corrosion deposits and force
them out.
Radiator
1. Remove the rad iator upper and lower hoses and
replace the radiato r cap.
2. Attach a lead-away hose at the top of the
radiator.
3. Attach a new piece o f hose to the radiator outlet
connection and insert the flushing gun in this hose.
4. Connect the w ater hose o f the flushing gun to a
water outlet and the air hose to an air line.
CAUTION: Apply air gradually as a clogged
radiator will sta n d only 20 p.s.i. pressure.
5. Turn on the w ater and when the radiato r is full,
turn on the air in short blasts, allowing the radiator to fill
between blasts o f air.
6. Continue this flushing until the water from the
lead-away hose runs clear.
Cylinder Block and Cylinder Head
1. With the thermostat removed, attach a leadaway hose to the water pum p inlet and a length o f new
hose to the water outlet connection at the top of the
engine.
NOTE: Disconnect the heater hose and cap
connections at engine when reverse flushing
engine.
2. Insert the flushing gun in the new hose.
3. T u rn on the w ater and when the engine water
jacket is full, turn on the air in short blasts.
4. C ontinue this flushing until the w ater from the
lead-away hose runs clear.
H eater Core
1. Remove w ater outlet hose from heater core pipe.
2. Remove inlet hose from engine connection.
3. Insert flushing gun and flush heater core. Care
must be taken when applying air pressure to prevent
dam ag e to the core.
Fan Belt Adjustment
1. Loosen bolts at Delcotron mounting.
2. Pull Delcotron away from engine until desired
tension reading is obtained with a strand tension gauge.
Refer to Engine T u n e -U p Specifications.
3. Tighten all Delcotron bolts securely.
water outlet and gasket from thermostat housing (fig. 6B5).
3. Inspect thermostat valve to make sure it is in
good condition.
4. Place thermostat in a 33% glycol solution 25 °
above the tem perature stamped on the thermostat valve.
5. Submerge the valve completely and agitate the
water thoroughly. U nd er this condition the valve should
open fully.
6. Remove the thermostat and place in a 33%glycol
solution 10“ below tem perature indicated on the valve.
7. With valve completely submerged and water
agitated thoroughly, the valve should close completely.
8. If thermostat checks satisfactorily, re-install,
using a new housing gasket.
9. Refill cooling system.
T H E R M O S T A T IC FAN CLUTCH
Radiator Cap
REPLACEMENT
The ra d ia to r cap should be washed with clean water
and pressure checked at regular tune-up intervals.
Inspect ru b b e r seal on cap for tears or cracks. Install
rad iato r cap on tester (fig. 6B-4). If the pressure cap will
not hold pressure or does not release at the proper
pressure, replace the cap.
All m ating surfaces (water p u m p hub and fan clutch
hub) should be inspected for smooth m ating surfaces
and reworked as necessary to eliminate burrs or other
imperfections. Except for the fan belt, components
should be assembled to the engine (See W ater Pump
Removal and Installation Procedures). Radial run-out
should be checked as follows:
1. Secure the fan blade to prevent rotation. (See
Figure 6B-6).
2. M ount a dial indicator (.001 graduations) to the
engine and place the indicator pointer on the fan blade
spider. Preferably on the longest band or space on the
spider. (See Figure 6B-7).
3. Rotate the w ater pum p pulley in one direction
and note the total am ount of indicator needle movement.
This represents the total radial run-out. Mark the point
on the pulley at which the highest reading is obtained.
4. If the total indicator reading is less than .006
inch, the assembly is within specification. Install fan belt
and adjust.
T herm ostat
The therm ostat consists o f a restriction valve
actuated by a thermostatic element. This is mounted in
the housing at the cylinder head water outlet above the
w ater pump. T hermostats are designed to open and close
at predeterm ined tem peratures and if not operating
properly should be removed and tested as follows:
Replacement
1.
2.
Remove radiator to w ater outlet hose.
Remove therm ostat housing bolts and remove
6.
Recheck total indicator run-out to verify that
run-out is within .006 inch. Install fan belt and adjust.
W ater Pump
Removal
WARNING: If you siphon coolant from
the radiator, do not use mouth to start
siphoning action. The coolant solution
is POISONOUS and can cause death or
serious illness if swallowed.
Fig. 6B-7-C hecking Run-Out
If the total indicator run-out exceeds .006 inch,
proceed to Step 5.
5.
Divide the total indicator reading in half
obtain this thickness from shim stock (1/2 x 3/4 ) and
rework per Figure 6B-8. Place this shim pack between
the w ater p u m p pulley and fan clutch hub at the bolt
closest to the point m arked on the pulley in Step 3. If the
mark on the pulley is between two bolts so that it is
difficult to determ ine which bolt is closest, place two shim
packs; one un der each bolt on either side of the mark.
(See Figure 6B-9).
Bolt Torque Sequence
a. W hen one shim pack is used, first, torque the
bolt over which the shim pack has been placed; second,
the bolt opposite the first; and finally, the other two.
Recom m ended torque is 25 lbs. ft.
b. W hen two shim packs are used, each bolt
must be torqued partially; then to full torque alternating
between opposite bolts; then the other two bolts in the
same m anner. Recommended torque is 25 lbs. ft.
N O T E : Excessive run-out m ay result if the above
sequence and recom m ended torque is not used.
1. D rain coolant from the radiator and break loose
the fan pulley bolts.
2. Disconnect heater hose, radiator lower hose and
by pass hose (as required) at water pump.
3. Remove Delcotron upper brace (V8 only),
loosen
swivel bolt, and remove fan belt. On M ark IV
and
engines disconnect power steering and air conditioning
belts and swivel power steering pu m p to one side.
4. Remove fan blade assembly attaching bolts, fan
and pulley.
CAUTION: I f a fa n blade is bent or dam aged
in any way, no attem pt should be made to
repair and reuse the dam aged part. A bent or
dam aged fa n assembly should always be
replaced with a new fa n assembly.
It is essential that fan assemblies rem ain in proper
balance and p ro p er balance cannot be assured once
a fan assembly has been bent or dam aged. A fan
assembly that is not in proper balance could fail and
fly apart during subsequent use creating an
extremely dangerous condition.
NOTE: Thermostatic fan clutches must be kept in
an "in -c a r" position. W hen removed from the car
the assembly should be supported so that the clutch
disc rem ains in a vertical plane to prevent silicone
fluid leakage.
5.
Remove pum p-to-cylinder block and power
steering-to-pump bolts and remove pum p and old gasket
from engine.
CAUTION: On in line engines, p u ll the pum p
straight out o f the block first, to avoid damage
to impeller.
Installation
1. Install pu m p assembly on cylinder block then,
using a new sealer-coated pump-to-block gasket, tighten
bolts to specifications.
2. Install p u m p pulley and fan on pu m p hub and
tighten bolts to specifications.
NOTE: A guide stud (5/16"-24 bolt with the head
removed) installed in one hole o f the fan hub will
aid in aligning hub, pulley and fan. Remove stud
after starting the remaining three bolts. On Mark
IV engines install power steering and air condition
ing bolts.
3. Connect hoses and fill cooling system.
4. Install Delcotron upper brace (V8 only), and
install fan belt. Install power steering pu m p bolt.
NOTE: G rind a slight taper to threaded end of
bolt. This will serve as a pilot during installation
and also serve to pick-up threads on nut.
5. Adjust belts to specifications as previously
outlined.
6. Start engine and check for leaks.
SECTION 6C
FUEL SYSTEM
CONTENTS
G e n e ra l D escription.........................................
C a rb u r e ti o n .........................................................
Model l ME C a rb u re to r...............................
Model 2 G C /2 G V C arb u re to r....................
Model M 4 M C /M 4 M E /4 M V C arbureto r
Fuel Supply.........................................................
Fuel F ilte r .........................................................
6C-1
6C-1
Fuel P u m p ....................................................................... 6C-42
Fuel T a n k ......................................................................... 6C-44
^
Fuel Feed and V apor L in e s .................................... 6C-50
!
oL- ll
6C-21
6C-42
6C-42
Evaporative Control System (E C S ) ........................ 6C-50
Accelerator C o n tro ls .................................................... 6C-51
Special T o o ls .................................................................... 6C-54
GENERAL DESCRIPTION
Carburetor
All engines are equipped with either a 1-barrel,
2-barrel, or 4-barrel carburetor attached to the intake
manifold.
FUEL FILTER
All light duty emissions engines have a pleated
p ap er fuel filter and check valve assembly located in the
carburetor inlet.
All vehicles have a woven plastic fuel filter in the
fuel tank on the lower end o f the pick-up pipe.
In all series the tank is vented during filling by an
internal baffle inside the filler.
In all series the tank outlet consists of a com bination
fuel pickup, filter and fuel gage tank unit. The tank unit
can be removed by removing a cam ring which retains
the unit.
The fuel feed pipes are coated, welded steel tubing.
Connections from the tank unit to the line and from the
line to the fuel pu m p are made with synthetic rubber
hose attached with spring clamps.
FUEL P U M P
The fuel pum p is located on the right front of the
engine.
FUEL T A N K AND FEED PIPES
All filler necks with light duty emissions have
restrictors to prevent the entry o f leaded fuel nozzles.
EVAPORATIVE CONTROL SYSTEM (ECS)
The Evaporative Control System is a closed system
that prevents gasoline vapors in the fuel tank and
carburetor from entering the atmosphere.
CARBURETION
ALL N E W 1977 CHEVROLETS ARE CERTIFIED BY THE U N ITED
STATES D E P A R T M E N T OF HEALTH, E D U C A TIO N A N D W EL
FARE AS C O N F O R M IN G TO THE R E Q U IR E M E N T S O F THE
R EG U L A T IO N S FOR THE C O N T R O L OF AIR PO LLU TIO N FR O M
N E W M O TO R VEHICLES. THIS CERTIFICATION IS C O N T IN G E N T
O N C E R T A IN A D JU S T M E N T S BEING SET TO FA C T O R Y
STA N D A RD S. F O R THIS REASON, THE FACTORY P R O C E D U R E
FOR S ETTIN G IGN ITIO N T IM IN G , A N D SLOW IDLE M U ST BE
F O L L O W E D EXACTLY W H E N A D JU STM EN TS ARE MADE.
MODEL 1ME CARBURETOR
GENERAL DESCRIPTION
The Monojet, carburetor (Fig. 6C-1) is a single bore
d o w n d ra ft c a rb u re to r using a triple venture in
conjunction with a plain tube nozzle.
Fuel flow through the main metering system is
controlled by a m ain well air bleed and a variable orifice
jet. A power enrichment system is used to provide good
ELECTRIC
Fig. 6C -2-M odel 1ME C arburetor Id entification
CAM
FOLLOWER
Fig. 6 C -l-M o d e l 1ME Carburetor-Rear View
perform ance during m oderate to heavy acceleration and
at higher engine speeds.
The idle system, on certain models, incorporates a
hot idle com pensator (A.T. only) to m a intain smooth
engine idle during periods o f extreme hot engine
operation.
The model 1ME incorporates an integral automatic
choke system which uses an d electrically heated choke
coil. The vacuum d ia p h ra g m unit is mounted externally
on the air horn and connects to the thermostatic coil
lever through a connecting line.
The electric choke coil is contained in a choke
housing m ounted on a bracket attached to the float bowl.
A n integral, pleated-paper fuel inlet filter is
m ounted in the fuel bowl behind the fuel inlet nut to
give m a x im u m filtraton o f incom ing fuel. A check valve
on light duty emissions is used in the filter inlet to
prevent fuel d rain in g from the fuel system after roll
over.
O th er features o f the M onojet carburetor include an
alum inum throttle body for decreased weight and
improved h eat distribution and a thick throttle body to
bowl insulator gasket to keep excessive engine heat from
the float bowl. The carburetor has internally balanced
venting through a vent hole in the air horn, which leads
from the float bowl into the bore beneath the air cleaner.
The carburetor model identification is stam ped on a
vertical portion o f the float bowl, adjacent to the fuel
inlet nut (Fig. 6C-2).
If replacing the float bowl, follow the m anufactu r
e r ’s instructions contained in the service package so that
the identification nu m b e r can be transferred to the new
float bowl.
An electrically operated idle stop solenoid is used on
all models.
Dual throttle return springs are used on all
carburetors.
The throttle lever has a spun-in plastic bushing, this
is used as the bearing surface for the dual throttle return
springs.
NOTE: The spun-in plastic return spring bushing
will w ith sta n d no rm al cleaning time in an
approved cold im mersion type carburetor cleaner.
The bushing is not serviced separately and should
not be removed from the carburetor throttle lever.
An Exhaust G as Recirculation system (EG R ) is used
on light duty emission and heavy duty emission 454 CID
Calif, to control oxides o f nitrogen. The vacuum supply
port necessary to operate the recirculation valve is
located in the throttle body and connects through a
channel to a tube which is located at the top o f the air
horn casting. See Idle System (Fig. 6C-4) for port
location and operation.
Six basic systems of operation are used: float, idle,
main metering, power enrichment, pum p and choke. 6C3 through 9).
IN T E R N A L V E N T
M A IN W E L L A IR B LE E D
PRESSURE
RELIEF V A L V E
POW ER PIS TO N
M E T E R IN G R O D
M A IN D IS C H A R G E NOZZLE
POW ER PIS TO N
'S P R IN G
BO O ST V E N T U R I
M A IN V E N T U R I
,M A IN M E T E R IN G
„ C A L IB R A T IO N
SCREW
POW ER P IS TO N
A C T U A T IN G L IN K A G E
LOW ER ID L E A IR B LE E D
^3
THR O TTLE VALVE
POW ER P IS TO N V A C U U M
Fig. 6C -5-M ain M etering System
Fig. 6C-3--Float System
M A IN
DISC H A R G E
NOZZLE
D R IV E ROD
BOOST VEN TURI
TO P A IR BLEED
T U B E TO
E G R * vV A L V E
POWER PISTO N
E G R (E X H A U S T G A S
R E C IR C U L A T IO N )
^ M E T E R IN G
ROD
M A IN VENTUR I
. IDLE C H A N N E L
R E S T R IC T IO N
M A IN M E TER IN G
JET
- IDLE TUB E
POWER PISTO N
A C T U A T IN G LIN K A G E
_ M A IN M E T E R IN G J E T
H O T IDLE
COMPENSATO R
T IM E D V A C U U M
PORTS FOR E.G .R.*
-P O W E R PISTON V A C U U M
LOW ER IDLE AIR BLEED
Fig. 6C-6--Power E nrichm ent System
THR OTTLE VALVE
ID L E M IX T U R E NEEDLE
IDLE D IS C H A R G E HO LE
" J " D IS C H A R G E
S P R IN G R E T A IN E R
OFF— IDLE
O P E R A T IO N
-P U M P L E V E R
Fig. 6C-4--ldle System
P UM P P L U N G E R
D U R A T IO N
S P R IN G
PUM P D IS C H A R G E
S P R IN G & B A L L
P UM P R E T U R N
S P R IN G
P UM P A C T U A T IN G L IN K
P UM P CUP O P E R A T IO N
C H O K E RO D
CHOKE
H O U S IN G
CHOKE VALVE
ELE CTRIC
CHOKE
C O IL
C H O K E C O IL
LIN K
FILTER
BLEED
HOLE
FAST IDLE
CAM FOLLOWER
...wIDE
C O IL LEVER
VACUUM
IN LE T
CHECK
BALL
F A S T IDLE
CAM
CHOKE V A C U U M
D I A P H R A G M U N IT
VACUUM
B R E A K L IN K
T IM E
DELAY
VALVE
M A N IF O L D
VACUUM
HOSE
Fig. 6C-8-Choke System
ON-VEHICLE SERVICE
1 M E C A R B U R E TO R A D J U S T M E N T S
Refer to figure 6C-9 for the following adjustments:
• Float Level
• M etering Rod
• Fast Idle
R efer to figure 6C-10 for the following adjustments:
• Choke Coil Lever
• A utomatic Choke
• Choke Rod (Fast Idle Cam)
Choke Checking Procedure
1. Remove air cleaner. W ith engine off, hold
throttle half open. Open an d close choke several times.
W atch linkage to be certain all links are connected and
there are no signs o f damage.
2. If choke or linkage binds, sticks, or works
sluggishly, clean w ith Choke C lean er X-20-A or
equivalent. Use cleaner as directed on can. Refer to
disassembly instructions for additional direction if
cleaning does not correct.
3. Visually inspect carburetor to be certain all
vacuum hoses are connected. Inspects hoses for cracks,
abrasions, hardness or other signs of deterioration.
Replace or correct as necessary.
4. Make sure vacuum break d ia p h ra g m shaft is
fully extended when engine is off. If shaft is not fully
extended, replace vacuum break assembly. Start engine vacuum break d iaph ragm shaft should fully retract
within 10 seconds. If unit fails to retract, replace vacuum
break assembly.
5. Allow choke to cool so that when throttle is
opened slightly choke blade fully closes.
N OTE: This check must be perform ed at an
am bient tem perature o f 60 °F to 80 T .
6. Start engine and determ ine time for choke
©
GAUGE
1
CARB. IMO.
FROM TOP OF
GAUGE
C A S T IN G TO TO P O F
I N D E X P O IN T A T TO E
O F FLOAT
M jH O L D
FLO A T R E T A IN IN G
P I N FI R M L Y I N P L A C E -
( 3JBEND
H E R E TO
PUSH DO W N ON E N D O F
ADJUST FLO AT
F LO A T A R M . A G A IN S T
UP OR DOW N
TOP O F FLO AT N E E D LE
ALL WITH
LIGHT DUTY
EMISSIONS
3/8"
ALL WITH
HEAVY DUTY
EMISSIONS
5/16"
CARB. IMO.
PLUG GAUGE
17057001
17057002
17057004
17057005
17057010
17057302
.008
17057303
090
17057006
17057007
070
17057008
17057009
17057308
17057309
.0 6 5
FL O A T L E V E L A D JU S T M E N T
( " T ')H O L D
2
—
POWER
P IS T O N D O W N A N D SW ING
M E T E R IN G
OVER
HERE
TO ADJUST
ROD HO LDER
FLAT SURFACE
(G A S K E T
REMOVED)
O F BO W L C A S T IN G
TO CA RBURE TO R
T lJ R E M O V E
|B E N D
M E T E R IN G
NEXT
BORE
ROD
BY H O L D IN G T H R O T T L E
i
V A L V E W ID E O P E N . PUSH
4 J S P E C IF IE D PLUG
GAUGE
D O W N W A R D ON M E T E R IN G
-
S L ID E
FIT
R O D A G A IN S T S P R IN G
B A C K O UT ID LE
T E N S IO N . T H E N S L ID E
M E T E R IN G
REMOVE
STOP S O LE N O ID
ROD O U T OF
S L O T IN H O L D E R
HOLD THRO TTLE
AND
VA LV E COMPLETELY
FROM M A IN
CLOSED
M E T E R IN G JET.
M E T E R IN G ROD A D JU S T M E N T
NOTE:
M A N U A L CHOKE MODELS
W IT H S M O O T H C O N T O U R
C A M S U R F A C E -R O T A T E
FAST ID L E C A M C L O C K
W IS E T O IT S F A R T H E S T
UP P O S IT IO N .
(V )sU P P O R T
LIGHT DUTY EMISSIONS
2100 RPM
(IN NEUTRAL)
L E V E R W IT H
P L IE R S -B E N D T A N G
IN
O R O U T T O O B T A IN S P E C IF IE D
FAST ID LE
R .P.M . (SEE IN S E T )
CLEARANCE
SECO
PLACE C AM
HEAVY DUTY EMISSIONS
2400 RPM
(IN NEUTRAL)
FOLLOW ER
T A N G O N H IG H STEP
O F C A M (SEE N O T E )
F A S T ID L E C A M S TEPS
Ci j
A D JU S T C U R B ID LE
SPEED W IT H ID L E STOP
S O L E N O I D (SEE L A B E L )
FAST ID L E A D JU S T M E N T
©2 JCH OO ML DP LCEHTOE KL EY
VALVE
C A R B . NO.
PLUG G AUG E
ALL
.120
CLO SED
(
3)
.1 2 0 " P LU G
GAUGE MUST
PASS T H R O U G H
H O L E IN L E V E R
1
A N D E N TE R H O LE
IN C A S T IN G
O
PLACE C A M
F O LLO WE R ON
HI G H E S T STEP
OF F A S T IDLE C A M
BEND
L IN K
TO A D JU S T
C HO KE C O IL L E V E R A D JU S T M E N T
C A R B . NO.
NDEX MARK
ALL
IN D E X
C A R B . IMO.
PLU G G A U G E
IN D E X
o
LO O SEN T H R E E
©
R E T A IN IN G S C R E W S
W IT H CH OK E COIL LEVER LOCA TED
INSIDE COIL T A N G (SEE INSET) SE T M A R K O N ELECTRIC CHOKE
T O SPECIFIED P O IN T O N CHOKE
H O U S IN G A N D T IG H TE N SCRE WS
PLACE C A M FOLLO WER
O N HIGH STEP OF C A M
IN S E T
A U T O M A T IC C H O K E A D JU S T M E N T
G)
6
G AUG E BETW EEN
OF CHOKE V A LV E
IN S I D E
UPPER EDG E
(A T C E N T E R ) A N D
Al R HORN W ALL
G A U G E V E R T IC A L
4j B E N D
ROD AT
P O IN T S H O W N
TO A D JU S T
.1 2 5
17057005
(.2 3 0 B O T T O M )
17057002
17057004
17057302
17057010
©2 j OH NO LCDH OD OK EW NV A L V E
(
17057001
17057303
O
W IT H FA ST IDLE
A D J U S T M E N T M AD E ,
C A M FO LLO WE R M U S T
BE HELD FI RM LY ON
S E C O N D STEP OF FA ST
IDLE C A M A G A I N S T
HI G H E S T STEP
17057006
17057007
17057008
17057009
17057308
17057309
CHO KE ROD (FA S T ID L E CAM ) A D JU S T M E N T
.110
(.1 9 0 B O T T O M )
.1 5 0
(.2 7 5 B O T T O M )
FUEL SYSTEM
6C-7
N O T E : H O L D G A U G E V E R T IC A L
(
7^
T O A D JU S T
( b J g aug e
^ -^ U P P E R
5)
(
„
b e tw e e n
EDGE
CHOKE
OF
VALVE
R O D IN E N D O F
CENTER) AN D
SLOT
A IR
N O TE: ON
D E L A Y FEA
T U R E MODELS
PLUG END
C O VER W ITH
M A S K IN G
TAPE
©
C A R B . NO .
PLUG G AU G E
17057001
17057303
.1 5 0
(.2 7 5 B O T T O M )
17057002
17057004
17057302
(.2 4 5 B O T T O M )
B E IM D R O D
HORN
(A T
IN S I D E
W ALL
(^ 4 J PUSH UP O N C H O K E
.135
C O IL L E V E R
U S E O U T S ID E
1 ) PLACE FA S T IDLE
C A M FO LLO W E R O N
H IG H E S T STEP OF
FA S T IDLE C A M
- S
3 J D IA P H R A G M
V A C U U M SOURCE
V—
T O S E A T D IA P H R A G M
PLUNG ER
OUT AN D SEATED
( B U C K I N G S P R IN G
C O M P R E S S E D -W H E R E U S E D I
V A C U U M B R EA K A D JU S T M E N T
8
( iM H O L D I N G
©
RE M O V E
M A S K IN G
TA P E , IF
US ED
17057005
17057006
17057007
17057008
17057009
17057308
17057309
.1 8 0
(.3 2 5 B O T T O M )
C A R B . NO.
PLU G G A U G E
DOW N
ON CH O KE V A L V E , G AU G E
BE TW EEN UPPER ED G E O F
CHOKE V A LV E
A N D IN S I D E
A IR
HORN W ALL
ALL WITH
LIGHT DUTY
EMISSIONS
.3 2 5
(.6 0 0 B O T T O M )
(^ T )bend
NO TE: HO LD
TANG
G A U G E V E R T IC A L
TO
AD JU S T
(S E E I N S E T )
( T ) ho ld
TH RO TTLE VALVE
ALL WITH
HEAVY DUTY
EMISSIONS
W ID E O P E N
.2 7 5
(.5 0 0 B O T T O M )
U N L O A D E R A D JU S T M E N T
3)
G
^
O1 ) WE NA GR IMN -EC HMOUKSET WB EI D E
CAM
FOLLOW ER
STEPS OF C A M
E M IS S IO N
TO A D J U S T BA SE
IDLE, T U R N 1 /8 "
HEX SC REW
(S O LE N O ID N O T
ENERGIZED)
BASE IDLE — LDX
425 RPM (N) — M.T.
(D) - A.T.
CURB IDLE — LDX
750 RPM (N) M.T. EX CALIF.
850 RPM (N) M.T. CALIF.
550 RPM (D) A.T. NO A/C
49 STATES
600 RPM (D) A.T. A/C
49 STATES
600 RPM (D) A T. H. ALT.
AND CALIF.
OPEN-
OFF
(SEE
LABEL)
f
2
)
S E T C U R B ID L E
T O S P E C IF IC A T IO N S - T U R N
A S S E M B L Y IN O R O U T
BASE IDLE — HDX
450 RPM (N)
T O A D J U S T R .P .M .
(S O L E N O ID E N E R G IZ E D )
IDLE SPEED ADJUSTM ENT
CURB IDLE — HDX
600 RPM (N)
blade to reach full open position. (Start timer when
engine starts).
7. If the choke blade fails to open fully within 3-1/
2 minutes proceed with steps 8-9-10 below.
8. Check voltage at the choke heater connection.
(Engine must be running). If the voltage is approx
imately 12-15 volts, replace the electric choke unit.
9. If the voltage is low or zero, check all wires and
connections. If the connections at the oil pressure switch
are faulty, the oil w arn in g light will be off with the key
" o n " and engine off. If the fuse is blown, the radio or
turn signal indicator will be inoperative. Repair wires or
replace fuses as required.
10. If step 9 is good, replace oil pressure switch.
N OTE: No gasket is used between the choke cover
and the choke h ousing due to gro u n d in g
requirements.
Refer to figure 6 C -1 1 for the following adjustments:
• Vacuum Break
• U nloader
• Idle Speed
Checking Solenoid
1. T urn on ignition, but do not start engine.
2. O pen throttle to allow solenoid plunger to
extend.
3. Hold throttle lever wide open, feel end o f
plunger and disconnect wire at solenoid.
4. Plunger should move. Some spring tension
should be felt.
5. If plunger did not move, back out 1/8 hex screw
(counterclockwise) one full turn and repeat steps 3 and 4.
6. If plunger moves in step 5, connect wire to
solenoid and adjust idle speed.
7. If plunger did not move in step 5 insert test
lam p (1893 bulb or smaller) between solenoid feed wire
and ground.
8. If lamp lights, replace solenoid.
9. If lam p does not light, locate cause o f open
circuit in solenoid feed wire.
Idle M ixtu re A djustm ent
1. Set parking brake and block drive wheels.
2. Remove air cleaner for access to carburetor, but
keep vacuum hoses connected.
3. Disconnect and plug other hoses as directed on
Emission Control Inform ation Label under the hood.
4. Engine must be at norm al operating tem pera
ture, choke open, air conditioning off.
5. Connect an ACCURATE tachom eter to engine.
6. Disconnect vacuum advance and plug hose.
Check ignition timing. If necessary, adjust to specifica
tion shown on Emission Control Inform ation Label.
Reconnect vacuum advance.
7. Carefully remove cap from idle mixture screw.
Be careful not to bend screw. Lightly seat screw, then
back out just enough so engine will run.
8. Place transmission in Drive (automatics with
light duty emissions) or Neutral (all m anuals and
automatics with heavy duty emissions).
9. Back screw out (richen) 1/8 turn at a time until
maximum idle speed is obtained. Then set idle speed to
value shown in Chart Column A o f specifications. Repeat
Step 9 to be certain you have m aximum idle speed.
10. Turn screw in (lean) with 1/8 turn increments
until idle speed reaches value shown in C h art Column B
of specifications.
11. Reset idle speed to specification shown on
Emission Control Inform ation Label.
12. Check and adjust fast idle as described on the
Emission Control Inform ation Label.
13. Reconnect vacuum hoses. Install air cleaner.
Idle Mixture
Idle mixture screw has been preset at the factory
and capped. Do not remove the cap during normal
engine m aintenance.
Before suspecting the carburetor as the cause of
poor engine perform ance or rough idle, check ignition
system including distributor, timing, spark plugs and
wires. Check air cleaner, evaporative emission system,
EFE System, PCV system, E G R valve and engine
compression. Also inspect intake manifold, vacuum hoses
and connections for leaks and check torques o f
carb uretor m ounting bolts/nuts.
In the case o f m ajor carburetor overhaul, throttle
body replacement, high idle CO as indicated by state or
local emission inspection, the idle mixture may be
adjusted. Adjusting mixture by oth er than the following
method m ay violate Federal a n d / o r C alifornia or other
state laws.
IN S U L A T O R
T O R Q U E SE Q U E N C E
T IG H T E N
N U T S T O 36 IN . LBS. . . .T H E N
TO 18 FT. LBS.
i
I •'
H E A T STOVE
14.
specilication.
Recheck
idle
speed.
If
necessary,
reset
C A R B U R E TO R R E P LACE M E NT (FIG. 6C-12)
Removal
F lo oding , stum ble on acceleration a n d o th e r
perform an ce complaints are, in many instances, caused
by presence o f dirt, water, or other foreign m atter in
carburetor. To aid in diagnosing cause, carburetor
should be carefully removed from engine without
drain in g fuel from bowl. Contents o f fuel bowl may then
be e x a m in e d fo r c o n ta m in a tio n as ca rb u re to r is
disassembled. Check filter.
1.
Remove air cleaner.
2. D iscon nect
carburetor.
fuel
an d
vacuum
lines
3.
4.
Disconnect electrical connector at choke.
Disconnect accelerator linkage.
5.
Disconnect solenoid electrical connector.
fro m
6. Remove carburetor attaching nuts and remove
carb uretor and solenoid assembly attachment.
7.
Remove insulator gasket.
Installation
It is good shop practice to fill carburetor bowl before
installing carburetor. This reduces strain on starting
motor and battery and reduces the possibility of
backfiring while attem pting to start engine. A small
supply o f fuel will enable c arburetor to be filled and the
operation of float and intake needle and seat to be
checked. O perate throttle lever several times and check
discharge from pu m p jets before installing carburetor.
1. Be certain throttle body and intake m anifold
sealing surface are clean.
2.
Install carburetor insulator.
3.
Install carburetor over m anifold studs.
4.
Install vacuum and fuel lines at carburetor
5. Install attaching nuts and tighten alternately to
16 pounds-feet (21 N m ) .
6.
Tighten fuel line.
7.
Connect accelerator linkage.
8. C o nn ect
connectors.
9.
choke
an d
solenoid
electrical
Install air cleaner.
10.
Check and adjust idle speed.
SO LEN O ID R E P LA C E M E N T
An inoperative solenoid should be replaced.
Removal
1.
Remove carburetor air cleaner.
2.
Disconnect electrical connector at solenoid.
3. Unscrew and remove solenoid from float bowl
assembly.
to Installation
1. Hold choke valve wide open so that fast idle
cam follower clears fast idle cam.
2.
tang.
3.
Install solenoid and turn in until it contacts lever
Connect electrical connector.
4.
Install air cleaner.
5.
Check and adjust idle speed.
CHOKE COIL R EPLACEM ENT
Choke m echanism should be checked for free
operation. A binding condition may have developed
from petroleum gum form ation on the choke shaft or
from damage. Choke shafts can usually be cleaned
without disassembly by using C arbon X(X55) or
equivalent.
1. Remove air cleaner and disconnect choke
electrical connector.
2. Remove screws attaching choke assembly to
housing and remove choke as an assembly.
3.
Install new choke and coil assembly.
4.
Install screws and loosely tighten.
5. Adjust choke setting as specified and tighten
screws.
6.
Connect choke electrical connector.
7. Start engine, check operation o f choke and then
install air cleaner.
AIR HORN T IG H T E N IN G SEQUENCE
R efer to Figure
tightening sequence.
6C-13
for
proper
air
horn
S P E C IF IC A T IO N S
ID L E M IX T U R E
(L E A N D R O P )
L IG H T D U T Y E M IS S IO N S
ENGINE
COLUMN B
SPEED A FTE R LEAN DROP
COLUMN A
SPEED BEFORE LEAN DROP
2 5 0 CID
M A N U A L TRANS.
900 RPM (N)
750 RPM (N)
575 RPM (D)
550 RPM (D)
620 RPM (D)
600 RPM (D)
63 0 RPM (D)
600 RPM (D)
62 0 RPM (D)
60 0 RPM (D)
1100 RPM (N)
85 0 RPM (N)
LOW A L T I T U D E
25 0 CID
A U T O M A T IC TRANS.
LOW A L T . NO A /C
25 0 CID
A U T O M A T IC TRANS.
LOW A L T . A / C
250 CID
A U T O M A T IC TRANS.
C A L IF O R N IA
250 CID
A U T O M A T IC TRANS.
H IG H A L T I T U D E
250 CID
M A N U A L TRANS.
C A L IF O R N IA
ID L E M IX T U R E
(L E A N D R O P)
H E A V Y D U T Y E M IS S IO N S
ENGINE
COLUMN A
COLUMN B
SPEED BEFORE LEAN DROP
SPEED A FTE R LE AN DROP
250 CID
600 RPM (N)
70 0 RPM (N)
29 2 CID
T O R Q U E S P E C IF IC A T IO N S
IM E C A R B U R E T O R
SCREW
TORQUE
SCREW
(IN. LBS.)
TORQUE
(IN. LBS.)
400
A I R H O R N T O BO W L
45
FU EL IN LE T NUT
A I R C L E A N E R B R ID G E
70
F A S T I D L E C AM
50
CHOKE LEVER
25
PUMP L E V E R
30*
T H R O T T L E B O D Y T O BO W L
180
N EED LE SEAT
45
M E T E R I N G JET
40
* L o c t it e A V V or equivalent
MODEL 2GC CARBURETOR
GENERAL DESCRIPTION
T he Model 2G C carburetor (Figs. 6C-14 and 15) is
equipped with a n integral choke attached to the throttle
body assembly.
All light duty emission models use a fuel inlet check
valve to shut off fuel flow to the carburetor float bowl to
prevent fuel leaks if a vehicle roll-over should occur.
All models (except California) use full vacuum for
distributor advance obtained through a tube pressed into
the float bowl (choke side location "h " ). On C alifornia
models, timed vacuum for distributor advance is
supplied through this same tube (location "h").
A n Exhaust G a s Recirculation (E.G.R.) system is
used to meet emission requirem ents for oxides o f
N itrogen (NOx). In addition, a cup restriction is added
in the float bowl behind the Exhaust G a s Recirculation
(E.G.R.) vacuum tube (location "j"), to delay E.G.R.
valve operation for im proved engine perform ance as the
throttle valves are opened.
A electrically operated solenoid is used on all 2G C
models equipped with automatic transmission and air
conditioning. The solenoid is used to m ain tain proper
idle speed when the air conditioning is in operation.
Fuel for the pu m p system is obtained through a hole
located in a raised cast-in boss on the floor o f the float
bowl which prevents the entry of dirt into the accelerator
p u m p fuel inlet passage. The p u m p plunger head is
designed with an expander spring beneath the pum p cup
to m aintain good pum p wall contact during pu m p
operation.
The end o f the pu m p plunger stem is upset in
m a nufacturing to provide the "clipless" retaining in
feature. The p u m p plunger assembly may be removed
from the inner lever by twisting upset end with small
pliers until it breaks. The service pum p assembly has a
grooved end and is provided with a retaining clip.
The carburetor p art n um b e r is stam ped on the flat
section o f the float bowl next to the fuel inlet nut. (Fig.
6C-17). W hen servicing the carburetor unit, refer to the
O n-Car Service section for proper procedures and
specifications.
Incorporated in the Model 2 G C carburetor are six
basic systems. They are Float, Idle, M ain Metering,
Power, Pump and Choke (Figs. 6C-17 through 23).
IDLE R ESTRICTIO N
---------------^
I-----------------
IDLE PASSAGE
• E.G.R (E X H A U S T GAS
^
ID L E T U B E i
\
IDLE AIR
\
MAIN WELL INSERT^_
M A IN
R E C IR C U L A T IO N I
-■
^
I
\
M E T E R IN G --------------JETS
1
S
T IM E D SPARK TUBE-;--------- H
'
(
BLEEDS
T
j
III ■
-■■E.G.R. VALVE & SPARK
J
T IM E D
TIMED VACUUM
C ANISTER ----- \ ^ PORT.
PURGE
/
EGR -------- n
R E S T R I C T I O N '^ ^ L _ ^ J S f f l ^ j ,¥^ 3 ^ ^
“2G ” TYPE
IDLE N
E
E
D
L
I
E
-
&
(
_L
L.
\
STEP OF FAST ID LE CAM
AG AINST HIGH STEP
,
,
C HO KE R OD (FA S T ID L E CA M ) A D JU S T M E N T
4 ) GAUGE
3 1STEM
BETW EEN
EDGE O F CH O KE
PU LLED O UT
/
U N T IL S E A T E D
UPPER
C A R B . NO.
VALVE
A N D W A L L O F A IR
HORN
.1 3 0
B ELO W
P L A C E ID L E S P E E D S C R E W
O N H IG H E S T S T E P O F
FAST
ID L E C A M
VACUUM
PLUG G AUGE
ALL
EXCEPT
17056137
—
2 2 .5 0 0 M l
.1 6 0
ABOVE
2 2 .5 0 0 M l
D IA P H R A G M
S
SEATED
j
BEND
ROD
TO AD JU S T
N O TE : PLUG EN D C O VE R
\ \
'j
^
W IT H A P I E C E O F M A S K I N G
/ &
T A P E M A K IN G S U R E T O
CO VER PURGE BLEED H O LE .
REM O VE TAPE AFTER
(
\
17056137
.190
L _ \ ------- ^
f T ^ U S E O U T S ID E V A C U U M S O U R C E
A D JU S TM E N T.
V A C U U M B R EA K A D JU S TM E N T
C A R B . NO.
G A U G E B E T W E E N UPPER
EDGE O F C H O K E V A L V E
A N D W A L L OF A IR HORN
PLU G G A U G E
BEND TA NG
TO AD J U S T
SEE INSET
ALL
HOLD THROTTLE
V A L V E W ID E OPEN
INSET
C H O K E U N L O A D E R A D JU S T M E N T
.325
10
©
P R E P A R E V E H IC L E FOR A D J U S T M E N T S - SEE
E M IS S IO N L A B E L O N V E H IC L E . N O T E : IG N IT IO N
T IM IN G SET PER L A B E L .
LIGHT DUTY EMISSIONS
MANUAL TRANSMISSION
600 RPM (N)
AUTOMATIC TRANSMISSION
500 RPM (D)
HEAVY DUTY EMISSIONS
700 RPM (N)
IDLE SPEED A D JU S T M E N T — W IT H O U T SOLENOID
11 ©
OPEN T H R O T T L E S L IG H T L Y TO A L L O W
S O L E N O ID P L U N G E R TO F U L L Y E X T E N D
T U R N ID L E SPEED SCREW TO
SET C U R B ID L E SPEED TO
S P E C IF IC A T IO N S - A /C O F F
(SEE E M IS S IO N L A B E L )
© S O L E N O I D E N E R G IZ E D A /C CO M PR E SS O R L E A D
D IS C O N N E C T E D A T A /C
CO M PRE SS O R , A /C O N,
A /T T R A N S M IS S IO N IN
D R IV E .
L I G H T D U T Y E M IS S IO N S
M A N U A L T R A N S M IS S IO N
I D L E S P E E D S C R E W - 6 0 0 R P M (N )
S O L E N O I D S C R E W - 7 0 0 R P M (N )
A U T O M A T I C T R A N S M IS S IO N
E L E C T R IC A L
C O N N E C T IO N / '
I D L E S P E E D S C R E W - 5 0 0 R P M (D )
S O L E N O I D S C R E W - 6 5 0 R P M (D )
© TURN
S O L E N O ID SCREW TO
A D J U S T TO S P E C IF IE D RPM.
(R E C O N N E C T A /C COM PRESSOR
LE A D A F T E R A D JU S TM E N T)
0
PR E P A R E V E H IC L E FOR A D J U S T M E N T S SEE E M IS S IO N L A B E L O N V E H IC L E .
N O T E : IG N IT IO N T IM IN G SET PER L A B E L .
IDLE A D JU STM EN T — WITH SOLENOID
wires. Check air cleaner, evaporative emission system,
E FE System, PCV system, E G R valve and engine
compression. Also inspect intake manifold, vacuum hoses
and connections for leaks and check torques of
c arburetor m ou ntin g bolts/nuts.
In the case o f major carb uretor overhaul, throttle
body replacement, high idle CO as indicated by state or
local emission inspection, the idle mixture m ay be
adjusted. Adjusting mixture by other than the following
m ethod may violate F ederal a n d / o r C alifornia or other
state laws.
Idle M ix tu re A d ju stm ent
1. Set parking brake and block drive wheels.
2. Remove air cleaner for access to carburetor, but
keep vacuum hoses connected.
3. Disconnect an d plug o ther hoses as directed on
Emission Control Info rm atio n Label under the hood.
4. Engine must be at norm al operating tem p e ra
ture, choke open, air conditioning off.
5. Connect an ACCURATE tachometer to engine.
6. Disconnect vacuum advance and plug hose.
Check ignition timing. If necessary, adjust to specifica
tion shown on Emission Control Inform ation Label.
Reconnect vacuum advance.
7. Carefully remove caps from idle misture screws.
Be careful not to bend screws. Lightly seat screws then
back out EQUALLYjust enough so engine will run.
8. Place transmission in Drive (automatics on light
duty emissions) or N eutral (all manuals and automatics
with heavy duty emissions).
9. Back each screw out (richen) 1/8 turn at a time
until m axim um idle speed is obtained. T hen set idle
speed to value shown in C h a r t C olum n A of
specifications. Repeat Step 9 to be certain you have
m axim um idle speed.
10. T u rn each screw in (lean) with 1/8 turn
increments until idle speed reaches value shown in Chart
Colum n B o f specifications.
11. Reset idle speed to specification shown on
Emission Control In form atio n Label.
12. Check and adjust fast idle as described on the
Emission Control In form ation Label.
13. Reconnect vacuum hoses. Install air cleaner.
14. Recheck idle speed. If necessary, reset to
specification.
C A R B U R E TO R R E P LA C E M E N T (FIG .6C -28)
Removal
Flo od in g, stum ble on acceleration and o ther
perform ance complaints are, in m any instances, caused
by presence o f dirt, water, or other foreign m atter in
carburetor. To aid in diagnosis, carburetor should be
carefully removed from engine without draining fuel
from bowl. Contents o f fuel bowl may then be examined
for contam ination as carburetor is disassembled. Check
filter.
Fig. 6C-28--Carburetor and Choke Pipes
V8,2Bb1
1. Remove air cleaner and gasket.
2. Disconnect solenoid wire if equipped.
3. D isconnect fuel and vacuum lines from
carburetor.
4. Disconnect fresh air hose and choke hose from
choke system.
5. Disconnect accelerator linkage.
6. If e q u ip p e d with au to m atic transm ission,
disconnect downshift cable.
7. If equipped with cruise control, disconnect
linkage.
8. Remove carburetor attaching bolts and remove
carburetor and insulator.
Installation
1. Fill carburetor bowl before installing carburetor.
2. With clean sealing surfaces on carburetor and
intake manifold, install new insulator.
3. Postion carburetor over insulator and install
bolts. Tighten bolts alternately to 145 inch pounds.
4. Connect downshift cable as required.
5. Connect cruise control cable as required.
6. Connect accelerator linkage.
7. Connect choke system.
8. Connect fuel pipe and vacuum hoses.
9. Connect solenoid wire as required.
10. Install air cleaner.
11. Check and adjust idle speed.
AIR HORN T IG H T E N IN G SEQUENCE
Refer
to figure 6C-29 for
air
horn
tightening sequence.
Fig. 6C-29 -Air Horn T ightening Sequence
S P E C IF IC A T IO N S
ID L E M IX T U R E
(L E A N D R O P )
L IG H T D U T Y E M IS S IO N S
COLUM N B
COLUMN A
SPEED BEFORE LEAN DROP
ENGINE
SPEED A FT E R LEAN DROP
305 CID
M A N U A L TRANS.
650 RPM (N)
600 RPM (N)
5 3 0 RPM (D)
500 RPM (D)
30 5 CID
A U T O M A T IC TRANS.
ID L E M IX T U R E
(L E A N D R O P )
H E A V Y D U T Y E M IS S IO N S
COLUMN B
SPEED A FTE R LEAN DROP
COLUMN A
SPEED BEFORE LEAN DROP
ENGINE
70 0 RPM (N)
8 00 RPM (N)
305 C ID
T O R Q U E S P E C IF IC A T IO N S
2G C C A R B U R E T O R
TORQUE
SCREW
(IN. LBS.)
T H R O T T L E BODY
T H R O T T L E B O D Y TO B O W L
72
BO W L
CLUSTER
46
F A S T I D L E CAM
58
M E T E R I N G JET
40
C H O K E H O U S IN G
CHOKE LEVER
14
CHOKE H S G .T O T H R O T T L E BODY
46
C H O K E H O U S IN G C O V E R
26
A I R HO R N
A I R H O R N T O BOWL
46
V A C U U M B R E A K U N IT
26
CHOKE SHAFT
FU EL IN L E T N U T
NEEDLE SEAT
14
400
45
MODEL M4MC/M4ME/4MV CARBURETOR
GENERAL DESCRIPTION
T he Model M 4 M C /M 4 M E /4 M V carburetor (Figs.
6C-30, 3 1 and 32) are two stage carburetor o f dow ndraft
Fig. 6 C - 3 0 - M o d e l
M 4M C
C a rb u re to r
design. The triple venture system is used on the prim ary
side fo the carburetor with 1-3/8 inch throttle valve
bores.
The secondary side has two 2 -1/4 inch bores. Using
the air valve principle in the secondary side, fuel is
metered in direct proportion to the air passing through
the secondary bores. A baffle is attached to the secondary
side o f the air horn above the main well bleed tubes to
deflect incoming air to improve secondary nozzle
operation on heavy acceleration.
The solenoid is used on air conditioned equipped
vehicles with automatic transmission and light duty
emissions to increase idle speed slightly w hen the air
conditioning is in operation. This allows the engine to
idle at the same speed when the air conditioning is in
operation, as when it is off.
The float assembly is used along with a windowless
type needle seat for better fuel handling in the float
bowl. Also, a plastic filler block is used above the float
ch am ber to reduce fuel slosh in this area. A fuel inlet
filter check valve is used on light duty emission models to
shut off fuel flow to the carburetor float bowl to prevent
fuel leaks if a vehicle roll over should occur.
The m ain m etering system on all models uses
separate m ain wells to feed each fuel nozzle for
improved fuel flow in the venturi system.
Adjustable Part T h ro ttle-M 4M C /M 4M E
In order to provide a close tolerance adjustm ent in
the main metering system, an adjustm ent is provided to
very accurately set the depth o f the metering rods in the
main metering jets.
The adjustm ent feature consists o f a pin pressed in
the side of the power piston which extends through a slot
in the side o f the piston well. W hen the power piston is
C H O K E VALVE
A C C E L E R A T O R P U M P ROD
A IR V A LV E
PART N U M B E R
THRO TTLE LEVER
F U EL IN LET
PR IM A R Y TH ROTTLE
LEVER
IDLE M IX T U R E
C U R B IDLE S C R E W
down (economy position), the side o f the p in stops on top
o f a flat surface on the adjustm ent screw located in the
cavity next to the power piston. The adjustment screw is
held from tu rning by a tension spring beneath the head
of the adjustm ent screw. D urin g production flow test this
adjustm ent screw is turned up o r down which, in turn,
raises or lowers the power piston and metering rod
assembly. This very accurately controls the fuel flow
between the rods and jets to meet emission requirements.
CAUTION: No attempt should be made to
change the A P T adjustment. I f float bowl
replacement is required, the new bowl assembly
will include an adjustment screw pre-set by the
factory.
A n exp and er (garter) spring beneath the plunger
cup on the accelerator p u m p assembly improves pum p
fuel delivery.
All M 4 M C /M 4 M E models use the bowl mounted
choke housing with thermostatic control assembly.
The choke shaft and some other parts o f the choke
system are Teflon coated to insure smooth choke
operation.
The carburetor p a rt nu m b er (Fig. 6C-33) is stamped
on a vertical section o f the bowl, near the secondary
throttle lever. Refer to the part nu m b e r on the bowl
when servicing this carburetor. W hen replacing the float
bowl assembly, follow the instructions contained in the
service package. Stam p or engrave the model nu m b e r on
the new float bowl.
The prim ary side o f the carburetor has six systems
o f operation. They are float, idle, m ain metering, power,
pump, and choke. The secondary side has one metering
system which supplements the prim ary m ain metering
system and receives fuel from a com m on float chamber.
(Figs. 6C-34).
S H IF T
-
YEAR
— D A Y OF Y E A R
CARBURETOR IDENTIFICATION
PULL C LIP
IN T E R N A L V E N T T U B E
IN T E R N A L V E N T SLOT
FLO A T H IN G E
PIN
c
FU EL IN L E T FILTER
(IN L E T N U T S ID E E N T R Y )
FLO A T A S S E M B L Y
FLO AT BOW L
Fig. 6C -34-Float System
M A IN WELL A IR
BLEEDS
BOOST VEN TU R I
FACTORY-METERING
A DJUSTM ENT SCREW
A -
u
r
NOTE:
SIDE FUEL ENTRY
M A IN VENTURI
THROTTLE VALVE
M A IN POW ER PISTON
(D O W N )
POWER PISTON
SPRING
maim
VACUU M
PASSAGE
^ f ' NR|N G
METERING
JETS( 2)
M A IN
METERING
RODS (2 )
Fig. 6C -36-M ain M etering System -M 4M C/M 4M E
PO W ER PISTON
POWER PISTON
SPRING
PA R T T H R O T T LE .
A D JU ST M E N T S C R E W
MAIN M ET ERIN G '
JE T
SECO NDARY
M E T E R IN G RODS ( 2 )
BOOST
VENTURI
ACC E LE R A TO R
WELL & TUBE
F A C T O R Y -M E T E R IN G
A D JU S TM E N T SCREW
M E T E R IN G
R O D LEVER
M A IN P O W E R
P IS T O N (U P )
M E T E R IN G
DISC
P O W E R P IS T O N
S P R IN G
VACUUM
PA S S A G E
AIR
VA LVE
M A IN
M E T E R IN G
J E T S (2 )
M A IN
M E T E R IN G
RODS (2 )
Fig. 6C-38- Power System -M 4M C /M 4M E
SECO NDARY BAFFLE
ACCELERATOR
WELL & TUBE
|E C C E N T R IC
►CAM
SECONDARY
THROTTLE VA LVE
Fig. 6C-41 -Air Valve Dashpot-4MV
PUM P
LEVER
EXPANDER SPRING
Fig. 6C -42-Accelerating Pump System-M4MC/IVI4ME
Fig. 6C -43-Accelerating Pump System-4MV
CHOKE
ROD
CHOKE
VALVE
V A C U U M BREAK
A D J U S T IN G SCREW
VACUUM
BREAK
D IA P H R A G M
THERMOSTA
C O IL
[
IN S ID E
CUP
BAFFLE
SECONDARY
LOCKOUT
LEVER
FAST
IDLE
CAM
FO LLO W E R
FAST
IDLE
A D J U S T IN G
SCREW
CHOKE SYSTEM
(H O T A IR TYPE)
Fig. 6C-44-Choke System-M4MC
UNLOADER
TANG
CHOKE
VALVE
CHOKE
ROD
DASHPOT
VACUUM
D IA P H R A G M
ELE C TR IC
CHOKE
ASSEM BLY
(SEE IN S E T )
T H E R M O S T A T IC
C O IL
PLUNGER
B U C K IN G
S P R IN G
SECONDARY
LOCKOUT
LEVER
IN S E T
UNLO ADER TA N G
F A S T ID LE C A M
FO LLO W ER
CHOKE SYSTEM
(E LE C T R IC C H O K E T Y P E )
Fig. 6C-45-Choke System-M4ME
F A S T IDLE
A D J U S T IN G
SCREW
ON-VEHICLE SERVICE
M 4 M C / M 4 M E / 4 M V C A R B U R E TO R
ADJUSTMENTS
R efer to figure 6C-47 for the following adjustments:
• Float
• Pump
• Secondary Opening
• Air Valve Spring
Refer to figure 6C-54 for the following adjustments:
• Air Valve Spring
• Idle Speed-W ithout Solenoid
• Idle Speed-W ith Solenoid
Checking Solenoid
R e fe r to figure 6C-48 for the following adjustments:
• Fast Idle
• Choke Coil Lever
• Choke Rod (Fast Idle C a m )-M 4 M C /M 4 M F
Refer to figure 6C-49 for the following adjustments:
• Choke Rod (Fast Idle Cam)-4MV
• Air Valve R o d -M 4 M C /M 4 M E
• Air Valve Rod-4MV
Refer to figure 6C-50 for the following adjustments:
• Vacuum Break
• R ear Vacuum Break
• V acuum Break-4MV
1. Turn on ignition, but do not start engine.
2. Turn A /C to " o n " position.
3. Open throttle to allow solenoid to extend, close
throttle.
4. Disconnect lead at solenoid. Solenoid plunger
should drop away from throttle lever.
5. Connect solenoid lead. Plunger should move out
and contact the throttle lever. Solenoid m ay not be
strong enough to open the throttle, but the plunger
should move.
6. If plunger does not move in and out as lead is
disconnected and connected, insert test light (1893 bulb
or smaller) between the solenoid feed wire and ground.
7. If light lights, replace solenoid.
8. If light does not light, locate cause o f open
circuit in solenoid feed wire.
Idle Mixture
R e fe r to figure 6C-51
• Automatic Choke
• A utomatic Choke
• A utomatic Choke
for the following adjustments:
Coil-M4MC
Coil-M4ME
Coil Rod-4MV
Checking Carburetor Choke
1. Remove air cleaner. W ith engine off, hold
throttle h a lf open. O pen an d close choke several times.
W atch linkage to be certain all links are connected and
there are no signs o f damage.
2. If choke or linkage binds, sticks or works
sluggishy, clean with choke cleaner X-20-A or equivalent.
Use cleaner as directed on can. Refer to disassembly
instructions for additional direction if cleaning does not
correct.
3. Visually inspect carbu retor to be certain all
vacuum hoses are connected. Inspect hoses for cracks,
abrasions, hardness or o ther signs o f deterioration.
Replace or correct as necessary.
4. M ake sure vacuum break d iaphrag m shaft is
fully extended w hen engine is off. If shaft is not fully
extended, replace vacuum break d ia p h ra g m shaft should
fully retract within 10 seconds. If unit fails to retract,
replace vacuum break assembly.
R efer to figure 6C-52 for the following adjustments:
• U n lo a d e r-M 4 M C /M 4 M E
• U nloader-4M V
• Secondary Lockout
R e fe r to figure 6C-53 for the following adjustments:
• Secondary Closing
Idle mixture screws have been present at the factory
and capped. Do not remove the caps during normal
engine maintenance.
Before suspecting the carburetor as the cause of
poor engine perform ance or rough idle, check ignition
system including distributor, timing, spark plugs and
wires. Check air cleaner, evaporative emission system,
EFE System, PCV system. E G P valve and engine
compression. Also inspect intake manifold, vacuum hoses
and connections for leaks and check torques of
carburetor m ounting bolts/nuts.
In the case of m ajor carburetor overhaul, throttle
body replacement, high idle CO as indicated by state or
local emission inspection, the idle mixture may be
adjusted. Adjusting mixture by other than the following
method may violate Federal a n d / o r C alifornia or other
state laws.
Idle M ixtu re A d ju stm ent
1. Set parking brake and block drive wheels.
2. Remove air cleaner for access to carburetor, but
keep vacuum hoses connected.
3. Disconnect and plug other hoses as directed on
Emission Control Inform ation Label under the hood.
4. Engine must be at norm al operating tem pera
ture, choke open, air conditioning off.
5. Connect an ACCURATE tachom eter to engine.
6. Disconnect vacuum advance and plug hose.
Check ignition timing. If necessary, adjust to specifica
tion shown on Emission Control Inform ation Label.
Reconnect vacuum advance.
7. Carefully remove caps from idle mixture screws.
1
CARB. NO.
©
© '
GAUGE
F R O M T O P O F C A S T IN G T O T O P O F F L O A T -
P O IN T 3 / 1 6 " B A C K
FROM END O F
G A U G IN G
17057202
17057204
17057502
17057582
17057584
17057503
17057504
GAUG E
15/32”
F L O A T A T T O E (S E E I N S E T )
H O L D R E T A IN E R
17057209
17057218
F IR M L Y IN P L A C E
17057222
17057518
17057522
17057586
17057588
17057219
17057519
TO E
©
PUSH F LO A T DO W N
L IG H T L Y
A G A IN S T N E E D L E
G A U G IN G
P O IN T
(3 /1 6 " B A C K
7/16"
17057512
17057517
FRO M TO E)
©
REMOVE
FLO AT AND
17056212
17057221
17056217
BEND FLO AT ARM
UP O R D O W N T O
AD JU S T
jV IS U A L L Y
AFTER
CHECK
3/8”
F L O A T A L IG N M E N T
A D J U S T IN G
1 7 0 57 2 1 3
1 7 0 57 2 1 5
17057216
1 7 0 57 5 2 5
1 7 0 57 5 1 4
1 7 0 57 5 2 9
11/32”
17057229
F L O A T A D JU S T M E N T
7045583
7045585
7045586
CARB. NO.
©
G AUGE
HOLE l
LOC.
G A U G E FR O M TO P O F C H O K E
V A L V E W A LL . N E X T TO VE N T
B E N D PUMP
S T A C K . TO TO P O F PUM P ST EM
ALL
EXCEPT
LE VER TO
A S S P E C IF I E D
A D JU S T
1 7 0 57 5 8 6
17057588
9 /3 2 "
INNER
9 /3 2 ”
OUTER
R O D I N S P E C IF IE D H O L E
O F PUMP L E V E R
©
TH RO TTLE VALVES
C O M P LE TE LY CLOSED
IF
NECESSARY, BEND SECONDARY
C L O S IN G
PUMP A D JU S T M E N T
P R IM A R Y
TANG
A W A Y TO CLOSE
VALVES. THEN
RE AD JU S T
1 7 0 57 5 8 6
17057588
N O T E *: A N G L E G A U G E M E T H O D CAN BE USED
[L O O S E N T H R E E R E T A I N I N G S C R E W S A N D
PLUG
GAUGE
C A R B . NO.
R E M O V E T H E T H E R M O S T A T IC C O V E R A N D
C O I L A S S E M B L Y F R O M C H O K E H O U S IN G
CHOKE V A LV E
BEND CHOKE
ROD
A T T H IS P O IN T
TO AD JU S T
(S E E I N S E T )
( ^ 2 ^ P U S H UP O N T H E R M O S T A T IC
I
V " 'C O I L
TANG
(C O U N T E R C L O C K W IS E )
^ ------- U N T I L C H O K E V A L V E IS C L O S E D
.120 "
ALL
LO W E R ED G E O F L E V E R S H O U LD
J U S T C O N T A C T S ID E O F P L U G
GAUGE
I N S E R T S P E C IF I E D
PLUG G AUG E
7 J IN S T A L L COVER A N D REFER
-— 'T O A U T O M A T IC CHOKE
A D JU S TM E N T
CHOKE COIL LEVER A D J U S T M E N T — M 4 M C /M 4 M E
o1
I P O S IT IO N T R A N S M IS S IO N
IN PARK OR N E U T R A L
L IG H T D U T Y E M IS S IO N S
M A N U A L T R A N S M IS S IO N
1 300 RPM (N )
©
AUTOMATIC TRANSMISSION
1600 RPM (N )
H O LD
CAM
FO LLO W ER ON
H IG H E S T S T E P
H E A V Y D U T Y E M IS S IO N S
3 5 0 /4 0 0 C ID
1600 RPM (N )
O F F A S T ID L E C A M
L
®
3 J D IS C O N N E C T A N D PLUG
V A C U U M H O SE A T
EGR V A L V E
T U R N F A S T IDLE SC REW
T O O B T A IN SPECIFIED
FA S T IDLE RPM
454
1700 RPM (N)
FAST ID L E A D JU S T M E N T
©
G A U G E B E T W E E N UPPER
CARB. NO.
EDGE O F C H O K E V A L V E &
PLUG ANGLE
GAUGE GAUGE
I N S I D E A I R H O R N W A L L (S E E N O T E * )
6
)B E N D T A N G
ON
NO TE:
H O LD GAUGE
F A S T ID L E C A M
T O A D JU S T
V E R T IC A L
ALL WITH
LIGHT DUTY
EMISSIONS
.3 2 5
46°
ALL WITH
HEAVY DUTY
EMISSIONS
.2 8 5
46°
4 JC LO S E C H O K E BY
© . P U S H IN G
UPW ARD ON
C H O K E C O IL L E V E R
PLAC E C AM FO LLO W ER
1M AKE F A S T IDLE A D J U S T M E N T
ON SECO ND STEP O F
C A M N E X T TO
^R E M O V E T H E R M O S T A T IC COVER
H IG H S T E P
^ IN S T A L L COVER A N D REFER TO A U T O M A T IC C H O K E A D J U S T M E N T
CHOKE ROD (FA ST IDLE C A M ) A D J U S T M E N T — M 4 M C /M 4 M E
CARB. NO.
PLACE SPECIFIED
G A U G E BE TW E E N W A L L
A N D UPPER EDGE OF
----CHOKE V A LV E
7045583
7045585
7045586
17056212
17056217
B E N D CHOKE ROD
TO O B T A IN
G A U G E D IM E N S IO N
O P E N IN G
P O S IT IO N C A M
FO LLO W E R O N
SE C O N D STEP
OF C A M
(4
)
PLUG
ANGLE
GAUGE
.2 9 0
ALL
OTHERS
.220
CARB. NO.
PLUG G A U G E
ALL
.0 1 5 "
42°
RECHECK F A S T IDLE A D J U S T M E N T
CHOKE ROD (FAST IDLE CAM) ADJUSTMENT — 4MV
(3 JPLAC E
G AUG E BETW EEN
A N D E N D O F S L O T IN
T )A IR
ROD
LEVER
1 )S E A T C H O K E V A C U U M
VALVE
C O M P LE TE LY CLO SED
-^ D IA P H R A G M
U S E O U T S ID E
U
VA C U U M SOURCE
4 jB E N D H E R E
F O R S P E C IF I E D
— 'C L E A R A N C E B E T W E E N
ROD
(
NOTE:
A N D E N D O F S L O T IN L E V E R
PLUG PURGE
B LE E D HO LE
W IT H T A P E
( W H E R E U S E D ).
REMOVE A FTE R
A D JU S TM E N T
AIR VALVE ROD ADJUSTMENTS — M4MC/M4ME
A IR V A L V E S M U S T BE
C O M P LE TE LY CLOSED
B EN D R O D HERE
T O O B T A IN S P E C IF IE D
C LE A R A N C E BETW EEN
R O D A N D E N D OF S L O T
IN LEVER
SEAT DIAPHRAGM
USING OUTSIDE
V A C U U M SOURCE
PLACE .015 GUAGE BETWEEN
ROD A N D END OF SLOT
IN LEVER
AIR VALVE ROD ADJUSTMENT — 4MV
N O T E *: A N G L E G A U G E M ET H O D CAN ALSO BE USED
8
6
N O TE: H O LD
(V y P L A C E
GAUGE
G AUG E BETW EEN
CARB. NO.
U P P E R ,E D G E O F C H O K E
V E R T IC A L L Y
S E A T D IA P H R A G M
17057202
17057204
17057218
U S IN G O U T S ID E
17057222
V A L V E A N D IN S ID E W A L L
O K A I R H O R N (S E E N O T E * )
JTU R N SCREW TO A D JU S T
N O TE: PLUG PURG E
B L E E D H O L E W IT H
CAM
A P I E C E O F M A S K IN G
FO LLO W ER ON
TAPE ON D E LA Y
H IG H E S T S T E P
FEATU RE M O D ELS.
O F FA S T ID L E C A M
REMOVE AFTER
A D JU S TM E N T.
©
©7
(T J P U S H
R E M O V E T H E R M O S T A T IC
COVER
)
IN S ID E C H O K E C O IL
LE V E R C O U N TER C LO C K
W IS E U N T I L T A N G O N V A C U U M
IN S T A L L COVER A N D REFER TO
A U T O M A T IC C H O KE A D J U S T M E N T
BR EAK LEVER CONTACTS TANG
ON VACU UM B R EA K PLUNG ER
V A C U U M B R EA K A D J U S T M E N T - M 4 M
C?)
BEND
C
s te m
ROD TO
A D JU S T
G A U G E B E T W E E N A IR
.1 6 0
( .2 1 5
27
BOTTOM )
17057219
V A C U U M SOURCE
(2 J P L A C E
PLUG
ANGLE
GAUGE GAUGE
HORN
W A L L & U P P E R E D fiF O F
17057502
17057503
17057504
17057512
17057517
17057518
17057519
17057522
17057582
17057584
17057586
17057588
C A R B . NO.
.1 6 5
( .2 3 0
2 8 .5 °
BOTTOM )
.1 8 0
( .2 4 5
30
BOTTOM )
PLUG
ANGLE
GAUGE GAUGE
C H O K E V A L V E (S E E N O T E * )
N O TE: PLUG PURGE
B L E E D H O L E W IT H A
P IE C E O F M A S K IN G
TAPE ON D E LA Y FE A TU R E
M O D ELS. REM O VE A FTE R
7 ) IN S T A L L COVER
A N D REFER TO
A U T O M A T IC
CHOKE
A D JU S TM E N T
A D JU S TM E N T.
( jM S E A T
.1 6 0
27°
REAR VACUUM
B R E A K D I A P H R A G M U S IN G
© ©
P U S H UP O N C H O K E C O I L L E V E R
O U T S ID E V A C U U M S O U R C E © '
©
17057221
D IA P H R A G M P L U N G E R P U L L E D
O U T U N T IL S E A T E D —
R E M O V E COVER A N D PLACE
C A M FO LLO W E R O N H IG H E S T
STEP O F F A S T IDLE C A M
B U C K IN G S P R IN G C O M P R E S S E D
O N M O D ELS W HERE USED
R EA R V A C U U M B R EAK A D J U S T M E N T -M 4 M E
10
G A U G E B E T W E E N A IR H O R N W A L L
CARB. NO.
A N D U P P E R E D G E O F C H O K E V A LV E
PLUG ANGLE
GAUGE GAUGE
17057213
17057215
V A C U U M PLUN G ER
M U S T BE FULLY
SEA T ED U S IN G
O U T S ID E V A C U U M
SO URCE
17057529
17057229
L IG H T LY RO TATE C H O K E
C O IL LE V ER C O U N T E R C L O C K
W IS E U N T IL E N D O F RO D IS
IN E N D O F SLO T IN LEVER
25 .3
.110
2 5 .3
.120
2 6 .5
7045583
7045585
7045586
O P E N P R IM A R Y THRO TTLE
V A L V E S S O TH A T FAST IDLE
C A M F O L L O W E R C L EA R S
FA ST IDLE C A M
17056212
17056217
17057514
17057525
V A C U U M B R EA K A D JU S T M E N T - 4 M V
.1 1 5
17057216
TT
© A L IG N M A R K O N C O V E R W IT H S P E C IF IE D P O IN T ON
H O U S IN G . N O T E : O N M O D E L S W IT H S L O T T E D C O IL
PIC K -U P L E V E R , M A K E SURE C O IL T A N G IS IN S T A L L E D
IN S L O T IIM L E V E R (SEE IN S E T tr 2 )
LO O S EN TH R E E
(D
R E T A IN IN G SCREWS
(N O T E : T IG H T E N
SCREWS A F T E R
A D J U S T M E N T ).
RO TATE COVER AN D
C O IL A S S E M B L Y
C O U N T E R C L O C K W IS E
U N T IL C H O K E V A L V E
JU S T C LO SES
IN D E X
C A R B . NO .
MARK
17057503
ONE NO TCH
170E7519
LEAN
17057202
17057204
17057218
17057222
17057502
17057504
17057518
2 NOTCHES
LEAN
17057522
17057582
17057584
17057586
17057588
T H E R M O S T A T IC
C H O K E C O IL LE V E R
P LA C E C A M
FO LLO W ER ON
H IG H E S T STEP
OF C A M
IN S E T # 2
17057209~
IN S E T # 1
AUTOMATIC CHOKE COIL ADJUSTMENT— M4MC
12
17057219
3 NOTCHES
LEAN
17057512
170157517
INDEX
CARB. NO.
INDEX
MARK
S E T M A R K O N E L E C T R IC C H O K E
T O S P E C IF IE D P O IN T O N C H O K E
H O U S IN G
17057221
2 NOTCHES
COUNTER
C LO C K W IS E
P L A C E F A S T ID L E
C A M FOLLO W ER ON
H IG H S T E P O F C A M
V
/
AUTOMATIC CHOKE COIL ADJUSTMENT — M4ME
13
CHOKE VALVE
C O M P LE TE LY
C LO SED (
AUTOMATIC CHOKE COIL ROD ADJUSTMENT — 4MV
N O T E *: A N G LE G A U G E M E T H O D CAN ALSO BE USED
14
( T ^ g aug e
b e t w e e n
ON W ARM
E N G IN E , C L O S E C H O K E
CARB. NO.
UPPER ED G E O F
V A L V E B Y P U S H IN G U P O N T A N G
CHOKE V A LV E
IN T E R M E D IA T E C H O K E L E V E R (H O L D
A IR
AND
HORN W ALL
P O S IT IO N W IT H
ON
IN
RUBBER BAND)
(S E E N O T E * )
®
AN G LE
PLUG
G AUG E GAUGE
17057221
17057209
.325
46°
17057512
17057517
.240
40°
ALL OTHERS
.280
42c
BEND TANG
TO AD JU S T
(^ J H O L D
TH RO TTLE
V A L V E S W ID E O P E N
o1
I
CH EC K IN D E X M A R K
P O S ITIO N (STEP 11
OR 12)
UNLOADER ADJUSTMENT — M4MC/M4ME
15
CARB. NO.
( 3 ) G A U G E B E T W E E N A IR
H ORN W ALL AN D
U P P E R E D G E OF
C H O KE V A LV E
(SEE NO TE *)
UNLOADER ADJUSTMENT — 4MV
16
CHOKE VA LVE
PLUG ANGLE
GAUGE GAUGE
17057213
17057215
17057216
17057529
17057229
.205
40°
17057525
17057514
.225
43=
17056212
17056217
7 0 4 5583
7 0 4 5585
7045586
.295
CARB. NO.
PLUG
GAUGE
PUSH DOW N
O N T A IL O F
| CAM
£
j/\
( S T E P 2)
H O L D C H O K E V A L V E W ID E
CHO KE VALVE
O P E N BY P U S H IN G D O W N O N
CLO SED
T A IL O F F A S T ID L E C A M
ALL
C H E C K L O C K O U T P IN
FO R C L E A R A N C E
F IL E E N D O F P IN
B E N D P IN
TO A D J U S T
015 MAX
CLEARANCE
(C H E C K FO R N O
B U R R S A FTE R
F IL IN G )
S E C O N D A R Y L O C K O U T LEVER
(7 )
^G A U G E
FO R C L E A R A N C E
S ID E C L E A R A N C E
SEC ON DARY LOCKOUT
(J)
O P E N IN G C L E A R A N C E
S E C O N D A R Y L O C K O U T A D JU S T M E N T
.0 1 5 "
20
Q
PR E P A R E V E H I C L E FOR A D J U S T M E N T S SEE EMI SS IO N L A B E L ON V E H I C L E .
N O T E : I G N I T I O N T I M I N G SET PER L A B E L .
LIGHT DUTY EMISSIONS
MANUAL TRANSMISSION
700 RPM (N)
L I G H T D U T Y E M IS S IO N S
A U T O M A T I C T R A N S M IS S IO N
( A L L E X C E P T H IG H A L T I T U D E
& 4 5 4 C ID )
5 0 0 R P M (D )
( H I G H A L T I T U D E & 4 5 4 C ID )
6 0 0 R P M (D )
IDLE SPEED ADJUSTMENT — WITHOUT SOLENOID
HEAVY DUTY
EMISSIONS
700 RPM
EP AR E V E H I C L E FOR A D J U S T M E N T S © PR
SEE EMI SS IO N L A B E L ON V E H I C L E .
21
N O TE : I G N I T I O N T I M I N G SET PER L A B E L .
S O LEN O ID EN ER GIZED A / C CO M PRE SS OR L E A D
DISCONNECTED A T A /C
COM PRE SS OR, A / C ON, A / T
T R A N S M I S S IO N IN D R IV E .
L I G H T D U T Y E M IS S IO N S
A U T O M A T IC T R A N S M IS S IO N
&
A I R C O N D IT IO N I N G
©
O
J
T U R N SCREW T O A D J U S T TO
SP E C IF IE D RPM. (R E C O N N E C T
A / C COM PRESSOR L E A D A F T E R
ADJUSTMENT)
( A L L E X C E P T H IG H
A L T I T U D E & 4 5 4 C ID )
I D L E S P E E D S C R E W - 5 0 0 R P M (D )
S O L E N O I D S C R E W - 6 5 0 R P M (D )
( H I G H A L T I T U D E & 4 5 4 C ID )
© O P E N T H R O T T L E S L IG H T LY
TO A L L O W SO LENOID
P L U N G E R TO F U L L Y E X T E N D .
IDLE SPEED ADJUSTMENT — WITH SOLENOID
T U R N I D L E SPEED SCREW TO
SET C U R B I D L E SPEED TO
S P E C IF I C A T IO N S - A / C O FF
(SEE EM IS SI ON L A B E L )
ID L E S P E E D S C R E W - 6 0 0 R P M (D )
S O L E N O I D S C R E W - 6 5 0 R P M (D )
Be careful not to bend screws. Lightly seat screws then
back out EQUALLYjust enough so engine will run.
8. Place transmission in Drive (automatics with
light duty emissions) or N eu tral (all manuals and
automatics with heavy duty emissions).
9. Back each screw out (richen) 1/8 turn at a time
until m axim um idle speed is obtained. Then set idle
speed to value shown in C h a rt C olum n A of
specifications. Repeat Step 9 to be certain you have
m axim um idle speed.
10. T urn each screw in (lean) with 1/8 turn
increments until idle speed reaches value shown in Chart
Colum n B o f specifications.
11. Reset idle speed to specification shown on
Emission Control Inform ation Label.
12. Check and adjust fast idle as described on the
Emission Control Inforam tion Label.
13. Reconnect vacuum hoses. Install air cleaner.
14.
specification.
Recheck
idle
speed.
If necessary,
Choke Valve Angle Gauge (Fig. 6C-55)
1. Choke valve angle measuring gauge J-26701 tool
may be used with carburetor on or off engine. If off
engine, place carburetor on holding fixture so that it will
rem ain in the same position when gauge is in place.
2. Rotate degree scale until zero (0) is opposite
pointer.
3. With choke valve completely closed, place
m agnet squarely on top o f choke valve.
4. Rotate bubble until it is centered.
5. Rotate scale so that degree specified for the
particular adjustment is opposite pointer.
LEVELING
BUBBLE
(CENTERED)
CHOKE
VALVE
CLOSED
DEGREE
SCALE
SPECIFIED
ANGLE
(SEE SPECS.)
POINTER
MAGNET
STEP
A
reset
STEP
B
to
3. Install c arburetor and new insulator with
attaching bolts. Tighten bolts alternately to 144 pound
inches.
4. Connect downshift cable as required.
5. Connect cruise control cable as required.
6. Connect accelerator linkage.
7. Connect choke system.
8. Connect fuel pipe and vacuum hoses.
9. Connect solenoid as required.
10. Install air cleaner.
11. Check and adjust idle speed.
Model 4M V (Fig. 6C-57)
Removal
Flooding, stum ble on acceleration a n d oth e r
perform ance complaints are, in m an y instances, caused
by presence o f dirt, water, or other foreign matter in
carburetor. To aid in diagnosis, carburetor should be
carefully removed from engine without draining fuel
from bowl. Contents o f fuel bowl may then be examined
for contam ination as carburetor is disassembled. Check
filter.
1. Remove air cleaner and gasket.
2. D isconnect fuel a n d vacuum lines fro m
Fig. 6C-56--Carburetor and Choke Pipes-M4MC/
carburetor.
M4ME
3. Remove clip from choke linkage.
4. Disconnect accelerator linkage.
6.
Adjust the choke linkage to center the bubble.
5. If equipped with automatic downshift cable,
This completes adjustment.
disconnect cable.
6. Remove carb ureto r attaching bolts an d remove
C A R B U R E T O R R E P LA C E M E N T
carburetor.
Model M 4 M C /M 4 M E (Fig. 6C-56)
Removal
F lo oding , stum ble o n acceleration an d o th e r
p e rfo rm an ce complaints are in m any instances, caused
by presence o f dirt, water, or o ther foreign m atter in
carburetor. To aid in diagnosis, carburetor should be
carefully removed from engine without draining fuel
from bowl. Contents o f fuel bowl m ay then be examined
for contam in atio n as carburetor is disassembled. Check
filter.
1. Remove air cleaner and gasket.
2. Disconnect wire at solenoid, if equipped.
3. Disconnect fuel pipe and vacuum lines.
4. Disconnect fresh air hose (hot air choke) or
electrical connector (electric choke) from choke system.
5. Disconnect accelerator linkage.
6. If e q u ip p e d with a u to m a tic transm ission,
disconnect downshift cable.
7. If equipped with cruise control, disconnect
linkage.
8. Remove carburetor attaching bolt, carburetor
an d insulator.
Installation
1. Clean sealing surfaces on intake m anifold and
carburetor.
2. Fill carb uretor bowl before installing carburetor.
7.
Remove insulator.
Installation
1. Clean sealing surfaces on intake manifold and
carburetor.
2. Fill carburetor bowl before installing carburetor.
3. Install carburetor and new insulator with
attaching bolts. Tighten bolts alternately to 144 pound
inches.
4. Connect downshift cable as required.
5. Connect accelerator linkage.
6. Connect choke linkage and install clip.
7. Connect solenoid as required.
8. Install air cleaner.
9. Check and adjust idle speed.
AIR HORN T IG H T E N IN G SEQUENCE
Refer
sequence.
Fig. 6C-58--Air Horn Tightening Sequence
to figure 6C-58
for
air horn
tightening
S P E C IF IC A T IO N S
ID L E M IX T U R E (L E A N D R O P )
L IG H T D U T Y E M IS S IO N S
ENGINE
COLUMN A
SPEED BEFORE LEAN DROP
COLUMN B
SPEED A FTE R LE AN DROP
8 0 0 RPM (N)
7 0 0 RPM (N)
550 RPM (D)
500 RPM (D)
650 RPM (D)
6 00 RPM (D)
6 5 0 RPM (D)
6 00 RPM (D)
350 CID
M A N U A L TRANS.
LOW A L T & C A L I F .
350 CID
A U T O M A T IC TRANS.
LOW A L T . & C A L I F .
3 50 C ID
A U T O M A T IC TRANS.
H IG H A L T I T U D E
4 5 4 CID
A U T O M A T IC TRANS.
ID L E M IX T U R E (L E A N D R O P )
H E A V Y D U T Y E M IS S IO N S
ENGINE
COLUMN A
SPEED BEFORE LEAN DROP
COLUMN B
SPEED AFTER LEAN DROP
3 50 C ID
8 75 RPM (N)
EXCEPT C A L IF O R N IA
350 CID
8 0 0 RPM (N)
C A L IF O R N IA
770 RPM (N)
400 CID
700 RPM (N)
454 CID
800 RPM (N)
EXCEPT C A L IF O R N IA
454 C ID
75 0 RPM (N)
C A L IF O R N IA
T O R Q U E S P E C IF IC A T IO N S
M 4 M C /M 4 M E C A R B U R E T O R
4M V CARBURETOR
TORQUE
SCREW
TORQUE
(IN. LBS.)
SCREW
(IN. LBS.)
T H R O T T L E BODY
T H R O T T L E B O D Y T O BO W L
46
C H O K E H O U S IN G
A I R H O R N T O B O W L 10-32
46
A I R H O R N T O B O W L 8-32
26
CHOKE LEVER
14
A IR HORN TO T H R O T T L E BODY
46
C H O K E H O U S IN G A T T A C H I N G
46
T H R O T T L E B O D Y T O BO W L
46
C H O K E H O U S IN G C O V E R
26
V A C U U M B R E A K U N IT
26
A IR HORN
S O LE N O ID B R A C K E T
71
46
FUEL IN LE T NUT
A I R H O R N T O B O W L 8-32
26
M E TE R IN G JET
40
A I R H O R N T O T H R O T T L E BO D Y
46
NEEDLE SEAT
45
A I R H O R N TO B O W L 10-32
CHOKE LEVER
14
V A C U U M B R E A K U N IT
26
F U EL IN L E T NU T
400
NEEDLE SEAT
45
M E T E R I N G JE T
40
S O L E N O IS B R A C K E T
71
40 0
FUEL SU PPLY
FUEL FILTER
GENERAL D E S C R IP TIO N
All engine fuel filters are located in the carburetor
fuel inlet. These fuel filter elements are o f pleated paper.
Elements are placed in the inlet hole with the gasket
surface outward. A spring holds the element outward,
sealing it by com pressing a gasket surface against the
inlet fitting.
ON-VEHICLE SERVICE
The carburetor inlet fuel filter should be
every 15,000 miles or 12 months.
A fter assembling any filter element in
buretor, always start the engine and check for
the fuel line and fittings before installing the air
replaced
the car
leaks in
cleaner.
Other Filters or Strainers
A woven plastic filter is located on the lower end of
the fuel pickup pipe in the gas tank. This filter prevents
dirt from en tering the fuel line and also stops water
unless the filter becomes completely submerged in water.
This filter is self cleaning and normally required no
m aintenance. Fuel stoppage at this point indicates that
the gas tank contains an ab n o rm a l am ou nt of sediment
or water; the tank should therefore be removed and
thoroughly cleaned.
2.
3.
4.
Remove fuel inlet filter nut from carburetor.
Remove filter and spring.
If removed, install check valve in fuel inlet filter.
CAUTION: The fu e l inlet check valve m ust be
installed in the filter to meet M otor Vehicle
S afety Standards (M. V.S.S.) f o r roll-over. New
service replacement filter include the check
valve.
5. Install fuel inlet filter spring, filter, and check
valve assembly in carburetor. Check valve end o f filter
faces toward fuel line.
NOTE: Ribs on closed end of filter element
prevent filter from being installed incorrectly
unless forced.
6. Install new gasket on fuel inlet filter nut and
install nut in carburetor. Tighten nut to 18 pound feet.
CAUTION: Tightening beyond specified torque
can dam age gasket.
7. Install fuel line and tighten connection.
Heavy Duty Emissions
A plugged fuel filter will shut off fuel flow into
carburetor.
1. Disconnect fuel line-connection at inlet fuel
filter nut.
2. Remove inlet fuel filter nut from carburetor.
Fuel Filter Replacem ent
3. Remove filter element and spring.
Light Duty Emissions
4. Install elem ent spring and filter element in
A plugged fuel filter a n d / o r check valve will restrict
carburetor.
5. Install new gasket on inlet fitting nut and install
fuel flow.
1.
Disconnect fuel line connection at fuel inletnut in carburetor and tighten securely.
6. Install fuel line and tighten connector.
filter nut.
FUEL PUMP
G ENER AL D E S C R IP TIO N
The fuel pu m p (Figs. 6C-59 through 61)) is a
d ia p h ra g m type pum p and is actuated by the rocker arm
through a link and a push rod.
Some vehicles have a fuel pum p which has a
m etering outlet for a vapor return system. Any vapor
which form s is returned to the fuel tank along with hot
fuel through a separate line. This greatly reduces any
possibility o f v a p or lock by keeping cool fuel from the
tank constantly circulating through the fuel pump.
ON-VEHICLE SERVICE
Inspection and Test
If the fuel system is suspected o f delivering an
im proper am ount o f fuel to the carburetor, it should be
inspected and tested in the vehicle, as follows:
Inspection of Fuel System
1. M ake certain that there is gasoline in the tank.
2. With the engine running, inspect for leaks at all
gasoline feed hose connections from fuel tank to
carburetor. Tighten any loose connections. Inspect all
hoses for flattening or kinks which would restrict the flow
o f fuel. Air leaks or restrictions on suction side o f
mechanical fuel pu m p will seriously affect pum p output.
3. Inspect for leaks at fuel pum p d iaphrag m
flange.
4. Disconnect feed pipe n ear carburetor. G ro un d
distributor terminal of coil with ju m p e r wire so that
engine can be cranked without firing. Place suitable
co n tain er at end o f pipe an d crank engine a few
revolutions. If no gasoline, or only a little flows from
pipe, the feed line is clogged or fuel pum p is inoperative.
Before con d em n in g the fuel pum p, disconnect feed line
at both ends and blow through it w ith air hose to m ake
certain that fuel p um p is o p eratin g w ithin specifications.
Fuel Pump Pressure Test
1. D isconnect gasoline line n ear carb u reto r and
connect a suitable pressure gage (such as Pressure L eakdow n T ester J-22109).
2. S tart engine and check pressure with engine
ru n n in g at slow idle speed. Fuel pum p pressure should
be as specified at the end o f this section On vehicles
eq u ip p ed w ith a v ap o r retu rn system, squeeze off the
retu rn hose so th at an accurate read in g can be obtained.
3. If fuel pum p pressure is below m inim um , pum p
m ust be replaced.
Fuel Pump Flow Test
1. D isconnect fuel line from carburetor. Run fuel
line in to a suitable m easuring container.
Fig. 6C-59~Fuel Pump-L6
2. W hile observing the sweep second hand o f a
clock o r w atch, run the engine at idle until there is one
p in t o f fuel in the co ntainer. O ne p in t should be pum ped
in 30 seconds o r less.
3. If flow is below m inim um , check for restriction
in the line.
Diagnosis
C om plete diagnosis o f all possible causes o f the
trouble p rio r to replacem ent o f the fuel pum p will save
tim e, expense and possible causes o f the trouble p rio r to
replacem ent o f the fuel p u m p will save time, expense
and possibly prevent a rep eat com plaint.
Low Pressure Complaint
1. D isconnect fuel inlet hose from pum p. D iscon
nect vapor return hose, if so equipped.
2. D isconnect fuel outlet pipe.
3. Remove two 1/2 inch hex head bolts, using a
3 /8 inch drive deep socket and a ratchet handle.
4. Remove fuel pum p.
Installation
The only way to check fuel pum p pressure is by
connecting an accurate pressure gauge to the fuel line at
c a rb u re to r level. N ever replace a fuel pum p w ithout first
m aking th at sim ple check.
Not Enough Fuel Flow Complaint
W hen an engine has a "starv in g -o u t" condition,
m any m echanics jum p to the conclusion that the fuel
pum p is not p u m p in g enough fuel. M any tim es the
"s tarv in g -o u t" condition is actually due to a w eakness in
the ignition system , since these two troubles are very
h ard to separate. Even when an engine is starving for
fuel, the cause is m ore likely to be a plugged fuel filter or
a restricted fuel line than a m alfunctioning fuel pum p.
Removal
1. Install new fuel pum p w ith new gasket.
2. Install two 1/2 inch hex head bolts, turning
them alternately and evenly.
3. Install fuel outlet pipe. If it is difficult to start
fitting, tim e can be saved by disconnecting up p er end o f
pipe from carburetor. T ighten fitting securely, m ean
w hile holding fuel p um p n u t w ith a wrench. Install and
tighten fitting at carburetor, if rem oved.
4. Install fuel inlet hose. Install vapor return hose,
if so equipped.
5. Start engine and check for leaks.
T IG H T E N
‘
4 BBL. C A R B U R E T O R
|
TO
POUND
FE E T
BBL. C A R B U R E T O R
T IG H T E N T O
25 P O U N D
GASKET
FE E T
PLA TE
GASKET
T IG H T E N TO
27 FT. LBS.
LU BE
T IG H T E N
TO
20 P O U N D
FE E T
T IG H T E N TO
36 IN. LBS.
T IG H T E N T O '
22 FT. LBS.
Fig. 6C-61--Fuel Pump-454 V8
V IE W
Fig. 6C -60-Fuel P u m p -3 0 5 /3 5 0 /4 0 0 V8
FUEL TANK
ON-VEHICLE SERVICE
Outside Frame Rail Fuel Tank-
Center and Auxiliary Fuel Tank CK 10 and 20 (06, 16) (Figs. 6C-66, 67, 68)
Fuel Tank-Van (Fig. 6C-69)
Cab and Crewcab (Figs. 6C-62 and 63)
1.
2.
D ra in tank.
D isconnect fuel lines, m eter w ire and ground
1.
D rain tank.
lead.
2.
Raise vehicle on hoist.
3. Rem ove strap supports (lines, vent) and clip.
4. Loosen clam ps from filler neck and vent line.
5. R em ove strap bolts and lock w ashers from tank
fro n t an d re a r locations on inside fram e rail.
6. R em ove tank from fra m e sim u ltaneously
d isen g ag in g filler neck hose from filler neck (Fig. 6C-64).
7. R em ove m eter assem bly from fuel tank using
Tool J-24187 (Fig. 6C-65).
8. Reverse rem oval procedure to install fuel tank.
3.
U nclam p upper filler neck and vent tube hose.
4.
U nclam p gauge unit hoses at fram e end.
5.
Support tank and rem ove support straps.
6.
Lower tank and disconnect m eter wire.
7.
Rem ove tank.
8. Install in the
antisqueak m aterial.
9.
reverse
ord er,
using
Lower vehicle and rem ove from hoist.
new
IN O T E I C e m e n t a n t i- s q u e a k s e c u r e ly to
ta n k w ith
4 .0 0
on
1 .0 0 w i d e
each
end
c o v e ra g e
fo r
a p p ro x .
FILLER
A N T I-S Q U E A K
FUEL T A N K
SO LD ER
FILLER
SO LD ER
C-K 107(03)
FUEL T A N K
C-K 109(03), C -K209-C309(03-63)
Fig. 6C-63-Fuel Tank-Cab and Crewcab
Fig. 6C-62- Fuel Tank M ounting-Cab and Crewcab
Frame Mounted Fuel Tank - P Model (Figs. 6C-70,
71, 72)
1. D rain tank.
2. Rem ove tiller neck.
3. D isconnect m eter unit fuel line and wiring.
4. Rem ove holts attaching tank supports to fram e.
5. R em ove tank com plete w ith m ounting bracket
and support straps.
6. Rem ove tank from brackets and support straps,
if necessary.
7. Install in reverse o rd er and replace antisqueak
m aterial.
CLEANING FUEL SYSTEM
Cleaning
If trouble is due to co n tam in ated fuel or foreign
m aterial th at has been put into the tank, it can usually be
cleaned. If tank is rusted internally, it should be
replaced.
1. Disconnect battery negative cable and d istrib
utor feed wire.
2. D rain fuel tank.
3. Remove fuel tank.
4. Remove fuel inlet filter at carb u reto r and
inspect for contam ination. If filter is plugged replace
(leave fuel line disconnected).
5. Locate tank away from heat, flame, or other
source o f ignition. Remove fuel gauge tank unit and
inspect condition o f filter. If filter is contam inated a new
filter should be installed upon reassem bly.
6. Com plete d ra in in g o f tank by rocking it and
allowing fuel to run out o f tank unit hole.
7. Purge fuel tank with steam or ru n n in g hot w ater
for at least five m inutes. Pour w ater out o f tank unit hole
(rock tank to assure com plete rem oval o f w ater).
WARNING: This procedure will not remove
fuel vapor. Do not attempt any repair on
tank or filler neck where heat or flame is
required.
8.
Disconnect inlet fuel line at pum p and use air
pressure to clean fuel line and fuel retu rn line (if
SIDE M EM BER
TORQUE AT
12 FT. LBS.
R.H.
PLA TFO R M ASSEM BLY
TORQUE AT
12 FT. LBS.
H O S E -V E N T
STRAP
BRACKET
VIEW A
CLAMP
HOSE-FILLER
SQUEAK
CEM ENT
T ig h te n lo w e r nut
a fte r u p p e r nut
has b ee n tig h te n e d .
[n o t e I H o o k m ust
be ass em b le d fo rw a rd .
Fig. 6C-64~Filler Neck-Cab Stake Body
equipped). A pply air pressure
norm ally flows through line.
9.
in the direction
fuel
Use low air pressure to clean pipes on tank unit.
10. C lean filter on fuel tank unit, if required.
Install fuel tank gauge unit, (with new gasket) into tank
and install tank. C onnect tank unit wires and all fuel
lines, except pum p to ca rb u re to r line (see "R em oval o f
T a n k " for p ro p er procedure).
11. C onnect a hose to fuel line at carb u reto r; insert
o th er end o f hose into a one gallon fuel can.
Fig. 6C-66-Fuel Tank, CK 10-20 (06, 16)
12. Connect battery cable. M ake sure distributor
feed wire is disconnected.
13. Put six gallons o f clean fuel in tank and
operate starter to pum p two quarts o f fuel into fuel can.
This will purge fuel pum p.
14. R em ove hose and connect fuel line to
carburetor.
15. Connect d istributor feed wire.
16.
Check all connections for leaks.
GASKET
SCREW
HOSE
CLAM P
BRACKET
NECK
ASSEM BLY
c a p
' ass e m b ly /
CLAM P
CLAM P
CLAM P
Fig. 6C 68 Filler Neck, CK10-20 (06, 16)
BRACKET
FUEL T A N K
ASSEMBLY
VIEW A
TO R Q U E A T 4 5
IN .
LBS.
CEM EN T
FUEL T A N K
ASSEMBLY
A N T I-S Q U E A K
REAR CROSS
SILL
u p p er nut
j w e r n ut
has been tig h te n e d
to specified to rq u e .
VIEW B
Position a n ti-s q u e a k to
a lig n w ith b ra c k e t.
VIEW C
A N T I-S Q U E A K
TAN K^~
ASSEMBLY
ANTI-SQ UEAK
CEMENTHO O K
STRAP
ASM
SPACER
STRAP
ASSEMBLY
ANTI-SQ UEAK
CEMENT
'SPACER
TORQUE A T '
10 FT. LBS.
ASSEMBLY: Cem ent anti-squeak to upper
surface of tank flange w ith 1.00 w ide
coverage before installation of tan k assembly.
Tighten upper nut a fter low er nut has been
tightened.
FW P»
J
I
BRACKET
ASSEMBLY
REAR SPRING
FRONT HANGER
STRAP
ASSEMBLY
FUEL TANK
ANTI-SQUEAK
Fig. 6C-71--Fuel T ank and M ounting - P20, 30
Fig. 6C-72--Fuel Tank (50 Gal.) Meter and Filler
Neck - P30
FUEL FEED AND VAPOR PIPES
GENERAL DESCRIPTION
Fuel feed pipes are secured to the u n derbody with
clam p and screw assem blies. Flexible hoses are located at
fuel tank fuel, v ap o r and retu rn lines and fuel pum p.
The pipes should be inspected occasionally fo r leaks,
kinks or dents. If evidence o f d irt or foreign m aterial is
found in carb u reto r, fuel pum p or pipes, pipe should be
disconnected and blown out. D irt or foreign m aterial
m ay be caused by a dam ag ed or om itted fuel strain er in
fuel tank.
ON-VEHICLE SERVICE
Replacement
If replacem ent o f fuel feed pipe, v apor pipe or
retu rn pipe is required, use only double w rap an d brazed
steel tubing m eeting G M Specification 123M or its
equivalent. U nder no condition use copper or alum inum
tubing to replace steel tubing. Those m aterials do not
have satisfactory fatigue durability to w ithstand norm al
vehicle vibrations.
Repair
1. Do not use fuel hose for pipe rep a ir w ithin 4
inches o f any part o f the exhaust system.
2. In rep airab le areas, cut fuel hose 4 inches longer
than the portion o f pipe rem oved. Use only hose stated
for fuel usage by the m anufacturer.
If m ore than a 6-inch length o f pipe is rem oved, use
a com bination o f steel pipe and hose so that hose lengths
will not be longer th an 10 inches.
3. The fuel hose should extend 2 inches on each
pipe and be clam ped at each end. Pipes must be properly
secured to the fram e to prevent chafing.
EVAPORATIVE CONTROL SYSTEM (ECS)
GENERAL DESCRIPTION
All light duty em issions and some heavy duty
em ission vehicles are eq uipped w ith a system designed to
preven t escape o f fuel v ap o r to the atm osphere. V apor
generated by ev ap o ratio n o f fuel in the tank, previously
exhausted to atm osphere, is tran sferred by an em ission
line to the engine com partm ent. D u rin g periods o f
o p eratio n , vapors are fed directly to the engine for
co n su m p tio n . D u rin g p erio d s o f in o p e ra tio n , an
activated charcoal canister located in the em ission line
stores any v ap o r g en erated for consum ption d uring the
next p eriod o f operation.
T he am ount o f vap o r draw n into the engine at any
tim e is too sm all to have any effect on fuel econom y or
engine operation.
W ith this closed system it is extrem ely im p o rtan t
th at only vapors be tran sferred to the engine. To avoid
the possibility o f liquid fuel being draw n into the system,
these follow ing features are included as p a rt o f the total
system :
1. A fuel tank overfill protector is provided on all
series to assure ad eq u ate room for expansion o f liquid
fuel volum e w ith tem p eratu re changes.
2. A one point fuel tank venting system is
provided on all series to assure that the tank will be
vented u n d er any conceivable vehicle attitude.
3. To protect the tank from m echanical d am age in
the event o f excessive in tern al or external pressures
resulting fro m the o p eratio n o f this closed system, a
pressure-vacuum relief valve, located in the gas cap, will
control the tank intern al pressure.
be replaced every 24 m onths or 30,000 miles (light duty
emissions), 24,000 miles (heavy duty em issions). U nder
extrem ely dusty conditions, m ore freq u en t attention may
be required.
Canister and Filter
Removal
1.
2.
3.
4.
canister
N ote installed position o f hoses on canister.
D isconnect hoses from top o f canister.
Loosen clam ps and icm ove canister.
If replacing filter, pull out filter from bottom of
with your fingers.
Inspection
1.
they are
2.
vacuum
Check hose connection openings. Assure that
open.
Check op eratio n o f purge valve by applying
to the valve. A good valve will hold vacuum .
Installation
1.
2.
3.
Install new filter.
Install canister and tighten clamp.
C onnect hoses in sam e order.
Canister Purge Valve
Disassembly
1. D isconnect lines at valve.
2. S nap off valve cap (slowly rem ove cap as
d iaphragm is under spring tension). Remove diaphragm ,
spring retain e r and spring.
3. R eplace p a rts as necessary. C heck orifice
openings.
Assembly
ON-VEHICLE SERVICE
M ain ten an ce req u irem en t is only th a t the oiled
fiberglass filter assem bled in the bottom o f the canister.
1.
Install spring, spring retainer, d iap h rag m and
2.
Connect lines to valve.
cap.
ACCELERATOR CONTROL
GENERAL
ACCELERATOR CONTROL CABLE
T he accelerator control system is cable type. There
are no linkage adjustm ents. A reference between the
bottom o f accelerator pedal and floor p an should be used
only as a check for bent bracket assembly. Check torque
references.
R efer to figures 6C-73 through 76 for rem oval and
installation o f accelerator control cable.
Check fo r correct opening and closing positions by
o p e ra tin g accelerator pedal an d if any binding is
present, check routing o f cable.
INNER
SPRING
OUTER
SPRING
NOTE:
ACCELERATOR PEDAL
R efer to figures 6C-77 through 80 for rem oval and
installation o f accelerator pedal.
W ith Inner Spring inside
O u te r Spring, an ch o r both Springs
thru nylon bushing in C a rb Lever
and hole in C a rb Bracket.
RETAINER
C A U T IO N : C a b le is not
to b e kinked or d a m a g e d in
an y w a y during assem bly
CABLE
FASTENER
LEVER
RETAINER
Fig. 6C -73-Accelerator C ontrols L6-Light Duty
Fig. 6C-74- Accelerator Controls L6-Heavy Duty
Emissions
Emissions.
C A U T IO N : FI e xib le co m p o n e n ts (hoses
wires, co n d u its, etc.) m ust n o t be rou te d
w ith in 2 inches o f m oving parts o f
accelerator linkage fo rw a rd o f S u p p o rt,
unless ro u tin g is p o sitive ly c o n tro lle d .
E N G IN E SUPPO RT
C ABLE A S SE M B LY
N O TE : Cable is n o t to be
k in ke d o r damaged in any
way d u rin g assembly.
C A R B U R E T O R ST U D
C AR BURETO R
SPR IN G O U T E R
N O TE : W ith In n er Spring inside O u te r Spring,
a n ch or b o th Springs th ru hole in C a rb u re to r
Lever and holes in S u p p o rt and Bracket.
FASTENER
Fig. 6C-75--Accelerator Controls V8-2Bbl.
I CAUTION 1 Flexible components (hoses,
wires, conduits, etc.), must not be routed
within 2 inches of moving parts of
accelerator linkage forward of Support
unless routing is positively controlled.
CABLE ASSEMBLY
I N O T E ] Cable is not to be
kinked or damaged in any
way during assembly.
NG OUTER
CARBURETOR STUD
FASTENER
LL____
/
SPRING INNER
/
NOtT I With Inner Spring inside Outer Spring,
anchor both Springs thru hole in Carburetor
Lever and holes in Support and Bracket.
N O TE : Slip accelerato r control
cable thru slot in rod. Install
retainer, being sure it is seated.
LUBRICATE
•CABLE RETAINER
C A U T IO N : C are must be used
in pressing the retainer into
hole in rod to assure cable is
not kinked or dam aged in any
w ay. ^ - ^ R E IN F O R C E M E N T
ROD
*s V
\
/
SUPPORT
SPRING'
ACCELERATOR
CONTROL CABLE
TIGHTEN TO
42 IN. LBS.
Fig. 6C-77--Accelerator Pedal-CK
Fig. 6C-79- Accelerator Pedal-P42
SPECIAL TOOLS
J 9 7 89 -0 2 UNIVERSAL CARBURETOR G A U G E SET
J 9 7 8 9 -1 18 CARBURETOR H O L D IN G STAND
J 9 7 8 9 -1 11 B E N D IN G TOOL
J25322 PUMP LEVER PIN DRIVE PUN CH
J 2 3417 CHOKE LEVER INSTALLING TOOL
J26701 CHOKE VALVE ANGLE G A U G E
SECTION 6D
ENGINE ELECTRICAL
CONTENTS
Electric Choke H e a te r........................................................6D-1
B attery .................................................................................. ..6D-2
G eneral D escription........................................................ ..6D-2
Common Causes of F a ilu re ........................................ ..6D-4
Care of B attery.................................................................6D-4
Battery R atin g ................................................................ ..6D-5
Selecting a Replacement B attery............................... ..6D-5
Safety Precautions......................................................... ..6D-5
Charging Procedures.......................................................6D-5
Testing Procedures........................................................ ..6D-6
Installing B atteries........................................................ ..6D-7
D iagnosis........................................................................... ..6D-7
Battery Test Procedure................................................ ..6D-7
M aintenance Free B a tte ry ...............................................6D-7
G eneral In fo rm atio n .......................................................6D-7
Green Dot Visible......................................................... ..6D-7
D ark-G reen D ot N ot Visible...................................... ..6D-7
Testing P ro ced u re......................................................... ..6D-7
Visual Inspection..............................................................6D-7
State of Charge In d ic a to r..............................................6D-7
Removing Surface C h arg e.............................................6D-8
Load T e s t........................................................................ ..6D-8
Charging P ro ced u re........................................................6D-8
Battery Charging G u id e .............................................. ..6D-8
Charging and Testing A d ap ters...................................6D-8
10 SI Series G enerator...................................................... ..6D-8
General D escription........................................................ ..6D-8
D iagnosis..............................................................................6D-10
Static C hecks.................................................................. ..6D-10
Indicator Lam p Circuit C heck.....................................6D-11
Undercharged Battery C ondition.............................. ..6D-11
Overcharged Battery C ondition....................................6D-12
G enerator O utput T e s t................................................ ..6D-12
O ther Harness C heck s................................................. ..6D-12
Diagnosis C h a rts........................................................... ..6D-14
On-Vehicle Service......................................................... ..6D-20
G enerator R eplacem ent............................................... ..6D-20
Pulley Replacem ent....................................................... ..6D-20
Unit R e p a ir......................................................................
Special T o o ls....................................................................
D istributor...........................................................................
General D escription........................................................
Diagnosis...........................................................................
On-Vehicle Service............................................................
Maintenance and A djustm ents...................................
Component Part Replacement....................................
Spark P lu g s.........................................................................
General D escription........................................................
Diagnosis...........................................................................
On-Vehicle Service...........................................................
Component Part Replacem ent....................................
Ignition Switch...................................................................
General D escription........................................................
Starter System ....................................................................
General D escription........................................................
Starter M o to r.................................................................
Solenoid...........................................................................
Diagnosis...........................................................................
No Cranking A ctio n ....................................................
Cranking Speed Abnormally Low.............................
Voltage T e s t...................................................................
Amperage T e st...............................................................
On-Vehicle Service...........................................................
Component Part Replacement....................................
Starting M otor................................................................
Checking Pinion Clearance.........................................
Bench T est......................................................................
Unit R e p a ir.......................................................................
Disassembly....................................................................
Cleaning and Inspection..............................................
Testing and R epairs......................................................
A ssem bly.........................................................................
Pinion Clearance Check...............................................
Starting Solenoid.............................................................
Specifications.......................................................................
6D-21
6D-25
6D-25
6D-25
6D-27
6D-33
6D-33
6D-33
6D-33
6D-37
6D-38
6D-41
6D-42
6D-42
6D-42
6D-43
6D 43
6D-43
6D-46
6D-48
6D-48
6D-48
6D 48
6D 49
6D-50
6D-50
6D-50
6D-50
6D-50
6D-51
6D-51
6D-51
6D-51
6D-54
6D-55
6D-55
6D-56
ELECTRIC CHOKE HEATER-OIL PRESSURE SWITCH
MK IV V-8 AND 6 CYL ENGINES
All M K IV and 6 cylinder engines have a two-terminal
oil pressure switch (sending unit) for controlling current to
the electric choke heater. This switch and its associated
circuitry provide for the illumination of the "Oil" tell tale
lamp in the event of loss of oil pressure or loss of voltage at
the choke heater.
The diagram in Figure 6D-1A shows how the dual
function is accomplished. The "Bulb Check" feature is same
as present system. T hat is, with ignition switch in "Run"
position with engine off. This circuit will also indicate
continuity in the choke heater and its connector.
If "Oil" tell tale lamp illuminates with engine running,
it could indicate one or more of the following:
1. Loss of oil pressure.
2. Loss of choke heater voltage.
3. Blown G A U G E fuse.
ELECTRIC C H O K E H EA TER C H E C K IN G
PROCEDURE
1. Allow choke to cool so that when throttle is opened
slightly, choke blade fully closes.
NOTE: This check must be performed with engine not
running and at an ambient temperature of 60°C to 27°C.
2. Start engine and determine time for choke blade to
reach full open position. (Start timer when engine starts).
3. If the choke blade fails to open fully within 3.5
minutes, proceed with steps 4-5-6 below.
4. Check voltage at the choke heater connection. (Engine
must be running). If the voltage is approximately 12-15 volts,
replace the electrical choke unit.
5. If the voltage is low or zero, check all wires and
connections. If any connections in the oil pressure switch
circuitry are faulty or if the oil pressure switch is failed open,
the oil warning light will be on with the engine running.
Repair wires or connections as required.
6. If all wiring and connections are good, replace oil
pressure switch.
Fig. 6D-1 A --E le ctric C hoke H ea te r D iagram
NOTE: No gasket is used between the choke cover and
the choke housing because of grounding requirements.
BATTERY
GENERAL DESCRIPTION
The battery (fig. 6D-1B) is made up of a number of
separate elements, each located in an individual cell in a hard
rubber case. Each element consists of an assembly of positive
plates and negative plates containing dissimilar active
materials and kept apart by separators. The elements are
immersed in an electrolyte composed of dilute sulfuric acid.
Plate straps located on the top of each element connect all
the positive plates and all the negative plates into groups. The
elements are connected in series electrically by connectors
that pass directly through the case partitions between cells.
The battery top is a one piece cover. The cell connectors, by
passing through the cell partitions, connect the elements
along the shortest practical path (fig. 6D-2B). W ith the length
of the electrical circuit inside the battery reduced to a
C H ARG E
IN D IC ATO R
DARKENED INDICATOR
WITH GREEN DOT
- OK FOR TESTING
DARKENED INDICATOR
NO GREEN DOT________
- CHARGE BEFORE TESTING
LIGHT YELLOW INDICATOR
- DO NOT CHARGE OR TEST
- REPLACE BATTERY
minimum, the internal voltage drop is decreased resulting in
improved performance, particuarly during engine cranking
at low temperatures.
The terminals of this type battery, passing through the
side of the case, are positioned out of the "wet" area
surrounding the vent holes. Norm al spillage, spewing,
condensation, and road splash are not as likely to reach or
remain on the vertical sides where the terminals are located.
This greatly decreases the cause of terminal corrosion. Also,
construction of the terminals is such that the mating cable
connector seals the junction and provides a permanently tight
and clean connection. Power robbing resistance in the form
of corrosion is thereby eliminated at these maintenance-free
connections.
The hard, smooth, one piece cover greatly reduces the
tendency for corrosion to form on the top of the battery. The
NEGATIVE
ELECTROLYTE
C O N T A IN E R
SEPARATOR
ELEMENT
2 VOLT BATTERY CELL
Fig. 6 D -3 B -B a tte ry E lem ent (Sim ple)
Fig. 6 D -4 B ~ T w o V o lt B a tte ry Cell
cover is bonded to the case forming an air-tight seal between
the cover and case.
Electrical energy is released by chemical reactions
between the active materials in the two dissimilar plates and
the electrolyte whenever the battery is being "discharged."
Maximum electrical energy is released only when the cells
are being discharged from a state of full charge.
As the cells discharge, chemical changes in the active
m aterials in the plates gradually reduce the potential
electrical energy available. "Recharging" the battery with a
flow of direct current opposite to that during discharge
reverses the chemical changes within the cells and restores
them to their active condition and a state of full charge.
The lead-acid storage battery is an electrochemical
device for converting chemical energy into electrical energy.
It is not a storage tank for electricity as is often believed, but
instead, stores electrical energy in chemical form.
Active materials within the battery react chemically to
produce a flow of direct current whenever lights, radio,
cranking m otor, or other current consuming devices are
connected to the battery term inal posts. This current is
produced by chemical reaction between the active materials
of the PLATES and the sulfuric acid of the
ELECTRO LY TE.
The battery performs three functions in automotive
applications:
1. It supplies electrical energy for the cranking motor
and for the ignition system as the engine is started.
2. It supplies current for the lights, radio, heater, and
other accessories when the electrical demands of these devices
exceed the output of the generator.
3. The battery acts as a voltage stabilizer in the electrical
system. Satisfactory operation of the vehicle is impossible
unless the battery performs each of these functions.
The simplest unit of a lead-acid storage battery is made
up of two unlike materials, a positive plate and a negative
plate, kept apart by a porous separator. This assembly is
called an "ELEM EN T" (Fig. 6D-3B).
When this simple element is put in a container filled with
a sulphuric acid and water solution called "electrolyte", a
two-volt "cell" is formed. Electricity will flow when the plates
are connected to an electrical load (Fig. 6D-4B).
An element made by grouping several positive plates
together and several negative plates together with separators
between them also generates two-volts but can produce more
total electrical energy than a simple cell (Fig. 6D-5B).
W hen six cells are connected in series, a "battery" of
cells is formed which produces six times as much electrical
pressure as a simple cell, or a total of 12 volts (Fig. 6D-6B).
If the battery continuously supplies current, it becomes
run-down or discharged. This is where the generator gets into
the act. The generator restores the chemical energy to the
battery. This is done by sending current through the battery
in a direction opposite to that during discharge. The
generator current reverses the chemical actions in the battery
and restores it to a charged condition.
2 VOLTS
DAYS STANDING
Fig 6 D -6 B ~ T y p ic a l 12 V o lt B a tte ry Cell A rra n g e m e n t
Fig. 6 D -7 B - Rate o f S e lf-D isch a rg e
C O M M O N C A U S E S OF FAILURE
Since the battery is a perishable item which requires
periodic servicing, a good m aintenance program will insure
the longest possible battery life. If the battery tests good but
fails to perform satisfactorily in service for no apparent
reason, the following are some of the more im portant factors
that may point to the cause of the trouble.
1. Vehicle accessories inadvertently left on overnight to
cause a discharge condition.
2. Slow speed driving of short duration, to cause an
undercharged condition.
3. A vehicle electrical load exceeding the generator
capacity.
4. Defect in the charging system such as high resistance,
slipping fan belt, faulty generator or voltage regulator.
5. Battery abuse, including failure to keep the battery top
clean, cable attaching bolts clean and tight, and improper
addition of water to the cells.
C A R E OF B A T T E R Y
Battery Storage
A wet charged battery will not maintain its charged
condition during storage, and must be recharged periodically.
During storage, even though the battery is not in use, a slow
reaction takes place between the chemicals inside the battery
which causes the battery to lose charge and "wear out"
slowly. This reaction is called "self-discharge." The rate at
which self-discharge occurs varies directly with tem perature
of the electrolyte.
Note from Figure 6D-7B that an battery stored in an
area at 100°F (38°C) for 60 days has a much lower specific
gravity and consequently a lower state of charge than one
stored in an area at 60°F (16°C) for the same length of time.
To minimize self-discharge, a wet battery should be
stored in as cool a place as possible, provided the electrolyte
does not freeze.
A wet battery which has been allowed to stand idle for
a long period of time without recharging may become so
badly damaged by the growth of lead sulfate crystals
(sulfation) in the plates that it can never be restored to a
normal charged condition. An battery in this condition not
only loses its capacity but also is subject to changes in its
charging characteristics. These changes, due to self
discharge, are often serious enough to prevent satisfactory
performance in a vehicle.
Periodic recharging, therefore, is necessary to maintain
a wet charged battery in a satisfactory condition while in
storage. See paragraph "Charging Wet battery in Storage."
C h a r g i n g W e t b a t t e r y in S t o r a g e
Before placing a battery on charge, always check the
battery charge indicator.
The battery should be brought to a fully charged
condition only when darkened indicator with no green dot
appears by charging as covered under heading of "Battery
Charging."
Trickle charging should not be used to maintain a
battery in a charged condition when in storage. The low
charge rate method applied every 30 days is the best method
of maintaining a wet charged battery in a fully charged
condition without damage.
Electrolyte Freezing
The freezing point of electrolyte depends on its specific
V A L U E OF
S PECIFIC
G R A V IT Y
@ 30 F
1.100
1.120
1.140
1.160
1.180
1.200
F R E E Z IN G
TEMP.
°F
°C
18
13
8
1
- 6
-1 7
- 8
-11
-1 3
-1 7
-21
-2 7
V A L U E OF
SPECIFIC
G R A V IT Y
@80 F
1.220
1.240
1.260
1.280
1.300
F R E E Z IN G
TEMP.
°F
°C
-3 3
-5 0
-7 5
-9 2
-9 5
-3 6
-4 6
-5 9
-6 9
-71
gravity. The following table gives the freezing temperatures
of electrolyte at various specific gravities.
Since freezing may ruin a wet battery, it should be
protected against freezing by keeping it in a charged
condition. This is true whether the wet battery is in storage
or in service.
Carrier and Hold-Down
The battery carrier and hold-down should be clean and
free from corrosion before installing the battery. The carrier
should be in sound mechanical condition so that it will
support the battery securely and keep it level.
To prevent the battery from shaking in its carrier, the
hold-down bolts should be tight (60-80 in. lbs.). However, the
bolts should not be tightened to the point where the battery
case or cover will be placed under a severe strain.
Cleaning
The external condition of the battery should be checked
periodically for damage such as cracked cover, case and vent
plugs or for the presence of dirt and corrosion. The battery
should be kept clean. An accumulation of acid film and dirt
may permit current to flow between the terminals, which will
slowly discharge the Battery. For best results when cleaning
batteries, wash first with a diluted ammonia or a soda
solution to neutralize any acid present; then flush with clean
water. Care m ust be taken to keep vent plugs tight, so that
the neutralizing solution does not enter the cells.
BATTERY RATING
A battery generally has two classifications of ratings: (1)
a 20 hour rating at 80 F and, (2) a cold rating at 0 F which
indicates the cranking load capacity. The A m pere/H our
rating found on batteries was based on the 20 hour rating.
That is, a battery capable of furnishing three (3) amperes for
20 hours while maintaining a specified average individual cell
voltage would be classified as a 60 ampere hour battery (e.g.
3 amperes X 20 hours = 60 A .H .) a PW R (Peak W att
Rating) has been developed as a measure of the battery’s cold
cranking ability. The num erical rating is embossed on each
case at the base of the battery. This value is determined by
multiplying the maximum current by the maximum voltage.
The PW R should not be confused with the ampere hour
rating since two batteries with the same ampere hour rating
can have quite different watt ratings. For battery
replacement, a unit of at least equal power rating must be
selected.
SELECTING A R E P L A C E M E N T BATTERY
Long and troublefree service can be more assured when
the capacity or wattage rating of the replacement battery is
at least equal to the wattage rating of the battery originally
engineered for the application by the m anufacturer.
The use of an undersize battery may result in poor
performance and early failure. Figure 6D-8B shows how
battery power shrinks while the need for engine cranking
power increases with falling temperatures. Sub-zero
tem peratures reduce capacity of a fully charged battery to
45% of its norm al power and at the same time increase
cranking load to 3-1/2 times the normal warm weather load.
Hot weather can also place excessive electrical loads on
the battery. Difficulty in starting may occur when cranking
is attem pted shortly after a hot engine has been turned off
or stalls. In fact, modern high compression engines can be
as difficult to start under such conditions as on the coldest
Fig. 6 D -8 B --B a tte ry P ow er vs F a llin g T e m p e ra tu re
winter day. Consequently, good performance can be obtained
only if the battery has ample capacity to cope with these
conditions.
A battery of greater capacity should be considered if the
electrical load has been increased through the addition of
accessories or if driving conditions are such that the generator
cannot keep the battery in a charged condition.
On applications where heavy electrical loads are
encountered, a higher output generator that will supply a
charge during low speed operation may be required to
increase battery life and improve battery performance.
SAFETY P RECAUTIONS
When batteries are being charged, an explosive gas
mixture forms in each cell. Part of this gas escapes through
the holes in the vent holes and may form an explosive
atmosphere around the battery itself if ventilation is poor.
This explosive gas may remain in or around the battery for
several hours after it has been charged. Sparks or flames can
ignite this gas causing an internal explosion which may
shatter the battery (Fig. 6D-9B).
The following precautions should be observed to prevent
an explosion:
1. Do not smoke near batteries being charged or which
have been very recently charged.
2. D o not break live circuits at the terminals of batteries
because a spark usually occurs at the point where a live circuit
is broken. Care must always be taken when connecting or
disconnecting booster leads or cable clamps on fast chargers.
Poor connections are a common cause of electrical arcs which
cause explosions.
CHARG ING PROCEDURES
Before charging a battery the electrolyte level must be
checked and adjusted if needed. Battery charging consists of
applying a charge rate in amperes for a period of time in
hours. Thus, a 10-ampere charge rate for seven hours would
be a 70 ampere-hour (A.H.) charging input to the battery.
Charging rates in the three to 20 ampere range are generally
satisfactory. No particular charge rate (expect that charge
rate should not exceed 20 amperes) or time can be specified
for an battery due to the following factors:
1.
The size, or electrical capacity in ampere-hours
(A.H.), of the battery.
E X A M P L E : A completely discharged 70 A.H. battery
IN S U L A T O R
PREVENTS
AND
STRAP
TO OL
LO SS
W HEN
S E P A R A T IO N
NOT
IN
USE
Fig. 6 D -9B --S parks o r Flam es
requires almost twice the recharging as a 40 A.H. battery.
2. Tem perature of the battery electrolyte.
E X A M P L E : About two hours longer will be needed to
charge a 0°F (-18°C). battery than a 80°F (27°C) battery.
3. Battery state-of-charge at the start of the charging
period.
E X A M P L E : A completely discharged battery requires
twice as much charge in ampere-hours as a one-half charged
battery.
4. Battery age and condition.
E X A M P L E : A battery that has been subjected to severe
service will require up to 50% more am pere-hour charging
input than a relatively new battery.
The following basic rule applies to any battery charging
situation:
If the charge indicator is dark and the green dot is not
visible, charge battery until dot appears, but not more than
60 ampere-hours (for example 15 amperes for four hours).
Do not exceed a charging rate of 20 amperes during charging.
N O T E : Some chargers are constant current chargers
while others are constant voltage chargers. If a constant
voltage charger is used for charging the battery and the
green dot fails to appear after prolonged charging, it may
be necessary to tip the battery slightly from side to side
a few times for the green dot to appear.
If the charge indicator is light replace battery. DO NOT
attem pt to charge or "jump" when charge indicator is light.
N O T E : A battery that failed prematurely, and exhibited
a light charge indicator condition, may indicate a need
for checking the charging system of the vehicle.
For the most satisfactory charging, the lower charging
rates in amperes are recommended.
An "emergency boost charge", consisting of a high
charging rate for a short period of time, may be applied as
a temporary expedient in order to crank an engine. However,
this procedure usually supplies insufficient battery reserve to
crank a second and third time. Therefore, the "emergency
boost charge" must be followed by a subsequent charging
period of sufficient duration to restore the battery to a
satisfactory state of charge. Refer to the charging guide in
this section.
When out of the vehicle, the sealed side term inal battery
will require adapters (Fig. 6D-10B) for the terminals to
provide a place for attachm ent of the charging leads.
Adapters are available through local parts service.
m
DAPTER
TOOL
TO
C H A R G IN G
ATTACHED
T E R M IN A L S
Fig. 6 D -10 B -C h a rg in g and T e stin g A d a p te rs
When the side terminal battery is in the vehicle, the studs
provided in the wiring harness are suitable for attachm ent of
the charger’s leads.
CAUTI ON: Exercise care when attaching charger
leads to side terminal studs to avoid contact with
vehicle m etal components which would result in
damage to the battery.
TESTING P RO CED UR ES
Testing procedures are used to determine whether the
battery is (1) good and usable, (2) requires recharging or (3)
should be replaced. Analysis of battery conditions can be
accomplished by performing a visual inspection, instrument
test and the full charge hydrometer test. Refer to test
procedure chart in this section.
Visual Inspection
The first step in testing the battery should be a visual
inspection, which very often will save time and expense in
determining battery condition.
• Check the outside of the battery for a broken or
cracked case or a broken or cracked cover. If any damage
is evident, the battery should be replaced.
• Observe battery state of charge indicator to determine
condition of battery.
• Check for loose cable connections. Correct as required
before proceeding with tests.
Instrument Test
A number of suppliers have approved testing equipment
available. These testers have a programmed test procedure
consisting of a series of timed discharge and charge events,
requiring approximately 2 to 3 minutes, that will determine
the condition of the battery with a high degree of accuracy.
When using these testers, the procedure recommended by the
tester m anufacturer should be followed.
IN S TA L LIN G BATTERIES
To install a battery properly, it is im portant to observe
the following precautions:
• Connect grounded term inal of battery last to avoid
short circuits which may damage the electrical system. Do
not connect primary lead until secondary negative cable wire
has been grounded to sheet metal.
• Be sure there are no foreign objects in the carrier, so
that the new battery will rest properly in the bottom of the
carrier.
• Tighten the hold-down evenly until snug (60-80 in.
lbs.). Do not draw down tight enough to distort or crack the
case or cover.
• Be sure the cables are in good condition and the
term inal bolts are clean and tight. Make sure the ground
cable is clean and tight at engine block or frame.
•
Check polarity to be sure the battery is not reversed
with respect to the generating system.
Do not over torque cable terminal studs.
Replacement
1. Disconnect battery negative cable and then the
positive cable.
2. Remove battery hold-down clamp bolt and clamp.
3. Remove battery from tray.
4. Position new battery, which has been properly
activated, in the battery tray.
5. Install battery hold down clamp and bolt.
N O T E : Recommended hold-down bolt torque is 70 in.
lbs.
6. Install battery positive and negative cables and tighten
terminal bolts to 70 in. lbs. torque.
DIAGNOSIS
BATTERY TEST PROCEDURE
To determine the ability of a battery to function properly
requires testing. The accuracy of the testing changes with
temperature, specific gravity, age of the battery, etc.
Therefore, an accurate test has more than one step:
Step 1. Visual inspection.
Step 2. Specific gravity check (hydrometer)
Step 3. Program m ed Instrum ent Test
Step 4. Load Test.
C AU TI ON : Wear safety glasses. D o not break live
circuits at battery terminals. When testing be
certain to rem ove gases at battery cover caused by
charging.
MAINTENANCE FREE BATTERY
GENERAL IN FO R M A TIO N
The state of charge indicator located on top of the
battery (Fig. 6D-1B) is to be used with accepted diagnostic
procedures only. It is not to be used to determine if the
battery is good or bad, or charged or discharged. The
indicator is actually a built-in hydrom eter in one cell of the
battery and provides visual information only for battery
testing.
On rare occasions, the state of charge indicator will turn
light yellow. Normally, a battery with this condition is
capable of further service but the indicator can no longer
provide information for battery testing. A light yellow
indicator is by no means a command to replace the battery.
However, if a problem exists, such as failing to crank, the
battery must be replaced. Do not charge, test or jum p start.
It is im portant when observing the state of charge
indicator, that the battery be relatively level and have a clean
indicator top to see the correct indication. An electric light
or flashlight may be required in some poorly-lit areas to verify
the correct indication. Under normal operation, two
indications can be observed:
GREEN D O T V IS IB LE
Any green appearance in the indicator is interpreted as
a "green dot" and the battery is ready for testing. On rare
occasions following prolonged cranking, the green dot may
still be visible even though the battery is in a discharged
condition. Should this occur, charge battery as described in
Charging Procedure portion of this manual.
DARK-G REEN D O T N O T VISIBLE
If there is a cranking complaint, the battery should be
tested as described in the Testing Procedure that follows:
TESTING PROCEDURE
VISUAL INSPECTION
Check for obvious damage, such as cracked or broken
case or cover, that could permit loss of electrolyte. If obvious
physical damage is noted, replace battery. Determine cause
of damage and correct as needed.
S T A T E OF C H A R G E I N D I C A T O R (Fig. 6 D - 1 B )
Green Dot Visible
If the indicator is dark and has a green dot in the center,
the battery is OK for testing. Proceed to step 3. On rare
occasions, such as after prolonged cranking, the green dot
may still be visible even though the battery is in a state of
discharge. Should this situation occur, charge battery as
described in Charging Procedure portion of this manual.
Dark-Green Dot Not Visible
If the indicator is dark but the green dot is not visible,
charge the battery as described in Charging Procedure
portion of this manual and proceed to Remove Surface
Charge step.
Light or Yellow
On rare occasions the indicator will turn light yellow and
the battery must not be tested. Replace the battery. Do not
charge, test or jum p start.
REMOVE SURFACE CHARGE
BATTERY C H A RG IN G PROCEDURE
Charging equipment for ordinary batteries is suitable for
Maintenance- Free type batteries.
Do not charge a battery if the green dot is visible except
N O T E : If battery is out of vehicle, use adapters as
on rare occasions following prolonged cranking when the
shown in Charging and Testing A dapters portion of this
battery is discharged but the green dot still appears. Should
manual.
this situation occur, a boost-charge of 20 ampere-hours is
LOAD TEST
recommended.
Do not charge a battery if the state of charge indicator
a.
Connect a voltm eter and a specified load as indicated
is
light
yellow.
below across terminals of battery.
Connect a 300-ampere load across battery terminals for
15 seconds to remove surface charge.
BATTERY C H A R G IN G GUIDE
BATTERY
TYPE
85-5
854
87-5
AMPS FOR
LOAD TEST
Stop charging battery when green dot appears in state
of charge indicator or when the maximum charge rate shown
below is reached:
170
130
210
BATTERY
T Y PE
85-4
85-5
87-5
b. Read voltage on voltmeter after 15 seconds with load
connected, then disconnect load.
SL O W
C H A R G IN G
R A TE
5A (a 10 H o u rs
10A @ 5 H o u rs
5A (a 15 H o u rs
10A @ V /2 H o u rs
FAST
C H A R G IN G
RATE
20A (a 2 V2 H o u rs
30A @ 1 Ms-Hours
20A @ 3% H o u rs
30A (a 2 Vi H o u rs
40A @ 2 H o u rs
50A (a 1% -H ours
c. If minimum voltage is *9.6 volts or more, battery is
good.
d. If minimum voltage is less than *9.6 volts, replace
battery.
*This voltage is to be used for battery ambient
tem perature 21°C (70°F) and above. For tem peratures below
2 1i°C (70°F), use the following:
M IN IM U M V O L T A G E
TEM PERATURE
F
C
9 .6
70
21
9 .5
60
16
9.4
50
10
9 .3
40
9.1
30
-
1
8.9
20
-
7
8 .7
10
-1 2
8.5
0
-1 8
4
To avoid damage, charging rate must be reduced or
temporarily halted if battery case feels hot (52°C) (125°F) or
if violent gassing or spewing of electrolyte through the vent
holes occur.
After charging in accordance with the tables, the green
dot may appear in the state of charge indicator after slightly
tipping the battery from side to side a few times. If the green
dot does not appear, the battery is still sufficiently charged
for testing.
C H A R G IN G A N D TESTING A DA PTERS
Freedom type batteries should be charged or tested onthe-vehicle, using existing terminals. However, when the
battery is out-of-the-vehiele, adapters similar to the ACDelco adapters Kit #ST -238 shown in Figure 6D-10B are
required.
THE CHARGING SYSTEM
10-SI SERIES GENERATOR SYSTEM
GENERAL DESCRIPTION
The 10-SI series generator shown in Figure 6D-1C is
typical of a variety of models. A solid state regulator having
an integrated circuit is built into the end frame. Although
models are available with different outputs at idle and
different maximum outputs, their basic operating principles
are the same.
The generator consists primarily of two end frame
assemblies, a rotor assembly and a stator assembly. A typical
cross-sectional view is shown in Figure 6D-1C. The rotor
assembly is supported in the drive end frame by a ball bearing
and in the slip ring end frame by a roller bearing. These rotor
bearings contain a supply of lubricant sufficiently adequate
to eliminate the need for periodic lubrication. Two brushes
carry current through the two slip rings to the field coil
mounted on the rotor and under normal conditions will
provide long periods of attention - free service. No periodic
adjustments or maintenance are required on the generator
assembly.
The stator windings are assembled on the inside of a
laminated core that forms part of the generator frame. A
Fig. 6 D -1 C -1 0 -S I Series G e n era to r
rectifier bridge connected to the stator windings contains six
diodes, (three positive and three negative) molded into an
assembly which is connected to the stator windings. This
rectifier bridge changes the stator a.c. voltages to d.c. voltage
which appears at the output terminal. The blocking action
of the diodes prevent battery discharge back through the
generator. Because of this blocking action, the need for a
cutout relay in the circuit is eliminated. G enerator field
current is supplied through a diode trio which is also
connected to the stator windings.
A capacitor, or condenser, mounted in the end frame
protects the rectifier bridge and diode from high voltages, and
suppresses radio noise.
The typical passenger car integral charging system is
made up of two com ponents-a generator with a built-in solid
state voltage regulator and battery. These components work
together to supply electrical power for ignition, lights, radio,
cranking motor, etc. A typical wiring diagram is illustrated
in Figure 6D-2C. The basic operating principles are explained
as follows.
When the switch is closed, current from the battery
flows through the indicator lamp to the generator No. 1
terminal, through resistor R l, diode D l, and the base-emitter
of transistor TR1 to ground, and then back to the battery.
This turns on transistor TR1, and current flows through the
generator field coil and TR1 back to the battery. The
indicator lamp then turns on. Resistor R5 carries some of the
indicator lamp current and is shown in figure 6D-2C.
W ith the generator operating, a.c. voltage is generated
in the stator windings, and the stator supplies d.c. field
current through the diode trio, the field, TR1, and then
through the grounded diodes in the rectifier bridge back to
the stator. Also, the six diodes in the rectifier bridge change
the stator a.c. voltages to a d.c. voltage which appears
between ground and the generator "BAT" terminal. As
generator speed increases, current is provided for charging
the battery and operating electrical accessories. Also, with the
generator operating, the same voltage appears at the "BAT"
and No. 1 terminals, and the indicator lamp goes out to
indicate the generator is producing voltage.
The No. 2 terminal on the generator is always connected
to the battery, but the discharge current is limited to a
negligible value by the high resistances of R2 and R3. As the
generator speed and voltage increase, the voltage between R2
and R3 increases to the point where zener diode D2 conducts.
Transistor TR2 then turns on and TR1 turns off. With TR1
off, the field current and system voltage decrease, and D2
then blocks current flow, causing TR1 to turn back on. The
field current and system voltage increase, and this cycle then
repeats many times per second to limit the generator voltage
to a pre-set value.
Capacitor C l smooths out the voltage across R3, resistor
R4 prevents excessive current through TR1 at high
temperatures, and diode D3 prevents high-induced voltages
in the field windings when TR1 turns off.
Resistor R2 is a therm ister which causes the regulated
voltage to vary with temperature, thus providing optimum
voltage for charging the battery.
Fig. 6 D -2 C --ln te g ra l C h a rg in g System C irc u itry
DIAGNOSIS
Most charging system troubles show up as a faulty
indicator lamp, an undercharged or an overcharged battery.
Since the battery itself may be defective, it should be checked
first to determine its condition. Also, in the case of an
undercharged battery, check for battery drain caused by
grounds or by accessories being left on.
A basic wiring diagram showing lead connections is
presented in Figure 6D-3C. The following precautions must
be observed when working on the charging circuit. Failure
to observe these precautions will result in serious damage to
the electrical equipment.
• Do not polarize the generator.
• Do not short across or ground any of the terminals
in the charging circuit except as specifically instructed in
these procedures.
• Never operate the generator with the output terminal
open circuited.
• Make sure the generator and battery are of the same
ground polarity.
• W hen connecting a charger or a booster battery to the
vehicle battery, connect negative terminal to negative
terminal and positive terminal to positive terminal.
S T A T IC C H E C K
Before making any electrical checks, visually inspect all
connections, including slip-on connectors, to make sure they
are clean and tight. Inspect all wiring for cracked, frayed or
broken insulation. Be sure generator mounting bolts are tight
and unit is properly grounded. Check for loose fan belt.
NOTE: In some circuits an ammeter may be used
instead of an indicator lamp. In this case, the section
pertaining to faulty indicator lamp operation may be
omitted from the trouble shooting procedure.
TAB
INSERT SCREWDRIVER
GROUND TAB TO
END FRAME
END
FRAME
HOLE
GEN ER AT O R
Fig. 6D -3C --B asic W irin g D iagram
I N D I C A T O R L A M P C IR C U I T C H E C K
Check the indicator lamp for norm al operation as shown
below.
If the indicator lamp operates normally, proceed to
"U ndercharged Battery" or "Overcharged Battery" section.
Otherwise, proceed to either one of the following three
abnorm al conditions.
Fig. 6 D -4 C ~ G e n e ra to r End V ie w
I.
Switch Off, Lamp O n - In this case, disconnect the two
leads from the generator No. 1 and No. 2 terminals. If the
lamp stays on, there is a short between these two leads. If the
periods.
lamp goes out, replace the rectifier bridge as covered in the
2. Check the drive belt for proper tension.
"Chassis Overhaul M anual". This condition will cause an
3. Check battery. Test is not valid unless battery is good
undercharged battery.
and fully charged.
4. Inspect the wiring for defects. Check all connections
for tightness and cleanliness, including the slip connectors at
Engine
Switch
Lamp
the generator and firewall, and the cable clamps and battery
OFF
OFF
STOPPED
posts.
ON
STOPPED
ON
5. With ignition switch "on" connect a voltmeter from
OFF
ON
RUNNING
generator "BAT" terminal to ground, generator No. 1
terminal to ground and generator No. 2 terminal to ground.
A zero reading indicates an open between voltmeter
connection and battery.
NOTE: An open No. 2 lead circuit on generators will
cause uncontrolled voltage, battery overcharge and
2. Switch On, Lam p Off, Engine Stopped-This condition
possible damage to battery and accessories. Generators
can be caused by the defects listed in step 1 above, by reversal
supplied for current applications have a built-in feature
of the No. 1 and No. 2 leads at these two terminals, or by
which avoids overcharge and accessory damage by
an open in the circuit. This condition can cause an
preventing the generator from turning on if there is an
undercharged battery. To determ ine where an open exists,
open in the wiring harness connected to the No. 2
proceed as follows:
generator terminal. Opens in the wiring harness
a. Check for a blown fuse, or fusible link, a burned out
connected between the No. 2 generator terminal and
bulb, defective bulb socket, or an open in No. 1 lead circuit
battery may be between the terminals, at the crimp
between generator and ignition switch.
between the harness wire and terminal, or in the wire.
b. If no defects have been found, proceed to
6. If previous Steps 1 through 5 check satisfactorily,
U ndercharged Battery section.
check generator as follows:
3. Switch On, Lamp On, Engine R unning-The possible
a. Disconnect battery ground cable.
causes
of
this
condition
are
covered
in
the
b. Connect an am m eter in the circuit at the "BAT"
"U N D E R C H A R G E D BATTERY" section.
terminal of the generator.
U N D E R C H A R G E D B A TTE RY C O N D IT IO N
c. Reconnect battery ground cable.
CHECK
d. Turn on radio, windshield wipers, lights high beam
This condition, as evidenced by slow cranking and low
and blower m otor high speed. Connect a carbon pile across
specific gravity readings, can be caused by one or more of the
the battery.
following conditions even though the am m eter may be
e. Operate engine at moderate speed as required, and
adjust carbon pile as required, to obtain maximum current
operating normally.
1.
Insure that the undercharged condition has not been output.
f. If ampere output is within 10 percent of rated output
caused by accessories having been left on for extended
as stamped on generator frame, generator is not defective;
recheck Steps l through 5.
g. If ampere output is not within 10 percent of rated
output, ground the field winding by inserting a screwdriver
into the test hole (Fig. 6D-4C).
CAUTION: Tab is within 3 /4 inch (19m m ) o f
casting surface. D o n o t force screwdriver deeper
than one inch (25m m ) into end frame.
h. Operate engine at moderate speed as required, and
adjust carbon pile as required to obtain maximum current
output.
i. If output is within 10 percent of rated output, replace
regulator as covered in the Chassis Overhaul M anual and
check field winding.
j. If output is not within 10 percent of rated output,
check the field winding, diode trio, rectifier bridge, and stator
as covered in the Chassis Overhaul Manual.
k. Remove am m eter from generator and turn accessories
off.
OHMMETER
INSULATING
WASHERS
RESISTOR
O V E R C H A R G E D B A TTE R Y C O N D IT IO N CHECK
1. Determine battery condition. Test is not valid if
battery is not good and fully charged.
2. Connect a voltm eter from generator No. 2 terminal
to ground. If reading is zero, No. 2 lead circuit is open.
3. If battery and No. 2 lead circuit check good, but an
obvious overcharge condition exists as evidenced by excessive
battery water usage, proceed as follows:
a. Separate end frames as covered in generator
"Disassembly" section in the Chassis Overhaul Manual.
Check field winding for shorts. If shorted replace rotor and
regulator.
b. Connect ohm m eter using lowest range scale from
brush lead clip to end frame as shown in Step 1, Figure 6D5C, then reverse lead connections.
c. If both readings are zero, either the brush lead clip
is grounded, or regulator is defective.
d. A grounded brush lead clip can result from omission
of insulating washer (Fig. 6D-5C), omission of insulating
sleeve over screw, or damaged insulating sleeve. Remove
screw to inspect sleeve. If satisfactory, replace regulator as
covered in the Chassis Overhaul Manual.
G E NE R ATO R O U T P U T TEST
To check the generator in a test stand, proceed as
follows:
1. Make connections as shown in Figure 6D-6C, except
leave the carbon pile disconnected. Use a fully charged
battery and a 10 ohm resistor rated at six watts or more
between the generator No. 1 term inal and the battery.
2. Slowly increase the generator speed and observe the
voltage.
3. If the voltage is uncontrolled with speed and increases
above 16 volts, check for a grounded brush lead clip as
covered under heading of "O V E R C H A R G E D BATTERY",
Step 3. If not grounded, replace the regulator.
NOTE: The battery must be fully charged when making
this check.
DIODE
CAPACITOR
RECTIFIER
BRIDGE
ATTACHING
NUTS
TRI°
Fig. 6 D -5 C -S lip Ring End Frame
4. Connect the carbon pile as shown.
5. Operate the generator at moderate speed as required
and adjust the carbon pile as required to obtain maximum
current output.
6. If output is within ten percent of rated output as
stamped on generator frame, generator is good.
7. If output is not within ten percent of rated output,
ground generator field (Fig. 6D-4C).
8. Operate generator at moderate speed and adjust
carbon pile as required to obtain maximum output.
9. If output is within ten percent of rated output, replace
regulator as covered in "Regulator Replacement" section.
10. If output is not within ten percent of rated output,
check the field winding, diode trio, rectifier bridge and stator
as previously covered.
OTHER H A RN ES S CHECKS
Wires in the charging system may be checked for
continuity by us of an ohmmeter or a test light (12 volt).
Connect the test so the wire in question is in series in in the
test circuit.
CARBON
PILE
/^ \
—
f
&-----
c=5
L.
>
VOLTMETER
m s 'K K K
\ \\ \
V \
\
\> v
D
BATTERY
RESISTOR
TEST
AMMETER
sS
GENERATOR
S5 SV \ D
C =^
C h a rt 1
GENERATOR
PROBLEM:
generator light ON engine RUNNING
GENERATOR
BELT
STEP
FUSE BLOCK
SEQUENCE
RESULT
GENERATOR
L IG H T OFF
R E P L A C E IF
GO TO
NECESSARY
CHECK
S TEP 2
ADJ US T
GENERATOR
S T A R T E N G IN E
T E N S I O N T O 8 0 LBS.
GENERATOR
L IG H T ON
BELT
(D IM OR BRIG HT)
T U R N E N G IN E
OFF
VCHECK FOR CAUSE
I G N IT IO N ON
IF A L L
LIG HTS OFF
S T A R T E N G IN E
' A N D REPLACE
G A U G E S FU SE
GENERATOR
L I G H T ON
GO T O
STEP 4
TEST LIG H T
F U L L Y BR IG H T
CONNECT
TEST L IG H T
TEST LIG H T
GROUND
T O NO. 1
1/2 B R I G H T
GENERATOR
T E R M IN A L
GO TO
S TE P 5
" D ” SHAPED
TEST LIG H T
HOLE
1/2 B R I G H T
GO TO
STEP 5
TEST V OLTAG E
RE G U L A T O R WITH
REPLA CE
A P P R O V E D TE ST ER
VOLTAGE REGULATOR
RE P AIR G E N E R A T O R
G E N E R A T O R L IG H T
C h a rt 2
I
^
CLUSTER
CO NNECTOR
GENERATOR( 1
PROBLEM:
generator light OFF ignition ON
engine NOT RUNNING
BU LKH EAD
FU SE B L O C K
CO NNECTOR
STEP
IG N IT IO N ON
RESULT
SEQUENCE
CHECK ALL
IF A L L
IN D IC A T O R LIG HTS
LIGHTS O FF
REPLACE
G A U G E S FUSE
LIG H T OFF
C H E C K F O R P I N C H E D OR
G R O U N D E D W IRE IN G AUG E S C IR C U IT S
GENERATOR
LIG H T ON
( V i
REPAIR
GO TO
ST E P 3
IF N E C E S S A R Y
REPLACE
G A U G E S FU SE
GENERATOR
LIG H T OFF
GENERATOR
LIG H T ON
GO TO
STEP 4
R E P A I R O P E N IN
NO . 18 P I N K W I R E
GENERATOR
(IN D IC A T O R FEED WIRE)
LIG H T OFF
GENERATOR
LIG H T ON
G O TO
REPLACE
CHECK G EN ER A TO R
ST EP 5
IF N E C E S S A R Y
IN D IC A T O R BULB A N D
GENERATOR
S O C K E T AS SY.
LIG H T OFF
GO TO
ST EP 6
D ISCO NNECT
B R O W N/W HITE
WIRE
GENERATOR
LIG H T ON
G O TO
ST EP 7
G R O U N D NO. 1
TE R M IN A L
WIRE
GENERATOR
LIG H T OFF
C h a rt 4
C O IL
CARBURETO R
GENERATOR
BATTERY
PROBLEM:
battery UNDERCHARGED
GENERATOR
BELT
STEP
SEQUENCE
R E P L A C E IF N E C E S S A R Y
RESULT
CONNECT TEST
AD JU S T T E N S I O N
L IG H T BETWEEN
T O 80 LBS.
CABLE & B A T TER Y
G O TO
ST E P 2
POST
TEST LIG H T
M A K E S U R E NO
ON
ACCESSORIES
W E R E L E F T ON,
IG N IT IO N OFF,
CHECK
DOORS CLOSED
GENERATOR
UNDER HOOD
G O TO
STE P 3
TEST L IG H T OFF -
L IG HTS DIS
BELT
NO D R A IN ON
CONNECTED
2
BATTERY
__ l ^ r n p l
TAP CABLE A G A IN S T
POS T
.
/ ^
\
TRACE & CORRECT
TE ST L IG H T OFF
CO N TIN U O U S
TEST LIG HT
GO TO I
D R A IN ON B A T T ER Y
ON
STE P 3 |
T E S T L I G H T ON
CONNECT
VOLTMETER
(+) T E R M I N A L
AND GROUND
RECONNECT
NE G A TIVE
CA B L E
CONNECT
G O TO
JUMPER
C R A N K E N G IN E
(-) T E R M I N A L
LONG E NO UG H
AND GROUND
( O N H. E .I. D I S C O N N E C T
FEED W IR E )
IF R E A D I N G IS
W I T H I N .5 V O L T
O F V O L T A G E A T G EN .
IF R E A D I N G IS N O T
CHECK
W I T H I N .5 V O L T O F
VOLTAGE
R E A D I N G A T G EN .
AC R O S S
CHECK FOR B A T TER Y
POST
CABLE A N D STA R TE R
W H IL E
TO DE LC O TR O N
CR A N K IN G
C IR C U IT R E S IS TAN CE
STE P 4
FOR S T A B IL IZ E D
N E E D L E BELOW
R E A D IN G
9 .0 V O L T S
TEST BATTER Y
GO TO
USING B A T T E R Y
STEP 6
L O A D TEST
PROCEDURE
BATTER Y OK
C H A R G E AS
S P E C I F I E D BY
TEST
G O TO
ST EP 5
BATTERY
N O T OK
REPLACE
BATTERY
G O TO
ST EP 6
STEP
SEQUENCE
CONNECT
RESULT
P L A C E CA R B.
VOLTMETER
ON H I G H STEP
ACROSS
FAST IDLE CAM
BATTERY
GO TO
STEP 7
D IS C O N N E C T
CO IL J U M P E R
S T A R T E N G IN E
OR RECONNECT
DO NO T TO UCH
HEI FEED WIRE
ACCELERATOR
PEDAL
IF V O L T A G E
R E A D S LOWER
H E A D LIG H TS -H I
T U R N ON
A /C -
T H A N PRE VIO US
REA D IN G
GO T O
STEP 9
HI
ACCESSORIES
R A D IO
BLOWER TYPE
DEFOGGER
JO
IF V O L T A G E
i l
CHECK
VOLTAGE
READS H IG HER
I
GO T O
R E A D IN G
T H A N PRE VIO US
R EA D IN G
STEP 8
IF M E T E R
READS
GO T O
ST EP 9
U N D E R 12.5
IF M E T E R
TURN O F F
GO TO
READS
ACCESSORIES
S TE P 10
O V E R 15.5
IF M E T E R
W A I T U N T I L UP P ER
R A D IA T O R IN L E T
VOLTMETER
AND
N E E D L E STOPS
IS H O T
READS
1 2 . 5 T O 15.5
SEE N O T E
IF V O L T A G E
READS H IG HER
GO TO
T H A N PRE VIO US
ST EP 10
R E A D IN G
CHECK
GROUND
VOLTAGE
GENERATOR
R E A D IN G
IF V O L T A G E
REA D S LOWER
GO T O
T H A N PRE VIO US
ST EP 11
R E A D IN G
NOTE:
IF N O T H I N G H A S B E E N F O U N D R E - E D U C A T E O W N E R O N E X C E S S I V E I D L I N G ,
SLOW OR S H O R T D IS T A N C E D R I V I N G W IT H A L L ACCESSORIES ON.
ON-VEHICLE SERVICE
GENERATOR A SSEM BLY
Replacement (Fig. 6D-7C)
1. Disconnect the battery ground cable at battery.
2. Disconnect wiring leads at generator.
3. Remove generator brace bolt, then detach drive belt
(belts).
4. Support the generator and remove generator mount
bolt and remove from vehicle.
G E N E R A T O R PU L L EY
Replacement
1. Place 15/16" box wrench on retaining nut and insert
a 5/16" alien wrench into shaft to hold shaft while removing
nut (fig. 6D-8C).
2. Remove washer and slide pulley, fan and spacer from
shaft.
3. Reverse Steps 1 and 2 to install, use a torque wrench
with a crow-foot adapter (instead of box wrench) and torque
the nut to 50 ft. lbs. (fig. 6D-9C).
5. Reverse the removal procedure to install then adjust
drive belt(s) as outlined in Section 6A of this manual.
Fig. 6 D -7C --G e ne ra to r In s ta lla tio n T y p ic a l
Fig. 6 D -8 C -P u lle y Rem oval
UNIT REPAIR
D I S A S S E M B L Y (FIG. 6 D -1 C )
1. Hold generator in a vise, clamping the mounting
flange lengthwise.
2. Remove the four thru-bolts and separate the slip ring
end frame and stator assembly from the drive end and rotor
assembly by prying apart with a screwdriver at the stator slot.
N OTE: A scribe mark will help locate the parts in the
same position during assembly.
3. Place a piece of tape over the slip ring end frame
bearing to prevent entry of dirt and other foreign material,
and also a piece of tape over the shaft at the slip ring end.
CAUTION: Brushes m a y drop onto the rotor shaft
a nd become contam inated with bearing lubricant.
Clean brushes prior to installing with a non-toxic
cleaner such as trichlorethylene or a so ft dry cloth.
4. Remove the stator lead attaching nuts and separate
stator from end frame.
N OTE: A t this point, with the two end frames separated
the stator disconnected and the rotor removed electrical
checks of the rotor, rectifier bridge, stator and diode trio
brush lead clip may be made without further
disassembly. Refer to the specific checks as outlined in
this section.
5. Remove screw attaching diode trio to brush holder
assembly and remove diode trio from end frame.
6. Remove the rectifier bridge attaching screw and the
"BAT" term inal screw, and disconnect the capacitor lead.
Remove rectifier bridge from the end frame.
7. Remove two attaching screws, and remove brush
holder and regulator assemblies.
N OTE: Two insulators are assembled over the top of the
brush retaining clips and the two screws have special
insulating sleeves over the screw body.
8. Remove retaining screw and capacitor from end of
frame.
9. Remove slip ring end frame bearing (if necessary).
Refer to bearing replacement covered in this section.
10. Remove pulley retaining nut and slide washer,
pulley, fan and spacer from shaft.
a. Single groove pulley-place 15/16" box wrench on the
shaft nut and insert a 5/16" alien wrench into the shaft end
hole to hold the shaft while removing the nut (fig. 6D-8C).
b. Double groove pulley-place a 15/16" socket (with
wrench flats on the drive end or use adapter J-21501 and a
box wrench on the pulley retaining nut, insert a 5/16" alien
wrench through the socket and adapter into hex hole in the
shaft to hold the shaft while removing the nut.
11. Remove rotor and spacers from the drive end frame
assembly.
12. Remove drive end frame bearing retainer plate
screws, plate, gasket, bearing, and slinger from end frame (if
necessary).
roughness.
3. Inspect rotor slip rings, they may be cleaned with 400
grain polishing cloth. Rotate rotor for this operation to
prevent creating flat spots on slip rings.
4. Slip rings which are out of round may be trued in a
lathe to .002" maximum indicator reading. Remove only
enough material to make the rings smooth and concentric.
Finish with 400 grain polishing cloth and blow dry.
5. Slip rings are not replaceable-excessive damage will
require rotor assembly replacement.
6. Inspect brushes for wear. If they are worn halfway,
replace. Inspect brush springs for distortion or weakening.
If brushes appear satisfactory and move freely in brush
holder, springs may be reused.
T E S T IN G
Where specified, conduct the following tests using an
ohmmeter with a 1-1/2 volt cell and use the lowest range
scale for the readings.
Rotor Field Winding Checks (Fig. 6D-10C)
The rotor may be checked electrically with a 110-volt
test lamp or an ohmmeter.
Open C irc u it
Connect one test lamp or ohmmeter lead to each slip
ring. If the lamp fails to light or if the ohmmeter reading is
high, the windings are open.
Sh o rt C irc u it
The windings are checked for shorts by connecting a 12
volt battery and an am m eter in series with the two slip rings.
Note the ammeter reading. An ammeter reading above the
specified field amperage draw indicates shorted windings.
Refer to Specifications at the end of this manual.
C L E A N IN G A N D IN S P E C T IO N
W ith
generator
completely
disassembled
the
components should be cleaned and inspected. Be sure testing
equipment is in good working order before attem pting to
check the generator.
1. W ash all metal parts except stator and rotor
assemblies.
2. Clean bearings and inspect for sealing, pitting or
OHMMETER
(CHECK FOR SHORTS AND OPENS)
(CHECK FOR OPENS)
OHM METER
O HM METER
(CHECK FOR OPENS)
(CHECK FOR GROUNDS!
Fig. 6D-1 1C --C hecking S ta to r
Stator Checks (Fig. 6D-11C)
G ro u n d s
Connect a 110-volt test lamp or an ohm m eter from any
stator lead to the stator frame. If test lamp lights or if
ohmmeter reads low, the windings are grounded.
O p e n C ir c u it
If lamp fails to light or if ohmmeter reads high when
successively connected between each pair of stator leads, the
windings are open.
Fig. 6 D -12C --D iode T rio Checks
between the grounded heat sink and the other two terminals,
and between the insulated heat sink and each of the three
terminals. When this is done all six diodes are checked with
BRUSH
HO LDER
RESISTOR
S h o r t C ir c u it
A short in the stator windings is difficult to locate
without special test equipment due to the low resistance of
the windings. However, if all other electrical checks are
normal and the generator fails to supply rated output, shorted
stator windings are indicated. Also, look for heat
discoloration on the windings.
Diode Trio (Fig. 6D-12C)
With the diode trio unit remove from the end frame,
connect an ohm m eter to the single connect and to one of the
three connectors. Observe the reading, then reverse the
ohm m eter leads to the same connectors. A good diode trio
will give one high and one low reading. If both readings are
the same, replace the diode trio. Repeat this test between the
single connector and each of the other two connectors.
NOTE: There are two diode trio units differing in
appearance used in the generator but they are completely
interchangeable.
CAUTION: D o not use high voltage such as 110
volt test lam p to check the diode trio.
Rectifier Bridge Check (Fig. 6D-13C)
Connect an ohm m eter to the grounded heat sink and one
of the three terminals. Then reverse the lead connections to
the grounded heat sink and same terminal. If both readings
are the same, replace the bridge. A good rectifier bridge will
give one high and one low reading. Repeat this same test
REGULATO R
INSULATED
HEAT SINK
IN S U L A T IN G
W ASHER
GROUNDED
HEAT SINK
OHM M ETER
two readings taken for each diode.
NOTE: The diodes are not replaced individually. The
entire rectifier bridge is replaced if one or more diodes
are defective.
CAUTION: D o n o t use high voltage to check the
rectifier bridge, such as a 110 volt test lamp.
Voltage Reg./Brush Lead Clip Check (Fig. 6D-5C)
Connect an ohmm eter from the brush lead clip to the
end frame as shown in Step 1, Figure 6D-7C. Then reverse
lead connections. If both readings are zero, either the brush
lead clip is grounded or the regulator is defective.
A grounded brush lead clip can result from omission of
the insulating washer, omission of the insulating sleeve on the
screw, or a damaged insulating sleeve. Remove the screw and
inspect the sleeve. If it is satisfactory, replace the regulator
unit.
R E P A IR S
Brush Holder and Regulator Replacement (Fig.
6D-5C)
1. If not previously removed, remove the three stator
lead attaching nuts, the stator, diode trio brush lead screw
and diode trio from the end frame.
2. Remove the remaining two screws from the brush
holder and regulator and remove these units from the end
frame.
NOTE: The two screws retaining the brush clips have
insulating washers over the tops of the brush clips and
special insulating sleeves over the screw body above the
threads. If they are damaged or missing a ground will
result causing uncontrolled or no output.
3. Replace defective unit and reassemble using reverse
of removal procedures.
NOTE: The screw nearest regulator terminals does not
have an insulating washer, but may or may not have an
insulating sleeve.
Slip Ring Servicing
If the slip rings are dirty, they may be cleaned and
finished with 400 grain or finer polishing cloth. Spin the
rotor, and hold the polishing cloth against the slip rings until
they are clean.
CAUTION: The rotor m u st be rotated in order that
the slip rings will be cleaned evenly. Cleaning the
slip rings b y hand w ithout spinning the rotor m ay
result in flat spots on the slip rings, causing brush
noise.
Slip rings which are rough or out of round should be
trued in a lathe to .002 inch maximum indicator reading.
Remove only enough material to make the rings smooth and
round. Finish with 400 grain or finer polishing cloth and blow
away all dust.
Drive End Frame-Bearing Replacement/
Lubrication
1. The drive end frame bearing can be removed by
detaching the retainer plate bolts and separating retainer
plate and seal assembly from end frame, and then pressing
bearing out using suitable tube or pipe on outer race.
2. Refill bearing one-quarter full with Delco-Remy No.
1948791 grease or equivalent. Do not overfill.
3. Press bearing into end frame using tube or pipe as in
Step 1 with bearing and slinger assembled as shown in Figure
6D-8C.
Fig. 6 D - 1 4C ~D rive End B e a rin g Cross S ection
4.
Install retainer plate. Use new retainer plate if felt seal
is hardened or excessively worn.
NOTE: Stake retainer plate bolts to plate.
Slip Ring End Frame-Bearing Replacement
1. Replace the bearing if the grease supply is exhausted.
Make no attem pt to re-lubricate and reuse the bearing.
2. Press out from outside of housing, using suitable tool
over outer race of bearing.
3. To install, place a flat plate over the bearing and press
in from outside of housing until bearing is flush with the
outside of the end frame. Support inside of end frame around
bearing bore with a suitable tool to prevent distortion. Use
extreme care to avoid misalignment.
4. Install new seal whenever bearing is replaced. Lightly
coat the seal lip with oil and press seal into the end frame
with the seal lip toward the inside of the end frame.
REASSEMBLY
1. Install rotor in drive end frame and attach spacer, fan,
pulley, washer, and nut.
2. Using adapter J-2 1501, insert an alien wrench into hex
shaped hole at end of shaft and torque the shaft nut to 40-50
ft. lbs. (fig. 6D-9C).
3. Install capacitor and retaining screw in slip ring end
frame.
4. Position brush holder and regulator assemblies in end
frame and install two retaining screws.
N OTE: The two screws retaining the brush clips have
insulating washers over the top of the brush clips and
special insulating sleeves over the screw body above the
threads. If the third screw does not have an insulating
sleeve, it must not be interchanged with either of the
other two screws.
5. Position rectifier bridge to end frame. Install attaching
screw and the "BAT" terminal screw. Connect capacitor lead
to bridge.
6. Position diode trio on rectifier bridge terminal and
install screw attaching brush lead clip to brush holder.
8.
Position slip ring end frame to drive end frame and
install four thru bolts.
CAUTION: Insulating washer on the screw m u st be
assembled over top o f the connector.
NOTE: Remove tooth pick from brush holder at
opening in slip ring end frame before operating machine
on vehicle.
7.
Position stator in end frame. Connect stator leads to
rectifier bridge term inals and install attaching nuts.
SPECIAL TOOLS
J 21501
PULLY
ADAPTER
Fig. 6 D -15C --S pecial T ool
IGNITION SYSTEM
DISTRIBUTOR
GENERAL DESCRIPTION
There are two types of H EI distributors. The 8 cylinder
distributor (Fig. 6 D -li) combines all ignition components in
one unit. The ignition coil is in the distributor cap and
connects directly to the rotor. The 6 cylinder distributor (Fig.
6D-2i) has an external mounted coil. Both operate basically
in the same manner as a conventional ignition system except
the module and pick-up coil of the H EI system replace the
contact points of the conventional system.
The High Energy Igntion is a pulse triggered, transistor
controlled, inductive discharge ignition system. The magnetic
pick-up assembly located inside the distributor contains a
perm anent magnet, a pole piece with internal teeth, and a
pick-up coil. When the teeth of the timer core rotating inside
the pole piece line up with teeth of the pole piece, an induced
voltage in the pick-up coil signals the all electronic module
to open the coil primary circuit. The primary current
decreases and a high voltage is induced in the ignition coil
secondary winding which is directed through the rotor and
high voltage leads to fire the spark plugs. The capacitor in
the distributor is for radio noise suppression.
The module autom atically controls the dwell period,
stretching it with increasing engine speed. The H EI system
also features a longer spark duration, made possible by the
higher am ount of energy stored in the coil primary. This is
desirable for firing lean and EGR diluted mixtures.
Ignition Coil
In the 8 cylinder HEI system, the igntion coil is built
into the distributor cap. In the 6 cylinder HEI system, the
ignition coil is mounted externally. The coil is somewhat
smaller physically than a conventional coil, but has more
primary and secondary windings. It is built more like a true
transformer with the windings surrounded by the laminated
iron core. A conventional coil has the iron core inside the
windings. Although the H EI coil operates in basically the
same way as a conventional coil, it is more effective in
generating higher secondary voltage when the primary circuit
is broken.
Electronic Module
The electronic module is a solid state unit containing five
complete circuits which control spark triggering, switching,
current limiting, dwell control and distributor pick-up. Dwell
angle is controlled by a transistor circuit within the module
and is varied in direct relation to engine speed.
BAT. TERMINAL
(CONNECTED TO
IGNITION SWITCH)
Pick-Up Assembly
The pick-up assembly consists of the following:
1. A rotating tim er core with external teeth which is
turned by the distributor shaft.
2. A stationary pole piece with internal teeth.
3. A pick-up coil and magnet which are located between
the pole piece and a bottom plate.
Centrifugal and Vacuum Advance
CONNECT TACHOMETER
FROM THIS TERMINAL
TO GROUND.
TACH TERMINAL
(SOME TACHOMETERS
MUST CONNECT FROM
THIS TERMINAL TO
ENERGIZER POSITIVE ( + ).
CONSULT TACHOMETER
MANUFACTURER.)
The centrifugal and vacuum advance mechanisms are
basically the same types of units that provide spark advance
in the breaker-type system. Centrifugal advance is achieved
through the rotation of the timer core in relation to the
distributor shaft. Vacuum advance is achieved by attaching
the pick-up coil and pole piece to the vacuum advance unit
actuating arm.
Wiring (Fig. 6D-3i)
Fig. 6 D -1 i—8 C y lin d e r HEI D is trib u to r
IG N ITIO N COIL
CONNECT TACHOMETER
FR O M THIS TERMINAL
TO G R O U N D .
(SO M E TACHOMETERS
MUST CONNECT FRO M
THIS TERMINAL TO
ENERGIZER POSITIVE (+).
SO M E TACHOMETERS
M A Y NOT W O R K AT ALL.
CONSULT TACHOMETER
M AN UFACTURER.)
CONNECTOR
BAT. TERMINAL
(CONNECTED TO
IG N ITIO N SWITCH)
H IG H EN ERG Y
IG N ITIO N DISTRIBUTOR
LEAD
SPARK
PLUG
V A CUU M
UNIT
LATCH (4)
The pick-up coil is connected to transistors in the
electronic module. The electronic module is connected to the
primary windings in the coil. As the distributor shaft turns
the tim er core teeth out of alignment with the teeth of the
pole piece a voltage is created in the magnetic field of the
pick-up coil.
The pick-up coil sends this voltage signal to the
electronic module, which determines from RPM when to
start current building in the primary windings of the ignition
coil.
Each time the tim er core teeth align with the pole piece
teeth the pick-up coil magnetic field is changed creating a
different voltage. The pick-up coil sends this different voltage
signal the electronic module which electronically shuts off the
ignition coil primary circuit. This in turn collapses the coil
magnetic field, induces high secondary voltage and fires one
spark plug.
The electronic module delivers full battery voltage to the
ignition coil which is limited to five to six amperes. There is
no primary resistance wire in the H E I system. The electronic
module triggers the closing and opening of the primary
circuit instantaneously with no energy lost due to breaker
point arcing or capacitor charging time lag. The capacitor in
the H EI unit functions only as a radio noise suppressor.
H O U SIN G
This instantaneous and efficient circuit triggering
enables the H EI system to deliver up to approximately 35,000
volts through the secondary wiring to the spark plugs.
G EA R
Because of the higher voltage, the HEI system has larger
diameter (8 millimeter) spark plug wires with silicone
insulation. The silicone wire is gray in color, more heat
resistant than standard black wire and less vulnerable to
deterioration. Silicone insulation is soft, however, and must
not be mishandled.
Fig. 6 D -3i--H ig h E nergy Ig n itio n Basic W irin g
D IA G N O S IS
HIGH ENERGY IGNITION SYSTEM V8 engine
PROBLEM:
3-WIRE
CONNECTOR
engine CRANKS but
COIL ( 7
WILL NOT START
ROTOR( 6
PICK-UP COIL
MODULE
SEQUENCE
STEP
RESULT
AU TO TRANS.
L E V E R IN P A R K
TE S T L IG H T
ON
M A N U A L TR ANS.
C O NN EC T TE ST L IG H T /
L E V E R IN N E U T R A L
T E S T L IG H T
O FF
T O BAT. L E A D
TERM .
STARTS
T E S T L IG H T
R E P A IR
O FF
L E A D OR
T E S T L IG H T
I___
ON
C O NNECTOR
NO S T A R T
IN S E R T T E S T L IG H T
IN R E D B+ W IR E
T E S T L IG H T
ON
IG N IT IO N SW.
- ~ Q ) --------( ^ )
STARTS
0
—
R E P A IR OR
R E P L A C E AS
< D “
T E S T L IG H T |
ON
|____
NECESSARY
NO S T A R T
O
R E M O V E A S P A R K P LU G W IR E,
IN S E R T E X T E N S IO N A N D
P E R F O R M S P A R K TE S T
NO
SPARK
P R O B L E M IS
N O T IG N IT IO N
S Y S TE M
CHECK
U S IN G IN S U L A T E D P L IE R S
H O L D S P A R K P L U G W IR E 1 /4 '
A W A Y F R O M EN G . B L O C K
W H IL E C R A N K IN G E N G IN E
F U E L SYSTEM
E X T E N S IO N
SPARK
•P L U G S
•F L O O D E D
_ _ _ _ _ _ _ HIGH ENERGY IGNITION SYSTEM V8 engine_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
STEP
SEQUENCE
RESULT
REMOVE
C A P A S SY.
STARTS
IG N IT IO N
O FF
D IS C O N N E C T
V I S U A L L Y INSPEC T
R E P A IR AS
FO R M O IS T U R E , DUST
NECESSARY
C R A C K S , B U R N S , ETC.
3-W IR E C O N N E C T O R
NO
START
O HM M ETER
STARTS
READS AB O V E 1 OHM
(X 1
SC ALE)
R E P LA C E
C O IL
CO NNECT
O HM M ETER
NO S T A R T
READS 0 TO 1 OHM
(X 1 S C A L E )
OHMMETER
E IT H E R
READS
TO
TEST
6 ,0 0 0
3 0 ,0 0 0 O H M S
STARTS
CO NNECT
BO TH TESTS
R E A D IN F IN IT Y
OHM M ETER
R E P LA C E
C O IL
NO S TA R T
R E M O V E G R E E N & W H IT E
LE A D S FR O M M O D U LE
STARTS
^M_ESS
T H A N IN F I N I T Y
R E P LA C E C O IL
(X 100 0 S C A L E )
(P IC K UP)
CO NNECT
O H M M E T E R FR O M
f
NO S T A R T
G R O U N D T O E IT H E R
R E A D S IN F IN IT E
LEAD
(X 100 0 S C A L E )
CONNECT O HM M ETER
R E P E A T STEPS 8 A N D 9
W H IL E M O V IN G V A C .
ACROSS 2 LE A D S
R E A D S 5 0 0 TO
150 0 O HM S
A D V A N C E W IT H SCREW
D R IV E R . IF R E A D IN G
IS S T IL L O K
STARTS
DO E S N O T R E A D
5 0 0 TO 150 0 O H M S
R E P LA C E C O IL
(P IC K UP)
NO S T A R T
R E P E A T STEPS
5 THRU 9
CHECK M O D U LE
W ITH TESTER
REMOVE AND
REPLACE M O D U L E
HIGH ENERGY IGNITION SYSTEM V8 engine
PROBLEM: engine RUNS ROUGH or CUTS OUT
’
SEQUENCE
STEP
RESULT
® - ---------------------- j ------------/T-N
-------------------
( S o - ----------- 0
CH ECK S P A R K
PLU G S & PLU G W IR E S
_
^
>
-
R E P A IR OR
REPLA C E
-
i
R UN S SMOOTH
4 ^ -r
RU N S ROUGH
r — 0
@
. —
RUNS SMOOTH
O
I
V IS U A L L Y IN SPECT
R E P A IR AS
U
FO R M O IST U R E, DUST, N E C E S S A R Y
C R A C KS, BU R N S, ETC.
D ISC O N N EC T
3 W IR E CO N N ECTO R
(J)
—
■- j
RUN S ROUGH
EITHER TEST
READS 6 000
TO 30,000 OHMS
C
CONNECT
^ > —
BOTH TESTS
READ IN F IN IT Y
OHMMETER
- - 0
- 0 K
REPLA C E
CO IL
R EM O V E G R E E N & W H IT E
L EA D S FR O M M O DULE
RUN S SMOOTH
LESS
TH A N IN F IN IT Y
(X 1000 S C A L E )
R E P L A C E CO IL
(PICK UP)
f
CONNECT
O H M M ET ER FRO M
G RO UN D TO E IT H E R
LEA D
RU N S ROUGH
R E A D S IN F IN IT E
(X 1000 S C A L E )
CONNECT O H M M ET ER
A C R O SS 2 LEA D S
R EA D S 500 TO
1500 OHMS
R E P E A T ST EPS 4 AND 5
W H IL E M O VING VAC.
A D V A N C E W ITH SC R EW
D R IV E R . IF R E A D IN G
IS S T IL L OK
R U N S SMOOTH
DOES NOT R EA D
500 TO 1500 OHMS
R E P L A C E C O IL
(P IC K U P )
R UN S ROUGH
R E P E A T ST EPS
1 THRU 5
CHECK M ODU LE
W IT H TESTER
REMOVE AND
REPLACE M ODU LE
HIGH ENERGY IGNITION SYS1EM L-6 engines
PROBLEM:
engine CRANKS but
WILL NOT START
COIL
PICK UP COIL
I
MODULE
STEP
SEQUENCE
RESULT
A U T O TRANS.
L E V E R IN PA R K
T EST LIG H T
ON
M A N U A L TRANS,
j
CONNECT T EST LIGH T
TO BAT. L EA D
TERM .
L E V E R IN N EU T R A L
T EST LIG H T
O FF
IG N ITIO N SW.
ST A R T S
0
~
R E P A IR OR
R E P L A C E AS
N EC ESSA R Y
-
€>
-|
TEST L IG H T |
ON
NO S T A R T
R E M O V E A S P A R K PLU G W IRE,
IN S E R T E X T E N S IO N AND
P E R F O R M S P A R K T EST
f V —
NO
S PA R K
USIN G IN S U L A T E D P L IE R S
HOLD S P A R K PLU G W IR E 1/4'
A W A Y F R O M ENG. BLO CK
W H IL E C R A N K IN G EN G IN E
P R O B L E M IS
NOT IG N ITIO N
SYSTEM
CHECK
• FU E L SYSTEM
• PLU G S
• FLO O D ED
S PA R K
E X T E N SIO N
-
Q
----------------------
STARTS
V IS U A L L Y INSPECT
R E P A IR AS
FO R M O IST U R E, DUST, N E C E S S A R Y
C RA CKS, B U R N S, ETC.
NO S T A R T
HIGH ENERGY IGNITION SYSTEM L-6 engines
RESULT
SEQUENCE
CONNECT
» \ V — ^ / _ _ .
O H M M ET ER R E A D S A B O V E 1 O HM
(X 1
STARTS
SC ALE)
R E P LA C E
C O IL
NO S T A R T
D ISC O N N EC T
CO N N ECTO R
R E A D S 0 TO 1 O H M
(X I
SC ALE )
R E A D S 6 .0 0 0 TO
3 0 .0 0 0 O HM S
CONNECT
O HM M ETER
STARTS
R E A D S M O R E T H A N 3 0 ,0 0 0
O HM S OR LESS T H A N
R E P LA C E
C0|L
6 ,000 O H M S
NO ST A R T
CONNECT
O H M M ET ER
STARTS
T H A N I N F IN IT Y
R E P LA C E C 0 IL
NOSTART
R E A D S IN F IN IT E
(X 1000 S C A L E )
R E M O V E G R EE N & W H IT E
LE A D S F R O M M O D U L E
STARTS
_ tc @
© X / X
> -----------------
-
T H A N I N F IN IT Y
CONNECT
f
O H M M E T E R FR O M
R E P LA C E C O IL
(X 100 0 S C A LE )
(P IC K UP)
NO S T A R T
"s
» V
G R Q U N D T O E IT H E R
LE AD
----------- ' V _
R E A D S IN F IN IT E
(X 100 0 S C A LE )
R E P E A T STEPS 8 A N D 9
W H IL E M O V IN G V A C .
CO NNECT O HM M ETER
AC R O S S 2 LE A D S
A D V A N C E W IT H SCREW
R E A D S 5 0 0 TO
1500 O HM S
D R IV E R . IF R E A D IN G
IS S T IL L O K
STARTS
D O ES N O T R E A D
5 0 0 TO 150 0 OHM S
R E P L A C E CO IL
(PICK-UP)
NO ST A R T
R E P E A T ST EPS
5 THRU 9
CH EC K M O D U LE
W IT H TESTER
RE M O VE A N D
R EPLACE M O D U LE
HIGH ENERGY IGNITION SYSTEM L-6 engines
PROBLEM: engine RUNS ROUGH or CUTS OUT
STEP
SEQUENCE
I
RESULT
----------- ------------- 1
i
CONNECT O H M M ET ER
ACRO SS 2 L EA D S
R EA D S 500 TO
1500 OHMS
R U N S SMOOTH
|
/^ r\
w m .
R E P E A T ST EPS 4 AND 5
W H IL E M O VING VAC.
A D VA N C E W ITH S C R EW
D R IV E R . IF R EA D IN G
IS S T IL L OK
RU N S SMOOTH
-------DOES NOT R EA D
500 TO 1500 OHMS
R E P L A C E CO IL
(PICK-UP)
RU N S ROUGH
6
\J
R E P E A T ST EPS
(OK)
1 THRU 5
IF OK
©
C H EC K M O D U LE
W IT H T E S T E R
-----------IF NOT OK
R E M O V E AND
R E P L A C E M O D U LE
@
ON-VEHICLE SERVICE
manufacturer’s instructions.
CAUTION: G rounding "tach" terminal could
damage the H E I electronic module.
M A IN T E N A N C E AN D A D JU S TM E N TS
Routine Maintenance
The H EI system is designed to be free from routine
maintenance. If component part replacement should become
necessary, however, several items specific to the H E I system
should be noted.
Electronic Module
Other Test Equipment
Oscilliscopes require special adaptors. Distributor
machines require a special amplifier. The equipment
manufacturers have instructions and details necessary to
modify test equipment for H E I diagnosis.
the electronic module is serviced by complete
replacement only. W hen replacing the module a liberal
coating of special silicone grease MUST be applied to the
metal m ounting surface on which the module will be
installed. If this grease is not applied the module will not cool
properly which can cause the module to malfunction. A tube
of this special silicone grease is supplied with each
replacement module.
Vacuum and Centrifugal
Advance Specifications
Spark Plug Wires (Figs. 6D-4i, 6D-5i)
Removal
The 8 millimeter silicone insulation spark plug wire
boots seal more tightly to the spark plugs. Twist the boot
about a half turn in either direction to break the seal before
pulling on the boot to remove the wire.
W A R N I N G : D o N o t rem o ve spark plug
w ir e s w i t h t h e eng in e running. The higher
s econdary v o lta g e is c apable o f ju m p in g an
arc of g re a te r d istance and could cause an
elec tric shock.
Vacuum and centrifugal advance specifications are listed
in the Specifications Section of this manual.
C O M P O N E N T PART REPLACEMENT
Distributor
1. Disconnect wiring harness connectors at side of
distributor cap.
2. Remove distributor cap and position out of way.
3. Disconnect vacuum advance hose from vacuum
advance mechanism.
4. Scribe a m ark on the engine in line with rotor. Note
approximate position of distributor housing in relation to
engine.
5. Remove distributor hold-down nut and clamp.
6. Lift distributor from engine.
In stallation
Timing Light Connections
Timing light connections should be made in parallel
using an adapter at the distributor number one terminal.
Tachometer Connections
In the distributor cap connector is a "tach" terminal.
Connect the tachom eter to this terminal and to ground. Some
tachom eters must connect from the "tach" terminal to the
battery positive ( + ) terminal. Follow tachometer
1. Install distributor using same procedure as for
standard distributor.
2. Install distributor hold-down clamp and snugly install
nut.
3. Move distributor housing to approximate position
relative to engine noted during removal.
4. Position distributor cap to housing with tab in base
CYL N O . 6
CYL N O . 5
CYL N O . 4
CYL N O . 3
CYL N O . 2
CYL N O . 1
DISTRIBUTOR
*7
#5
A D V A N C E W E IG H T (2 )
Fig. 6 D -6 i~ D is trib u to r C e n trifu g a l A d va n ce
of cap aligned with notch in housing and secure with four
latches.
5. Connect wiring harness connector to terminals on side
of distributor cap. C onnector will fit only one way.
6. Adjust ignition timing as described in Specification
C hart in Section 6E of this manual.
Distributor
D is as se m b ly (Figs. 6 D -6 i and 6D-8i)
1. Remove distributor as described above.
2. Remove rotor from distributor shaft by removing two
screws.
3. Remove two advance springs, weight retainer, and
advance weights.
4. Remove two screws holding module to housing and
move module to a position where connector may removed
from ’B’ and ’C ’ terminals.
5. Remove wires from "W" and "G " terminals of
module.
6. Remove roll pin from drive gear.
Fig. 6 D-7 i—Ro 11 Pin Removal
A ssem bly (Figs. 6 D -6 i - 6D-9i)
1. Position vacuum advance unit to housing and secure
with two screws.
2. Position felt washer over lubricant reservoir at top of
housing.
3. Lubricate felt wick with a few drops of motor oil and
install replacement pole piece and plate assembly over upper
bushing and vacuum advance unit. Make sure the connector
or retainer (bow) that holds the white and green electrical
leads together is color coded yellow.
4. Install lock ring pole piece and plate assembly.
5. Place distributor shaft (with rotor attached) in
distributor housing.
VA C U U M UNIT
ATTACHING SCREWS
CAUTION: D istributor gear should be supported
in such a way that no damage will occur to
distributor shaft while rem oving pin.
7. Remove gear, shim and tanged washer from
distributor shaft. Remove any burrs that may have been
caused by removal of pin.
8. Remove distributor shaft from housing.
9. Remove washer from upper end of distributor
housing.
10. Remove lock ring at top of housing and remove pole
piece and plate assembly and felt washer.
NOTE: No attem pt should be made to service the shaft
bushings in the housing.
11. Remove vacuum advance mechanism by removing
two screws.
12. Disconnect capacitor lead and remove capacitor by
removing one screw.
13. Remove wiring harness from distributor housing.
THIN " C ”
W A SH ER
CAPACITOR
PIC K U P
COIL
LEADS
ATTACHING
SCREW
MODULE
C O N N ECTO R
GROUND
SCREW
MODULE
6. On 8 cylinder distributors, install tanged washer, shim
and drive gear on distributor shaft.
7. On 6 cylinder distributors, install drive gear on
distributor shaft.
8. Align holes of drive gear with hole of distributor shaft
so that locating m ark on drive gear is in line with tip of rotor.
Support distributor shaft on a wooden block or other suitable
object and install roll pin. Make sure distributor is supported
in such a way that no damage will occur to distributor shaft
while installing roll pin.
9. Check to make sure shaft is not binding by spinning
shaft a few times by hand.
10. Position capacitor to housing and loosely install one
m ounting screw.
11. Install connector to "B" and "C" terminals on
module with tab on top.
12. Apply special silicone lubricant liberally to bottom
of module and secure with two screws.
13. Position wiring harness with grommet in housing
notch.
14. Connect pink wire to capacitor stud, and black wire
to capacitor mounting screw. Tighten screw.
15. Connect white wire from pick-up coil to terminal
"W" module.
16. Connect green wire from pick-up coil to terminal
"G" of module.
17. Install centrifugal advance weights, weight retainer
(dimple facing down), and springs.
18. Install rotor and secure with two screws.
CAUTION: N otch on side o f rotor m u st engage tab
on cam weight base.
19. Install distributor as described above.
Electronic Module
R e p la c e m e n t (Fig. 6 D -8i)
The electronic module is serviced by complete
replacement only. When replacing the module a liberal
coating of special silicone grease M UST be applied to the
metal m ounting surface on which the module will be
installed. If this grease is not applied, the module will not cool
properly, which can cause the module to malfunction. A tube
of this special silicone grease is supplied with each
replacement module.
1. Raise hood and remove air cleaner.
2. Release distributor cap and place aside in an out-ofthe-way place.
3. Remove two screws and remove rotor from distributor
shaft.
4. Remove two screws holding module to housing and
move module to a position where electrical connector may
be removed from B and C terminals of module.
5. Use needle nose pliers or similar tool to remove pole
piece and plate assembly electrical leads from W (White) and
G (Green) term inals of module. Do not remove leads by
pulling on the wires as damage to the leads may occur.
6. Install replacement module in reverse order of
removal. During installation, make sure a liberal am ount of
special silicone grease is applied to the metal mounting
surface of module to insure proper cooling.
7. Check operation of new module by starting and
running vehicle.
Pole Piece and Plate Assembly
R e p la c e m e n t (Figs. 6 D -7 i - 6D-9i)
The pole piece and plate assembly is serviced by
complete replacement only. The three screws securing
stationary pole piece and permanent magnet should not be
disturbed except under extreme conditions since the pole
piece is adjusted by the factory to critical dimensions. During
replacement, make sure the replacement pole piece and plate
assembly is the correct specified part. One quick method of
assuring a correct part is to observe the connector or retainer
(bow) that holds the white and green electrical leads together
is color coded yellow The correct pole piece and plate
assembly for all 6 and 8 cylinder engines is color coded
yellow.
1. Remove distributor as described previously in this
section.
2. Support distributor gear on a block of wood or other
suitable object (Fig. 6D-7i) and drive roll pin from drive gear.
Make sure distributor is supported in such a way that no
damage will occur to distributor shaft while removing roll
pin.
3. On 8 cylinder distributors, remove drive gear, shim
and tanged washer from distributor shaft.
4. On 6 cylinder distributors, remove drive gear from
distributor shaft.
5. Remove any burrs that may have been caused by
removal of roll pin and remove shaft (with rotor attached)
from distributor housing.
6. Use needle nose pliers or similar tool to remove pole
piece and plate assembly electrical leads from W (white) and
G (Green) terminals of module. Do not remove leads by
pulling on the wires as damage to the leads may occur.
7. Remove lock ring from top of pole piece and plate
assembly (Fig. 6D-8i) and remove pole piece and plate
assembly from distributor housing.
8. Lubricate felt wick with a few drops of m otor oil and
install replacement pole piece and plate assembly over upper
bushing and vacuum advance unit. Make sure the connector
or retainer (bow) that holds the white and green electrical
leads together is color coded yellow.
9. Install lock ring (Fig. 6D-8i) and then connect green
electrical lead of pole piece and plate assembly to G terminal
of module. Then connect white lead of pole piece and plate
assembly to W terminal of module.
10. Place distributor shaft (with rotor attached) in
distributor housing.
11. On 8 cylinder distributors, install tanged washer,
shim and drive gear on distributor shaft.
12. On 6 cylinder distributors, install drive gear on
distributor shaft.
13. Align holes of drive gear with hole of distributor
shaft so that locating mark on drive gear is in line with tip
of rotor. Support distributor shaft on a wooden block or other
suitable object and install roll pin. Make sure distributor is
supported in such a way that no damage will occur to
distributor shaft while installing roll pin.
14. Check to make sure shaft is not binding by spinning
shaft a few times by hand.
15. Install distributor as described previously in this
section.
COVER
COIL
SEAL
Fig. 6 D -9 i—RolI Pin In s ta lla tio n
Ignition Coil--8 Cylinder
S P R IN G
CAP
R em o val (Fig. 6 D - 1 0 i)
1. Disconnect battery wire and harness connector from
distributor cap.
2. Remove three screws securing coil cover to distributor
cap.
3. Remove four screws securing ignition coil to
distributor cap.
4. Remove ground wire from coil.
5. Push coil leads from under side of connectors and
remove coil from distributor cap.
ROTOR
VACUUM
UNIT
In s ta lla tio n (Fig. 6 D - 1 0 i)
1. Position coil into distributor cap with terminals over
connector at side of cap.
2. Push coil lead wires into connector on side of cap as
follows: black (ground) in center; brown next to vacuum
advance unit; pink opposite vacuum advance unit.
3. Secure ignition coil with four screws. Place ground
wire under coil mounting screw.
4. Install coil cover onto distributor cap and secure with
three screws.
Ignition Coil--6 Cylinder
R em o val (Fig. 6 D -5i)
1. Disconnect ignition switch to coil lead at coil.
2. Disconnect coil to distributor leads at coil.
3. Remove 4 screws securing coil to side of engine and
remove coil.
HOUSING
WASHER
GEAR
Fig. 6 D -10 i--E xplod e d V ie w o f 8 C y lin d e r HEI D is trib u to r
In s ta lla tio n (Fig. 6D-5i)
1. Install coil to side of engine with 4 screws.
2. Connect coil to distributor leads at coil.
3. Connect ignition switch to coil lead at coil.
SPARK PLUGS
GENERAL DESCRIPTION
The spark plug (Fig. 6 D -11 i) consists of a metal shell
in which is fastened a porcelain insulator and an electrode
extending through the center of the insulator. The metal shell
has a short electrode attached to one side and bent in toward
the center electrode. There are threads on the metal shell that
allow it to be screwed into a tapped hole in the cylinder head.
The two electrodes are of special heavy wire, and there is a
specified gap between them. The electric spark jum ps this gap
to ignite the air-fuel mixture in the combustion chamber,
passing from the center, or insulated, electrode. The seals
between the metal base, porcelain, and center electrode, as
well as the porcelain itself, m ust be able to withstand the high
pressure and tem perature created in the combustion chamber
during the power stroke.
Some spark plugs have been supplied with a built-in
resistor which forms part of the center electrode. The purpose
of this resistor is to reduce radio and television interference
from the ignition system as well as to reduce spark-plugelectrode erosion caused by excessively long sparking. We
have been talking of the high-voltage surge from the ignitioncoil secondary as though it were a single powerful surge that
almost instantly caused the spark to jum p across the spark
plug gap. Actually, the action is more complex than that.
There may be a whole series of preliminary surges before a
full-fledged spark forms. At the end of the sparking cycle the
spark may be quenched and may reform several times. All
this takes place in only a few ten-thousandths of a second.
The effect is that the ignition wiring acts like a radio
transmitting antenna; the surges of high voltage send out
impulses that causes radio and television interference.
However, the resistors in the spark plugs tend to concentrate
the surges in each sparking cycle, reduce their number, and
thus reduce the interference and also the erosive effect on the
plug electrodes.
H e a t R ange S y ste m
The "heat range" of a spark plug is determined primarily
by the length of the lower insulator. The longer this is, the
hotter the plug will operate; the shorter it is, the cooler the
plug will operate (Fig. 9-12i).
Spark plugs, to give good performance in a particular
engine, must operate within a certain temperature range
(neither too hot nor too cool). If the spark plug remains too
cool: oil, soot, and carbon compounds will deposit on the
insulator causing fouling and missing. If the plug runs too
hot, electrodes will wear rapidly, and under extreme
conditions, prem ature ignition (pre-ignition) of the fuel
mixture may result.
Frequently, the wrong type of spark plugs, one with an
improper heat range for the engine, may have been installed
when replacing spark plugs originally fitted by the engine
manufacturer and such misapplication may lead to poor
performance. The heat range system makes it possible to
select the type of spark plug that will operate within the
correct tem perature range for each specific engine.
Where abnormal operating conditions cause chronic
carbon or oil fouling of the plugs, the use of a type one
number higher' (a "hotter" type) than recommended will
generally remedy the trouble; and by the same formula, where
chronic pre-ignition or rapid electrode wear is experienced,
a type with one num ber lower (a "cooler" type) will generally
U i
P
P
-------
COLDER
tt-SS*
HOTTER
be found satisfactory.
The last digit of the type num ber indicates the heat range
position of the plug in the heat range system. Read the
numbers as you would a therm om eter-the higher the last
digit, the "hotter" the spark plug will operate in the engine;
the lower the last digit, the "cooler" the spark plug will
operate.
S p a rk Plug R ea ch and T h re a d s
Spark plugs are m anufactured in a num ber of thread
sizes and "reaches." Reach is the distance from the gasket
seat to the end of the shell. Spark Plugs have a type number
on the insulator which designates plug thread size as well as
the relative position in the heat range system as previously
explained.
DIAGNOSIS
U nder normal operating conditions, spark plugs wear
out due to the destructive action, under intense heat, of
sulphur and lead compounds in the fuel and the
bom bardm ent of the electric spark on the electrodes.
It is reasonable to expect over 22,000 miles of useful life
from a spark plug. However, operating conditions are an
important factor and life expectany of the spark plug will vary
with the type of service in which the engine is used.
The same type of spark plug used in two different
engines of the same make and model may frequently show
wide variation in appearance. The cause of such differences
lies in the condition of the engine, its piston rings, carburetor
setting, kind of fuel used, and under what conditions the
engine is operated, namely, sustained high speeds or heavy
loads; or continual low speed, stop-and-go driving or light
loads.
Spark Plugs are frequently blamed for faulty engine
operation which they do not cause. Replacement of old spark
plugs by new may temporarily improve poor engine
performance because of the lessened demand new plugs make
on the ignition system. This cannot permanently cure poor
engine performance caused by worn rings or cylinders, weak
coil, worn contact points, faulty carburetion or other engine
ills.
On the following pages are pictures of some commonly
encountered appearances and causes of spark plug problems.
N O R M A L OPERATION
Brown to grayish-tan deposits and slight electrode wear indicate correct spark
plug heat range and mixed periods of high and low speed driving. SPARK PLUGS
HAVING THIS APPEARANCE MAY BE REINSTALLED. IF MISFIRING PER
SISTS, SPARK PLUGS SHOULD BE REPLACED.
When reinstalling spark plugs, be sure to use new gaskets on spark plugs that
utilize engine seat gaskets.
N orm al O pe ra tion
DEPOSIT F O U L IN G —" A "
Red, brown, yellow and white colored coatings which accumulate on the insula
tor are by-products of combustion and come from the fuel and lubricating oil, both
of which today generally contain additives. Most powdery deposits have no adverse
effect on spark plug operation; however, they may cause interm ittent missing under
severe operating conditions, especially at high speeds and heavy load. SPARK PLUGS
HAVING THIS APPEARANCE SHOULD BE REPLACED.
D eposit F o u lin g " A "
DEPOSIT F O U L IN G —" B "
Most powdery deposits, as shown in “A” , have no adverse effect on the operation
of the spark plug as long as they remain in the powdery state. However, under certain
conditions of operation, these deposits melt and form a shiny yellow glaze coating on
the insulator which, when hot, acts as a good electrical conductor. This allows the
current to follow the deposits instead of jumping the gap, thus shorting out the spark
plug.
Glazed deposits can be avoided by not applying sudden load, such as wide open
throttle acceleration, after sustained periods of low speed and idle operation. SPARK
PLUGS HAVING THIS APPEARANCE SHOULD BE REPLACED.
CARBON FOULIN G
D eposit F o u lin g " B "
Dry, fluffy black carbon deposits may result from overrich carburetion, excessive
hand choking, a faulty automatic choke, or a sticking manifold heat valve. A clogged
air cleaner can restrict air flow to the carburetor causing rich mixtures. Poor ignition
output (faulty breaker points, weak coil or condenser, worn ignition cables) can
reduce voltage and cause misfiring. Fouled spark plugs are the result—not the
cause of this problem. AFTER THE CAUSE HAS BEEN ELIMINATED, SPARK
PLUGS HAVING THIS APPEARANCE SHOULD BE REPLACED.
Excessive idling, slow speeds under light load also can keep spark plug tempera
tures so low that normal combustion deposits are not burned off. In such a case a
hotter type spark plug will better resist carbon deposits.
DETO N A TIO N
Overadvanced ignition timing, or the use o f low octane fuel will result in detona
tion commonly referred to as engine knock.
This causes severe shock inside the combustion chamber resulting in damage to
the adjacent parts which include spark plugs. A common result of detonation is to
have the sidewire of a spark plug torn off.
INSTALL A NEW PLUG OF THE RECOMMENDED HEAT RANGE AFTER
PROBLEM HAS BEEN CORRECTED.
D e to n a tio n
IN SU F F IC IE N T IN S T A L L A T IO N TORQUE
Failure to install a spark plug with sufficient torque results in poor contact
between the spark plug and the engine seat. The lack of proper heat transfer,
resulting from poor seat contact, causes excessive overheating of the spark plug and,
in many cases, severe damage as shown.
A NEW SPARK PLUG OF THE RECOMMENDED HEAT RANGE SHOULD BE
INSTALLED IN ACCORDANCE WITH AC INSTALLATION INSTRUCTIONS.
In s u ffic ie n t
In s ta lla tio n T o rq u e
PRE—IG N IT IO N
Pre-ignition, causing burned or blistered insulator tip and badly eroded elec
trodes, indicates excessive overheating. Cooling system stoppages or sticking valves
can also result in pre-ignition. Lean fuel-air mixtures are an additional cause.
INSTALL A NEW PLUG OF THE RECOMMENDED HEAT RANGE AFTER
PROBLEM HAS BEEN CORRECTED.
Sustained high speed, heavy load service can produce high temperatures which
will cause pre-ignition and, in this instance a colder spark plug should be used.
P re-ign ition
IMPROPER IN S T A L L A T IO N
Dirty threads in an engine head will result in the plug seizing before it is actually
seated. This results in poor heat transfer and causes the spark plug to overheat.
To insure proper seating of a new spark plug in the head, dirty cylinder head
threads should be cleaned with a greased thread chaser of the proper size.
ELIMINATE THE CAUSE AND INSTALL A NEW PLUG OF THE RECOM
MENDED HEAT RANGE.
O IL
F O U L IN G
Wet, oily deposits with a minor degree o f electrode wear may be caused by oil
pumping past worn rings. “Break-in” o f a new or recently overhauled engine before
rings are fully seated may also result in this condition. Other possibilities o f intro
duction o f oil into the combustion chamber are a porous vacuum booster pump
diaphragm or excessive valve stem guide clearances.
A HOTTER TYPE SPARK PLUG WILL REDUCE OIL DEPOSITS, but too hot a
spark plug can cause pre-ignition and, consequently, severe engine damage. An engine
overhaul may be necessary in severe cases to obtain satisfactory service.
O il F oulin g
H E A T SH O C K F A IL U R E
Heat shock is a common cause of broken and cracked insulator tips. Over
advanced ignition timing and low grade fuel are usually responsible for heat shock
failures. Rapid increase in tip temperature under severe operating conditions causes
the heat shock and fracture results.
Another common cause of chipped or broken insulator tips is carelessness in
regapping by either bending the centerwire to adjust the gap, or allowing the gapping
tool to exert pressure against the tip of the center electrode or insulator when
bending the side electrode to adjust the gap.
ELIMINATE THE CAUSE AND INSTALL A NEW PLUG OF THE RECOM
MENDED HEAT RANGE.
Heat Shock Failure
ON-VEHICLE SERVICE
C O M P O N E N T PART REPLACEMENT
Spark Plug
instructions of the m anufacturer of the cleaner being used,
cleaning each plug until the interior of shell and the entire
insulator are clean; however, avoid excessive blasting.
R em oval
1. To disconnect wires, pull only on the boot and gently
twist boot while pulling away. Pulling on the wire might
cause separation of the core of the wire. Remove spark plugs
and gaskets using a 5 /8 " deep socket on the 5/8" hex tapered
plugs. Use care in this operation to avoid cracking spark plug
insulators.
2. Carefully inspect the insulator and electrodes of all
spark plugs. Replace any spark plug which has a cracked or
broken insulator. If the insulator is worn away around the
center electrode, or the electrodes are burned or worn, the
spark plug is worn out and should be discarded.
Examine interior of plug in good light. Remove any
cleaning compound with compressed air. If traces of carbon
oxide remain in plug, finish the cleaning with a light blasting
operation. Clean firing surfaces of center and side electrodes
with several strokes of a fine file.
When spark plugs have been thoroughly cleaned,
carefully inspect for cracks or other defects which may not
have been visible before cleaning.
A d ju stin g S p a rk Plug Gap (Fig. 6 D -1 3 i)
C lean in g
Spark plugs which have carbon or oxide deposits should
be cleaned in a blast type spark plug cleaner. Scraping with
a pointed tool will not properly remove the deposits and may
damage the insulator. If spark plugs have a wet or oily deposit
dip them in a degreasing solvent and then dry thoroughly
with dry compressed air. Oily plugs will cause the cleaning
compound to pack in the shell. Carefully follow the
Use round wire feeler gages to check the gap between
spark plug electrodes of used plugs. Flat feeler gages will not
give a correct measurement if the electrodes are worn. Adjust
gap by bending the side electrodes only Adjust gaps to
specifications. Setting spark plug gap to other than
specification to effect changes in engine performance is not
recommended.
In s ta lla tion of S p a rk Plugs
When installing spark plugs, make sure that all surfaces
on plugs and in cylinder heads are clean. When installing the
5/8" hex tapered seat spark plugs, tighten to 15 lb. ft., using
a 5/8" deep socket, an extension and a torque wrench.
CAUTION: I f tapered seat spark plugs are over-
tightened, there is a possibility they can crack and
be w ore difficult to rem ove at the next tune-up.
Fig. 6 D -1 3 i~ C h e c k in g S p a rk Plug Gap
IGNITION SWITCH
GENERAL DESCRIPTION
The electrical switching portion of the assembly is
separate from the key and lock cylinder. However, both are
synchronized and work in conjunction with each other
through the action of the actuator rod assembly. For a
complete explanation of the key and lock cylinder, and the
actuator rod assembly, refer to the Steering section of this
manual.
The ignition switch is key operated through the actuator
rod assembly to close the ignition primary circuit and to
energize the starting m otor solenoid for cranking. The
ignition switch used on all cars have five positions: OFF,
LOCK, ACCESSORY, RU N and START. O F F is the center
position of the key-lock cylinder, and LOCK is the next
position to the left. ACCESSORY is located one more detent
to the left of LOCK. Turning the key to the right of the O FF
position until spring pressure is felt will put the ignition
switch in the RU N position, and when turned fully to the
right against spring pressure, the switch will be in the START
position.
In the RU N position, the ignition primary circuit is
activated through a resistance wire. The ignition resistor wire
is used in the ignition running circuit to reduce the voltage
to the ignition coil. The resistor wire is bypassed when the
engine is being started. The purpose of this is to compensate
for the drop in voltage which occurs as the result of the heavy
drain on the battery during starting, and to provide a hotter
spark for starting.
All ignition switches have five terminals which are
connected in different combinations for each of the three
operating positions. A brass plate, inside the switch, has three
contacts which connect these terminals. Figure 12i shows the
positions o f the contacts in all positions as viewed from the
key side of the switch. There is also a ground pin in the
switch which contacts the “ ground” terminal when the
ignition switch is in the START position. This pin contacts
the IGN. terminal when in the OFF position.
Ignition S t a r t and Run C ircuit
The ignition switch is fed from the battery to the BAT.
terminal of the switch. When the ignition switch is in the OFF
position, no current flows through the switch. When the
ignition switch is turned to the ACC. position, the BAT.
terminal is connected to the ACC. terminal. This permits
operation of accessories when the engine is not running.
When the ignition switch is turned to the START
position, the BAT. terminal is connected to the SOL. and
IGN. terminals. When the clutch or automatic transmission
neutral start switches are closed, current flows to the starter
solenoid. This energizes the solenoid windings. The solenoid
has two sets of windings: a "pull-in" winding and a "hold-in"
winding. Both windings are used to create the magnetic field
to actuate the the solenoid plunger and move the starter
pinion into engagement with the flywheel. As the solenoid
plunger reaches the end of its travel, it closes a switch which
connects battery voltage to the starter motor. With battery
voltage applied to both terminals of the "pull-in" windings,
the "pull-in" winding is no longer energized, so that only the
"hold-in" winding keeps the starter solenoid engaged.
NOTE: The instrument panel warning lights are fed
from the ignition terminal of the ignition switch and
have battery voltage applied to them when the ignition
switch is in the STA RT and RU N position. These
circuits are explained in the Chassis Electrical Section.
When the ignition switch is released from the START
to the RUN position, the IGN. terminal is still connected to
the BAT. terminal, but the solenoid is no longer energized
and so the feed for the coil from the IGN. terminal on the
ignition switch, through the ignition resistor wire and to the
coil, dropping the battery voltage at the coil to approximately
nine volts. W ith the ignition switch in the RU N position, the
BAT. terminal is connected to the IG N . terminal and the
ACC. terminal. This permits operation of all accessories and
the ignition system.
12 R
1 2 P P L /W
12 O R N
IGN 3
BAT 1
BAT 2
BAT 3
GRD 1
-h
IGN 1
GRD 2
ACC
12 P
2 4 B R N /W
12 B R N
2 0 DG
IG N IT IO N
(V IE W
FROM
S W IT C H
T E R M IN A L
P O S IT IO N S —
S ID E
OF
S W IT C H )
IG N - 3
□
LO CK
I
L ig n -iJ
P O S IT IO N
IG N -3
G R D -2
RUN
P O S IT IO N
I
ACCESSORY
P O S IT IO N
Fig. 6 D -14 i—Ig n itio n S w itc h C irc u it
STARTER SYSTEM
GENERAL DESCRIPTION
The function of the starting system, composed of the
starting motor, solenoid and battery, is to crank the engine.
The battery supplies the electrical energy, the solenoid
completes the circuit to the starting motor, and the motor
then does the actual work of cranking the engine.
The starting m otor (fig. 6D -ls) consists primarily of the
drive mechanism, frame, arm ature, brushes, and field
windings. The starting m otor is a pad mounted 12-volt
extruded frame type, having four pole shoes and four fields,
connected with the arm ature. The aluminum drive end
housing is extended to enclose the entire shift lever and
plunger mechanism, protecting them from dirt, splash, and
icing. The drive end frame also includes a grease reservoir
to provide improved lubrication of the drive end bearing. The
flange m ounted solenoid switch operates the overrunning
clutch drive by means of a linkage to the shaft lever.
The starting system is made up of the cranking motor
with its drive mechanism, the starter motor solenoid and the
battery. These units are connected together and work as a
team to crank the engine. The simplified diagram (Fig. 6D2s) shows the electrical components in a typical starting
system. Although modern day applications use more
circuitry and controls than shown in Figure 6D -ls, the
function of the components is always the sam e-to convert
electrical energy from the battery into mechanical energy at
the starter m otor to crank the engine.
STARTER M O TO R
To understand the operating principles of a starter
motor, think of a straight wire conductor located in the
magnetic field of a horseshoe-shaped magnet. Current is
flowing through the wire as shown in Figure 6D-3s. There
will be two separate magnetic fields-the one produced by the
SWITCH
TERMINAL
SOLENOID
GROMMET
PLUNGER
RETURN
SPRING
\
O J S -—
SHIFT
LEVER
BUSHING
PINION
STOP
INSULATED
BRUSH
HOLDER
BRUSH
RISER BARS
TO RISER BARS
TO ARMATURE
OVERRUNNING
CLUTCH
Fig. 6 D -1 s~ S ta rtin g M o to r Cross S e ctio n (T yp ica l)
horseshoe magnet and the one produced by the current flow
through the conductor.
Since magnetic lines always leave a N orth pole and enter
a South pole, the direction of the magnetic lines between the
two poles of the horseshoe magnet will be upward as shown.
The current-carrying conductor will produce a magnet field
shown as circles around the wire. The net result is more
magnetic lines on the left hand side of the wire than on the
right (Fig. 6D-4s).
W ith a strong field on one side of the conductor and a
weak field on the other side, the conductor will move from
the strong to the weak field, or from left to right. This
magnetic force makes the cranking m otor operate.
A basic motor is shown in Figure 6D-5s. A loop of wire
is placed between two iron pole pieces and is connected to
two separate com m utator bars. Riding on the commutator
MAGNETIC FIELD
CURRENT FLOW
Fig. 6 D -5s~ B asic M o to r
Fig. 6 D -3 s -M a g n e tic Field o f a H orseshoe M a g n e t
bars are two brushes, which are connected to the battery and
to the windings located over the pole pieces.
Current flow can be traced from the battery through the
pole piece windings, to a brush and com m utator bar, through
the loop of wire to the other com m utator bar and brush, and
then back to the battery. The magnetic fields create a turning
or rotational effect in the same clockwire direction as shown
in Figure 6D-6s.
The basic m otor we have used in our illustrations has
no practical value. It would produce very little torque to
crank an engine. It has served, however, to show the
fundam ental principles that operate a starter motor.
In the simplest terms, the arm ature is rotated by a
concentration of magentic lines on one side of the arm ature
conductor and a lack of magnetic lines on the other side of
the conductor.
STRONG
FIELD
W E A K FIELD
Construction
A cross-sectional view o f a typical starter m otor with a
solenoid is shown in figure 6D-ls.
The starting m otor assembly is made up of field coils
placed over pole pieces which are attached to the inside of
a heavy iron frame, an arm ature, an overrunning clutch-type
drive mechanism, and a solenoid.
The iron frame and pole shoes not only provide a place
for the field coils, but also provide a path for the magnetic
lines produced by the field coil windings.
A rm a tu re
The arm ature assembly (Fig. 6D-7s), consists of a stack
of iron laminations placed over a steel shaft, a com m utator
assembly and the arm ature winding. The windings are heavy
copper ribbon that are assembled into slots in the iron
laminations. The winding ends are soldered or welded to the
com m utator bars which are electrically insulated from each
other and from the iron shaft.
The arm ature is supported by bushings in the end
frames. Brushes are supported on the field frame and ride on
the com m utator bars.
HOLD-IN W IN D IN G
Fig. 6 D -7 s~ A rm a tu re A sse m b ly
D riv e M e c h a n is m
(NOT A PART OF SOLENOID)
The starting m otor drive mechanism (Fig. 6D-8s) is a
roll-type overrunning clutch that is assembled onto the
armature shaft. Through this drive component power is
transm itted from the armature to the engine during the
starting cycle.
The overrunning clutch drive contains a pinion which
is made to move along the shaft by means of a shift lever to
engage the engine ring gear for cranking. A gear reduction
is provided between the pinion and ring gear to meet the
cranking requirements of the engine. W ith this gear
reduction, the m otor operates to crank the engine at speeds
required for starting.
The overrunning clutch drive has a shell and sleeve
assembly which is splined internally to match the spiral
splines on the arm ature shaft. The pinion is located inside the
shell along with spring-loaded rollers that are wedged against
the pinion and a taper inside the shell. The springs may be
either a helical or accordion type. Four rolls are used. A
collar and spring, located over the sleeve, are the other major
clutch components.
When the shift lever is operated by the solenoid, it moves
the collar endwise along the shaft. The spring pushes the
pinion into mesh with the ring gear. If a tooth abutment
occurs, the spring compresses until the switch is closed, at
which time the arm ature rotates and the tooth abutment is
cleared. The compressed spring then pushes the pinion into
mesh and cranking begins.
Torque is transm itted from the shell to the pinion by the
C L U T C H ----------PINIO N AND
COLLAR ASSEMBLY
BUSHINGS
SHELL AND
SLEEVE ASSEMBLY
LOCK WIRE
Fig. 6 D -9 s -S o le n o id Cross S ection
rolls which are wedged tightly between the pinion and taper
cut into the shell.
When the engine starts, the ring gear drives the pinion
faster than the arm ature and the rolls move away from the
taper, allowing the pinion to overrun the shell. The start
switch should be opened immediately when the engine starts
to avoid prolonged overrun. When the shift lever is moved
back by the return spring, the pinion moves out of mesh and
the cranking cycle is completed.
S O L E N O ID
A sectional view of a typical solenoid is shown in Figure
6D-9s. It performs two functions in the starting system. First,
it is used to provide a circuit of short length and low
resistance between the battery and motor. Since the motor
amy draw several hundred amperes during operation, heavy
cables of short length are needed to reduce the voltage drop
in the circuit.
If a solenoid switch were not used and the high motor
currents were carried directly through the start switch, cables
of excessive size would be required to limit the voltage drop
to an acceptable value.
Since the start switch is usually some distance from the
battery and solenoid switch, the long leads connected to the
switch can be of reasonable size since they conduct only the
small current drawn by the solenoid switch winding (Fig.
6D-10s).
Second, when the start switch is closed, the solenoid
moves the pinion into mesh, and the cranking cycle begins.
When the start switch is opened, the cranking cycle ends. The
neutral safety switch in this type of circuit is closed only when
the transmission shift lever is in the proper position, thereby
preventing cranking of the engine with the transmission in
gear.
The solenoid switch consists basically of two windings
mounted around a hollow cylinder containing a moveable
core or plunger (Fig. 6D-9s). A shift lever is connected to the
plunger. When the push rod and contact disc is pushed into
firm contact with the battery and motor terminals of the
solenoid, with the m otor windings connected directly to the
battery, cranking takes place.
The two windings in the solenoid are called the hold-in
winding and the pull-in winding (Fig. 6 D -lls).
The hold-in winding contains many turns of fine wire
and the pull-in winding the same num ber of turns of larger
wire. When the start switch is closed, current flows from the
battery to the solenoid (S) terminals, through the hold-in
winding to ground, and then back to the battery. Current also
flows through the solenoid (M) term inal and then through
the m otor windings to the ground.
The magnetism created by each winding adds together
to form a strong magnetic field that attracts the plunger into
the core. Plunger movement shifts the pinion into mesh with
the ring gear and also moves the contact disc to close the
circuit between the solenoid battery (B) and M otor (M)
terminals. W ith the m otor windings connected directly to the
battery through the contact disc, cranking takes place.
The pull-in winding operates to assist the hold-in
winding in pulling the plunger into the core. Once the plunger
movement has been completed, much less magnetism is
needed to hold the plunger in the cranking position. W ith the
contact disc contacting the battery and m otor terminals of
the solenoid, the pull-in winding is shorted and no current
flows through it. This design feature reduces current draw
on the battery and also reduces the am ount of heat created
in the solenoid.
W hen the start switch is opened, current flows for a very
brief instant through the contact disc to the solenoid motor
(M) terminal, through the pull-in winding in a reverse
direction to the solenoid (S) terminal and then through the
hold-in winding in a normal direction back to the battery.
The magnetisms created by each winding oppose and cancel
out each other and the return spring moves the entire shifting
mechanism to the at-rest position, to complete the cranking
cycle.
Fig. 6 D -1 0 s ~ S ta rt S w itc h C irc u it (T yp ica l)
NO C R A N K IN G A C T IO N
DIAGNOSIS
1. Make sure that control lever is neutral (N) or park
(P) position or that clutch pedal is depressed on manual
transmission.
2. Make quick check of battery and cables. If battery is
low, the solenoid usually will produce a clattering noise,
ecause a nearly discharged battery will not sustain the
8ltage required to hold solenoid plunger in after solenoid
switch as been closed.
3. If starter m otor spins and drive pinion engages ring
gear but does not drive it, overrunning clutch is slipping.
Remove m otor to replace drive assembly.
4. If starter m otor does not operate, note whether
solenoid plunger is pulled into solenoid when solenoid curcuit
is closed. Ordinarily the plunger makes a loud click when it
is pulled in. If plunger is pulled in, solenoid circuit is okay
and trouble is in solenoid switch, cranking m otor, or cranking
m otor circuit. The starter m otor must be removed for repairs
to switch or motor.
5. If plunger does not pull into solenoid when ignition
switch is turned to "STA RT", the solenoid circuit is open,
or solenoid is at fault.
6. To find reason why plunger does not pull into
solenoid, connect jum per between solenoid battery terminal
and terminal on solenoid switch to which purple wire is
connected. If cranking m otor operates, solenoid is okay;
trouble is in ignition switch, neutral start switch, or in wires
and connections between these units.
7. If starter m otor still does not operate, remove motor
for inspection and test of solenoid switch.
C R A N K IN G SPEED A B N O R M A L L Y L O W
Abnormally low cranking speed may be caused by low
battery or defective cables, defective solenoid switch,
defective cranking m otor, or an internal condition of engine.
1. M ake quick check of battery. If low battery is
indicated, test battery. If defective cables are indicated, test
cables.
NOTE: Check generator belt tension for cause of low
battery.
2. If battery and cables are okay, test cranking motor
and solenoid switch.
3. If starter m otor and solenoid switch test okay, the
trouble is due to an internal condition of engine. This may
be due to use of engine oil which is too heavy for prevailing
temperatures.
V O L T A G E T E S T OF S T A R T IN G S Y S T E M A N D
S O L E N O ID S W I T C H
The voltage across the starter motor and switch while
cranking the engine gives a good indication of any excessive
resistance.
NOTE: Engine m ust be at normal operating
tem perature when test is made.
1. Inspect battery and cables to make certain that battery
has ample capacity for cranking and ignition.
2. Connect jum per wire to distributor term inal of coil
and to ground on engine, so that engine can be cranked
without firing.
3. Connect voltmeter positive lead to the m otor terminal
on solenoid switch; connect voltmeter negative lead to ground
(Fig.6D-12s).
4. T urn ignition switch on, crank engine and take
voltmeter reading as quickly as possible. If cranking motor
turns engine at norm al cranking speed with voltmeter reading
Fig. 6 D - 12 s -C ra n k in g V o lta g e T est C o n n e ction s
9 or more volts, the m otor and switch are satisfactory. If
cranking speed is below norm al and voltmeter reading is 9
volts or greater, the cranking motor is defective.
CAUTION: D o not operate starter m otor more
than 30 seconds at a tim e without pausing to allow
m otor to cool for at least two minutes; otherwise,
overheating and damage to m otor m ay result.
5. If starter m otor turns engine at low rate of speed with
voltmeter reading less than 9 volts, test solenoid switch
contacts as follows:
6. With voltmeter switch turned to any scale above 12
volts, connect voltmeter negative lead to the motor terminal
of solenoid switch, and connect positive lead to battery
terminal of switch (Fig. 6D-13s).
7. Turn ignition switch on and crank engine.
Immediately turn voltmeter switch to low scale and take
reading as quickly as possible, then turn switch back to higher
scale and stop engine.
The voltmeter will read not more than 2/10 volt if switch
contacts are satisfactory. If voltmeter reads more than 2/10
volt, switch should be repaired or replaced.
"S' T E R M IN A L
S O L E N O ID
A M P E R A G E T E S T OF S O L E N O ID S W IT C H
W IN D IN G S
VO LTM ETER
1 2 -V O L T
BATTERY
Fig. 6 D - 14s--A m p e ra g e T e st o f S o le n o id
(1) Current draw of both windings in parallel.
(2) Current draw of hold-in winding alone.
1. Remove screw from solenoid m otor terminal and bend
field leads slightly until clear of terminal. Then ground
solenoid motor terminal with a heavy jum per wire (Fig. 6D14s).
2. Connect a 12-volt battery, a variable resistance, and
an ammeter of 100 amperes capacity in series with solenoid
"S" terminal. Connect a heavy jum per wire from solenoid
base to ground post of battery.
3. Connect a voltmeter between base of solenoid and
small solenoid "S" terminal.
4. Slowly adjust resistance until voltmeter reads 10 volts
and note ammeter reading. This shows current draw of both
windings in parallel. Refer to Delco-Remy bulletin for
specifications on the starter being tested.
5. Remove jum per wire from solenoid motor terminal
and re-adjust resistance until voltmeter reads 10 volts, then
note ammeter reading. This shows current draw of hold-in
winding alone. Refer to Delco-Remy bulletin for
specifications.
6. If solenoid windings do not test within specifications
given, solenoid switch assembly should be replaced.
O N-VEH IC LE SERVICE
M A IN T E N A N C E A N D A D J U S T M E N T S
Lubrication
No periodic lubrication of the starting m otor or solenoid
is required. Since the starting m otor and brushes cannot be
inspected w ithout disassembling the unit, no service is
required on these units between overhaul periods.
C O M P O N E N T PART REPLACEM ENT
S T A R T IN G M O T O R
R e p la c e m e n t
The following procedure is a general guide for all
vehicles and will vary slightly depending on series and model.
1. Disconnect battery ground cable at battery.
2. Raise vehicle to a good working height.
3. Disconnect all wires at solenoid terminals.
NO TE: Reinstall the nuts as each wire is disconnected
as thread size is different but may be mixed and stripped.
4. Loosen starter front bracket (nut on V-8 and bolt on
L-4) then remove two m ount bolts.
N O TE: On V-8 engines incorporating the solenoid heat
shield, remove the front bracket upper bolt and detach
bracket from starter motor.
5. Remove the front bracket bolt or nut and rotate
bracket clear of work area then lower starter from vehicle by
lowering front end first — (hold starter against bell housing
and sort of roll end-over-end).
6. Reverse the removal procedure to install. Tighten the
m ount bolts first, then tighten the brace bolt.
7. Check operation of starter on vehicle.
C H E C K IN G P IN IO N C L E A R A N C E
W henever the starter m otor is disassembled and
reassembled, the pinion clearance should be checked. This is
to make sure that proper clearance exists between the pinion
and pinion stop retainer when pinion is in cranking position.
Lack of clearance would prevent solenoid starter switch from
closing properly; too much clearance would cause improper
pinion engagement in ring gear.
1. Connect a source of approximately 6 volts (3 battery
cells or a 6 volt battery) between the solenoid "S" terminal
and ground.
C A U TIO N : D o not use m ore than 6 volts or the
m otor will operate. A s a further precaution to
prevent motoring, connect a heavy ju m p e r wire
from the solenoid m o to r terminal to ground.
2. A fter energizing the solenoid, push the pinion away
from the stop retainer as far as possible and use feeler gauge
to check clearance between pinion and retainer (Fig. 6D-15s).
3. If clearance is not between .010'' and . 140" it indicates
excessive wear of solenoid linkage, shift lever mechanism, or
improper assembly of these parts.
NO TE: Pinion clearance cannot be adjusted. If
clearance is not correct, m otor must be disassembled and
checked for the above mentioned defects. Any defective
parts m ust be replaced.
B EN C H T E S T OF S T A R T IN G M O T O R
To obtain full performance data on a cranking motor,
or to determine the cause of abnormal operation, the motor
should be removed from the engine and be submitted to a
no-load test with equipment designed for such tests. A high
current carrying variable resistance should be connected into
the circuit so that the specified voltage at the starter motor
may be obtained, since a small variation in the voltage will
produce a marked difference in the current draw.
(a) No-Load Test. Connect the starter motor in series
with a 12 volt-battery and an ammeter capable of indicating
several hundred amperes. If an RPM indicator is available,
set it up to read arm ature RPM. Check current draw and
arm ature RPM at the specified voltage.
1. Low no-load speed and high current draw may result
from:
(a) Tight, dirty, or worn bearings, bent arm ature shaft
or loose field pole screws which would allow the arm ature
to drag.
(b) Shorted armature. Check arm ature further on
growler.
(c) A grounded arm ature or field.
Check for grounds by raising the grounded brushes and
insulating them from the com m utator. If the starter motor
has shunt field coils which are grounded to the field frame,
disconnect these fields from gound. Then check with a test
lamp between the insulated terminal and the frame. If lamp
lights, raise other brushes from com m utator and check fields
separately to determine whether it is the fields or arm ature
that is grounded:
2. Failure to operate with high current draw may result
from:
(a) A direct ground in the terminal or fields.
(b) Frozen shaft bearings which prevent the arm ature
from turning.
3. Failure to operate with no current draw may result
from:
(a) Open field circuit. Inspect internal connections and
trace circuits with test lamp.
(b) Open arm ature coils. Inspect the com m utator for
badly burned bars.
(c) Broken or weakened brush springs, worn brushes,
high mica on the com m utator, or other causes which would
prevent good contact between the brushes and commutator.
Any of these conditions will cause burned com m utator bars.
4. Low no-load speed with low current draw indicates:
(a)
An open field winding. Raise and insulate
ungrounded brushes from com m utator and check fields with
test lamp.
(b)
High internal resistance due to poor connections,
defective leads, dirty com m utator and causes listed under
item 3 (c).
5.
High no-load speed with high current draw indicates
shorted fields. There is no easy way to detect shorted fields,
since the field resistance is already low. If shorted fields are
suspected, replace the fields and check for improvement in
performance.
UNIT REPAIR
D IS A S S E M B L Y (Figs. 6 D -1 S and 6 D -1 6 S )
1. Disconnect the field coil connector(s) from the motor
solenoid terminal.
2. Remove through bolts.
3. Remove com m utator end frame, field frame assembly
and arm ature assembly from drive housing.
4. Remove overrunning clutch from arm ature shaft as
follows:
a. Slide two piece thrust collar off end of arm ature shaft.
b. Slide a standard half-inch pipe coupling or other metal
cylinder of suitable size (an old pinion of suitable size can be
used if available) onto shaft so end of coupling or cylinder
butts against edge of retainer (fig. 6D-17S). Tap end of
coupling with hammer, driving retainer towards arm ature
end of snap ring.
c. Remove snap ring from groove in shaft using pliers
or other suitable tool. If the snap ring is too badly distorted
during removal, it may be necessary to use a new one when
reassembling clutch.
d. Slide retainer and clutch from arm ature shaft.
5. Disassemble brush rigging from field frame.
a. Release "V" spring from slot in brush holder support.
b. Remove support pin.
c. Lift brush holders, brushes and spring upward as a
unit.
d. Disconnect leads from each brush.
e. Repeat operation for other set of brushes.
C L E A N IN G A N D IN S P E C T IO N
W ith the starting m otor completely disassembled except
for removal of field coils, the component parts should be
cleaned and inspected as described below. Field coils need be
removed only where defects in the coils are indicated by the
tests described in this section.
1. Clean all starting m otor parts, but do not use grease
dissolving
solvent
for
cleaning
the
overrunning
clutch,arm ature, and field coils since such a solvent would
dissolve the grease packed in the clutch mechanism and
would damage arm ature and field coil insulation.
2. Test overrunning clutch action. The pinion should
turn freely in the overrunning direction and must not slip in
the cranking direction. Check pinion teeth to see that they
have not been chipped, cracked, or excessively worn. Check
the spring for norm al tension and drive collar for wear. If
necessary, the spring or collar can be replaced by forcing the
collar toward the clutch and removing lock ring from end of
tube.
3. Check brush holders to see that they are not deformed
or bent, but will properly hold brushes against the
comm utator.
4. Check the condition of the brushes and if pitted or
worn to one-half their original length, they should be
replaced.
5. Check fit of arm ature shaft in bushing of drive
housing. Shaft should fit snugly in the bushing. If the bushing
is worn, it should be replaced. Apply a silicone lubricant to
this bushing before reassembly. Avoid excessive lubrication.
6. Check fit of bushing in com m utator end frame. If this
bushing is damaged or worn excessively, the end frame
assembly must be replaced. Apply a silicone lubricant to this
bushing before reassembly. Avoid excessive lubrication.
Lubricant forced onto the com m utator would gum and cause
poor commutation with a resulting decrease in cranking
motor performance.
Som e starter m otor models use a
m olded armature com m utator design and no
attem pt to undercut the insulation should be made
or serious damage m ay result to the commutator.
Undercutting reduces the bonding o f the molding
material which holds the com m utator bars and
since the m olding material is softer than the copper
bars, it is n o t necessary to undercut the material
between the bars o f the m olded commutator.
7. Inspect arm ature commutator. If com m utator is
rough or out of round, it should be turned down and
undercut. Inspect the points where the arm ature conductors
join the com m utator bars to make sure that it is a good firm
connection. A burned com m utator bar is usually evidence of
a poor connection. See "Turning the Com m utator,"
described under Testing and Repairs.
C A U TIO N :
T E S T IN G A N D R E P A IR S
Armature Test For Shorts
Check the arm ature for short circuit by placing on
growler and holding hack saw blade over arm ature core while
arm ature is rotated (fig. 6D-18S). If saw blade vibrates,
arm ature is shorted. Recheck after cleaning between the
com m utator bars. If saw blade still vibrates, replace the
armature.
Armature Test For Ground
Place one lead on the arm ature core or shaft and the
other on the com m utator (fig. 6D-19S). If the lamp lights,
the arm ature is grounded and must be replaced.
Field Coil Test For Open Circuit
Place one lead on the insulated brush and the other to
the field connector bar (fig. 6D-20S). If the lamp does not
light, the field coils are open and will require replacement.
'3
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6
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12
11
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14
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1. D riv e H o u s in g
2 . S h if t L e ve r B o lt,
N u t and L o ck
W asher
3 . Pin
4 . S h if t Leve r
5. S o le n o id P lunge r
6 . S o le n o id R e tu rn S p rin g
7.
8.
9.
10.
11.
12.
13.
14.
S o le n o id Case
S c re w and L o c k W asher
G ro m m e t
F ie ld F ra m e
T h ro u g h B o lts
T h r u s t C o lla r
Snap R in g
R e ta in e r
'2 6
15. O v e rru n n in g C lu tc h A s
s e m b ly
16. A rm a tu re
17. B ra k in g W ashing
18. C o m m u ta to r E n d F ra m e
19. B rush S p rin g s
2 0 . W asher
2 1 . In s u la te d B rush H o ld e rs
22.
23.
24.
25.
26.
27.
28.
G ro u n d e d B rush H o ld e rs
Brushes
Screw s
F ie ld C o ils
In s u la to rs
Pole Shoes
Screw s
Fig. 6D-1 6S--Starting Motor Parts Layout
Field Coil Test For Ground
NO TE: Be sure to disconnect the shunt coil before
performing this test (when applicable).
Place one lead on the connector bar and the other on
the grounded brush (fig. 2 IS). If the lamp lights, the field
coils are grounded.
Field Coil Replacement
Field coils may be removed from the field frame using
a pole shoe screwdriver and a pole shoe spreader. The
spreader prevents distortion of the field frame. Careful
installation of field coils is necessary to prevent shorting or
grounding of the field coils as the pole shoe screws are
tightened in place. Formed insulators are used to protect the
field leads from grounding to the frame and must be replaced
with assembly.
Loose Electrical Connections
When an open soldered connection of the arm ature to
com m utator leads is found during inspection, it may be
resoldered provided resin flux is used for soldering. Acid flux
should never be used on electrical connections.
When inspection shows com m utator roughness, it
should be cleaned as follows:
CYLINDER
Fig. 6D-19S-Armature Ground Test
RETAINER
2. Undercut insulation between commutator bars 1/32".
This undercut must be the full width of insulation and flat
at the bottom; a triangular groove will not be satisfactory.
After undercutting, the slots should be cleaned out carefully
to remove any dirt and copper dust.
Fig. 6D-1 7S-Driving Retainer Off Snap Ring
3. Sand and the com m utator lightly with No. 00
sandpaper to remove and slight burrs left from undercutting.
4. Recheck arm ature on growler for short circuits.
Turning The Commutator
Brush Holder Replacement
1.
Turn down com m utator in a lathe until it is
thoroughly cleaned.
If brush holders are damaged, they can be replaced by
special service units.
C A U T IO N : Som e starter m o to r models use a
m olded armature com m utator design and no
Overrunning Clutch
attem pt to undercut the insulation should be made
or serious damage m ay result to the commutator.
The overrunning clutch (roll clutch design) used in the
Undercutting reduces the bonding o f the molding
various starting motors is (fig. 6D-22S) designed to be
material which holds the com- m utator bars and
serviced as a complete unit.
since the m olding material is softer than the copper
bars, it is not necessary to undercut the material
between the bars o f the m olded commutator.
SN A P
SN A P
GROOVE
Fig. 6D-21S~Field Coil Ground Test
ASSEM BLY
After all parts have been thoroughly tested and
inspected and worn or damaged parts replaced, the starter
should be reassembled.
1. Assemble brush rigging to field frame.
a. Assemble brushes to brush holders.
b. Assemble insulated and grounded brush holder
together with the "V" spring and position as unit on the
support pin. Push holders and spring to bottom of support
and rotate spring to engage the "V" in slot in support.
c. A ttach ground wire to grounded brush and field lead
wire to insulated brush.
d. Repeat for other set of brushes.
2. Assemble overrunning clutch assembly to arm ature
shaft.
a. Lubricate drive end of arm ature shaft with silicone
lubricant.
b. Slide clutch assembly onto arm ature shaft with pinion
outward.
c. Slide retainer onto shaft with cupped suraface facing
end of shaft (away from pinion).
d. Stand arm ature on end of wood surface with
com m utator down. Position snap ring on upper end of shaft
Fig. 6D-23S~Forcing Snap Ring Over Shaft
and hold in place with block of wood. Tap wood block with
hammer forcing snap ring over end of shaft (fig. 6D-23S).
Slide snap ring down into groove.
e. Assemble thrust collar on shaft with shoulder next to
snap ring.
f. Place arm ature flat on work bench, and position
retainer and thrust collar next to snap ring. Then using two
pair of pliers at the same time (one pair on either side of
shaft), grip retainer and thrust collar and squeeze until snap
ring is forced into retainer (fig. 6D-24S).
3. Lubricate the drive housing bushing with a silicone
RETAIN ER
SN A P RIN G
lubricant. Make sure thrust collar is in place against snap ring
and retainer and slide arm ature and clutch assembly into
place in drive housing engaging shift lever with clutch.
4. Position field frame over arm ature and apply special
sealing compound between frame and solenoid case. Position
frame against drive housing using care to prevent damage to
the brushes.
5. Lubricate the bushing in the commutator end frame
with a silicone lubricant. Place leather brake washer on
arm ature shaft and slide com m utator end frame onto shaft.
6. Reconnect the field coil connectors to the "motor"
solenoid terminal.
7. After overhaul is completed, perform "Pinion
Clearance Check".
P IN IO N C L E A R A N C E C H E C K
Fig. 6D-25S~Circuit for Checking Pinion Clearance
1. Connect a battery, of the same voltage as the solenoid,
from the solenoid switch terminal to the solenoid frame or
ground terminal (fig. 6D-25S).
N OTE: Disconnect the motor field coil connector for
this test.
2. M omentarily flash a jum per lead from the solenoid
motor terminal to the solenoid frame or ground terminal. The
pinion will now shift into cranking position and will remain
there until the jum per lead is disconnected.
3. Push the pinion back towards the com m utator end to
eliminate slack movement.
4. Measure the distance between the pinion and pinion
stop (fig. 6D-15S). If clearance is not within specified limits
(.010-. 140) it may indicate excessive wear of solenoid linkage
shift lever yoke buttons or improper assembly of the shift
lever mechanism. W orn or defective parts should be replaced.
STARTING SOLENOID
Removal
Installation
1. Remove the outer screw and washer from the motor
connector strap terminal.
1. With solenoid return spring installed on plunger,
position solenoid body to drive housing and turn
counterclockwise to engage the flange key in the keyway slot.
2. Install two screws retaining solenoid housing to end
frame.
3. Install outer screw and washer securing motor
connector strap terminal.
4. Install starter m otor as previously described.
2. Remove the two screws retaining solenoid housing to
end frame assembly.
3. Twist solenoid clockwise to remove flange key from
keyway slot in housing; then remove solenoid assembly.
Replacement of Contacts (Fig. 6D-26S)
1. W ith solenoid removed from motor, remove nuts and
washers from switch and m otor connector strap terminals.
2. Remove the two solenoid end cover retaining screws
and washers and remove end cover from solenoid body.
3. Remove nut and washer from battery terminal on end
cover and remove battery terminal. Remove resistor by-pass
term inal and contactor.
4. Remove motor connector strap terminal and solder
new terminal in position.
5. Using a new battery terminal, install terminal washer
and retaining nut to end cover. Install by-pass terminal and
contactor.
6. Position end cover over switch and m otor terminals
and install end cover retaining screws. Also install washers
and nuts on the solenoid switch and starting m otor terminals.
7. Bench test solenoid for proper operation.
MOTOR CONNECTOR
STRAP TERMINAL
END
COVER
SPECIFICATIONS
GENERATOR
MODEL N O .
A P P L IC A T IO N
FIELD CURRENT
C O LD O U T P U T *
AM PS 2 7 °C (80°F)
A/APS @
@ 12 VOLTS
5 0 0 0 RMP
4519
4 -4 .5
33
37
4521
4 -4 .5
38
42
4522
4 -4 .5
57
61
4525
4 -4 .5
76
80
DELCO REMY
SPEC. N O .
1102394
A ll L-6 (B ase)
1102491
(E x c e p t G -2 0 , 3 0 &
1102889
RATED H O T
O U T P U T ** AM PS
P -Truck)
A ll C -K -G T ru ck Base V -8
(E x c e p t K 3 1 3 0 3 &
G 30003)
1102485
29 2 L-6 (L25) (B ase)
1102841
(G -2 0 , 3 0 & P-Truck)
1102887
A ll P -T ruck Base V -8
(E x c e p t P 3 1 8 3 2 )
1102480
P 3 1 8 3 2 T ru ck (B ase)
1102486
1102886
A ll L-6 o r V -8 w ith RPO K76
1102888
4 5 4 V -8 (FL8) (B ase)
K31303 & G 30003
T ru ck Base V -8
1101016
O p t io n a l (C O P O )
1101028
* G e n e r a to r te m p e ra tu re a p p r o x im a t e ly 2 7 °C . (8 0 °F .).
* * A m b ie n t te m p e r a tu r e 2 7 °C . (8 0 °F .).
N o te : The o n ly d iffe r e n c e b e tw e e n g e n e ra to rs w ith in e a ch g r o u p a b o v e is th e p o s itio n e n d fr a m e is ro ta te d .
SPECIFICATIONS
DISTRIBUTOR & SPARK PLUGS
D is tr ib u to r a n d s p a rk p lu g s p e c ific a tio n s a re show n in th e Em ission C o n tro l C h a rt in S e ctio n 6E S p e c ific a tio n s .
BATTERY
M ODEL N O .
A P P L IC A T IO N
C O LD CRANK RATE
AM PS FOR
25 A M P . RESERVE
@ 0°F ( - 1 8°C)
LO A D TEST
C A P A C IT Y (M IN U T E S )
8 5 -4
2 5 0 L-6 (LD4)
2 7 5 A m ps
130
60
8 5 -5
2 9 2 L-6 (L25)
350 Am ps
170
80
4 6 5 A m ps
230
125
430 Am ps
210
100
3 0 5 V -8 (LG 9)
3 5 0 V -8 (LS9)
4 0 0 V -8 (LF4)
8 9 -5
4 5 4 V -8 (LF8)
RPO UA1
8 7 -5
RPO TP2
STARTING MOTOR
MODEL N O .
1108778
A P P L IC A T IO N
2 5 0 L-6 (LD4)
SPEC. N O .
FREE SPEED
VOLTS
AMPERES
RPM
35 7 3
9
5 0 -8 0 *
5 5 0 0 -1 0 5 0 0
(C & K -1 0 )
1108779
2 5 0 L-6 (LD 4) (G -V a n )
3573
9
5 0 -8 0 *
5 5 0 0 -1 0 5 0 0
1108780
29 2 L-6 (L25)
2438
9
5 0 -8 0 *
3 5 0 0 -6 0 0 0
1109056
3 0 5 V -8 (LG 9 ) (C & K)
3573
9
5 0 -8 0 *
5 5 0 0 -1 0 5 0 0
1109798
3 0 5 V -8 (LG 9) (G -V a n )
3573
9
5 0 -8 0 *
5 5 0 0 -1 0 5 0 0
1109052
3 5 0 V -8 (LS9)
3563
9
6 5 -9 5 *
7 5 0 0 -1 0 5 0 0
1108776
4 0 0 V -8 (LF4)
3563
9
6 5 -9 5 *
7 5 0 0 -1 0 5 0 0
4 5 4 V -8 (LF8)
* ln c lu d e s S o le n o id
S E C T IO N
6E
ENGINE EMISSION CONTROLS
C O N TE N TS
G en eral D escrip tio n .........................................................................
G en eral D escription o f Emission
C ontrol C o m p o n e n ts........................................................................
E ngine P erform ance D iagnosis C h a rts....................................
Early Fuel F .vaporation-E F E ........................................................
Exhaust G as R e c ircu la tio n -E G R ................................................
Positive C rankcase V entilation System -PC V ..........................
T herm ostatic A ir C leaner-T A C ...................................................
A ir Injection R e a c to r-A IR ............................................................
T hrottle R eturn C o n tro l-T R C .....................................................
Vacuum Advance C o n tro l.............................................................
GENERAL
D E S C R IP T IO N
,
.
T he norm al operation of the engine results in the
release ol several com pounds to the atm osphere. F ederal
G ov ern m en t and State o f C alifornia legislation has
placed lim itations on the quantities of three com pounds
u- l
i
.1
.I !
•
w hich can be em itted. Ihe three controlled com pounds
'
a rc
• H ydrocarbons - HC
• C arbon M onoxide - CO
• Oxides o f N itrogen - N O x
T he F ederal regualtions have been revised for 1977
req u irin g th at some vehicles sold for initial licensing,
registration, or titling at altitudes greater than 1219
m eters (4000 feet) be capable or m eeting em ission
stan dard s at such altitudes. In most cases, the revised
F ederal and C alifo rn ia regualtions make it necessary to
have specific engines and em ission control systems for
vehicles sold in areas above 1219 meters, areas below
1219 m eters, and C alifornia.
6E-1
6E-1
6E-10
6E-16
6E-18
6E-24
6E-25
6E-31
6E-35
6E-37
The em ission control section will consist o f a general
descrip tion o f em ission control com ponents and
subsystem s, f0 n0wed by vacuum hose schem atics or each
me t
dm gnosis and service procedure section.
The em ission control systems include:
^ .
.
„ ,.,
.
• C arb u reto r C alibration
..
_ ...
• D istributor C alibration
* Catalytic C onverter (Light D uty Emissions)
. \ E arly Fuel E vaporation (EFE) (Light D uty
Emissions)
*. Exhaust G as R ecirculation (EG R ) (Lt. D uty
Emissions 454 Calif. H -D uty Emissions)
* Positive C rankcase V entilation (PCV)
* Choke C alibration
• T herm ostatic A ir Cleaner(TAC)
• E vaporation Control System (ECS)
The emission control systems for some engines may
use an additional em ission control device called Air
Injection Reaction (AIR).
GENERAL DESCRIPTION OF EMISSION CONTROL COMPONENTS
C A R B U R ETO R C A LIB R A TIO N
D IS TR IB U TO R C A LIB R A TIO N
W hile the c a rb u re to r’s m ain function is to provide
the engine with a com bustible a ir/fu e l m ixture, the
carb u reto r calibration is critical to m ain tain in g p roper
em ission levels.
The distribu to r is an integral p a rt o f the engine
ignition system and the distributor calibratio n is an
im portant p a rt o f exhaust em ission control.
The initial tim ing centrifugal advance and vacuum
advance are calibrated to provide the best engine
perform ance and fuel econom y at varying speeds and
loads while rem aining w ithin exhaust em ission limits.
D istributor diagnostics and service procedures are in
Section 6D, Engine Electrical.
T he c a rb u re to r’s idle, off-idle, m ain m etering, power
enrichm ent, and accelerating pum p systems are cali
brated to provide the best possible com bination o f
engine perform ance, fuel econom y and exhaust em ission
control. C a rb u reto r adjustm ents and service must be
perform ed using the recom m ended procedures to insure
engine exhaust em ission levels rem ain w ithin legislated
limits.
See Section 6C, Fuel System, for carb u reto r
adjustm ent specifications and recom m ended service
procedures.
CATALYTIC CONVERTER
T he catalytic converter on a light duty em ission
vehicle is an em ission control device added to the
exhaust system to reduce hydrocarbon and carbon
m onoxide pollutants from the exhaust gas stream . The
converter contains m aterial w hich %is coated w ith a
catalytic m aterial co n tain in g p latin u m and palladium .
EARLY FUEL E V A P O R A TIO N SYSTEM (EFE)
N OTE: If an engine is idling too slow or rough,
this m ay be caused by a clogged ventilator valve or
plugged hose; therefore, never adjust the car
buretor idle w ithout first checking the PCV valve
and hose.
A fter installing a new PCV valve, readjust engine
idle if necessary.
W ith this system, any blow-by in excess o f the
system capacity (from a badly-w orn engine, sustained
heavy load, etc.) is exhausted into the air cleaner and is
draw n into the engine.
D iagnosis and service procedures fo r the PCV
system can be found in this section.
Light Duty Emissions
CHOKE SYSTEM
The E FE system is used to provide a source o f rapid
heat to the engine induction system d uring cold
driveway. R apid h eatin g is desirable because it provides
for quick fuel ev ap o ratio n and m ore u n ifo rm fuel
d istribu tio n to aid cold driveability. It also reduces the
length o f tim e ca rb u re to r choking is req u ired m aking
reductions in exhaust em ission levels possible.
E FE system s uses a valve w hich increases the
exhaust gas flow u n d er the intake m an ifo ld durin g cold
engine op eratio n . T he valve is vacuum o p erated and is
controlled by a th erm al vacuum switch (TVS) which
applies vacuum w hen the coolant tem perature is below
the c alib ratio n valve.
D iagnosis and service procedures o f the EFE system
can be found in this section.
An autom atic choke system, m aintains proper
engine perform ance during engine w arm -up. M odifica
tions to the choke system have been necessary in recent
years to m eet the lower legislated exhaust em ission
levels.
T H E CATALYTIC CON VE R TE R REQUIRES THE USE
OF UNLEADED FUEL ONLY.
P eriodic m aintenance o f the exhaust system is not
required; however, if the vehicle is raised for other
service, it is advisable to check the general condition o f
the underfloor catalytic converter, pipes and mufflers.
R efer to Section 6F, E ngine E xhaust System, for
catalytic converter service procedures and diagnostics.
E X H A U S T GAS R E C IR C U LA TIO N SYSTEM
(E G R )
Light Duty Emissions and 454-C alif. Heavy
Duty Emission.
The E xhaust G as R ecirculation System m eters
exhaust gas into induction system fo r recirculation
through the com bustion cycle to reduce oxides o f
n itro g en em issions.
The E G R valve rem ain s closed durin g periods o f
engine idle and deceleration to prevent rough idle from
excessive exhaust gas dilution in the idle a ir/fu e l
m ixtures.
All exhaust gas recirculation systems p erfo rm the
sam e function, however, differences in o p eration o f
system will be covered in the Service Procedure Section.
D iagnosis and service procedure o f E G R system can
be foun d in this section.
CLOSED P O SITIV E CRA NKCASE
V E N T IL A T IO N SYSTEM (P C V )
All engines have closed Positive Crankcase V entila
tion System to provide m ore com plete scavenging o f
crankcase vapors.
An en g in e w hich is o p erated w ithout any crankcase
ventilatio n can be dam aged seriously. T herefore, it is
im p o rtan t to replace the ven tilato r valve periodically.
T H E R M O S T A T IC AIR CLEANER (T A C )
The T herm ostatic A ir C leaner (TAC) is on all
engines. The TAC uses a dam per assem bly in the air
cleaner inlet, controlled by a vacuum m otor to mix p re
heated and non pre-heated air entering the a ir cleaner to
m a in ta in a co ntrolled a ir te m p e ra tu re into the
carburetor. The vacuum m otor is m odulated by a
tem perature sensor in the air cleaner. The p re-heating o f
the air cleaner inlet air allows leaner carb u reto r and
choke calibrations resulting in lower em ission levels,
w hile m ain tain in g good driveability. D iagnostics and
service procedures fo r the therm ostatic air cleaner can be
found in this section.
AIR IN JE C T IO N REACTOR SYSTEM
An air injection reactor (AIR) is used on some
engines to provide additional oxygen to continue the
com bustion process after the exhaust gases leave the
com bustion cham ber. An engine driven pu m p provides
pressurized air which is injected into the exhaust port of
the cylinder head o r exhaust pipe and then into the
exhaust system. The AIR system operates at all tim es and
will bypass air only for a short du ratio n o f tim e during
deceleration and at high speeds. The diverter valve
perform s the bypass function, and the check valve
protects the air pum p from dam age by prev enting a
back flow o f exhaust gas.
D iagnosis and service procedures fo r a ir injection
reactor system is in this section.
V A C U U M CO NTRO LS
V arious types o f vacuum controls are used in the
em ission control system to m odify or control the
operation o f the various em ission control com ponents to
optim ize em ission control effectiveness, w hile m inim izing
any negative effect on driveability.
R efer to the vacuum hose schem atics (Figs. 6E-1
through 6E-14) fo r usage o f these systems.
Fig. 6E-1--Vacuum Hose Schematic-L6 250 CID ■LD Emissions
DISTRIBUTOR
PCV
VALVE
MANIFOLD
VAC FITTING
DISTRIBUTOR
V A LV E
Fig. 6E-3~Vacuum Hose Schematic-L6 292 CID • Calif. - HD Emissions
V A LV E
Fig. 6E-5--Vacuum Hose Schematic-V8 305 CID - HD Emissions
Fig. 6E-7--Vacuum Hose Schematic-V8 350 CID High Altitude&Calif.-LD Emissions
VALVE
Fig. 6E-9--Vacuum Hose Schematic-V8 3 5 0 /4 0 0 CID Except Calif.-HD Emissions
CA N IS TER
PCV
VALVE
Fig. 6E-13--Vacuum Hose Schematic V8 454 CID Except Calif - HD Emissions
ENGINE PERFORMANCE DIAGNOSIS CHARTS
INTRODUCTION
Engine P erform ance D iagnosis procedures are
guides th a t will lead to the m ost pro b ab le causes o f
engine p erfo rm an ce com plaints. T hey consider all o f the
p arts o f the fuel, ignition, and m echanical systems that
could cause a p articu lar com plaint, and then outline
rep airs in a logical sequence.
Each Sym ptom is defined, an d it is vital th at the
correct one be selected based on the com plaints reported
or found.
Review the Sym ptom s and th e ir definition to be sure
th at only the correct term s are used.
The w ords used m ay not be w hat you are used to in
all cases, but because these term s have been used
in terch an g eab ly fo r so long, it w as necessary to decide
on the m ost com m on usage and then define them . If the
definition is not understood, an d the exact Sym ptom is
not used, the D iagnostic procedure will not work.
It is im p o rta n t to keep two facts in m ind:
1. T he procedures are w ritten to diagnose p ro b
lems on vehicles th a t have "ru n well at one tim e" and
th at tim e and w ear have created the condition.
2. All possible causes cannot be covered, p a rtic u
larly w ith reg ard to em ission controls th at affect vacuum
advance. If doing the w ork prescribed does not correct
the com plaint, then eith er the w rong Sym ptom was used,
or a m ore detailed analysis will have to be m ade.
All o f the Sym ptom s can be caused by w orn out or
defective parts such as Spark Plugs, Ignition W iring,
etc. If tim e a n d /o r m ileage indicate th a t parts
should be replaced, it is recom m ended th a t it be
done.
SYMPTOM DEFINITIONS
Dieseling - E ngine continues to run a fte r the switch
is turned off. It runs unevenly and may m ake knocking
noises.
Detonation - A m ild to severe ping, usually worse
under acceleration. The engine m akes sharp m etallic
knocks that change with throttle opening.
Stalls - The engine quits running. It m ay be at idle
or while driving.
Loads - The engine misses due to excessively rich
fu e l/a ir m ixture. Usually occurs during cold engine
operation and is characterized by black smoke being
em itted from the tail pipe.
Rough Idle - The engine runs unevenly at idle. If
bad enough, it m ay m ake the vehicle shake.
M iss - Steady pulsation or je rk in g that follows
engine speed, usually more pronounced as engine load
increases. N o t norm ally felt above 1500 RPM o r 30
M PH. The exhaust has a steady spitting sound at idle or
low speed.
H esitation - M om entary lack o f response as the
accelerator is depressed. C an occur at all vehicle speeds.
U sually m ost severe w hen first trying to m ake the vehicle
move, as from a stop sign. M ay cause the engine to stall
if severe enough.
Sag - The engine responds initially, then flattens out
or slows down, and then recovers. M ay cause the engine
to stall if severe enough.
Surges - E ngine Power v ariatio n under steady
throttle or cruise. Feels like the vehicle speeds up a id
slows down with no change in the accelerator pedal
position. C an occur at any speed.
Sluggish - E ngine delivers lim ited pow er under load
or at high speed. W o n ’t accelerate as fast as norm al;
loses too m uch speed going up hills; or has less top speed
than norm al
Poor Gas M ileage - G as m ileage significantly less
than the average for the vehicle and drivetrain
com bination in question.
Cuts Out - T em porary com plete loss o f power. The
engine quits at sharp, irregular intervals. M ay occur
repeatedly, o r interm ittently. Usually worse u n der heavy
acceleration.
Backfire - Explosion type noise em an atin g from the
exhaust system. U sually occurs d u ring deceleration.
E N G IN E A N D CO DE
2 5 0 C ID
IG N IT IO N
T IM IN G
B.T.D .C .
D E G R E ES
C UR B
ID L E
(RPM)
T YPE & GAP
L -6 E N G IN E 1 B B L 1 M E C A R B U R E T O R
BASE
ID L E
(R PM )
FAST
CARBURETO R
ID L E ID E N T IF IC A T IO N
1 7 0 5 7 ____
(R PM )
4 1 0 0
006
RPO L25
009
008
8 ° @ 600
R 44T
.035
6 0 0 (N )
4 5 0 (N )
2400
'
309
0° @ 1 0 " Hg
10 @ 1 3 " Hg
cu
680
5 20
308
3 0 5 C I D V - 8 E N G IN E 2 B B L 2 G C C A R B U R E T O R
4 9 S T A T E S M . T.
U T F - CK
6 ° @ 700
R 44T
.045
A. T.
M. T .
TAC
RPO LG 9
7 0 0 (N)
0 ° @ 110 0
6 ° @ 2000
1 4 ° @ 2300
2 4 ° @ 4100
14° @ 2 3 0 0
520
PCV
TAC
TR C (C A L IF O R N IA )
ECS ( C A L
IF O R N IA )
C A L I F O R N I A A . T.
T H T CKP
T H U C 3 0, P30 T U C G
24° @ 4 1 0 0
0° @ 1 1 0 0
679
4 9 S T A T E S A . T.
T H K CKP
T H L C 3 0 , P 30 T U A G
CONTROLS
BBL 1M E C A R B U R E T O R
4 9 S T A T E S M. T.
T H H CKP
TUB G
EMISSION
2 9 2 C I D L -6 E N G IN E
4 9 S T A T E S A . T.
U T H - CK
V A C U U M A N D M E C H A N IC A L A D V A N C E
VACUUM ADVANCE
@ IN C H E S O F V A C U U M
(IN C R A N K D E G R E ES )
RPO LD 4
007
6 ° @ 600
C A L I F O R N I A M. T.
TH R CKP
TUD G
VACUUM
M ODEL
1 973____
ENGINE
4 9 S T A T E S M. T.
T A T C10
D IS T R IB U T O R
FAST
IG N IT IO N
E N G IN E A N D CO D E
1103____
-------
A U T O M A T IC T R A N S M IS S IO N
M A N U A L T R A N S M IS S IO N
T H E R M O S T A T IC A IR C L E A N E R
17056137
PCV
TAC
TRC
ECS
PCV
TRC
-------
CT
237
516
0 ° @ 8 " Hg
1 0 ° @ 13” Hg
0 ° @ 1000
1 0 ° @ 17 0 0
2 0 ° @ 3800
E V A P O R A T IO N C O N T R O L S Y S TE M
P O S IT IV E C R A N K C A S E V E N T IL A T IO N
TH R O TTLE RETURN CO NTROL
6 E -1 3
6E-14
E N G IN E A N D C O D E
IG N IT IO N
T IM IN G
B .T .D .C .
DEGREES
S P A R K P LU G
T Y P E & GA P
CURB
ID L E
(R P M )
BASE
ID L E
(R P M )
CARBURETO R
FAST
IO L E ID E N T IF IC A T IO N
1 7 0 5 7 ____
(R P M )
(N )
E M IS S IO N
CONTROL
D E V IC E S
D IS T R IB U T O R
V A C U U M A N D M E C H A N IC A L A D V A N C E
EGR
VALVE
MODEL
E M IS S IO N
LA B E L
CODE
D IS T R IB U T O R
VACUUM
MODEL
--
CT
1103274
1973482
0 ° @ 6 " Hg
1 5 ° @ 12” Hg
0 ° @ 1200
1 5 °@ 2700
2 0 ° @ 4200
—
CU
1973516
0 ° @ 8 " Hg
1 0° @ 13” Hg
0 ° @ 1150
17 °@ 2900
2 2 ° @ 4200
VACUUM ADVANCE
@ IN C H E S O F V A C U U M
( IN C R A N K D E G R E E S )
M E C H A N IC A L A D V A N C E
(C R A N K D E G R E E S )
@ E N G IN E RPM
3 5 0 C ID V -8 E N G IN E 4 B B L 4 M V /M 4 M C C A R B U R E T O R R P O LS 9
213
4 9 STA TE S M. T.
T X R -P 2 0 -3 0
T X X -P 3 0
216
8 ° @ 700
R44T
.045
700 (N)
---
1600
213
216
49 S T ATES A. T.
T X U P30 (M O TO R HO M E)
215
7045583
C A L IF O R N IA M. T.
T Y S G 2 0 -3 0
T X J G30
514
C A L IF O R N IA M. T.
T X M P 20-30
T X Y P30
7045586
C A L IF O R N IA A. T.
T X A C K 2 0 -3 0
T Y Y C K 1 0 -2 0
2 ° @ 700
R 44TX
.060
700 (N)
---
1600
7045583
C A L IF O R N IA A. T.
T Y R G2 0 -3 0
514
C A L IF O R N IA A. T.
TX S P2 0 -3 0
TW V P30
7045586
C A L IF O R N IA A. T.
TX W P30 (M O TO R HOME)
7045585
A. T.
M. T.
TA C
ECS
A U T O M A T IC T R A N S M IS S IO N
M A N U A L T R A N S M IS S IO N
T H E R M O S T A T IC A IR C L E A N E R
E V A P O R A T IO N C O N T R O L SYSTEM
TRC (C A L
IF O R N IA )
ECS (C A L
IF O R N IA )
PCV
A IR
STVS
TRC
MANUAL
C A L IF O R N IA M. T.
T X C C K 2 0 -3 0
TYW C K 1 0 -2 0
PCV
TAC
A IR (C A L
IF O R N IA )
STVS(CKG
SERIES)
SERVICE
49 S T ATES A. T.
T X T -P 2 0 -3 0
TW T -P 30
TRUCK
49 STA TE S A. T.
T X B -C K 2 0 -3 0 T Y Z C K 1 0 -2 0
T Y U -G 2 0 -3 0
LIGHT
49 STATES M. T.
T X D -C K 2 0 -3 0 T Y X -C 1 0 -2 0
T Y T -G 2 0 -3 0 T X K -G 3 0
1103250
PO SITIVE C R AN KC A SE V E N T IL A T IO N
A IR IN JEC TIO N REACTOR
SPARK TVS
TH R O T T LE RE TUR N C O N T R O L
E N G IN E A N D C O D E
I G N IT IO N
T IM IN G
B .T .D .C .
DEGREES
D IS T R IB U T O R
SPARK PLUG
TY P E & GAP
ID L E
(R P M )
BASE
ID L E
(R P M )
FA ST
CARBURETOR
ID L E ID E N T IF IC A T IO N
(R P M )
1 7 0 5 ______
(N )
E M IS S IO N
CONTROL
D E V IC E S
EGR
VALVE
M ODEL
LABEL
CODE
V A C U U M A N D M E C H A N IC A L A D V A N C E
D IS T R IB U T O R
1 1 0 3 ____
VACUUM
MODEL
1 9 7 3 ____
249
482
VACUUM ADVANCE
@ IN C H E S O F V A C U U M
( IN C R A N K D E G R E E S )
M E C H A N IC A L A D V A N C E
(C R A N K D E G R E E S )
@ E N G IN E R P M
400 CID V-8 ENGINE 4 BBL IV4MC CAR 3URETOR RPO LF4
7229
4 ° @ 700
R 44T
.045
C A L IF O R N IA A . T.
T L T G 2 0 -3 0
700 (N)
-------
1600
7525
2 ° @ 700
7529
CT
0 ° @ 6 " Hg
1 5 ° @ 12” Hg
------250
516
0 ° @ 8 ” Hg
1 0 °@ 1 3 " Hg
0 ° @ 1000
8 ° @ 1600
1 9 ° @ 3450
0 ° @ 1150
1 7 °@ 2900
2 2 ° @ 420 0
EMISSION
C A L IF O R N IA A. T.
T L R K 1 0 -2 0
T L L K 2 0 -3 0
PCV
TA C
STVS
A IR (C A L
IF O R N IA )
T R C (C A L
IF O R N IA )
ECS (C A L
IF O R N IA )
454 CID V-8 ENGINE 4M V/M 4M C M4MC CARBURETOR RPO LF8
4 9 S T A T E S M. T.
TSC C 2 0 -3 0
621 2
700 (N)
4 9 S T A T E S A . T.
TR C P30
6517
8 ° @ 700
C A L IF O R N IA M. T.
T R Z C 2 0 -3 0
R44T
.045
1700
7512
C A L IF O R N IA A. T.
T S A C 2 0 -3 0 T S L C 1 0 -2 0
T R B P30 (M O T O R HO M E)
NO A /C
TSR P30 (M O T O R H O M E ) A /C
700 (N)
C A L IF O R N IA A . T.
T R D P30
7512
PCV
TAC
A IR (C A L
IF O R N IA )
EGR (C A L
IF O R N IA ) 170 50064
TSC (C
SERIES)
T R C (C A L
IF O R N IA ) 170 50064
ECS (C A L
IF O R N IA )
A U T O M A T IC T R A N S M IS S IO N
M A N U A L T R A N S M IS S IO N
E X H A U S T G A S R E C IR C U L A T IO N
T H E R M O S T A T IC A IR C L E A N E R
E V A P O R A T IO N C O N T R O L SY STE M
238
511
CU
240
481
0 ° @ 1 0 " Hg
1 5 ° @ 17” Hg
0 ° @ 1100
1 4 ° @ 2800
2 0 ° @ 420 0
0° @ 1100
0° @ 6 " Hg
20° @ 1 5 " Hg
4° @ 280 0
20° @ 420 0
170 50064
7517
A. T.
M. T.
EGR
TAC
ECS
CT
CONTROLS
49 S T A T E S A .T .
TSD C 2 0 -3 0 T S K C 1 0 -2 0
T R A P30 (M O T O R HO M E)
ENGINE
4 9 S T A T E S A . T.
T L U G 2 0 -3 0 T L M K 2 0 -3 0
T L S K 1 0 -2 0
UFC
PCV
A IR
TSC
TR C
U N D E R F L O O R C A T A L Y T IC C O N V E R T E R
P O S IT IV E C R A N K C A S E V E N T IL A T IO N
A IR IN J E C T IO N REAC TO R
T H E R M A L SP A R K C O N T R O L
T H R O T T LE RETURN CO NTRO L
6E-15
EARLY FUEL EVAPORATION (EFE)
GENERAL
IN S P E C T IO N
• V isually inspect exhaust h eat valve for dam age
or bind in g linkage.
• Check th at linkage is connected and vacuum
hoses are prop erly routed and connected (Figs. 6E-15
and 16).
• M ove exhaust h eat valve by hand. If binding or
stuck, free w ith m an ifo ld h eat valve lubricant, G M P art
N o. 1050422 or equivalent. If valve cannot be freed,
replace valve.
C H E C K IN G EFE SYSTEM
1. W ith engine cold, position transm ission in
neutral or park and apply p ark in g brake.
2. S tart engine and observe m ovem ent o f actuator
rod and exhaust h eat valve. Valve should move to its
closed position.
3. If valve does not close, disconnect hose at
actuator and check for vacuum .
• If there is vacuum , replace actuator.
• If there is no vacuum , disconnect hose at TVSto-vacuum source.
• If there is vacuum at hose, replace TVS.
• If there is no vacuum , check for d eteriorated
hose and vacuum source to determ ine lack o f vacuum.
4. W hen coolant reaches 180°F (82 C ) (V8), or oil
reaches 150°F ( 6 6 ^ ) (six cylinder), the exhaust heat
valve should move to its open position.
5. If valve does not move, disconnect hose at
actuator and check fo r vacuum .
• If there is vacuum , replace TVS.
• If there is no vacuum , replace actuator.
ON-VEHICLE SERVICE
TH E R M A L V A C U U M S W ITCH (TV S ) • V8
C oolant Tem perature
The TVS is located on the engine coolant outlet
housing.
Replacement
1. D rain coolant below level o f engine coolant
outlet housing.
2. D isconnect hoses at TVS ports.
3. Remove TVS.
4. A pply a soft setting sealant uniform ly on
replacem ent TVS m ale threads. N o sealant should be
applied to sensor end o f TVS.
5. Install TVS, tighten to 120 pound inches
(14.N m) and then hand torque clockwise as required to
align TVS to accom odate hoses.
6. Connect hoses to TVS ports.
7. Add coolant as required.
TH E R M A L V A C U U M S W ITCH (TV S ) ■ L6
Oil Tem perature
The TVS is located on right han d oil gallery.
Replacement
1.
2.
3.
4.
D isconnect hoses at TVS ports.
Remove TVS switch.
Install TVS switch.
Connect hoses to TVS ports.
A C TU A TO R AN D ROD ASSEMBLY
The actuator and rod assem bly is located on a
bracket attached to right exhaust m anifold on V8
engines (figs. 6E-17 and 6E -18) and on left side attached
to exhaust m anifold on L6 engine (fig. 6E-19).
POW ER ACTUATOR
Fig. 6E18--Actuator and Rod 454 V8
Fig. 6E-17-Actuator and Rod-305/350/400 V8
Replacement
1. D isconnect hose from actuator.
2. R em ove 2 nuts attaching actuator-to-bracket.
3. D isconnect rod from valve and rem ove actuator
and rod.
4. Install actuator and rod reversing steps l and 3.
T ighten nuts to 25 pound inches (3 N-m).
2.
3.
4.
5.
D isconnect rod from valve.
Rem ove valve.
Install valve and connect rod.
Install crossover exhaust pipe.
E XH AUST HEA T VALVE - L6
R eplacem ent
1. Rem ove 2 nuts attaching actuator bracket-tovalve
and exhaust m anifold.
EXH AUST H EAT VALVE - V8
2. Rem ove bracket and disconnect rod from valve.
Replacement
3. Rem ove 2 additional nuts from valve and
1.
Rem ove crossover exhaust pipe. R efer to Section rem ove valve.
6F for rem oval and installation.
4. Install valve reversing Steps 1 through 3.
Fig. 6E-19-Actuator and Rod-L6
EXHAUST GAS RECIRCULATION (EGR)
ON-VEHICLE SERVICE
SYSTEM F U N C T IO N A L TEST
1.
Initial p rep aratio n .
a. R em ove air cleaner so E G R valve d iap h rag m
m ovem ent can be observed o r felt.
N O T E : W hen a ir cleaner is rem oved, it is
recom m ended th a t the choke secondary vacuum
break TVS be unclipped an d rem oved from the air
clean er body ra th e r th a n rem oving hoses.
b.
Plug
intake
m an ifo ld
air cleaner vacuum
c.
C onnect a tachom eter.
d.
W arm up engine to o p eratin g tem perature.
fitting.
2.
O p en th ro ttle p a rt w ay an d then release.
3.
O bserve the E G R d iap h rag m fo r m ovem ent.
The valve should open slightly when the throttle is
opened and close when it is released.
4.
hose.
Rem ove E G R hose from E G R valve and plug
5. Place cam follow er on second step o f fast idle
cam and note speed
6. A ttach a vacuum hose betw een air cleaner
vacuum fitting and the E G R valve (or use an external
source in excess o f 11 in. hg. [ 37kPa]) and note speed
change Speed should d rop at least 200 RPM w ith A.T.
or at least 150 RPM w ith M.T.
7.
Sum m ary.
a.
following:
•
•
Speed m ust drop w hen d iap h rag m moves.
F U N C T IO N A L TEST OF IN D IV ID U A L EGR
SYSTEM C O M P O N E N T PARTS
1.
EGR VALVE (Valve can be left on or rem oved
from the engine).
a. D epress the valve diaphragm .
b. W ith the diaphragm still depressed, plug the
vacuum tube and release the diaphragm .
c. Observe diap h rag m a n d /o r pintle m ovem ent:
• Valve is satisfactory if it takes over 20
seconds fo r the pintle to seat or fo r the diap h rag m to
achieve full travel.
• Valve unsatisfactory and m ust be replaced if
it takes less than 20 seconds for the pintle to seat or for
d iaphragm to achieve full travel.
GENERAL DESCRIPTION
EGR Valve
The E G R valve (Fig. 6E-20) contains a vacuum
d iaphragm , which is operated by intake m anifold
vacuum . The diap h rag m vacuum signal supply p o rt is
located in the throttle body above the throttle valve, and
is exposed to engine m anifold vacuum in the off-idle and
p art throttle to wide open throttle operation. A .030 in.
orifice in the valve vacuum tube serves to m odulate flow.
BACK PRESSURE EGR VALVE
A back pressure E G R Valve (Fig. 6E-21) is used on
test m ust m eet the
all light duty em issions C alifornia and H igh A ltitude V8
and L6 engines.
E G R d iap h rag m m ust move.
A sm all diap h rag m control valve inside the E G R
A successful
function
V A C U U M TUBE C O N N E C T E D
T O TH E R M A L V A C U U M SW IT C H
D IA P H R A G M
COVER
V A LV E SH AFT
SEAL-
V A L V E S EAT,
V A LVE C H A M B E R
W hen power dem ands are m ade on the engine, and
exhaust gas recirculation is needed, exhaust back
pressure increases, closing the control valve, thereby
shutting off air flow through the valve. Vacuum builds up
in the vacuum ch am b er until the spring force holding
the E G R valve closed is overcome.
TO IN TA K E
m a n if o l d
Vacuum is applied to the E G R valve assem bly from
the carburetor spark port, to assure no exhaust gas
recirculation at idle. D uring off-idle operation, m anifold
vacuum is applied to the vacuum cham ber through a
restriction in the signal tube. W hen engine load is light,
and back pressure is low, the control valve is open,
allow ing air to flow from the 6 bleeds in the diap h rag m
plate, through the control valve orifice, into the vacuum
cham ber. The air bleeds off vacuum , decreasing the
signal trying to open the E G R valve. T herefore, if back
pressure does not close the control valve, sealing off the
a ir flow, there will not be any vacuum built up to open
the E G R valve for exhaust gas recirculation.
'
Fig. 6E-20-EGR Valve
valve assem bly acts as a pressure regulator. The control
valve receives an exhaust back pressure signal through
the hollow sh a ft w hich exerts a force on the bottom o f
the control valve d iap h rag m , opposed by a light spring.
A m etal deflector plate prevents hot exhaust gases from
flowing directly on the d iap h rag m .
F IL T E R
SCREEN
CONTROL VA LVE
OPEN
SPRING
Once the E G R valve opens, the exhaust pressure
decreases because som e o f the exhaust gas is flowing into
the intake m anifold through the E G R passage. In actual
operation, the system will reach a balanced condition
providing optim um E G R operation.
A ny increase in engine load will m om entarily
increase the exhaust signal, causing the control valve to
VACUUM
CHAMBER
CONTROL V A LVE
CLOSED
RESTRICTION
SPRING
(CONTROL
VALVE)
T IM E D
M AN IFO LD
VACUUM
TO
VACUUM
SOURCE
AIR
DIAPHRAGM
FLOW
IN
D EFLEC TO R
FIGURE 1
FIGURE 2
EXHAUST GAS TO
INTAKE M ANIFOLD
H I EXHAUST GAS
EXHAUST
GAS (IN)
close, allow ing a stronger vacuum signal. The system will
then stablize at a g reater E G R flow.
At m axim um engine load, w hen m anifold vacuum is
nearly zero, m o m entarily, there will be no E G R
operation. This is because o f insufficient vacuum to pull
the valve open, even though high exhaust back pressure
has closed the control valve.
Therm al Vacuum Switch
A th erm al vacuum switch shuts off vacuum to the
E G R valve until coolant tem p eratu re is approxim ately
100 °F (38 “C ) on L6 or 120 °F (49 -C) on V8.
DIAGNOSIS
R efer to D iagnosis C h art fo r diagnosis o f exhaust
gas recirculation system.
ON-VEHICLE SERVICE
Functional T e st (on vehicle) ■ EGR Valve
1. W ith the engine ru n n in g , the vehicle in " P a rk "
or "N e u tra l" , set the fast idle cam on second step to hold
throttle open (approxim ately 1400 - 1600 RPM ). Engine
coolant tem p eratu re m ust be above 120°F (4 9 'C).
2. Place finger b en eath E G R valve in a m an n er to
feel m ovem ent o f d iap h rag m .
3. D isconnect the vacuum hose and w atch for
m ovem ent o f the d iap h rag m dow nw ard (valve closed).
T his should be accom panied by increase in engine speed.
4. R econnect the hose. D iap h rag m should move
upw ard (valve open). E ngine R PM should decrease.
N O T E : A slight v ib ratio n o f the d iap h rag m plate
assem bly m ay be noticed in back pressure models.
T his is due to the control valve m odulating under
light load and does not indicate an undesirable
condition n o r one req u irin g correction.
Failure Diagnosis
Diaphragm Doesn’t Move:
1. V erify engine speed. Should be approxim ately
1400 - 1600 RPM .
2. V erify tem p eratu re: should be above 120 °F
(49 XI).
3. Check for vacuum at hose. If no vacuum
present, find cause for no vacuum . (Plugged or leaking
hose or ca rb u re to r port, defective E F E /E G R switch).
4. In back pressure m odels, check control valve
operatio n .
Diaphragm Moves With No Change In Engine RPM
Check m anifold E G R passages for blockage.
Function Test (off vehicle) Control Valve
(Back Pressure EGR M odel O nly)
1. R em ove vacuum hose.
2. R em ove two attach in g bolts an d E G R valve
assem bly from in tak e m anifold, discard gasket.
3. A pply external vacuum [10" Hg. (34 kPa) or
m ore] to signal tube. A constant vacuum supply m ust be
used.
4. Valve should not open. If it does, control valve
is stuck closed. C lean the valve. (See E G R valve
cleaning).
5. W ith the vacuum still applied, direct a stream o f
air from a low pressure source into the valve exhaust gas
intake.
6. Valve should open com pletely. If it does not
open at all, control valve is stuck open or exhaust
passages are plugged. Clean the valve (See E G R valve
cleaning).
7. If E G R valve and control valve are both
functioning properly, clean the m ounting surfaces, then
using a new gasket, install the valve to the intake
m anifold. Torque the bolts to 25 ft. lbs. (34 N m).
8. C onnect vacuum hose.
EGR Valve Cleaning
CAUTION: Do not wash valve assembly in
solvents or degreaser - permanent damage to
valve diaphragm may result. Also, sand
blasting o f the valve is not recommended since
this can affect the operation o f the valve.
1. Remove E G R valve and 2 attaching bolts,
discarding the gasket.
2. Hold the valve assem bly in hand, then tap
lightly on the sides and end o f the valve, and on the
pintle itself using a small wood dowel, w ith a small
plastic ham m er to rem ove the exhaust deposits from the
valve seat. Em pty loose particles. D O N O T PU T IN A
VISE.
3. W ith a w ire wheel, buff the exhaust deposits
from the m ounting surface and around the valve.
4. D epress the valve d iaphragm and look at the
valve seating area through the valve outlet for
cleanliness. If valve a n d /o r seat are not com pletely clean,
repeat step 3.
5. Look for exhaust deposits in the valve outlet.
Rem ove deposit build up with a screw driver.
6. C lean m ounting surfaces o f intake m anifold
and valve assembly, then using a new gasket install the
valve assem bly to the intake m anifold. T orque the bolts
to 25 ft. lbs. (34 N m).
7. C onnect vacuum hose.
EGR Passage
If inspection o f E G R passages in the inlet m anifold
indicates excessive build-up o f deposits, the passages
should be cleaned. Care should be taken to ensure that
all loose particles are com pletely rem oved to prevent
them from clogging the E G R valve or from being
ingested into the engine.
Replacem ent
1.
2.
3.
4.
using a
D isconnect E G R valve (Fig. 6E-22 and 23).
Rem ove bolts securing valve to m anifold.
Rem ove E G R valve from m anifold.
R eassem ble replacem ent valve to m anifold,
new gasket.
E X H A U S T G A S R E C IR C U L A T IO N S Y S T E M D IA G N O S IS C H A R T
C o n d itio n
Engine idles abnorm ally rough
and/or stalls.
Engine runs rough on light
th ro ttle acceleration, poor
part load performance and
poor fuel economy.
Possible Cause
C o rre c tio n
EGR valve vacuum hoses misrouted.
Check EGR valve vacuum hose
routing. Correct as required.
Leaking EGR valve.
Check EGR valve fo r correct
operation.
EGR valve gasket failed or loose EGR
attaching bolts.
Check EGR attaching bolts fo r
tightness. Tighten as required. If
not loose, remove EGR valve and
inspect gasket. Replace as required.
EGR thermal con tro l valve and/or
EGR-TVS.
Check vacuum in to valve fro m car
buretor EGR p o rt w ith engine at
normal operating tem perature and
at curb idle speed. Then check the
vacuum o u t o f the EGR therm al
c on tro l valve to EGR valve. If the
tw o vacuum readings are n o t equal
w ith in ± 1/2 in Hg. (1.7 kPa), then
proceed to EGR vacuum con tro l
diagnoses.
Im proper vacuum to EGR valve at
idle.
Check vacuum from carburetor EGR
p o rt w ith engine at stabilized
operating tem perature and at curb
idle speed. If vacuum is more than
1.0 in. Hg., refer to carburetor idle
diagnosis:
EGR valve vacuum hose misrouted.
Check EGR valve vacuum hose
routing. Correct as required.
Failed EGR vacuum con tro l valve.
Same as listing in "Engine Idles
Rough con dition.
EGR flo w unbalanced due to
deposit accum ulation in EGR passages
or under carburetor.
Clean EGR passages o f all deposits.
S ticky or binding EGR valve.
Remove EGR valve and inspect.
Clean or replace as required.
Wrong or no EGR gaskets.
Check and correct as required.
E X H A U S T G A S R E C IR C U L A T IO N S Y S T E M D IA G N O S IS C H A R T
C o n d itio n
Possible Cause
(C O N T 'D .)
C o rre c tio n
(Vehicle w ith back pressure
EGR valve.)
C ontrol valve blocked or air flo w
restricted.
Check internal c o n tro l valve fu n c tio n
per service procedure.
Engine stalls on decelerations.
R estriction in EGR vacuum line.
Check EGR vacuum lines fo r kinks
bends, etc. Remove or replace hoses
as required. Check EGR vacuum
c o n tro l valve fu n ctio n .
Check EGR valve fo r excessive
deposits causing sticky or binding
operation. Clean or repair as required.
S ticking or binding EGR valve.
Remove EGR valve and inspect clean
or repair as required.
(Vehicle w ith a back pressure
EGR valve.)
C ontrol valve blocked or air flo w
restricted.
Check internal c o n tro l valve fu n ctio n
per service procedure.
Part th ro ttle engine detonation.
Insu fficient exhaust gas recirculation
flo w during part th ro ttle accelerations.
Check EGR valve hose rou ting . Check
EGR valve operation. Repair or re
place as required. Check EGR therm al
con tro l valve and/or EG R-TVS as listed
in Engine Idles R ough" section. Re
place valve as required. Check EGR
passages and valve fo r excessive de
posit. Clean as required.
(Vehicle w ith a back pressure
EGR valve.)
C ontrol valve blocked o r air flo w
restricted.
Check internal co n tro l valve fu n c tio n
per service procedure.
(NO TE:
D etonation can be causec by several other engine variables.
Engine starts but im m ediately
stalls when cold.
(Vehicle w ith a back pressure
EGR valve.)
(NO TE:
Perform ignit on and carburetor related diagnosis.)
EGR valve hoses m isrouted.
Check EGR valve hose routings.
EGR system m alfu nctio nin g when
engine is cold.
Perform check to determ ine if the
EGR therm al co n tro l valve and/or
EG R-TVS are operational. Replace
as required.
C ontrol valve blocked o r air flo w
restricted.
Stalls after start can also be caused by carburetor problems.)
Check internal c o n tro l valve fu n c tio n
per service procedure.
6.
Install vacuum hoses to switch.
Functional Check
EGR TVS
Hot
PURPLE
STRIPE
Fig. 6E-22--EGR System-V8
NOTE: This is to be perform ed as p art o f the
em ission m aintenance routine at 12,000 m iles or 12
m onths on heavy duty em ission vehicles.
The E G R T herm al Vacuum D elay Switch should be
open above coolant tem perature 100 °F (38 “C ) on L6 and
120°F (49 °C) on V8 p erm itting the ported vacuum signal
to reach the E G R valve above th at tem perature. Check
as follows:
1. Remove E G R valve vacuum hose at E G R valve
and connect hose to a vacuum gage.
2. S tart engine. W ith transm ission selector lever in
N eu tral or Park open throttle partially. (D o not
overspeed engine.) As throttle is opened, the vacuum
gage should respond w ith an increase in vacuum reading.
(N ote: C oolant tem p eratu re must be above 120 °F (49 "C)
during this test. Allow about 3 m intues at idle to w arm
up a cold engine. If coolant is below 75 °F (24 ^C)) greater
tim e m ay be required.)
3. If operation is satisfactory, rem ove gage and
reconnect hose to E G R valve.
If gage does not respond to throttle opening,
proceed to Step 4.
4. Remove C arb-to-sw itch hose from switch and
connect hose to vacuum gage. R epeat Step 2.
5. If vacuum gage responds to throttle opening,
then switch is defective. Rem ove switch and replace w ith
new part.
If gage does not respond to throttle opening, then
check for plugged hose or defective carburetor.
Cold
5. ^ T o rq u e clam p bolt to 13-18 lb. ft.
6. C onnect carb u reto r vacuum signal line to tube
at top o f valve.
T H E R M A L V A C U U M S W ITC H (TV S )
Replacement
1. D isconnect vacuum lines (Figs. 6E-22 and 23)
from the th erm al vacuum switch.
2. Rem ove switch from therm o stat housing.
3. A pply an approved sealer to th read ed portion o f
switch.
4. Install switch in th erm o stat housing and torque
to 100 lbs. in.
5. R otate switch head as req u ired to align fo r
p ro p er hose routing.
N O TE: This check m ay be perfo rm ed in diagnos
ing com plaint o f stall after cold start o r poor
driveability im m ediately a fte r cold start.
The E G R therm al vacuum delay switch should be
closed below coolant tem perature 100 °F (3 8 ' t ) on L6 on
120°F (49 "C) on V8, thereby blocking the ported vacuum
signal from reaching the E G R valve below that
tem perature. Check as follows:
1. D ra in co o lan t below level o f th erm o stat
housing.
2. D isconnect vacuum lines and rem ove switch
from therm ostat housing.
3. Inspect switch to m ake sure it is in good
condition.
4. C onnect a vacuum hose to lower nipple o f
switch, m arked " C " or "C A RB:. C onnect a vacuum gage
to upper nipple, m arked " E " or "E G R ".
5. Place switch in w ater at 8 5 °F ( 2 9 ^ ) and
subm erge com pletely fo r 2 m intues while agitatin g w ater
thoroughly.
6. Apply 12 in. hg. (-41 kPa) vacuum to hose on
lower nipple o f switch. U n d er this condition, the switch
should be closed.
N O TE:
Leakage o f up to 2in. hg. (-7kPa) o f
vacuum in 2 m inutes is allowable and does not
3. D epress the valve d iaphragm and check the
constitute a defective switch.
seating area for cleanliness by looking thru the valve
7.
If o p eratio n is satisfactory, re-install switch in outlet. If pintle or seat are not com pletely clean, repeat
step 1.
therm o stat housing. If switch is defective, replace with
4. Inspect the valve outlet for deposits. Remove
new part.
any deposit build-up with a screw driver or o ther suitable
sh arp tool.
EGR SYSTEM - IN S P E C T IO N AND
5. Clean m ounting surface on the intake m anifold
C LEA NING
with a w ire wheel or wire brush.
The follow ing procedure is to be used for the
N O TE: Do not use solvents fo r cleaning.
inspection and cleaning o f the E G R valve and passages.
Intake M anifold Passages
Inspection
1. R em ove a ir cleaner.
2. Rem ove EG R valve from intake m anifold.
3. Look for deposits on the valve pintle.
4. D epress the valve d iap h rag m an d inspect for
deposits around the valve seatin g area thru the valve
outlet.
5. W ith the d iap h rag m still depressed, plug the
vacuum tube then release the d iap h rag m . If the pintle
has not closed in 20 seconds, the E G R valve is OK. If the
pintle is closed w ith in 20 seconds, the valve m ust be
replaced.
6. T he valve requires cleaning if deposits exist.
Cleaning
1. Hold the valve assem bly in hand. T hen, using a
light snap p in g action w ith a plastic ham m er, tap on the
end o f the round pintle to rem ove the exhaust deposits
from the valve seat. E m pty loose particles.
2. C lean the m ounting surface o f the E G R valve
w ith a w ire w heel or w ire brush, and the pintle w ith a
w ire brush.
1. Remove carburetor.
2. Remove the deposits from the E G R ports by
h and turning a drill into the passage. Finish cleaning
with a small screwdriver.
CAUTION: Do not use a power drill or file.
3. Brush any sm all particles down the E G R port
and blow com pressed air through the port.
NOTE: Do not use solvents for cleaning.
Reassembly
1. Reinstall carb u reto r using a new gasket and
torque hold-dow n bolts to 10-15 ft. lbs.
2. R einstall the E G R valve assem bly to the intake
m anifold using a new gasket and torque bolt to 12-17 ft.
lbs.
3. C onnect fuel line and all vacuum hoses.
4. W arm up engine and reset idle rpm to
specification if necessary per Em ission C ontrol In fo rm a
tion label.
5. P erform functional check o f E G R system to
ensure correct operation.
POSITIVE CRANKCASE VENTILATION SYSTEM (PCV)
GENERAL DESCRIPTION
V entilation air is draw n through a filter assem bly
located in the a ir cleaner, through a hose, down into the
crankcase, up through the v entilator valve, through a
hose an d into the intake m anifold. Intake m anifold
vacuum draw s any fum es from the crankcase to be
burned in the engine.
W h en air flow through the carb u reto r is high, added
air from the Positive C rankcase V entilation System has
no noticeable effect on engine operation; however, at idle
speed, air flow through the carb u reto r is so low th at any
large am o u n t add ed by the ventilating system would
upset the air-fuel m ixture, causing rough idle.
For this reason, a flow control valve is used which
restricts the ventilating system flow w henever intake
m anifold vacuum is high.
ON-VEHICLE SERVICE
1. Remove PCV valve from intake m anifold or
rocker arm shaft cover.
2. Run the engine at idle.
3. Place your thum b over end o f valve to check for
vacuum . If there is no vacuum at valve, check for
plugged hoses or valve. Hoses may be cleared with
com pressed air.
4. Shut off" the engine and rem ove PCV valve.
Shake valve and listen for the rattle o f check needle in
valve. If valve does not rattle, replace valve.
THERMOSTATIC AIR CLEANER (TAC)
IN S P E C T IO N
Vacuum M o to r Check
1. Check all hoses for p ro p er hook-up. Check for
kinked, plugged or dam ag ed hoses.
2. W ith the engine " O F F " , observe d am p er door
position th ro u g h snorkel opening. If position o f snorkel
m akes o bservation difficult, use the aid o f a m irror. At
this point d a m p e r d oor should be in such a position that
the h eat stove passage is covered (snorkel passage open)
(Fig. 6E-24). If not, check fo r binds in linkage.
3. A pply a t least 7 in Hg. o f vacuum to the
d ia p h ra g m assem bly through hose disconnected at sensor
unit. D am p er door should com pletely close snorkel
passage w hen vacuum is applied. (Fig. 6E-24). If not,
check to see if linkage is hooked up correctly and for a
vacuum leak.
4. W ith vacuum applied, bend or clam p hose to
tra p vacuum in d iap h rag m assem bly. D am p er door
should rem ain in position (closed snorkel passage) (Fig.
6E-24). If it does not, there is a vacuum leak in
d ia p h ra g m assem bly. Replace d iap h rag m assembly.
Sensor Check (Quick Check of System )
1. S tart test w ith engine cold, air cleaner at a
tem p eratu re below 7 9 °F (26 "C.). If the engine has been
in recent use. allow it to cool. (R em oving the air cleaner
from the engine and placing it on the bench will aid in
quickly cooling the sensor.
2. O bserve the d am p er door before starting the
engine: it should be in the open snorkel position (Fig.
6E-24).
3. S tart the engine and allow it to idle. Im m edi
ately after startin g the engine, the dam per door should
be in the closed snorkel passage position (Fig. 6E-24).
4. As the engine warm s up, the d am p er door
should start to allow outside air and heated air to enter
the carburetor inlet.
5. The system is operating norm ally as described
above. If the a ir cleaner fails to operate as above, or if
correct operation o f the air cleaner is still in doubt,
proceed to the therm om eter check (o f sensor).
Th e rm o m eter Check of Sensor
1. S tart test with air cleaner tem perature below
79 °F. (2 6 ‘C.). If engine has been run recently, rem ove air
cleaner and place on bench (this will help quickly cool
the air cleaner). Rem ove air cleaner cover and place
therm om eter as close as possible to the sensor. Let air
cleaner cool until th erm om eter reads below 79 °F. ( 2 6 ^ .)
about 5 to 10 m inutes. R einstall a ir cleaner on engine
and continue to step 2 below.
2. Start and idle engine. D am p er door should
move to close the snorkel passage im m ediately if engine
is cool enough. W hen dam p er door starts to open the
snorkel passage (in a few m inutes), rem ove a ir cleaner
cover and read tem perature gage. It must read 115 °F. ±
20 F. (46 V . ± 7 C).
3. If the d am p er door does not start to open up the
snorkel passage at tem perature indicated, tem perature
sensor is m alfunctioning and must be replaced.
V IE W B - U N D E R H O O D TEMPERATURE
BELOW 8 5 °F
V IE W A —ENG INE OFF
AIR BLEED VALVE
, CLOSED
DIAPHRAGM SPRING
VACUUM CHAMBER
SNORKEL TUBE
TEMP. SENSING
SPRING
SNORKEL TUBE
CONTROL DAMPER ASSM. 1 j j h - HOT AIR PIPE
CONTROL DAMPER ASSM
HOT AIR PIPE
VIE W C -U N D E R H O O D TEMPERATURE
A B O V E 1 2 8 °F
AIR BLEED VALVE OPEN SNORKEL TUBE
VIE W D -U N D E R H O O D TEMPERATURE
BETWEEN 8 5 °F A N D 1 2 8 °F
DIAPHRAGM SPRING
VACUUM CHAMBER
VACUUM CHAMBER r -= —^
AIR BLEED VALVE
TEMP. SENSING
SPRING
SNORKEL TUBE
" 't
AIR INLET
AIR INLET
/
CONTROL DAMPER ASSM.
r
^
1
HOT AIR PIPE
CONTROL DAMPER ASSM. I t t ^ HOT AIR PIPE
ON VEHICLE SERVICE
W IN G NUT
TORQUE AT 20 LBS. IN.
Checking Air C leaner
1. Inspect system to be sure all hoses and ducts are
connected.
2. If engine is w arm (above room tem perature)
rem ove air cleaner. P erm it it to cool to room
tem peratu re.
3. Install cooled air cleaner. If air cleaner has cold
air intake hose, disconnect it.
4. S tart engine. W atch d am p er valve in air cleaner
snorkel.
5. W hen engine is first started, valve should be
closed. As air cleaner w arm s up, valve should slowly
open.
N O TE: In hot w eather the room tem p erature may
be too hot for the snorkel valve to close w hen the
engine is started. In this case, cool the tem perature
sensor in the air cleaner w ith a cool w et rag.
6. If valve d o esn ’t close w hen the engine is started,
check for vacuum at the d iap h rag m .
7. If vacuum is present, check fo r b in d in g in the
d am p er valve and o p eratin g link. If d am p er moves
freely, replace d iap h rag m . (F ailu re o f the d iap h rag m to
close is m ore likely to result from m echanical bind due
to a d am ag ed or corroded snorkel assem bly than from a
failed d iap h rag m . This should be checked first, before
replacing the d iap h rag m ).
8. If no vacuum is present, check hoses for
disconnects, cracks or pinches. R ep air or replace as
necessary.
9. If hoses are OK, replace tem p eratu re sensor in
the a ir cleaner.
I N O T E ] Polyurethane Band must w rap
over both end seals of paper element as
PO LYW RA P A IR fc ,
CLEANER ELEMENT
(B A N D S H O W N ) ~
shown.
n o te]
AIR CLEANER
ELEMENT _
( PAPER FILTER
PORTION)
Polyurethane Band must
completely cover the outer screen
surface of paper element as shown.
PAPER FILTER PORTION
OF PO LYW RAP AIR
'CLEANER ELEMENT
Fig. 6E-25--Polywrap Air Cleaner Element
Air C leaner E lem ent R eplacem ent
Paper Element
1. Rem ove air cleaner cover.
2. Rem ove elem ent.
3. Install new elem ent in air cleaner w ith either
end up.
4. Install a ir cleaner cover. Do not over-torque
w ing nut.
Polywrap Element
1. Rem ove air cleaner cover.
2. R em ove elem ent.
3. R em ove polyw rap b and from p ap er elem ent
and discard elem ent (Fig. 6E-25).
4. C lean bottom section o f air cleaner and inspect
cover seal fo r tears or cracks. Replace seal if dam aged.
5. Inspect b and for tears and replace if dam aged.
6. If band is serviceable, wash in kerosene or
m ineral sp irits an d squeeze out excess solvent (Fig. 6E26).
N O T E : N ever use a hot deg reaser or any solvent
co n tain in g acetone or sim ilar solvent; also, never
Fig. 6E-26-Cleaning Polywrap Band
shake, swing or w ring the elem ent to rem ove excess
solvent as this m ay tear the polyurethane m aterial.
Instead, "squeeze" the excess solvent from the
elem ent.
7. D ip band into light engine oil and squeeze out
excess oil.
8. Install band around outer surface o f new p ap er
element.
9. Install elem ent in bottom section o f air cleaner
with either end up.
10. Install air cleaner cover. Do not over-torque
wing nuts(s).
GASKET (POSITION
COLORED SURFACE
DO W N)
EXTENSION
SUPPORT
TUBE
GASKET (POSITION
COLORED SURFACE
DOW N)
Fig. 6E-28-Air Cleaner-L6-Non-lntegrated Head
hole, then enlarge as required to rem ove the retaining
strap. D o not dam age the snorkel tube.
4. Rem ove m otor retaining strap.
5. Lift up m otor, cocking it to one side to unhook
the m otor linkage at the control dam p er assembly.
Installation
Fig. 6E-27-Air Cleaner-L6-lntegrated Head
Air Cleaner R eplacem ent
R efer to figures 6E-27 and 6E-28 for air cleaner
used w ith in line L6 engine.
R efer to figure 6E-29 fo r air cleaner used on CK
truck w ith 3 0 5 /3 5 0 /4 0 0 V8 engine.
R e fe r to figure 6E-30 fo r air cleaner used on G
truck w ith V8 engine.
R efer to figure 6E-31 fo r air cleaner used w ith 454
V8 engine.
R efer to figure 6E-32 for air cleaner used o f
P20(42), P30(42) and P30(32) truck with 350 V8 engine
and 4MV carburetor.
1. D rill a 7 /6 4 " hole in snorkel tube at center o f
vacuum m otor retain in g strap (Fig. 6E-35).
2. Insert vacuum m otor linkage into control
dam p er assembly.
3. Use the m otor retaining strap and sheet metal
screw provided in the m otor service package to secure
the retaining strap and m otor to the snorkel tube.
4. M ake sure the screw does not in terfere w ith the
operation o f the d am p er assembly. Shorten screw if
required.
5. Connect vacuum hose to m otor and install air
cleaner.
Sensor
Removal
R e fe r to figure 6E-33 and 6E-34 fo r rep air or
replacem ent o f air intake.
1. Rem ove air cleaner.
2. D etach hoses at sensor.
3. Pry up tabs on sensor retain in g clip (Fig. 6E36); rem ove clip and sensor from air cleaner. N ote
position o f sensor fo r installation.
Vacuum M o to r
Installation
Removal
1. Install sensor and gasket assem bly in original
position.
2. Press retain er clip on hose connectors.
3. C onnect vacuum hoses and install air cleaner on
engine.
Carburetor Air Intake
1.
2.
3.
R em ove air cleaner.
D isconnect vacuum hose fro m m otor.
D rill out the two spot welds initially with a 1 /6 "
Fig. 6E-29-Air Cleaner-305/350/400 V8 CK
W IN G NUT
GASKET
(P O S IT IO N RED
SURFACE D O W N )
EXTENSION
GASKET
(P O S IT IO N RED
SURFACE D O W N )
STOVE
Fig. 6E-31 -Air Cleaner-454 V8
Fig. 6E-30--Air Cleaner-V8 G
W IN G
NUT.
LOW ER S T O V E
N O T E : In b o a rd flang e
o f lo w e r stove m u s t be
in s ta lle d o n to p o f rib
o f e x h a u s t m a n ifo ld .
OP"
> U PPER S T O V E
■LO W ER S T O V E
AIR IN T A K E
DUCT
AIR INLET
AIR IN T A K E
DUCT
AIR INLET
L6 ENGINE
Hi
\\
i i
Fig. 6E-33--Carburetor Air lntake-L6
DRILL 7 / 6 4 " HOLE
IN CENTER P O S IT IO N
O F STRAP
VACUUM
RETAINING
STRAP
INSTALL REPLACEMENT
SENSO R ASSM . IN SAME
P O S IT IO N AS O R IG IN A L ASSM.
V 8 ENGINE
Fig. 6E-34--Carburetor Air lntake-V8
AIR INJECTION REACTOR (AIR) SYSTEM
G ENERAL D E S C R IP TIO N
T he A ir Injection R eactor (A.I.R.) System consists
of: an air injection pum p (with necessary brackets and
drive attachm ents), air diverter valve, a check valve and
air pipe hose necessary to connect diverter valve (Figs.
6E-37 and 38).
PIPE
The Air Injection Pum p (Fig. 6E-39) with an
integral filer, com presses the air and injects it through
the air m anifolds, into the exhaust system in the area o f
the exhaust valves. The fresh air helps burn the
unburned portion o f the exhaust gases in the exhaust
system, thus m inim izing exhaust contam ination.
The diverter valve Fig. 6E-40) w hen triggered by a
HOUSING
EXHAUST PIPE
FILTER
Fig. 6E-37 Air Pipe InstaIlation-Cl0 and 350 V8 Cal
HUB
ROTOR SHAFT
Fig. 6E-39--Air Injection Pump
EXHAUST A MANIFOLD
OUTLET ---------- ►J'
|
\
ft
,— METERING VALVE
PUMP
AIR IN
SILENCER
VACUUM
SIGNAL TUBE
VENT
DIAPHRAGM
TIMING VALVE
INTERNAL MUFFLER TYPE
sh arp increase in m anifold vacuum , shuts off the injected
air to the exhaust port areas and prevents backfiring
d u rin g this richer period.
O n engine overrun the total air supply is dum ped
through the muffler on the d iv erter valve. At high engine
speeds the excess air is dum ped through the pressure
relief valve w hich is in corporated in the diverter valve.
T he check valve (Fig. 6E-37 and 38) prevents
exhaust gases from en terin g and dam ag in g the air
injection pum p, as back flow can occur even under
norm al o p eratin g conditions.
O N-VEHICLE SERVICE
Drive Belt
Inspection
1. Inspect drive belt fo r w ear, cracks or d e terio ra
tion and replace if required.
2. Inspect belt tension and adjust if below 70 lbs.
using a tension gauge.
Adjustment
Loosen pu m p m ounting bolt and pum p adjustm ent
bracket bolt. Move pum p until belt is properly tensioned
then tighten adjustm ent bracket bolt and m ounting bolt.
Use a belt tension gauge to check adjustm ent.
CAUTION: Do not p ry on the pum p housing.
Distortion o f the housing will result in
extensive damage to the A ir Injection Pump.
Replace
1. Loosen pum p m ounting bolt and pum p adjust
m ent bracket bolt, then swing pum p until drive belt may
be rem oved.
2. Install a new drive belt and adjust as outlined
above.
Pump Pulley
Replace
1. Hold pum p pulley from turning by com pressing
drive belt then loosen pum p pulley bolts.
2. Rem ove drive belt as outlined above then
rem ove pum p pulley.
Install
1. Install pum p pulley w ith retain in g bolts hand
tight. Install and adjust drive belt as outlined above.
2. Hold pum p pulley from turning by com pressing
drive belt then torque pum p pulley bolts to 24 lb. ft.
(32N-m ).
3. R echeck drive belt tension and adjust if
required .
Pump Filter
Replace
1. R em ove drive belt an d p u m p pulley as
previously outlined.
2. Insert needle nose and pull fan from hub (Fig.
6F-41).
NOTE: Care should be taken to prevent fragm ents
from entering the air intake hole. Do not insert a
screw driver between pum p and filter. It is seldom
possible to rem ove the filter w ithout destroying it.
Do not attem pt to rem ove the m etal hub.
Install
1. Install the new filter by draw ing it on with the
pulley and pulley bolts (Fig. 6E-42). Do not attem pt to
install a filter by ham m ering it on or pressing it on.
2. D raw the filter down evenly by alternately
torquing the bolts. M ake certain th at the outer edge o f
the filter slips into the housing. The slight am ount o f
interference with the housing bore is norm al.
NOTE: The new filter m ay squeal upon initial
o peration until it’s O.D. sealing lip has worn in.
Air Hoses and Tubes
Inspection
1. Inspect all hoses for deterioration or holes.
2. Inspect all tubes for cracks or holes.
3. Check all hose and tube connections.
4. M ake repairs or replace p arts as needed.
5. Check all tube and hose routing. Interference
m ay cause wear.
6. If leak is suspected on the pressure side o f the
system or any tubes a n d /o r hoses have been discon
nected on the pressure side, the connections should be
checked for leaks w ith soapy w ater solution.
7. W ith the pum p running, bubbles will form if a
leak exists.
Replace
To replace any hose a n d /o r tube, note routing th en ,
rem ove hose(s) a n d /o r tube(s) as required.
Install
1. Install new hose(s) a n d /o r tube(s), routing them
as when rem oved.
2. Tighten all connections.
Check Valve
Inspection
1. The check valve should be inspected w henever
the hose is disconnected from the check valve or
w henever check valve failure is suspected. (A pum p that
had becom e inoperative and had shown indications o f
having exhaust gases in the pum p would indicate check
valve failure.)
2. Blow through the check valve (tow ard the
cylinder head) then attem pt to suck back through check
valve. Flow should only be in one direction (tow ard the
exhaust m anifold). Replace valve w hich does not
function this way.
Replace
D isconnect
pum p
outlet
hose
at
check
valve.
DIAGNOSIS
C O N D IT IO N
N o a ir s u p p ly — accelerate engine to
P O S S IB L E C A U S E
1. Loose d riv e b e lt.
1. T ig h te n to s p e c ific a tio n s .
2. Leaks in s u p p ly hose.
2
3.
3. T ig h te n o r replace clam ps.
1500 rp m and observe a ir flo w fro m
hoses. If th e flo w increases as the
rp m 's increase, th e p u m p is fu n c tio n in g
C O R R E C T IO N
Leak at fittin g s .
Locate leak and re p a ir
n o rm a lly . If n o t, check possible cause.
4 . A ir e x p e lle d th ro u g h by-pass
valve.
4a. C o n n e c t a vacu um lin e d ire c tly
4a. If th is co rre c ts th e p ro b le m go to
fro m engine m a n ifo ld vacu um
step b. If n o t, replace a ir by-pass
to by-pass valve.
vaIve.
4b. C o n n e ct va cu u m lin e fro m engine
m a n ifo ld vacu um source to by-pass
4b
I f th is c o rre cts th e p ro b le m , check
d iffe re n tia l va cu u m , d e la y and
valve th ro u g h va cu u m d iffe re n tia l
sep arator valve and vacu um
valve d ir e c tly , b y passing th e
source lin e fo r plug ging .
d iffe re n tia l va cu u m d e la y and
Replace as re q u ire d .
se p a ra to r valve.
I f it d o e s n 't, replace vacuum
d iffe re n tia l vaive.
5. C heck valve in o p e ra tiv e .
5. D is c o n n e c t hose and b lo w
th ro u g h hose to w a rd check
valve. I f a ir passes, fu n c tio n is
n o rm a l. If a ir can be sucked
fro m check valve, replace
che ck valve.
6.
Excessive p u m p noise, c h irp in g ,
P um p fa ilu re .
1. Leak in hose.
ru m b lin g , k n o c k in g , loss o f engine
p e rfo rm a n c e .
6. R eplace p u m p .
1. Lo cate source o f leak using soap
s o lu tio n and c o rre c t.
2. Loose hose.
2. Reassemble and replace o r tig h te n
hose cla m p .
3. Hose to u c h in g o th e r engine parts.
3. A d ju s t hose p o s itio n .
4. V a cu u m d iffe re n tia l valve
4. Replace vacu um d iffe re n tia l
in o p e ra tiv e .
valve.
5. By-pass valve in o p e ra tive
5. R eplace by-pass valve.
6. P um p m o u n tin g fasteners loose.
6. T ig h te n m o u n tin g screws as
sp e cifie d .
Excessive b e lt noise.
Excessive p u m p noise. C h irp in g
7. P um p fa ilu re .
7. R eplace p u m p .
8. C heck valve in o p e ra tiv e .
8. R eplace che ck valve.
1. Loose b e lt
1. T ig h te n to spec.
2. Seized p u m p
2. R eplace p u m p .
1. In s u ffic ie n t bre a k-in
1. R un ve h icle 10 -15 m iles a t
in te rs ta te spe eds-reche ck.
C e n trifu g a l filte r fan damaged
1. M echanical dam age
1. Replace c e n trifu g a l filte r fa n .
E xhau st tu b e b e n t o r dam aged.
1. M echanical damage
1. R eplace exh aust tu b e .
P oor id le o r d r iv e a b ility .
1. A d e fe c tiv e A .I.R . system
o r b ro k e n .
c a n n o t cause p o o r idle
o r d riv e a b ility .
1. D o n o t replace A .I.R . system .
Rem ove check valve from pipe assembly, being careful
not to bend or twist the assem bly.
D iverter Valve and Silencer Assembly
Inspection
1. Check condition and routing o f all lines
especially the signal line. All lines m ust be secure w ithout
crim ps and not leaking. Replace d eterio rated lines.
2. D isconnect signal line at valve. A vacuum signal
must be available w ith engine running.
3. Check d iverter valve attaching screws for
tightness. Screws should be torq u ed to 85 lb. in. (lON m).
4. D efectiv e valves should be rep laced (see
Functional Test).
Replace
1. D isconnect vacuum signal line. D isconnect valve
outlet hose.
2. Rem ove d iverter valve from pum p or elbow.
Install
1. Install d iverter valve to p u m p or elbow w ith new
gasket. T orque valve attach in g screws to 85 lb. in.
(9.5N-m).
2. Install outlet and vacuum signal hoses and check
system for leaks.
2. Check for a leaky pressure relief valve. A ir may
be heard leaking w ith the pum p running.
N OTE: The AIR System is not com pletely
noiseless. U nder norm al conditions, noise rises in
pitch as engine speed increases. To determ ine if
excessive noise is the fault o f the A ir Injection
R eactor System, operate the engine w ith the pum p
drive belt rem oved. If excessive noise does not exist
w ith the belt rem oved proceed as follows:
3. Check for a seized A ir Injection Pum p.
4. Check hoses, tubes and all connections for leaks
and proper routing.
CAUTION: Do not oil A IR pump.
5. Check diverter valve.
6. Check AIR injection pum p for pro p er m ounting
and bolt torque.
7. R epair irregularities in these com ponents as
necessary.
8. If no irregularities exist and the A IR injection
pum p noise is still excessive, rem ove and replace pum p.
Replace
1.
2.
3.
pump.
Air Injection Pump
Install
Inspection
1.
2.
3.
4.
5.
48N-m).
A ccelerate engine to approxim ately 1500 RPM and
observe air flow from hose(s). If air flow increases as
engine is accelerated, pum p is o p eratin g satisfactorily. If
air flow does not increase or is not present, proceed as
follows:
1. Check for pro p er drive belt tension.
D isconnect the hoses at the pum p.
Remove pum p pulley as outlined.
Rem ove p um p m ounting bolts and
remove
Install pum p with m ounting bolts loose.
Install pum p pulley as outlined.
Install and adjust belt as outlined.
Connect the hoses at the pum p.
T ighten m ounting bolts to 20-35 lb. ft. (27 N-m -
THROTTLE RETURN CONTROL (TRC)
GENERAL DESCRIPTION
A throttle retu rn control system (TR C) is used on
10-30 Series Trucks in C alifo rn ia w ith heavy duty
em issions systems. Also, 305 C.I.D. heavy duty em issions
(except C alifo rn ia) vehicles use the TRC system.
W hen the vehicle is coasting against the engine, the
T R C valve will open at high m anifold vacuum levels to
allow vacuum to operate the throttle lever actuator. The
throttle lever actuator pushes the throttle lever slightly
open, thus reducing hydro-carbon em issions during coast
down. W hen m anifold vacuum drops below a p re
d eterm in ed level (TR C valve set point) the control valve
closes, the throttle actuator retracts, and the throttle lever
retu rn s to idle position.
ON-VEHICLE SERVICE
SYSTEM O P E R A TIO N
T he T R C valve and actu ato r system should function
to slightly o pen the throttle at high m anifold vacuum
o v errun conditions (ab o u t 21-23 in. hg. [71 -78kPa]
d ep en d in g on the p articu lar engine application) and
retu rn to the curb idle position at lower m anifold
vacuum s. F ailure to function in this m an n er indicates the
T R C valve or actuator is m isadjusted, a vacuum leak
exists, the valve vent is plugged or there is binding
som ew here in the system.
C heck hoses fo r cracking, abrasion, or deterioration
and replace as necessary. Check system function for
p ro p er o p eratio n and adjust as as necessary.
C HECK IN G A N D A D JU S TIN G SYSTEM
Control Valve (Figs. 6E -43,44, 4 5 )
Checking and Adjusting
1. D isco n n ect v a lv e -to -c arb u re to r hose at the
c a rb u re to r an d connect to an external vacuum source
with an accurate vacuum gage inserted n ear the valve.
2. A pply a m inim um o f 25 in. Hg. (84 kPa)
vacuum to the control valve vacuum supply fitting and
seal off the vacuum supply betw een the gage and the
source. The vacuum gage re a d in g will indicate the valve
set p o in t value.
If the gage read in g is not w ith in .5 in. Hg. (7kPa) o f
the specified value fo r the p articu lar engine being
checked, then the valve needs adjustm ent. If the
trap p ed vacuum drops off faster th an .1" Hg. per
second, then the valve is leaking and must be
replaced.
3.
a.
b.
To adjust the valve set point:
G ently p ry off the conical plastic cover.
D isengage the ja m nuts by holding the larger
nut and loosening the sm aller nut. A djust the valve by
turning the larger nut in (clockwise) to raise the set point
or out (counter-clockwise) to lower the set point value.
c. Recheck the valve set p o in t per Step 2.
d. R epeat Steps b and c as necessary to obtain
the pro p er set point value.
292-22.5 in. hg
.5 (m aroon)
305-22.5 in. hg
.5 (orange)
350-21.5 in. hg
.5 (black)
400-21.5 in. hg
.5 (black)
454-23.0 in. hg
.6 (green)
T IG H T E N T O
150 LBS. IN .
THROTTLE
LEVER
ACTUATOR
CO NTRO L
VALVE
Fig. 6E-45-Control Valve-454 V8
e. Hold the larger adjusting nut and retorque the
sm aller ja m nut to 25-30 in. lbs. (3-3.4 N m).
f. R einstall plastic cover.
g. If the valve cannot be readjusted, it m ust be
replaced.
Replacement
D isconnect vacuum hoses at control valve. Remove
nut, w asher and control valve. Reverse procedure to
install, then check o p eratio n o f new control valve.
T h ro ttle Lever A ctuator (Fig. 6E -46 and 4 7 )
Check and Adjustment
Fig. 6E-46-Throttle Lever Actuator-L6
d. Release and reapply 20 in. hg. (68kPa) vacuum
to the actuator and note the RPM to which the engine
speed increased (do not assist the actuator).
e. If the RPM obtained in Step d is not w ithin 150
RPM o f th at obtained in c, then the actuator plunger
m ay be binding due to dirt, corrosion, varnish, etc. If
binding is indicated and cannot be corrected, then the
actuator m ust be replaced.
f. Release the vacuum from the actuator and the
engine speed should return to w ithin 50 R PM o f the idle
Throttle Lever Actuator Checking and Adjusting
Procedure
1. D isconnect valve-to-actuator hose at valve and
connect to an external vacuum source eq uipped with a
vacuum gage n e a r the actuator.
N O T E : If an external vacuum source is not readily
available, the actuator m ay be plum bed directly to
m an ifo ld vacuum to extend the plunger.
2. A pply 20 in. hg. (68 kPa) vacuum to the actuator
and seal off the vacuum source. If the vacuum gage
read in g drops, then the actuator is leaking and m ust be
replaced.
3. To check the actuator fo r pro p er operation:
a. C heck the throttle lever, shaft, and linkage to be
sure th a t they o p erate freely w ithout bind in g or sticking.
b. S ta rt engine and ru n until w arm ed up and idle
is stable. T u rn a ir conditioning "off" if so equipped.
N ote idle RPM .
c. A pply 20 in. hg. (68kPa) vacuum to the actuator.
M anually open the throttle slightly and allow to close
against the extended actuator plunger. N ote the engine
RPM .
THROTTLE
LEVER
ACTUATOR
V.'
'^'T H R O T T L E LEVER
• 292-1600 RPM
speed noted in Step b. If it does not. the plunger may be
• 305-1600 RPM
bin d in g due to d irt, corrosion, varnish, etc. If the
• 350-1500 RPM
problem cannot be corrected, the actuator must be
• 400-1500 RPM
replaced.
• 454-1500 RPM
g.
If the engine RPM noted in c is not w ithin the
specified T R C speed range, the T R C actuator m ust be
adjusted.
4. To adjust the throttle lever actuator.
Replacement
a. Apply 20 in. hg. (68kPa) vacuum to the
actuator. M anually open the throttle slightly and allow to
D isconnect vacuum hose at actuator. Rem ove two
close against the extended actuator plunger.
screws and actuator (454 only). O n all o th er applications
b. To adjust the throttle lever actuator, turn the
unlock spider w asher and loosen large nut to remove
hex-end plunger on the actuator to o btain the specified
actuator from bracket. Reverse procedure to install new
speed.
unit and refer to 4 above for p ro p er speed adjustm ent.
VACUUM ADVANCE CONTROL
TR A P P E D V A C U U M SPARK
to the distributor. The delay valve in the m ode o f
operation acts as a connector.
G eneral Description
T rap p ed vacuum spark (Figs. 6E-13 and 14) is on all
454 C ID engines w ith heavy duty emissions. A therm al
vacuum switch (TVS) is m ounted in the cylinder head
sensing engine coolant tem p eratu re and a delay valve is
betw een m anifold vacuum , d istrib u to r and therm al
vacuum switch.
W hen engine tem p eratu re is below specified valve,
the m an ifo ld vacuum signal is routed through the delay
valve to the distrib u to r. Ports on TVS are blocked. The
delay valve will keep the vacuum to the distributor at
vacuum levels h igher th an m anifold depression during
vehicle acceleration. A sm all sintered iron bleed is
provided in the delay valve to allow for a leak-down to
enable restarts in case o f engine stalls.
W hen engine tem p eratu re is above specified valve,
the ports on TVS will be open to allow m anifold vacuum
SPARK C O N TR O L S W ITC H
General Description
Spark control switch (Figs. 6E-9 and 6E-11) system
is used on some 350/400 CID engines w ith heavy duty
em ission to help protect the engine during an over-heat
mode.
W hen coolant is at norm al op eratin g tem perature,
ported vacuum is directed through a therm al vacuum
switch (TVS) to the distrib u to r vacuum advance.
W hen coolant is above norm al op eratin g tem p era
ture, full vacuum is directed through the TVS to
distributor vacuum advance. This advances the tim ing
and allows the engine to run cooler. At this time, full
vacuum is directed to the d istributor vacuum advance at
idle.
SECTION 6F
ENGINE EXHAUST SYSTEM
GENERAL DESCRIPTION
F o r alig n m en t purposes, the muffler outlet flange is
notched and m ates to a w elded tab located on the outside
d ia m e te r o f the tailpipe. T he exhaust pipes and muffler
use locater tabs for alignm ent.
T he CIO w ith light duty em issions (except 454 V8)
and GIO vehicles have an exhaust system with a catalytic
converter betw een the fro n t exhaust pipe and the rear
exhaust pipe.
T he catalytic converter is an em ission control device
ad ded to the exhaust system to reduce hydrocarbon and
carbon m onoxide pollutants from the exhaust gas stream .
The converter contains beads which are coated with a
catalytic m aterial containing platinum and palladium .
The catalytic converter requires the use o f unleaded
fu e l only.
Periodic m aintenance o f the exhaust system is not
required; however, if the vehicle is raised fo r other
service, it is advisable to check the general condition o f
the catalytic converter, pipes and mufflers.
CAU TION : When ja c kin g or lifting vehicle
from fra m e side rails, be certain lift pads do
not contact catalytic converter as dam age to
converter will result.
DIAGNOSIS
EXHAUST SYSTEM
C O N D IT IO N
Leaking Exhaust Gases
Exhaust Noises
POSSIBLE CAUSE
C O R R E C T IO N
Leaks at pipe jo ints.
Tighten U -bolt nuts at
leaking jo in ts to 30
foot-pounds.
Damaged or im properly
installed seals or packing.
Replace seals or packing
as necessary.
Loose exhaust pipe heat tube
extension connections.
Replace seals or packing as
required. Tighten
stud nuts or bolts
to specifications.
Burned o r rusted o u t exhaust
pipe heat tube extensions.
Replace heat tube extensions
as required.
Leaks at m anifold
or pipe connections.
Tighten clamps at leaking
connections to specified
torque. Replace gasket or
packing as required.
Burned or blow n out
m u ffle r.
Replace m u ffle r
assembly.
Burned o r rusted o u t
exhaust pipe.
Replace exhaust pipe.
Exhaust pipe leaking
at m an ifold flange.
Tighten attaching
bolts nuts to 17 f o o t
pounds.
Exhaust m anifold
cracked or broken.
Replace m anifold.
Leak between m anifold
and cylin d e r head.
Tighten m anifold to
cylinder head stud
nuts or bolts to specifications.
Loss o f engine power an d/or
internal rattles in m u ffle r.
Dislodged tu rning tubes and or
baffles in m u ffle r.
Replace m u ffle r.
Loss o f engine power.
Im plo ding (inner wall collapse)
of exhaust pipe (C T ruck)
Replace exhaust pipe.
ON-VEHICLE SERVICE
G ENERAL
Exhaust System Pipes and Resonators Rearward of
the Mufflers Must Be Replaced Whenever A New Muffler
Is Installed.
N O T E : W hen a muffler is replaced use sealing
com pound at the clam ped jo in t to prevent leaks.
T ruck exhaust systems vary according to series and
m odel designation. Series 10-30 trucks use a split-joint
design system in w hich the exhaust pipe-to-m uffler are
clam ped to g ether and m uffler-to-tailpipe connections are
w elded together. All mufflers an d tailpipes are welded
assem blies (no clam ps).
N O T E : All 10-20-30 series exhaust systems are
alum inized steel except: (1) " C " Series exhaust
pipes and (2) stainless steel exhaust pipes on
vehicles equipped with underfloor catalytic convert
ers. Always use correct replacem ent parts w hen
servicing these systems.
W h en in stalling a new exhaust pipe or muffler and
tailpipe, on any m odel, care should be taken to have the
correct alig n m en t an d relatio n sh ip o f the com ponents to
each other. P articu lar care should be given to the
installation o f the exhaust pipe and crossover pipe
assem b ly on V-8 en g in e single ex h aust system s.
Incorrectly assem bled parts o f the exhaust system are
freq u en tly the cause o f annoying noises and rattles due
to im p ro p er clearances or obstructions to the norm al flow
o f gases. Leave all clam p bolts and muffler bolts loose
until all parts are p roperly aligned and then tighten,
w orking from front to rear.
E xhaust system hangers, h an g er brackets, and
clam ps w hich are dam ag ed should be replaced to
m ain tain p ro p er exhaust system alignm ent.
N O TE: W hen reinstalling exhaust pipe to m an i
fold, always use new packings and nuts. Be sure to
clean m anil'old stud th read s with a w ire brush
w hen in stalling the new nuts.
CO N V E R TE R H EAT SHIELD
C 10 Series
R efer to Figure 6F-1 for converter h eat shield.
C A TA LY T IC CO NVERTER (FIGS. 6F-2 and 3 )
C IO and G 10 Series
Removal
1. R aise vehicle on hoist.
2. R em ove clam ps at fro n t and re a r o f converter.
3. Cut converter pipes at front and rear o f
converter and rem ove converter.
4. O n CIO m odels, rem ove support attaching
converter-to-transm ission.
5.
Rem ove converter pipe-to-front-exhaust
and converter pipe-to-rear exhaust pipe.
Installation
1. W ith sealer on exhaust pipes, install pipes into
converter.
2. On CIO m odel, loosely connect support attach
ing converter-to-transm ission.
3. Install new " U " bolts and clam ps at front and
rear o f converter.
4. Check all clearance and tighten clam ps and
support.
5. Lower vehicle and rem ove from hoist.
Catalyst Removal
If necessary, the catalyst in the converter can be
replaced on the vehicle with Tool N o. J-25077.
1. Install asp irato r J-25077-2 (Fig. 6F-4).
NOTE: Separate hoses should be attached to the
asp irato r and the v ibrator w ith m axim um available
pressure. M inim um o f 60 psi in each hose.
2. C onnect air supply line to aspirator to create a
vacuum in the converter to hold beads in place w hen fill
plug is rem oved.
3. Remove converter fill plug as follows:
a. T hreaded plug - Remove with 3 /4 " hex
wrench or Tool J-25077-3.
b. Pressed plug - D rive a small chisel between
the converter shell and the fill plug. Use care not to
dam age converter shell (Fig. 6F-5). C ontinue to deform
fill plug until it can be rem oved w ith pliers (Fig. 6F-6).
NO TE: Do not pry fill plug from converter as
dam age to fill plug sealing surfaces could result.
pipe
ASPIRATOR
■■■■I
4. C lam p on v ib rato r and catalyst co n tain er (Fig.
6F-7). Use a d a p te r J-25077-6 if converter was built with
pressed plug.
5. D isconnect air supply to asp irato r and connect
air supply to vibrator. C atalyst will now d rain from the
converter into the em pty container.
6. W hen all the catalyst has been rem oved from
the converter, disconnect air supply to v ib rator and
rem ove co n tain er from the converter.
7. D iscard used catalyst.
Fig. 6F-4--lnstalling Aspirator
2. Install fill tube extension to the fixture J-25077-1
(Fig. 6F-8). Use a d ap te r J-25077-6 if converter was built
with pressed plug.
Catalyst Replacement
1.
catalyst.
F ill
c o n ta in e r
w ith
ap p ro v ed
rep lacem en t
3.
C onnect air supply to asp irato r and vibrator.
4.
A ttach catalyst container to the fixture (6F-9).
A DAPTER
J -25077-6
DO NOT PRY FILL PLUG
FROM CONVERTER
. F I L L TUBE
E X TE N S IO N
Fig. 6F-6-Removing Pressed Plug With Pliers
Fig. 6F-8--lnstalling Fill Tube Extension
jC LA M P V IB R A T O R
!OVER CON VERTER
A D A PTER
J -25077-6
C LAM P
C LA M P LO CK
V IB R A T O R
LOCK
V IB R A T O R
C ATALYST
C O N TA IN ER
Fig. 6F-7-Installing Vibrator and Adapter
Fig. 6F-9--lnstalling Catalyst Container
5. A fter the catalyst stops flowing, disconnect air
supply to the vibrato r.
6. R em ove v ib rato r and check th at catalyst has
filled co n v erter flush w ith fill plug hole. A dd catalyst if
required.
7. A pply an anti-seize com pound to the fill plug;
install and tig h ten to 60 pound feet.
If built w ith a pressed plug, install service fill plug
(Fig. 6F-10), as follows: Install the bolt into the
bridge and position the bridge into converter
opening. Move bolt and bridge back and forth to
dislodge catalyst beads until bridge is positioned
(Fig. 6F-11).
8. Remove bolt from bridge then position the
w asher and fill plug, dished side out, over the bolt.
9. W hile holding the fill plug and w asher against
Fig. 6F-10-Service Fill Plug
the bolt head (Fig. 6F-12), th read the bolt 4 o f 5 turns
into the bridge. Release the fill plug and the aspirator
will pull the fill plug into position.
N O T E : If fill plug is allowed to seat against the
converter b efore installing bolt, the th read ed hole
in the bridge will fill w ith beads and it will be very
difficult to sta rt the bolt.
Fig. 6F-12-Installing Fill Plug
10. A fter m aking sure fill plug is correctly seated,
tighten the bolt and torque to 28 ft. lbs. (Fig. 6F-13).
11.
12.
D isconnect a ir supply to asp irato r and remove.
S tart vehicle and check fo r leaks.
| TORQUE 28 FT. LBSlf
B ottom Cover
7.
A ttach 2 clam ps over retain in g channels at each
end o f the converter (Fig. 6F-20).
If, fo r any reason, the bottom cover o f the converter
is torn or severely dam aged, it can be replaced with a
re p a ir kit.
Bottom Cover Replacement
1. Rem ove bottom cover by cutting close to the
bottom outside edge (Figs. 6F-14 and 15). Do not
rem ove the fill plug. The depth o f the cut must be very
shallow to prevent dam age to the in n er shell of the
converter.
2. R em ove insulation (Fig. 6 F - 16).
3. Inspect in n er shell o f the converter for dam age.
If there is dam age in the in n er shell, the converter
assem bly must be replaced (Fig. 6F-17).
4. Place new insulation in the replacem ent cover.
A pply sealing com pound, all around the cover after the
insulation is in position. Apply extra sealer at the front
and re a r opening fo r the pipes (Fig. 6F-18).
5. Install replacem ent cover on converter (Fig. 6F18).
6. Install cover retain in g channels on both sides o f
the converter (Fig. 6F-19).
Fig. 6F-15 -Removing Bottom Cover
CATALYTIC CONVERTER
INSULATION
Fig. 6F-14- Removing Bottom Cover
Fig. 6F-16-Catalytic Converter Insulation
Fig. 6F17-Catalytic Converter Inner Shell
RETAINING C HANNEL
Fig. 6F-19- Installing Eiottom Cover Retaining
Channels
CLAMP
INSULATIO N
SEALING
C O M PO U N D
Fig. 6F- 18 -lnstalling Bottom Cover Replacement
Fig. 6F 20--lnstalling Bottom Cover Clamps
SPECIAL TOOLS
n
1. J-2 50 77-1
V ibrator — Include Catalyst
C on tain er an d Fill Tube Extension
2. J- 2 5 0 7 7 -2 Aspirator
SECTION 7 A
AUTOMATIC TRANSMISSION
C O N T E N T S OF TH IS SECTION
CBC 350 T ra n sm issio n ..................................................................
THM 400 T ransm ission.................................................................
S pecifications......................................................................................
Special T o o ls......................................................................................
7A-1
7A-21
7A-37
7A-38
CBC 3 5 0 TRANSMISSION
INDEX
G en eral D e sc rip tio n ...........................................................7A-1
M ain ten an ce and A d ju stm e n t...................................... ..7A-4
T ransm ission F lu id ...........................................................7A-4
C hecking T ransm ission M o u n t.................................. ..7A-5
S h ift C o n tro ls......................................................................7A-5
D etent D ow nshift C a b le .............................................. ..7A-7
N eu tral Start S w itc h ........................................................7A-7
D ia g n o sis.............................................................................. ..7A-9
Sequence for D iagn osis................................................ ..7A-9
Fluid C hecking P rocedures............................................7A-9
Fluid Leak D ia g n o sis................................................... ..7A-9
Oil Pressure C h eck ...........................................................7A-10
Case Porosity R e p a ir.......................................................7A-10
Vacuum M odulator D ia g n o sis................................... .7A-10
Clutch Plate D ia g n o sis................................................. ..7A-11
Causes of Burned Clutch P la te s.................................7A-11
G o vern or Pressure C h e c k ............................................ .7A-12
M anual L in k a g e .............................................................. ..7A-12
Road Test.............................................................................7A-12
Trouble D iagn osis............................................................. .7A-13
D iagnosis C h a rt............................................................... .7A-14
Service O p e ra tio n s..............................................................7A-18
Transm ission Replacem ent (Except K M odels)... 7A-18
Transm ission R eplacem ent (K M o d els)................. ..7A-18
Extension H ousing Oil S e a l.........................................7A-18
Speedom eter D riven G e a r............................................7A-19
Speedom eter D rive G e a r ..............................................7A-19
M anual Shaft, R ange Selector Inner Lever and
Parking L in k ag e...........................................................7A-19
G o v e rn o r............................................................................ .7A-19
Vacuum M odulator and M odulator V a lv e .............7A-19
Valve Body A sse m b ly ................................................... .7A-20
l -2 A ccu m u lato r.............................................................. .7A-20
Oil Cooler Pipes.............................................................. .7A-20
GENERAL DESCRIPTION
T he CBC 350 transm ission is a fully autom atic unit
consisting p rim arily o f a 3-elem ent hydraulic torque
converter and two p lan etary g ear sets. Four m ultiple-disc
clutches, two roller clutches, and an interm ed iate overrun
band provide the friction elem ents required to obtain the
desired function o f the two p lan etary gear sets.
T he 3-elem ent torque converter consists o f a pum p,
tu rb in e and a stator assem bly. T he stator is m ounted on
a one w ay roller clutch which will allow the stator to turn
clockwise, but not counterclockwise. References to
clockwise an d counterclockw ise are determ ined by
looking tow ard rear o f vehicle.
T he torque converter is o f welded construction and
is serviced as a com plete assem bly. The unit is filled w ith
oil a n d is attached to the engine cran k sh aft by a
flywheel, thus always rotates at engine speed. The
converter p u m p is an integral p art o f the converter
housing, therefore, the pum p blades, ro tatin g at engine
speed, set the oil w ithin the converter into m otion and
direct it to the turbine, causing the turbine to rotate.
As the oil passes throughout the turbine it is
traveling in such a direction that if it were not redirected
by the stator it would hit the rear o f the converter pum p
blades and im pede its pum ping action. So at low turbine
speeds, oil is redirected by the stator to the converter
pum p in such a m an n er that it actually assists the
converter pum p to deliver power, or m ultiply engine
torque.
As turbine speed increases, the direction of oil
leaving the turbine changes and flows against the rear
side o f the stator vanes in a clockwise direction. Since
the stator is now im peding the smooth flow o f oil, its
roller clutch releases and it revolves freely on its shaft.
Once the stator becomes inactive, there is no fu rther
m ultiplication o f engine torque w ithin the converter.
At this point, the converter is merely acting as a
I
fluid coupling as both the converter p um p and turbine
are being d riven at approxim ately the sam e speed.
A hydraulic system pressurized by a g ear type pum p
provides the w orking pressure required to operate the
friction elem ents and autom atic controls.
E xternal control connections to the transm ission are:
• M a n u a l L in k ag e - To select the desired
o p eratin g range.
• E ngine V acuum - To operate the vacuum
m odulator.
• C able C ontrol - To operate the d eten t valve.
A vacuum m odulator is used to autom atically sense
any change in the torque input to the transm ission. The
vacuum m odulator transm its this signal to the pressure
regulator, w hich controls line pressure, so th at all torque
requirem ents o f the transm ission are m et and smooth
shifts are obtained at all throttle openings.
The detent valve is activated by a cable th at is
connected to the accelerator lever assembly. W hen the
throttle is h alf open, the valve is actuated causing
throttle dow nshift at speeds below 50 m ph. W hen the
throttle is fully open the detent valve is actuated causing
the transm ission to dow nshift from 3-1 at speeds below
40 m ph and 3-2 below 75 mph.
CONVERTER
ASSEMBLY
INTERMEDIATE
CLUTCH
INTERMEDIATE
OVERRUN BA N D
FORWARD
CLUTCH
LO W A N D
REVERSE
CLUTCH
SUN
GEAR
OUTPUT
SHAFT
L O W A N D REVERSE
OVERRUN ROLLER
View
INPUT
SHAFT
T R A N S M IS S IO N
350, Cross-Section
GO VER NO R
A U T O M A T IC
Fig. 7A-1B--CBC
REACTION
CARRIER
PARKING
PAWL
OUTPUT
CARRIER
STATOR
SHAFT
MANUAL
SHAFT
7 A -3
INTERMEDIATE
OVERRUN
ROLLER CLUTCH
MAINTENANCE AND ADJUSTMENTS
T R A N S M IS S IO N FLUID
Fluid Level and C a p a c ity
The fluid level indicator is located in filler tube at
right rear o f engine. To bring the fluid level from the
A D D mark to the F U L L mark requires one pint o f fluid.
Fluid level should be checked at every engine oil change.
Fluid level should be to the F U L L m ark with the
transmission fluid at norm al operating tem perature (200°
F). With w arm fluid (room tem perature 7 0 °F), the level
will be 1/4 inch below the A D D mark on the dipstick.
The norm al operating tem perature is obtained only after
at least 15 miles of highway type driving or the
equivalent o f city driving.
A pproxim ately 8 pints o f fluid are required to refill
transmission after oil p a n has been drained. The fluid
capacity o f the CBC 350 transmission and converter
assembly is approxim ately 21 1/2 pints but correct level
is determ in ed by the mark on the dipstick rath er than by
am o u n t added. Use only D EX R O N ® or D EX R O N ® II
autom atic transmission fluid or its equivalent.
N O T E: An early stage to a darker color from the
usual red color a n d / o r a strong odor that is usually
associated with overheated transmission fluid is
normal, and is not a positive sign of required
m aintenance or transmission failure.
C h e c k in g P ro ce d u re and A d d in g Fluid
To determ ine proper fluid level at norm al operating
tem perature, proceed as follows:
1. Position vehicle on a level surface, place selector
lever in park (P), apply park in g brake and have engine
running at norm al idle.
2. Remove fluid level indicator, wipe it clean and
reinstall fully until cap seats.
(190°-200° F.)
(88°-93° C.)
3. Remove indicator and reading o f fluid level
should be at full “ F ” mark.
4. If additional fluid is required, add DEXRON®
or D E X R O N ^ II automatic transmission fluid or its
equivalent to “ F ” mark on indicator.
If the vehicle cannot be driven sufficiently to bring
the transmission to operating tem perature and it
becomes necessary to check the fluid level, the
transmission may be checked at room tem perature (70
degrees F) as follows:
1. Position selector lever in park (P), apply parking
brake and start engine. D O N O T RACE E N G IN E .
Move selector lever through each range.
2. Immediately check fluid level with selector lever
in Park, engine running and vehicle on LEVEL surface.
Fluid level on indicator should be 1/4 inch below
the " A D D " mark.
3. If additional fluid is required, add enough fluid
to bring level to 1/4 " below the A D D m ark on the
dipstick. If transmission fluid level is correctly estab
lished at 70 °F, it will appear at the F U L L mark on the
dipstick when the transmission reaches its normal
operating tem perature o f 200 T .
C A U T IO N : D O N O T O V E R F IL L , as foam ing
and loss o f flu id through the vent pipe might
occur as flu id heats up.
If fluid is too low, especially when cold, complete
loss o f drive m ay result which can cause transm is
sion failure.
D ra in in g and R e fillin g T ran sm issio n
The oil pan should be drained and the strainer
cleaned at the intervals detailed in section O-B o f this
m anual, and fresh fluid added to o btain the proper level
on indicator. Section O-B also details intervals for
vehicles subjected to heavy city traffic during hot
weather, or in commercial use, or when the engine is
regularly idled for prolonged periods or when vehicle is
used for towing.
D rain fluid im mediately after operation before it
has had an opportunity to cool.
W A R N IN G : T ran sm issio n
can exceed 3 5 0 F.
WARM
NOTE:
DO NOT OVERFILL.
IT TAKES
ONLY ONE PINT TO RAISE
LEVEL FROM ADD TO FULL
WITH A HOT TRANSMISSION.
fluid te m p e ra tu re
1. Raise vehicle.
2. Support transmission with suitable jack at the
transmission.
3. With fluid receptacle placed under transmission
oil pan. remove oil pan attaching bolts from front and
side o f pan.
4. Loosen rear pan attaching bolts approximately
four (4) turns.
5. Carefully pry transmission oil pan loose with
screwdriver, allowing fluid to drain.
6. Remove rem aining screws and remove oil pan
and gasket. Discard gasket.
7. D rain fluid from oil pan. Clean pan with solvent
an d dry thoroughly with clean compressed air.
8. Remove two (2) strainer-to-valve body screws,
strainer and gasket. Discard gasket.
9. T horoughly clean strainer assembly in solvent
and dry throughly with clean compressed air.
10. Install new strainer-to-valve
strainer and two (2) screws.
body
gasket,
11. Install new gasket on oil pan and install oil
pan. Tighten its thirteen (13) attaching bolt and washer
assemblies to 12 pound-feet torque.
12. Lower vehicle add approximately 5 pints U.S.
measure (4 pints Imperial measure) o f D E X RO N ® or
D E X R O N * II autom atic transm ission fluid or its
equivalent through filler tube.
13. With selector lever in PARK position, apply
hand brake, start engine an d let idle (carburetor off fast
idle step). DO N O T RACE E N G IN E .
14. Move selector lever through each range and,
with selector lever in PARK range, check the fluid level.
15. Add additional fluid to bring level to 1/4"
below the A D D mark on the dipstick.
Fig. 7A-3B--Column S hift Linkage - CK Series
C A U T IO N :
Do not overfill. Foaming can result
i f overfilled.
A d d in g Fluid to Fill D ry T ran s m is s io n
an d C o n v e rte r A ssem bly
In cases o f transmission overhaul, when a complete
fill is required, including converter (approximately 20
pints), proceed as follows:
1.
screws or nuts
crossmember.
attaching
m ount
to transmission
or
S H IF T CO NTRO LS
Colum n S hift Linkage - CK and P Series
(Figs. 7A -3B and 7A -4B )
Add 8 pints o f transmission fluid through filler
tube.
2. With m anual control lever in park (P) position,
start engine and place on cold idle cam. D O N O T RACE
E N G IN E . Move m anual control lever through each
range.
3. Immediately check fluid level with selector lever
in park (P), engine ru nn in g an d vehicle on LEVEL
surface and add additional fluid to bring level to 1/4"
below the " A D D " mark on the dipstick. Do not overfill.
CH E C K IN G T R A N S M IS S IO N M O U N T
Raise vehicle on a hoist. Push up and pull down on
transmission tailshaft while observing transmission
mount. If ru b b e r separates from metal plate of m ount or
if tailshaft moves up but not down (mount bottomed out)
replace mount. If there is relative movement between a
metal plate o f m ount and its attaching point, tighten
1. The shift tube and lever assembly must be free
in the mast jacket. See Section 3B for alignm ent of
steering column assembly if necessary.
2. To check for proper shift linkage adjustment,
lift the transmission selector lever towards the steering
wheel. Allow the selector lever to be positioned in drive
(D) by the transmission detent.
N OTE: D o not use the indicator pointer as a
reference to position the selector lever. W hen
pe rfo rm in g linkage adjustment, pointer is adjusted
last.
3. Release the selector lever. The lever should be
inhibited from engaging low range unless the lever is
lifted.
4. Lift the selector lever towards the steering
wheel, and allow the lever to be positioned in neutral (N)
by the transmission detent.
5. Release the selector lever. The lever should now
be inhibited from engaging reverse range unless the
lever is lifted.
wheel is locked, and that transmission rem ains in 'Park'
when steering column is locked.
CAUTION: A n y inaccuracies in the above
adjustments may result in premature failure o f
the transmission due to operation without
controls in f u ll detent. Such operation results in
reduced oil pressure and in turn partial
engagement o f the affected clutches. Partial
engagement o f the clutches with sufficient
pressure to cause apparent normal operation o f
the vehicle will result in failure o f the clutches
or other internal parts after only a few miles o f
operation.
Column Shift Linkage - G Series
(Fig. 7A -5B )
1. The shift tube and lever assembly must be free
in the mast jacket.
2. Set transmission lever (C) in "neutral' position
by one of the following optional methods.
Fig. 7A-4ES -Column Shift Unkage-P Series
6. A properly adjusted linkage will prevent the
selector lever from moving beyond both the neutral
detent, and the drive detent unless the lever is lifted to
pass over the mechanical stop in the steering column.
7. If adjustm ent is required, remove screw (A) and
spring washer from swivel (B).
8. Set transmission lever (C) in Neutral position by
moving lever counterclockwise to LI detent and then
clockwise three (3) detent positions to Neutral.
9. Position transmission selector lever in Neutral
position as determ ined by the mechanical stop in
steering column assembly.
NO TE: Do not use the indicator pointer as a
reference to position the selector lever. W hen
perform ing linkage adjustment, pointer is adjusted
last.
10. Assemble swivel, spring washer and screw to
lever assembly (D) and tighten screw to 20 pound feet.
11. Readjust indicator needle if necessary to agree
with the transmission detent positions. See Section 9.
12. Readjust neutral start switch if necessary to
provide the correct relationship to the transmission
detent positions. See Section 8.
13. Check operation (CK Series):
a. With key in " R u n " position and transmission
in "R everse" be sure that key cannot be removed and
that steering wheel is not locked.
b. With key in "L ock" position and shift lever
in "P ark " , be sure that key can be removed, that steering
NOTE: O btain "n eutral" position by moving
transmission lever (C) counter-clockwise to " L I "
detent, then clockwise three detent positions to
"n eu tra l" or obtain "n e u tra l" position by moving
transmission lever (C) clockwise to the " p a rk "
detent then counter-clockwise two detents to
"neutral".
3. Set the column shift lever in "n e u tra l" position.
This is obtained by rotating shift lever until it locks into
mechanical stop in the column assembly.
NOTE: Do not use indicator pointer as a reference
to position the shift lever.
4. Attach rod (A) to shaft assembly (B) as shown
(Fig. 7A-5B).
5. Slide swivel (D) and clamp (E) onto rod (A)
align the column shift lever and loosely attach as shown.
P. W A S H E R
GRO M M ET
L. W A S H E R
\
,N U T
F
C O L U M N SH IFT LEVER.
B U S H IN G .
CLAM P
E
C O LU M N A SSEM BLY
S W IV E L D
ROD A
TRANS
LEV ER C
SID E R AIL
T R A N S M IS S IO N ( 7)'
R E T A IN E R
GRO M M ET
SH A F T A S S E M B L Y B
GRO M M ET
6. Hold column lever against "n e u tra l" stop
" p a r k " position side.
7. Tighten nut (F) to 18 foot pounds.
8. Readjust indicator needle if necessary to agree
with the transmission detent positions.
9. Readjust neutral start switch if necessary to
provide the correct relationship to the transmission
detent positions.
C A U T IO N : A n y inaccuracies in the above
adjustm ents m ay result in prem ature fa ilu re o f
the transmission due to operation without
controls in fu ll detent. Such operation results in
reduced oil pressure and in turn partial
engagem ent o f the affected dutches. Partial
engagem ent o f the clutches with sufficient
pressure to cause apparent norm al operation o f
the vehicle will result in failure o f the clutches
or other internal parts after only a few miles o f
operation.
3. Compress locking tabs and disconnect snap-lock
assembly from bracket.
4. Remove clam p around filler tube, remove screw
and washer securing cable to transm issio n and
disconnect detent downshift cable.
In s ta lla tio n
1. Install new seal on detent downshift cable.
Lubricate seal with transmission fluid.
2. Connect transmission end o f detent downshift
cable and secure to transmission case with bolt and
washer tightened to 75 inch pounds.
3. Route cable in front o f filler tube and install
clamp around filler tube, m odulator pipe and detent
downshift cable. Locate clamp approximately 2 inches
above filler tube bracket.
4. Pass cable through bracket and engage locking
tabs of snap-lock on bracket.
5. Connect cable to carburetor lever.
A d ju s tm en t
D E TE N T D O W N S H IFT CABLE
(Figs. 7A -6B and 7A -7B )
With snap-lock disengaged, position carburetor to
wide open throttle (W.O.T.) position and push snap-lock
downward until top is flush with rest o f cable.
R e m o va l
1. Push up on bottom of snap-lock and release lock
and detent downshift cable.
2. Disconnect cable from carburetor lever.
NE U TR A L S TA R T SW ITCH
The adjustment o f the neutral
described in Section 8. Electrical.
start
switch
is
Fig. 7A 6B D etent Downshift Cable
C, K and P Series
V - 8 E N G IN E
SNAP LO C K
ASSEM BLED
L - 6 E N G IN E
C A U T IO N :
Fle xibl e co m p o n e n t s (hoses,
wires, co ndu its , etc) mu st n o t be ro uted
w i t h i n 2 inches o f mo vin g parts o f
accelerator linkage fo r w a r d o f the Bracket
VIEW
unless r o u t in g is p osi ti ve ly con tr o lle d.
Fig. 7A-7B--Detent D ownshift Cable - G Series
DIAGNOSIS
SEQ UENC E FOR D IA G N O S IS
1.
Check and correct fluid level.
2.
3.
Check detent cable adjustment.
Check and correct vacuum line and fittings.
4.
Check and correct m anual linkage.
5.
Road test vehicle.
a. Install oil pressure gauge.
b. Road test using all selective ranges, noting
when discrepancies in operation or oil pressure occur.
c. A ttem pt to isolate the unit or circuit involved
in the malfunction.
d. If engine perform ances indicates an engine
tune-up is required, this should be perform ed before
road testing is completed or transmission correction
attempted. Poor engine perform ance can result in rough
shifting or other malfunctions.
FLUID CHECK IN G PROCEDURES
Refer to M aintenance and Adjustment Section for
fluid checking procedures.
FLUID LEAK DIA G N O S IS
Determ ining Source of Oil Leak
Before attem pting to correct an oil leak, the
source o f the leak must be determined. In m any
the source of the leak can be deceiving due to
flow" around the engine and transmission.
The suspected area should be wiped clean o f
before inspecting for the source o f the leak.
actual
cases,
"wind
all oil
The use o f a "Black Light" to locate the point at
which the oil is leaking is helpful. C om paring the oil
from the leak to that on the engine or transmission
dipstick, w hen viewed by black light, will determ ine the
source of the leak - engine or transmission.
Oil leaks around the engine and transmission are
generally carried toward the rear of the vehicle by air
stream. For example, a transmission oil filler tube to case
leak will sometimes appear as a leak at the rear o f the
transmission. In determ ining the source of a leak,
proceed as follows:
1. Degrease underside of transmission.
2. R oad test to get unit at operating temperature.
3.
Inspect for leak with engine running.
4. With engine off, check for oil leaks due to the
raised oil level caused by d rain back.
Possible Points of Oil Leak
1.
Transm ission Oil Pan Leak.
Attaching bolts not correctly torqued.
Improperly installed or dam aged pan gasket.
Oil pan gasket m ounting face not flat.
2. Extension Housing.
a. Attaching bolts not correctly torqued.
b. Rear seal assembly dam aged or improperly
installed.
c. Square seal, extension to case, dam aged or
im properly installed.
d. Porous casting. See su b p a ra g ra p h C.
3.
Case Leak.
a. Filler pipe " O " ring seal d am aged or missing;
misposition o f filler pipe bracket to engine.
b. M odulator assembly " O " ring seal dam aged
or im properly installed.
c. D e te n t cable c onnector " O " ring seal
d am ag ed or im properly installed.
d. G overnor cover not tight, gasket dam aged or
leak between case face and gasket.
e. Speedometer gear " O " ring dam aged.
f. M anual shaft seal dam aged or improperly
installed.
g. Line pressure tap plug loose.
h. Vent pipe (refer to item 5).
i. Porous casting. See S u bpa ra gra ph C.
4. Leak at Fron t o f Transmission.
a. Fron t pum p seal leaks.
1. Seal lip cut. Check converter hub, etc.
2. Bushing moved and dam aged, Oil return
hole plugged.
3.
N o oil return hole.
b. Front pum p attaching bolts loose or bolt
w asher type seals dam aged or missing.
c. Fron t pum p housing " O " ring dam aged or
cut.
d. Converter leak in weld area.
e. Porous casting (pump).
5. Oil Comes Out Vent Pipe.
a. Transmission over-filled.
b. W ater in oil.
a.
b.
c.
c. Foreign material between pum p and case or
between pum p cover and body.
d. Case - porous n ear converter bosses. Front
pump cover or housing oil channels shy or stock near
breather. See Sub paragraph C.
e. Pump to case gasket mis-positioned.
OIL PRESSURE CHECK
While vehicle is stationary (service brake on),
engine speed set to 1200 rrnp, transmission oil pressure
gauge attached as shown in Fig. 7A-10B, and vacuum
m odulator tube d is co n n ec ted the transmission line
pressure tap should read 167 psi in drive, 166 psi in LI
or L2. and 254 psi in reverse.
While vehicle is stationary (service brake on),
engine speed set to m aintain 12 inches hg. absolute
m anifold pressure, transmission oil pressure gauge
attached, and vacuum m odulator tube c o n n e c te d the
transmission line pressure tap should read 85 psi in
drive, 105 psi in LI or L2, and 129 psi in reverse.
CASE PO RO SITY REPAIR
Fxternal oil leaks caused by case porosity can be
successfully repaired with the transmission in the vehicle
by using the following recom m ended procedures:
1. Road test and bring the transmission to
operating temperature, approximately 180 degrees F.
2. Raise vehicle on a hoist or jack stand, engine
running, and locate source of oil leak. Check for oil leaks
in Low. Drive, and Reverse.
3. Shut engine off and thoroughly clean area to be
repaired with a suitable cleaning solvent and a brush air dry.
A clean, dry soldering acid brush can be used to
clean the area and also to apply the epoxy cement.
4. Using instructions o f the m anufacturer, mix a
sufficient am ount o f epoxy to make the repair. Make
certain the area to be repaired is fully covered.
5. Allow cement to cure for 3 hours before starting
engine.
6. Road test and check for leaks.
V A C U U M M O D U LA TO R DIA G N O S IS
A defective vacuum modulator can cause one or
more of the following complaints.
1. Harsh upshifts and downshifts.
2. Delayed upshifts.
3. Soft upshifts and downshifts.
4. Slips in low, drive and reverse.
5. Transmission overheating.
6. Engine burning transmission oil.
If any one of the above complaints are encountered,
the modulator must be checked.
Vacuum Diaphragm Leak Check
Insert a pipe cleaner into the vacuum connector pipe
as far as possible and check for the presence of
transmission oil. If oil is found, replace the modulator.
Gasoline or w ater vapor may settle in the vacuum
side of the modulator. If this is found without the
a. Install the modulator that is known to be
acceptable on either end o f the tool.
b. Install the modulator in question on the
opposite end o f the tool.
c. Holding the modulators in a horizontal
position, bring them together under pressure until either
m odulator sleeve just touches the tool. The indicator in
the gage will show white if the m odulator is acceptable.
A non-conforming m odulator will cause the indicator to
shift, thus showing blue. If white does not appear, the
modulator in question should be replaced.
Sleeve A lignm ent Check
Roll the m ain body of the modulator on a flat
surface and observe the sleeve for concentricity to the
cam. If the sleeve is concentric and the plunger is free,
the modulator is acceptable.
Once the modulator assembly passes all of the above
tests, it is an acceptable part and m ay be re-used.
Fig. 7A-8B--Vacuum M odulator Assembly
presence of oil, the m odulator is serviceable and should
not be changed.
T R A N S M IS S IO N CLUTCH PLATES
DIA G N O SIS
1.
Atm ospheric Leak Check
Apply a liberal coating of soap bubble solution
the vacuum connector pipe seam, the crimped upper
lower housing seam (Fig. 7A-8B). Using a short piece
ru b b e r tubing, apply air pressure to the vacuum pipe
blowing into the tube and observe for leak bubbles.
bubbles appear, replace the modulator.
to
to
of
by
If
N O T E : Do not use any method other than hum an
lung power for applying air pressure, as pressures
over 6 psi may dam age the modulator.
Spring Tension Comparison Check
Using tool J-24466, as shown in Figure 7A-9B.
com pare the load o f a known good modulator with the
assembly in question.
J -2 4 4 6 6
Lined Drive Plates.
a.
Dry plates with compressed air and inspect
the lined surface for:
1. pitting and flaking
2. wear
3. glazing
4. cracking
5. charring
6. chips or metal particles im bedded in lining.
If a lined drive plate exhibits any of the above
conditions, replacement is required. Do not
diagnose drive plates by color.
2. Steel Driven Plates
Wipe plates dry and check for heat discoloration. If
the surface is smooth and an even color smear is
indicated, the plate should be reused. If severe heat
spot discoloration or surface scuffing is indicated,
the plate must be replaced.
3. Clutch Release Springs
Evidence o f extreme heat or burning in the area of
the clutch may have caused the springs to take a
heat set and would justify replacement of the
springs.
CAUSES OF B UR NED CLUTCH PLATES
1.
H O LD M O D U LA T O R S IN A H O R IZ O N T A L P O S IT IO N , AS S H O W N ,
B R IN G TH E M SLOW LY TO G ETHER U N D E R PRESSURE
F O R W A R D CLU TCH
a. Check ball in clutch housing dam aged, stuck
or missing.
b. Clutch piston cracked, seals dam aged or
missing.
c. Low line pressure.
d. Pump cover oil seal rings missing, broken or
undersize; ring groove oversize.
e. Case valve body face not flat or porosity
between channels.
2. IN T E R M E D IA T E CLU TCH
a.
Intermediate clutch piston seals dam aged or
missing.
b. Low line pressure.
c. Case valve body face not flat or porosity
between channels.
3. D IR E C T CLU TCH
a. Restricted orifice in vacuum line to m odulator
(poor vacuum response).
b. Check ball in direct clutch piston damaged,
stuck or missing.
c. Defective m odulator bellows.
d. Clutch piston seals d am aged or missing.
e. Case valve body face not flat or porosity
between channels.
f. Clutch installed backwards.
N OTE: Burned clutch plates can be caused by
incorrect usage o f clutch plates. Also, anti-freeze in
transmission fluid can cause severe damage, such
as large pieces o f composition clutch plate material
peeling off.
G O VER NO R PRESSURE CHECK
1. Install line Pressure Gage, to tap location shown
in Fig. 7A-10B.
2.
Disconnect vacuum line to moldulator.
3. With car on hoist (rear wheels, off ground), foot
off brake, in drive, check line pressure at 1000 RPM.
4. Slowly increase engine RPM to 3000 RPM and
determ ine if a line pressure drop occurs (7 PS1 or more).
5. If no pressure drop occurs:
a. Inspect G overnor
1. Stuck valve.
2.
Free Weights.
3. Restricted orifice in governor valve.
b. G ov erno r Feed System
1. Check screen in control valve assembly.
2.
Check for restrictions in I'eed line.
3. Scored governor bore.
M A N U A L LINKAGE
Manual linkage adjustment and the associated
neutral safety switch are im portant from a safety
standpoint. The neutral safety switch should be adjusted
so that the engine will start in the Park and Neutral
positions only.
With the selector lever in the Park position, the
parking pawl should freely engage and prevent the
vehicle from rolling. The pointer on the indicator
q uadran t should line up properly with the range
indicators in all ranges.
ROAD TEST
Drive Range
Position selector lever in DRIVE R A N G E and
accelerate the vehicle from 0 MPH. A 1-2 and 2-3 shift
should occur at all throttle openings. (The shift points
will vary with the throttle opening). As the vehicle
decreases in speed to 0 MPH, the 3-2 and 2-1 shifts
should occur.
Low L2 Range
Position the selector lever in L2 R A N G E and
accelerate the vehicle from 0 MPH. A 1-2 shift should
occur at all throttle openings. (No. 2-3 shift can be
obtained in this range). The 1-2 shift point will vary with
throttle opening. As the vehicle decreases in speed to 0
MPH, a 2-1 shift should occur.
The 1-2 shift in IN T E R M E D IA T E R A N G E is
somewhat firmer than in DRIVE R A NG E. This is
normal.
Low L I Range
Position the selector lever in L I R A N G E and
accelerate the vehicle from 0 MPH. No upshift should
occur in this range.
2N D Gear — Overrun Braking: (L2)
Position the selector lever in DRIVE RA N G E, and
with the vehicle speed at approximately 35 MPH, move
the selector lever to L2 R A N G E . The transmission
should downshift to 2nd. An increase in engine RPM
and an engine braking effect should be noticed. Line
pressure should change from approximately 100 PSI to
approximately 125 PSI in 2nd.
1ST Gear — Overrun Braking: ( L I )
Position the selector lever in L2 R A N G E at
approxim ately 30 to 50 MPH, with throttle closed, move
the selector lever to LI. A 2-1 downshift should occur in
the speed range o f approximately 45 to 30 MPH,
depending on axle ratio and valve body calibration. The
2-1 downshift at closed throttle will be accompanied by
increased engine RPM and an engine braking effect
should be noticed. Line pressure should be approx
imately 150 PS1. Stop vehicle.
R everse Range: (R)
Position the selector lever in REVERSE POSITION
and check for reverse operation.
TRO UBLE D IA G N O S IS
Refer to Fig. 7A-1 IB, Diagnosis Chart, to determ ine
a possible cause of a transmission problem.
Additional diagnosis o f a malfunction is as follows:
No Drive in Drive Range
(Install pressure gauge)
• Low Oil Level - correct level and check for
external leaks or defective vacuum modulator (leaking
d ia p h ra g m will evacuate oil from unit).
• M anual Linkage - misadjusted, correct align
ment to m anual lever shift q u a d ra n t is essential.
• Low Oil Pressure - refer to LOW LINE
PR ESSU RE below.
• Forward Clutch:
a. Forward clutch does not apply - piston
cracked; seals missing or dam aged; clutch plates burned
(see B U R N E D CLU TCH PLATES below).
b. P um p feed circuit-to-forward clutch oil seal
rings missing or broken on pum p cover; leak in feed
circuits; pump-to-case gasket mispositioned or dam aged;
clutch drum ball check stuck or missing.
• Low and Reverse Roller Clutch Assembly broken spring, d am ag ed cage or installed backwards.
High or Low Oil Pressure
(R efer to OIL PR E SSU R E CHECKS)
H ig h Line Pressure
•
Vacuum Leak:
a. Vacuum line disconnected.
b. Leak in line from engine to moldulator.
c. Im proper engine vacuum.
d. Leak in vacuum-operated accessory (hoses,
vacuum advance, etc.).
• Moldulator:
a. Stuck modulator valve.
b. W ater in modulator.
c. Dam aged, not op erating properly.
• D etent System - detent valve or cable stuck in
detent position.
• Valve Body:
a. Pressure regulator a n d / o r boost valve stuck.
b. Boost valve sleeve broken or defective.
c. Incorrect pressure regulator valve spring.
Low Line Pressure
•
•
•
Low transmission oil level.
Defective vacuum moldulator assembly.
S trainer Assembly:
a. Blocked or restricted.
b. G asket omitted or dam aged.
• Oil Pump:
a. G e a r clearance, dam aged, worn, gear installed
backwards:
b. Pump-to-case gasket mispositioned.
c. Defective pum p body a n d / o r cover.
• Valve Body:
a. Pressure regulator or boost valve stuck.
b. Pressure regulator valve spring, too weak.
• Internal Circuit Leaks:
a. Forward clutch leak (pressure low in Drive
range, pressure norm al in Neutral and Reverse).
1. Check pum p oil seal rings.
2. Check forward clutch seals.
b. Direct clutch leak (pressure low in Reverse,
pressure normal in o ther ranges).
1. Check direct clutch outer seal.
2. Check 1-2 accumulator and 2-3 accumulator
pistons and rings for dam age or missing.
• Case Assembly - check ball missing from cored
passage in case face.
1-2 Shift - Full T h ro ttle Only
•
•
•
Detent Valve - sticking or linkage misadjusted.
Vacuum Leak - vacuum line or fittings leaking.
Control Valve Assembly:
a. Valve body gaskets - leaking, dam aged or
incorrectly installed.
b. Detent valve train stuck.
c. 1-2 valve stuck closed (in dow nshifted
position).
• Case Assembly - refer to case porosity repair.
First Speed O nly - No 1-2 Shift
•
•
Detent (downshift) cable - binding.
Governor Assembly:
a. G overnor valve sticking.
b. Driven gear loose, dam aged or worn (check
for pin in case and length o f pin showing; also, check
output shaft drive gear for nicks or rough finish if driven
gear shows damage).
• Control Valve Assembly:
a. Valve body gaskets - leaking, dam aged or
incorrectly installed.
b. G overnor feed channels blocked.
c. 1-2 shift valve train stuck closed (in
downshifted position).
• Intermediate Clutch:
a. Clutch piston seals - missing, im properly
installed or cut.
b. Intermediate roller clutch - broken spring or
dam aged cage.
• Case:
a. Porosity between channels.
b. G overnor feed channel blocked; governor
bore scored or worn, allowing cross pressure leak.
First and Second Speeds O nly - No 2-3
Shift
•
Control Valve Assembly:
a.
Valve body gaskets - leaking, dam aged or
incorrectly installed.
b.
2-3 shift valve tra in stuck closed
downshifted position).
• Direct Clutch:
a. Pump hub - direct clutch oil seal rings broken or missing.
b. Clutch piston seals - missing, improperly
assembled or cut.
c. Clutch
plates
b u rn e d
(see
BURNED
C LU T C H PLATES below).
No First Speed - Starts in Second Speed
(Locks up in LI Range)
Interm ediate Clutch:
1. Too m any plates in interm ediate clutch pack.
2. Incorrect interm ediate clutch piston.
Drive in Neutral
• M anual Linkage - misadjusted, (correct align
ment in m anual lever shift q u a d r a n t is essential).
• Internal Linkage - m anual valve disconnected or
end broken.
• Oil Pum p - line pressure leaking into forward
clutch apply passage.
• Forw ard Clutch - incorrect clutch plate usage or
burned clutches (see B U R N E D CL U TCH PLATES
below).
No M otion in Reverse or Slips in Reverse
(Install pressure gauge)
• Low Oil Level - add oil.
• M anual Linkage - misadjusted (correct align
ment in m anual lever shift q u a d ra n t is essential).
• Low Oil Pressure - refer to LOW LINE
PR E SSU R E above.
• Control Valve Assembly:
a. Valve body gaskets - leaking, dam aged or
incorrectly installed.
b. 2-3 shift valve train stuck open (in upshifted
position).
• Interm ediate Servo - piston or pin stuck so
interm ediate overrun band is applied.
• Low and Reverse Clutch - piston outer seal
dam aged or missing.
• Direct Clutch:
a. Outer seal d am ag ed or missing.
b. Clutch
plates
b u rn e d
(see
BURNED
C L U TC H PLATES below).
• Forw ard Clutch - clutch does not release (will
cause DRIVE in N E U T R A L ).
Slips in All Ranges or Slips on S tart
(Install pressure gauge)
• Low Oil Level - add oil.
• Low Oil Pressure - refer to LOW LINE
PR ESSU R E above.
• Forw ard clutch:
a. Clutch
plates
burned
(see
BURNED
C L U T C H PLATES below).
b. P um p cover oil seal rings broken or worn.
(in
•
Case - cross leaks or porosity.
Slipping 1-2 Shift
(Install pressure gauge)
• Low Oil Level - add oil.
• Low Oil Pressure - refer to LOW LINE
PRESSURE above.
• 2-3 Accumulator - oil ring dam aged or missing.
• 1-2 Accumulator - oil ring dam aged, missing or
case bore damaged.
• Pum p-to-C ase G a sk e t - m ispositioned or
damaged.
• Interm ediate Clutch:
a. Piston seals dam aged or missing.
b. Clutch
plates
bu rn ed
(See
BURNED
CL U TC H PLATES below).
• Case - porosity between channels.
Slipping 2-3 Shift
(Install pressure gauge)
• Low Oil Level - add oil.
• Low Oil Pressure - refer to LOW LINE
PRESSURE above.
• Direct Clutch:
a. Piston seals leaks, dam aged or missing.
b. Clutch
plates
b u rn ed
(see
BURNED
CLU TCH PLATES below).
c. Inspect for proper nu m b e r and type of clutch
plates.
• Case - refer to case porosity repair.
Rough 1-2 Shift
(Install pressure gauge)
• High Oil Pressure - refer to HIGH LINE
PRESSURE above.
• 1-2 Accumulator:
a. Oil rings damaged.
b. Piston stuck.
c. Broken or missing spring.
d. Bore damaged.
• Intermediate Clutch - check for burned and
num ber (type) of plates.
• Case:
a. Check for correct n um b e r and location of
check balls.
b. Porosity between channels.
Rough 2-3 Shift
(Install pressure gauge)
• High Oil Pressure - refer
PRESSUR E above.
• 2-3 Accumulator:
a. Oil ring damaged.
b. Piston stuck.
c. Broken or missing spring.
d. Piston bore damaged.
No Engine Braking in L2
to
H IG H
LINE
• Low Oil Pressure - pressure regulator a n d / o r
boost valve stuck.
• Intermediate Servo and 2-3 Accumulator:
a. Servo or accumulator oil rings or bores
leaking or dam aged.
b. Servo piston stuck or cocked.
• In te rm e d ia te O v errun Band - in te rm e d ia te
overrun band broken or burned (look for cause), not
engaged or servo pin.
No Engine Braking in L I
(Install pressure gauge)
• Low Oil Pressure - pressure regulator a n d / o r
boost valves stuck.
• M anual Low Control Valve Assembly - stuck.
• Low and Reverse Clutch - piston inner seal
da m a g e d or missing.
•
W o n 't Hold in Park
• Manual Linkage - misadjusted (correct align
ment in manual lever shift q u a d ra n t is essential).
• Internal Linkage:
a. Inner lever and actuating rod assembly defective or im properly installed.
b. Parking pawl - broken or inoperative.
c. Parking lock bracket loose, burred or rough
edges or incorrectly installed.
d. Parking pawl disengaging spring missing,
broken or incorrectly hooked.
Transmission Noisy
C A U T IO N : Before checking transmission fo r
noise, make certain that the noise is not coming
from the water pump, alternator, power
steering, etc. These components can be isolated
by removing the proper belt and running the
engine not more than two minutes at one time.
No P art T h ro ttle Dow nshift
(Install pressure gauge)
• Oil Pressure - vacuum modulator assembly,
m odulator valve or pressure regulator valve train (other
m alfunctions may also be noticed).
• D etent Valve and Linkage - sticks, disconnected
or broken.
• 2-3 shift valve - stuck.
No D e te n t (W ide Open T h ro ttle )
Dow nshift
• D eten t cable or retainer not adjusted properly.
• Detent cable disconnected at transmission or
throttle linkage.
• Valve Body:
a. D etent valve sticks.
b. D etent regulator valve sticks.
c. Incorrect spacer plate or gasket.
High or Low S hift Points
(Install pressure gauge)
• Oil Pressure:
a. Engine Vacuum - check at transmission end
o f m odulator pipe.
b. Check vacuum line connections at engine and
transmission.
c. V acuum m odulator assembly and valve and
pressure regulator valve train.
• G overnor:
a. Valve sticking.
b. F eed holes restricted or leaking.
• D etent Valve and Linkage - stuck open (will
cause high shift points).
•
Control Valve Assembly:
a. 1-2 shift valve train sticking.
b. 2-3 shift valve train sticking.
Case - refer to case porosity repair.
P ark, N e u tra l and all D riv in g R anges
•
Pump Cavitation:
a. Low oil level.
b. Plugged or restricted strainer.
c. Strainer-to-valve body gasket damaged.
d. Porosity in valve body intake area.
e. W ater in oil.
f. Porosity or voids at transmission case (pump
face) intake port.
g. Pump-to-case gasket off location.
• Pump Assembly :
a. G ears dam aged.
b. Driving g ear assembled backwards.
c. Crescent interference.
d. Oil seal rings dam aged or worn.
• Converter:
a. Loose flexplate-to-converter bolts.
b. Converter damage.
c. W ater in oil (causes whine).
First, Second a n d /o r R everse G ear
Planetary G e a r Set:
1. G ears or thrust bearings damaged.
2. Input or output ring gear damaged.
D u rin g A c ce le ratio n - A ny G ear
• T ra n sm issio n or cooler lines
underbody.
• Motor mounts loose or broken.
grounded
to
Squeal at Low V e h ic le Speed
Speedometer driven gear
lubrication or replacement.
shaft
sea!
- requires
CAR
LEGEND
X
*
PROBLEM
"O "
O
AREA
VACUUM
B A L L S /# 2 /3 /4
ROAD
7 A-1 6
Turbo H y d r a - M a f ic 3 5 0
Diagnosis C h art
TEST
•
VS.
CAUSE
ONLY
ONLY
L -L O C K E D
S -S T U C K
CAUSE
L E A K _____________________
M O D U LA TO R & /O R
S T R A IN E R & /O R
VALVE
G A S K E T ________
G O V E R N O R -V A L V E /S C R E E N
V A L V E B O D Y -G A S K E T /P L A T E
TRUCK
Fig. 7A-11B--CBC
L O W O IL L E V E L /W A T E R IN O IL
VACUUM
LIGHT
P OSSIB LE
PRES. REG . & / O R BO O ST V A L V E
( # 1 ) S H Y _____________________
350
1-2 S H I F T V A L V E ___________________
2 - 3 S H I F T V A L V E ___________________
DETENT VALVE
DETENT
& L IN K A G E
REG. V A L V E
2 - 3 A C C U M U L A T O R ________________
Chart
M A N U A L V A L V E /L IN K A G E
P O R O S I T Y / C R O S S L E A K __________
P U M P - G E A R S _______________________
P R I M I N G V A L V E S H Y ______________
COOLER
VALVE
L E A K ____________
C L U T C H S E A L R I N G S ______________
P O R O U S / C R O S S L E A K _____________
G A SK ET S C R E E N -P R E S S U R E
B A N D -IN T E R M .
C A S E -P O R O U S /X
O . R . ______________
L E A K __________
1-2 A C C U M U L A T O R ________________
I N T E R M E D . S E R V O ________________
F O R W A R D C L U T C H A S S Y ________
D I R E C T C L U T C H A S S ' Y ___________
I N T E R M E D . C L . A S S ' Y _____________
L & R E V . C L . A S S ' Y ________________
I N T . R O L L E R C L . A S S ' Y ___________
L . & R. R O L L E R C L . A S S Y
P A R K P A W L / L I N K A G E ____________
C O N V E R T E R A S S ' Y ________________
G E A R S E T & B E A R I N G S ___________
MANUAL
Diagnosis
M A N U A L LO W C O N T 'L . V A L V E
SERVICE
BALL
A U TO M A T IC
350
Hydraulic
Circuit
T R A N S M IS S IO N
Fig. 7A 12B--CBC
7 A -1 7
SERVICE OPERATIONS
T R A N S M IS S IO N R EPLA C EM EN T
(A ll Except K M odel)
N OTE: If necessary, the catalytic converter may
have to be disconnected to provide adequate
clearance for transmission removal. This procedure
will include removal o f the converter support
bracket.
1. Before raising the vehicle, disconnect the
negative battery cable detent downshift cable at
carburetor and release the parking brake.
2. Raise vehicle on hoist.
3. Remove propeller shaft.
4. Disconnect speedom eter cable, detent downshift
cable, modulator vacuum line and oil cooler pipes at
transmission.
5. Disconnect shift control linkage.
6. Support transmission with suitable transmission
jack.
7. D isconnect
re a r
m o unt
from
fra m e
crossmember.
8. Remove two bolts at each end o f fram e
crossmember. Remove crossmember.
9. Remove converter under pan.
10. Remove converter to flywheel bolts.
11. Lower transm ission until ja c k is barely
supporting it.
12. Remove transmission to engine m ounting bolts
and remove oil filler tube at transmission.
13. Raise transmission to its normal position,
support engine with jack and slide transmission rearw ard
from engine and lower it away from vehicle.
CAUTION: Use suitable converter holding tool
when lowering transmission or keep rear o f
transmission lower than front so as not to lose
converter.
The installation o f the transmission is the reverse of
the removal with the following added step. Before
installing the flex plate to converter bolts, make certain
that the attaching lugs on the converter are flush with the
flex plate and the converter rotates freely by hand in this
position. Then, h and start all three bolts and tighten
finger tight before torqueing to specification. This will
insure proper converter alignment.
A fter installation of transmission, lower vehicle and
remove vehicle from hoist. Check linkage for proper
adjustment.
Check transmission fluid level.
4.
Remove transfer case shift lever knob and boot.
5.
Raise vehicle on hoist.
6.
Remove flywheel cover.
7.
Remove torque converter to flywheel attaching
bolts. (Secure the converter.)
8.
D isconnect
transm ission
shift
9.
Remove engine crossunder pipe to manifold
bolts.
10.
Disconnect vacuum m odulator line, line to filler
tube clip and detent downshift cable to filler tube strap.
11.
Disconnect
detent
downshift
1.
2.
3.
Disconnect battery cable.
Remove transmission dipstick.
Disconnect detent downshift cable at carburetor.
cable
at
the
transmission.
12. Disconnect transmission oil cooler lines at the
transmission.
13.
bolts.
Remove transfer case adapter to crossmember
14.
Raise engine as necessary.
15.
Remove
crossm em ber
bolts
and
remove
crossmember.
16.
Remove exhaust system hanger bolts.
17.
Disconnect
18.
Disconnect parking brake cable.
rear propeller shaft
at transfer
case.
19.
Disconnect exhaust system. (Tie aside.)
20.
Disconnect front propeller shaft at front axle.
(Tie aside.)
21.
Support transmission and transfer case with
jack (use safety chains).
22.
Remove transfer case to fram e bracket bolts.
23.
Remove transmission to engine bolts, remove
transmission and transfer case.
24.
Remove
tra n sfe r
case
from
transm ission
(includes: new " O " ring seal).
25.
Move transmission to bench fixture.
26.
D rain transmission.
27.
Remove torque converter.
28.
Remove and discard front pum p seal.
29.
Refill transfer case.
Reverse removal procedure to install.
(K M o del)
Removal
and
speedometer cable.
In s ta lla tio n
T R A N S M IS S IO N R E P LACEM ENT
linkage
EXTEN S IO N H O U S IN G OIL SEAL
Removal
1.
Remove propeller shaft.
2.
chisel.
Pry out lip oil seal with screwdriver or small
In s ta lla tio n
1. Coat outer casing o f new lip oil seal with a n o n
h a rde ning sealer and drive it into place with Installer
J-21426.
2. Install propeller shaft and adjust fluid level.
SPEED O M ETER DRIVEN GEAR
R em o val
1. Disconnect speedometer cable.
2. Remove retainer bolt, retainer,
driven gear and O-ring seal.
speedometer
In s ta lla tio n
Installation o f speedom eter driven gear is the
reverse of REMOVAL. Install new O-ring seal (if
required) and adjust the fluid level.
SPE E D O M E TE R D RIVE GEAR
R e m o va l
1. Raise vehicle and support transmission with
suitable transmission jack.
2. Remove propeller shaft.
3. Disconnect speedom eter cable.
4. Disconnect transmission rear m ount from fram e
crossmember.
5. Remove two bolts at each end o f fram e cross
m e m b er and remove crossmember.
6. Remove extension housing.
7. Install Special Tools J-2 1427-01 and J-8105 on
output shaft and remove speedometer drive gear.
Remove retaining clip.
In s ta lla tio n
1. Place speedometer drive gear retaining clip into
hole in output shaft.
2. Align slot in speedom eter drive gear with
retain in g clip and install.
3. Install extension housing and tighten attaching
bolts to 25 p ound feet.
4. Connect speedom eter cable.
5. Install crossmem ber to fram e and transmission.
6. Install propeller shaft.
7. Remove transmission jack and lower vehicle.
M A N U A L SHAFT, RANGE SELECTOR IN N E R
LEVER A N D P A R K IN G LINKAG E
ASSEM BLIES
R em o val
1. R efering to drain in g procedures, drain trans
mission fluid from oil pan.
2. A fter oil pan and strainer have been removed,
remove valve body assembly. Discard gaskets.
3. Remove m anual shaft-to-case retainer and
unth read ja m nut holding rnage selector inner lever to
m anual shaft.
4. Remove ja m nut and remove manual shaft from
range selector inner lever and case.
NOTE: Do not remove m anual shaft lip oil seal
unless replacem ent is required.
5. Remove parking pawl actuating rod and range
selector inner lever from case.
6. Remove bolts and parking lock bracket.
7. Remove parking pawl disengaging spring and,
if necessary to replace park pawl or shaft, clean up bore
in case and remove parking pawl shaft retaining plug,
park pawl shaft and pawl.
In s ta lla tio n
Installation o f parking linkage, selector lever and
m anual shaft is the reverse of REMOVAL. Install new
plug (if required), new lip oil seal (if required) and new
gaskets. Adjust the fluid level.
NOTE: Before installing the propeller shaft,
liberally lubricate splines o f the transmission yoke
with a Lithium soap base lubricant. The lubricant
should seep from the vent hole (rear cap o f yoke)
when installing yoke on transmission output shaft.
It is essential that the vent hole is not obstructed.
G O VERNO R
R em ove
1. Raise vehicle and disconnect speedometer cable
at transmission.
2. Remove governor cover retainer and governor
cover.
NOTE: Be careful not to dam age cover and " O "
ring seal.
3. Remove governor. Inspect weights and valve for
freeness.
Install
1. Install governor.
2. Install governor cover using a brass drift around
the outside flange o f the cover.
NOTE: Do not distort cover on installation. Be
sure " O " ring seal is not cut or damaged.
3. Install retainer.
4. Connect speedom eter cable, lower vehicle and
check transmission fluid level.
VA C U U M M O D U L A TO R AN D M O D U LA TO R
VALVE ASSEMBLY
Removal
1. Disconnect vacuum hose from vacuum m odula
tor stem and remove vacuum modulator attaching screw
and retainer.
2. Remove m odulator assembly and its O-ring seal
from case.
3.
Remove m odulator valve from case.
Installation
Installation o f the modulator and m odulator valve is
the reverse o f REMOVAL. Install a new O-ring seal and
adjust the fluid level.
4. Remove tool and install oil pan holts.
VALVE BODY ASSEMBLY
R em o val
1. R efering to drain in g procedures, drain trans
mission fluid from oil pan.
2. A fter oil pan and strainer, have been removed,
discard gaskets.
3. Remove detent spring and roller assembly from
valve body and remove valve body-to-case bolts.
4. Remove valve body assembly while disconnect
ing m anual control valve link from range selector inner
lever and rem oving detent control valve link from the
detent actuating lever.
5. Remove m anual valve and link assembly from
valve body assembly.
In s ta lla tio n
Installation of the valve body assembly is the
reverse o f REMOVAL. Install new gaskets to strainer
and oil pan and adjust the fluid level.
1-2 A C C U M U L A TO R
R em o ve
1.
Remove two transmission oil pan bolts below
the 1-2 accumulator cover. Install J-23069 in place of
bolts removed.
2. Press in on cover and remove retaining ring.
3. Remove cover "O " ring seal, spring and 1-2
accumulator.
Install
1.
Install 1-2 accumulator piston.
NOTE: Rotating piston slightly when installing will
help to get rings started in bore.
2. Position spring, " O " ring seal and cover in
place.
3. Press in on cover with J-23069 and install
retaining ring.
4. Remove tool and install oil pan bolts.
OIL COOLER PIPES
If replacement o f transmission steel tubing cooler
pipes is required, use only double w rapped and brazed
steel tubing meeting G M specification I23M or its
equivalent. Under no condition use copper or aluminum
tubing to replace steel tubing. Those materials do not
have satisfactory fatique durability to withstand normal
vehicle vibrations.
Steel tubing should be flared using the upset (double
lap) flare method which is detailed in Section 5.
T H M 4 0 0 TRANSMISSION
INDEX
G eneral D e s c rip tio n ...........................................................7A-21
M aintenance and A d ju stm en t.........................................7A-22
Checking Transmission M o u n t.................................. ..7A-22
Transmission F l u i d ...........................................................7A-22
Colum n Shift Linkage A d ju s tm e n t............................7A-24
Detent Switch A d ju stm e n t.............................................7A-25
N eu tral Start Backup Lam p Switch Adjustment. 7A-25
D ia g n o sis.............................................................................. ..7A-25
Sequence for Diagnosis................................................ ..7A-25
Oil Checking P ro c e d u re ............................................... ..7A-25
Oil Leak D ia g n o s is ..........................................................7A-25
Oil Pressure C h e c k ...........................................................7A-26
Case Porosity R e p a i r .......................................................7A-26
Vacuum M odulator D ia g n o sis................................... ..7A-27
M anual L in k a g e .............................................................. .7A-28
Trouble D iagnosis............................................................7A-28
Service O p e ra tio n s.............................................................7A-34
Transmission R e p la c e m e n t...........................................7A-34
Rear S e a l ........................................................................... .7A-34
G o v e r n o r ............................................................................ .7A-34
Modulator and M odulator V alve.............................. .7A-34
Parking L in k a g e .............................................................. .7A-34
Control Valve Body.........................................................7A-35
Pressure Regulator V alve..............................................7A-35
Oil Cooler Pipes.............................................................. .7A-35
O ther Service O p e ra tio n s..............................................7A-36
Specifications........................................................................7A-37
Special T o o ls........................................................................7A-38
GENERAL DESCRIPTION
The THM 400 transmission is a fully automatic unit
consisting prim arily of a 3-element hydraulic torque
converter and a com pound planetary gear set. Three
multiple-disc clutches, one gear unit, one roller clutch,
and two bands provide the friction elements required to
obtain the desired function o f the compound planetary
gear set.
The torque converter couples the engine to the
planetary gears through oil and provides hydraulic
torque multiplication when required. The compound
planetary gear set produces three forward speeds and
reverse.
The 3-element torque converter consists o f a pum p
or driving m em ber, a turbine or driven member, and a
stator assembly. The stator is mounted on a one-way
roller clutch which will allow the stator to turn clockwise
but not counter-clockwise.
The torque converter housing is filled with oil and is
attached to the engine cran ksh aft by a flex plate and
always rotates at engine speed. The converter pum p is an
integral part o f the converter housing, therefore the
pum p blades, rotating at engine speed, set the oil within
the converter into motion and direct it to the turbine,
causing the turbine to rotate.
As the oil passes through the turbine it is traveling
in such a direction that if it were not re-directed by the
stator it would hit the rear o f the converter pump blades
and impede its pum ping action. So at low turbine speeds,
the oil is re-directed by the stator to the converter pum p
in such a m an n e r that it actually assists the converter
p u m p to deliver power or multiply engine torque.
As turbine speed increases, the direction of the oil
leaving the turbine changes and flows against the rear
side o f the stator vanes in a clockwise direction. Since
the stator is now im peding the smooth flow o f oil, its
roller clutch releases and it revolves freely on its shaft.
Once the stator becomes inactive, there is no further
multiplication of engine torque within the converter. At
this point, the converter is merely acting as a fluid
coupling as both the converter pum p and turbine are
being driven at approximately the same speed - or at
one-to-one ratio.
A hydraulic system pressurized by a gear type pum p
provides the working pressure required to operate the
friction elements and automatic controls.
External control connections to transmission are:
Manual Linkage - To select the desired operating
range.
Engine Vacuum - To operate a vacuum m odulator
unit.
12
Volt Electrical - To operate an electrical detent
solenoid.
A vacuum m odulator is used to automatically sense
any change in the torque input to the transmission. The
vacuum m odulator transmits this signal to the pressure
regulator for line pressure control, to the 1-2 accumulator
valve, and to the shift valves so that all torque
requirements of the transmission are met and smooth
shifts are obtained at all throttle openings.
The detent solenoid is activated by an electric switch
on the carburetor. W hen the throttle is fully opened, the
switch on the carburetor is closed, activating the detent
solenoid and causing the transmission to downshift for
passing speeds.
The selector q u a d ra n t has six selector positions: P.
R, N, D, L2, LI.
P. PARK position positively locks the output shaft
to the transmission case by means o f a locking pawl to
prevent the vehicle from rolling in either direction (not
on CL model). The engine may be started in Park
position.
R. REVERSE enables the vehicle to be operated in
a reverse direction.
Fig. 7A-1C--THM 400, Cross-Section View
N . N eutral postion enables the engine
started and ru n without driving the vehicle.
to
be
D. DRIVE Range is used for all norm al driving
conditions and m axim um economy. Drive R ange has
three gear ratios, from the starting ratio to direct drive.
D etent downshifts are available by depressing the
accelerator to the floor.
L2. L2 Range has the same starting ration as
Drive Range, but prevents the transmission from
shifting ration w hen extra perform ance is desired. L2
Range can also be used for engine braking. L2 Range
can be selected at any vehicle speed, a n d the
transmission will shift to second gear and rem ain in
second until the vehicle speed or the throttle are changed
to obtain first gear operation in the same m a n n e r as in
D Range.
LI. LI Range can be selected at any vehicle speed,
and the transmission will shift to second gear and
rem ain in second until vehicle is reduced to approx
imately 40 MPH, depending on axle ratio. LI Range
position prevents the transmission from shifting out of
first gear.
NOTE: It is very im portant that any com m unica
tion concerning the T HM 400 always contain the
transm isio n serial and vehicle identification
number.
MAINTENANCE AND ADJUSTMENTS
C H E C K IN G T R A N S M IS S IO N M O U N T
Raise the vehicle on a hoist. Push up and pull down
on the transmission extension while observing the
transmission mount. If the ru b b e r separates from the
metal plate o f the m ount o r if the extension moves up
but not down (m ount bottomed out), replace the mount.
If there is relative movement between a metal plate o f
the m ount a n d its attaching point, tighten the screws or
nuts attaching
crossmember.
the
mount
to
the
transmission
or
T R A N S M IS S IO N FLUID
Fluid Level and C a p a city
The fluid level indicator is located in the filler tube
at the right rear o f the engine. To bring the fluid level
COOL —
■HOT
(65°-85° F.)
(1 9 0 -2 0 0
F.)
(88°-93° C.)
(18°-29°C.)
L
J
r^ i
L
r _Ji
WARM
NOTE:
DO NOT OVERFILL.
IT TAKES
ONLY ONE PINT TO RAISE
LEVEL FROM ADD TO FULL
WITH A HOT TRANSMISSION.
Fig. 7A 2C D ipstick M arkings
from the A D D mark to the F U L L mark requires one
pint o f fluid. Fluid level should be checked at every
engine oil change.
Fluid level should be to the F U L L mark with the
transmission fluid at normal operating temperature (180°
F). W ith w arm fluid (room tem perature 70 F), the level
will be 3 /8 inch below the A D D mark on the dipstick.
The no rm al o perating tem perature is obtained only after
at least 15 miles of highway type driving or the
equivalent o f city driving.
A pproxim ately 9 pints o f fluid are required to refill
transmission after oil pan has been drained. The fluid
capacity of the THM 400 transmission and converter
assembly is approxim ately 22 pints but correct level is
determ ined by mark on the dipstick rather than by
am ou nt added. Use only D E X R O N * or DEXRONC? II
autom atic transmission fluid or its equivalent.
N O T E : An early stage to a darker color from the
usual red color a n d / o r a strong odor that is usually
associated with overheated transmission fluid is
norm al, and is not a positive sign of required
m ain tenan ce or transmission failure.
C h e c k in g P ro ce d u re and A d d in g Fluid
To determ ine proper fluid level at norm al operating
tem perature (180 T 7). proceed as follows:
1. Position vehicle on a level surface, place selector
lever in park (P), apply parking brake and have engine
run ning at norm al idle.
2. Remove fluid level indicator, wipe it clean and
reinstall fully until cap seats.
3. Remove indicator and reading of fluid level
should be at full “ F ” mark.
4. If additional fluid is required, add D E X R O N or D E X R O N * II automatic transmission fluid or its
equivalent to “ F ” mark on indicator.
If the vehicle cannot be driven sufficiently to bring
the transmission to operating tem perature and it
becomes necessary to check the fluid level, the
transmission may be checked at room temperature (70
degrees F) as follows:
1. Position selector lever in park (P), apply parking
brake and start engine. DO N O T RACE E N G IN E .
Move selector lever through each range.
2. Immediately check fluid level with selector lever
in Park, engine running and vehicle on LEVEL surface.
Fluid level on indicator should be 3 /8 inch below
the " A D D " mark.
3. If additional fluid is required, add enough fluid
to bring level to 3 /8 inch below the A D D m ark on the
dipstick. If transmission fluid level is correctly estab
lished at 70 F, it will ap pear at the F U L L m ark on the
dipstick when the transmission reaches its normal
operating tem perature of 180°F.
C A U T IO N : D O N O T O V E R F I L L , as foaming
and loss o f fluid through the vent pipe might
occur as fluid heats up.
If fluid is too low. especially when cold, complete
loss of drive m ay result which can cause transmis
sion failure.
D ra in in g and R e fillin g T ran sm issio n
The oil pan should be drained and filter replaced
and fresh fluid added to obtain the proper level on
indicator, at the intervals detailed in section O-B of this
manual. For vehicles subjected to heavy city traffic
during hot weather, or in commercial use, when the
engine is regularly idled for prolonged periods or when
vehicle is used for towing, oil pan should be drained and
filter replaced more frequently. See section O-B.
Drain fluid immediately after operation before it
has had an opportunity to cool.
W A R N IN G : T ran sm issio n
can exceed 3 5 0 F.
fluid te m p e ra tu re
1. Raise vehicle and support transmission w'ith
suitable jack at transmission.
2. With fluid receptacle placed under transmission
oil pan. remove oil pan attaching bolts from front and
side o f pan.
3. Loosen rear p a n attaching bolts approximately
four (4) turns.
4. Carefully pry transmission oil pan loose with
screwdriver, allowing fluid to drain.
5. Remove rem ain in g screws and remove oil pan
and gasket. Discard gasket.
6. D rain fluid from oil pan. Clean pan with solvent
and dry thoroughly with clean compressed air.
7. Remove oil filter re ta in e r bolt, oil filter
assembly, O-ring seal from intake pipe and discard the
filter and O-ring seal.
8. Install new O-ring seal on intake pipe and
install new filter on pipe assembly.
9. With O-ring seal on intak pipe, install pipe and
filter assembly, attaching filter to the control valve
assembly with its retainer bolt, torquing to 10 pound
feet.
10. Install new strainer-to-valve body gasket,
strainer and two (2) screws.
11. Install new gasket on oil pan and install oil
pan. Tighten its thirteen (13) attaching bolt and washer
assemblies to 12 pound-feet.
12. Lower vehicle add approximately 5 pints U.S.
measure (4 pints Imperial measure) of D EX RO N ® or
1)1 X R O N II a u to m a tic transm issio n fluid or its
equivalent through filler tube.
13. W ith selector lever in PARK position, apply
hand brake, start engine and let idle (carburetor off fast
idle step). D O N O T RACE E N G IN E .
14. Move selector lever through each range and,
with selector lever in PARK range, check the fluid level.
15. Add additional fluid to bring level to 1/4"
below the A D D m ark on the dipstick.
C A U T IO N :
Do not overfill. Foaming can result
i f overfilled.
A d d in g Fluid to Fill D ry T ra n s m is s io n and C o n v e rte r
A ssem bly
In cases o f transmission overhaul, when a complete
fill is required, including converter (approximately 22
pints), proceed as follows:
1. A dd 9 pints of transmission fluid through filler
tube.
2. W ith m anual control lever in park (P) position,
start engine and place on cold idle cam. D O N O T RACE
E N G IN E . Move m anual control lever through each
range.
3. Im m ediately check fluid level with selector lever
in park (P), engine run ning and vehicle on LEVEL
surface and add additional fluid to bring level to 3/8inch below the " A D D " mark on the dipstick. Do not
overfill.
S H IF T CO NTRO LS
Colum n S hift Linkage - CK and P Series
(Figs. 7A -3C and 7A -4C )
1. The shift tube and lever assembly must be free
in the m ast jacket. See Section 3B for alignment of
steering column assembly if necessary.
2. To check for proper shift linkage adjustment,
lift the transmission selector lever towards the steering
wheel. Allow the selector lever to be positioned in drive
(D) by the transmission detent.
N O TE : Do not use indicator pointer as a reference
to position the selector lever. W hen perform ing
linkage adjustment, pointer is adjusted last.
3. Release the selector lever. The lever should be
inhibited from engaging low range unless the lever is
lifted.
4. Lift the selector lever towards the steering wheel
and allow the lever to be positioned in neutral (N) by the
transmission detent.
5. Release the selector lever. The lever should now
be inhibited from engaging reverse range unless the
lever is lifted.
6. A properly adjusted linkage will prevent the
selector from moving beyond both the neutral detent,
and the drive detent unless the lever is lifted to pass over
the mechanical stop in the steering column.
7. If adjustm ent is required, remove screw (A) and
spring washer from swivel (B )8. Set transmission lever (C) in Neutral position by
moving lever counter-clockwise to LI detent and then
clockwise three (3) detent positions to Neutral.
9. Position transmission selector lever in Neutral
position as determined by the mechanical stop in
steering column assembly.
NOTE: Do not use the indicator pointer as a
reference to position the selector lever. When
perform ing linkage adjustment, pointer is adjusted
last.
10. Assemble swivel, spring washer and screw to
lever assembly (D) and tighten screw to 20 pound feet.
11. Readjust indicator needle if necessary to agree
with the transmission detent positions. See Section 3B.
12. Readjust neutral start switch if necessary to
provide the correct relationship to the transmission
detent positions. See Section 8.
13. Check operation (CK Series):
a. W'ith key in " R u n " position and transmission
in "R everse" be sure that key cannot be removed and
that steering wheel is not locked.
b. With key in "L ock" position and shift lever
in "P ark", be sure that key can be removed, that steering
wheel is locked, and that transmission rem ains in " P a r k "
when steering column is locked.
CAUTION: A ny inaccuracies in the above
adjustments may result in premature failure o f
Fig. 7A-5C -Detent D ownshift Switch
Fig. 7A-4C- Column Shift Linkage ■ P Series
the transmission due to operation without
controls in fu ll detent. Such operation results in
reduced oil pressure and in turn partial
engagement o f the affected dutches. Partial
engagement o f the clutches with sufficient
pressure to cause apparent normal operation of
the vehicle will result in failure o f the clutches
or other internal parts after only a few miles of
operation.
D E TE N T D O W N S H IF T S W ITC H
1.
2.
Install switch as shown in Figure 7A-5C.
A fter installing the switch, press the switch
plunger as far forward as possible. This presets the
switch for adjustment. The switch will then adjust itself
with the first wide open throttle application of the
accelerator pedal.
N E UTRA L S T A R T BACKUP LAM P S W ITC H
A D JU S T M E N T
The neutral start backup lamp switch must be
adjusted so that the car will start in the park or neutral
position, but will not start in the other positions. For
replacement and adjustm ent refer to Section 8 o f this
manual.
DIAGNOSIS
SEQ UENCE FOR D IA G N O S IS
1.
2.
3.
4.
5.
6.
Check and correct oil level.
Check detent switch.
Check and correct vacuum line and fittings.
Check and correct m anual linkage.
Install oil pressure gage.
Road test car.
a. Road test using all selective ranges, noting
when discrepancies in operation or oil pressure occur.
b. A ttem pt to isolate the unit or circuit involved
in the malfunction.
c. If engine perform ance indicates an engine
tune up is required, this should be perform ed before
road testing is completed or transmission correction
attempted. Poor engine perform ance can result in rough
shifting or other malfunctions.
FLUID C H ECK IN G PROCEDURES
Refer to M aintenance and Adjustment section for
fluid checking procedure.
FLUID LEAK DIA G N O S IS
D e te rm in in g Source o f Oil Leak
Before attem pting to correct an oil leak, the actual
source of the leak must be determined. In m any cases,
the source o f the leak can be deceiving due to "wind
flow" around the engine and transmission.
The suspected area should be wiped clean of all oil
before inspecting for the source o f the leak. Red dye is
used in the transmission oil at the assembly plant and
will indicate if the oil leak is from the transmission.
T h e use o f a " B l a c k L i g h t " to lo cate the p o in t at
w h i c h the o il is l e a k i n g is h e l p f u l . C o m p a r i n g the oil
f r o m the lea k to that o n the e n g in e o r t ra n s m is s io n
d ip s tic k , w h e n v i e w e d b y b la c k lig h t, w ill d e t e r m i n e the
so u rc e o f the le a k - e n g i n e o r tra n s m is s io n .
O il
le a k s a r o u n d the e n g i n e a n d t r a n s m is s i o n are
g e n e r a l l y c a r r i e d t o w a r d the r e a r o f the c a r b y the air
s t r e a m . F o r e x a m p l e , a t r a n s m i s s i o n oil fill p i p e to ca se
le a k w ill s o m e t im e s a p p e a r as a l e a k at the r e a r o f the
t r a n s m is s i o n . In d e t e r m i n i n g the s o urce o f a lea k,
p r o c e e d as fo llo w s :
1.
D e g r e a s e u n d e r s i d e o f t r a n s m is s io n .
2.
R o a d test to g e t u n it at o p e r a t i n g t e m p e r a tu r e .
(180 d e g r e e s F.)
3.
Possible Points of Oil Leak
1.
T r a n s m i s s i o n O il P a n L e a k
A t t a c h i n g bo lts n ot c o r r e c t l y t o rq u e d .
I m p r o p e r l y in sta lled o r d a m a g e d p a n g a s k e t.
O i l p a n g a s k e t m o u n t i n g f a c e n ot flat.
2. C a s e E x t e n s io n
a.
A t t a c h i n g bolts n o t c o r r e c tly t o rq u e d .
a.
b.
c.
R e a r se a l a s s e m b l y d a m a g e d o r i m p r o p e r l y
3.
P o r o u s c a s tin g . S e e p a r a g r a p h C.
O u tp u t shaft " O " rin g d a m a g ed .
C ase Leak
T r a n s m i s s i o n o ve r-filled .
b.
W a t e r in oil.
c.
F o r e i g n m a tt e r b e tw e e n
b e tw e e n p u m p c o v e r a n d b o d y .
pump
and
case
or
d. C a s e - p o ro u s, fr o n t p u m p c o v e r m o u n t i n g
fa c e s h y o f stock n e a r b r e a th e r . S e e s u b p a r a g r a p h C.
e.
P u m p to ca se g a s k e t m i s p o s it i o n e d .
f.
In co rrect d ip stick .
g.
C u t " O " r i n g o r g r o m m e t o n filter.
h.
P u m p - s h y o f stock o n m o u n t i n g faces,
p o r o u s ca s tin g , b r e a t h e r h o le p l u g g e d in p u m p co ve r.
Road or Normal Operating Conditions
W h i l e r o a d t es tin g (w ith the t ra n s m is s i o n oil
p re ss u re g a g e a t t a c h e d a n d the v a c u u m m o d u l a t o r tube
connected the t r a n s m is s io n p re ss u re s h o u ld c h e ck
a p p r o x i m a t e l y as s h o w n o n F i g u r e 7 A - 6 C .
Vehicle Stationary - Engine at 1200 RPM
W i t h the t r a n s m is s i o n oil p re ss u re g a u g e a tt a c h e d
a n d the v a c u u m m o d u l a t o r tu b e
disconnected the
t ra n s m is s io n p ressu res s h o u ld c h e c k a p p r o x i m a t e l y as
Vehicle Stationary - Engine at 1000 RPM
W i t h the t r a n s m is s io n oil p re ss u re g a u g e a tta c h e d
a n d the v a c u u m m o d u l a t o r tube connected f o r n o r m a l
m o d u l a t o r o p e r a t io n , the t r a n s m is s io n p re ss u re s h o uld
a.
F i l l e r p i p e " O " r i n g sea l d a m a g e d o r m is s in g ;
m i s p o s i t i o n o f filler p ip e b r a c k e t to e n g i n e " l o a d i n g "
o n e s id e o f " O " rin g .
ch e ck a p p r o x i m a t e l y as sh o w n in F ig . 7 A - 8 C .
N O T E : P ressu res a r e n ot s i g n i f ic a n t ly a ffe cted by
a ltitu d e o r b a r o m e t r i c p re ss u re w h e n the v a c u u m
b.
M o d u l a t o r a s s e m b l y " O " r i n g seal d a m a g e d
o r i m p r o p e r l y in sta lle d .
c.
E l e c tr i c a l c o n n e c t o r " O " r i n g seal d a m a g e d or
i m p r o p e r l y in s t a lle d .
d.
G o v e r n o r c o v e r bo lts not t o rq u e d ,
d a m a g e d o r leak b e t w e e n c a s e f a c e a n d g a s k e t.
e.
M a n u a l s h a f t lip seal d a m a g e d o r i m p r o p e r l y
g.
P a rkin g
pawl
i m p r o p e r l y in sta lle d .
h.
i.
gasket
S p ee d o m ete r g e a r " O " rin g d a m ag ed .
f.
in sta lle d .
sh aft
cup
p lug
dam aged,
L i n e p r e s s u r e b a n d r e l e a s e ta p p l u g loose.
V e n t p i p e ( r e f e r to i t e m 5).
j.
4.
a.
s h o w n in F ig . 7 A - 7 C .
c. E x t e n s i o n to c a s e , g a s k e t d a m a g e o r i m p r o p
e r l y in s t a lle d .
d.
e.
O il C o m e s O u t V e n t Pip e
OIL PRESSURE CHECK
In s p ect f o r leak w i t h e n g i n e r u n n in g .
4.
W i t h e n g i n e off, c h e ck f o r o il le a k s d u e to the
r a i s e d oil le v e l c a u s e d b y d r a i n b a c k .
b.
in sta lle d .
5.
P o r o u s c a s tin g . S e e s u b p a r a g r a p h C.
L e a k at F r o n t o f T r a n s m i s s i o n
a.
F r o n t p u m p sea l leaks.
Case Porosity Repair
E xternal
lea ks c a u s e d
by case p orosity
have
s u c c e s s f u lly b e e n r e p a i r e d w ith the t ra n s m is s io n in the
v e h i c l e b y u s in g the f o l l o w i n g r e c o m m e n d e d p ro ce d u re s :
1.
Road
test
and
b r in g
the
t r a n s m is s io n
to
o p e r a t i n g t e m p e r a t u r e , a p p r o x i m a t e l y 180 d e g re e s.
2.
R aise
vehicle
on
hoist
or jack
stan d ,
e n g in e
r u n n i n g a n d lo cate s o u rc e o f oil lea k . C h e c k f o r lea k in
all o p e r a t i n g p o sitio n s. U s e o f a m ir r o r is h e l p f u l in
fin d i n g leaks.
3.
S h u t e n g i n e o f f a n d t h o r o u g h l y c l e a n a r e a to be
r e p a i r e d w i t h a c l e a n i n g s o lv e n t a n d a bru sh a ir dry.
1.
S e a l lip cut. C h e c k c o n v e r t e r h u b f o r nicks,
4. U s i n g in str u ctio n s o f the m a n u f a c t u r e r , m ix a
sufficient a m o u n t o f e p o x y to m a k e r e p a ir . O b s e r v e
2.
3.
B u sh in g m o ved fo rw ard and d a m ag ed .
G a r t e r s p r i n g m i s s i n g f r o m seal.
c a u t i o n s o f m a n u f a c t u r e r in h a n d l in g .
etc.
b.
F r o n t p u m p a t t a c h i n g b o lts lo o se o r b o lt seals
d a m a g e d o r m is s in g .
c.
F r o n t p u m p h o u s i n g " O " r i n g d a m a g e d or
cut.
d.
e.
m o d u l a t o r tu b e is co n n e cte d .
C o n v e r t e r leak in w e l d area.
P o r o u s c a s t i n g (p u m p ) .
the
5. W h i l e the t ra n s m is s io n c a s e is still H O T a p p l y
e p o x y to the a r e a to be r e p a i r e d . A cle a n , d r y
s o l d e r i n g a cid brush ca n be used to c l e a n the a r e a a n d
also to a p p l y the e p o x y c e m e n t . M a k e c e r t a in the a r e a to
be r e p a i r e d is f u l l y c o v e r e d .
6. A l l o w c e m e n t to cu r e
s t a r tin g e n g in e .
for
three
h o u rs
befo re
M in im u m
M a x im u m
1 4 5 psi
1 5 5 psi
M in im u m
M a xim u m
L 2 - 2 n d G e a r - S t e a d y r o a d lo a d at a p p r o x i m a t e l y 2 5 m p h
S e lecto r L ev er P o sitio n
Gear
D rive
1s t
2nd
3 rd
3rd
Reverse
( “ Z e r o ” t h r o t t l e t o f u l l t h r o t t l e ......................................
..................
60
150
D r i v e R a n g e , Z e r o T h r o t t l e a t 3 0 m p h .................
R e v . ( Z e r o t o f u l l t h r o t t l e .............................................
..................
..................
60
95
260
Fig .
7.
7A-6C--OM P r e s s u r e C h e c k
o r N o r m a l O p e r a t in g
C o n d it io n s
sid e o f the m o d u la t o r . I f this is f o u n d w i th o u t the
p re se n c e o f oil, the m o d u l a t o r s h o u ld not be c h a n g e d .
R o a d test a n d c h e c k f o r leaks.
VACUUM MODULATOR DIAGNOSIS
A d e f e c t i v e v a c u u m m o d u l a t o r c a n be d e te r m in e d
b y p e r f o r m i n g the f o l l o w i n g p ro c e d u re s .
Vacuum Diaphragm Leak Check
In sert a p i p e c l e a n e r in to the v a c u u m c o n n e c t o r p ip e
as f a r as p o ss ib le a n d c h e c k f o r the p re se n c e o f
tra n s m is s io n oil. I f o il is f o u n d , re p la c e the m o d u la to r.
G a s o l i n e o r w a t e r v a p o r m a y settle in the v a c u u m
A p p ro x im a te
A ltitu d e o f C h e ck
( F t . a b o v e sea le v el)
Road
Atmospheric Leak Check
A p p l y a l i b e r a l c o a t i n g o f s o a p b u b b le so lu tion to
the v a c u u m c o n n e c t o r p ip e sea m , the c r i m p e d u p p e r to
lo w e r h o u s in g sea m , a n d the t h r e a d e d scre w seal ( F ig .
7 A - 9 C ) . U s i n g a sh o rt p ie c e o f r u b b e r t u b i n g a p p l y a ir
p ressu re to the v a c u u m p i p e b y b l o w i n g in to the tub e
a nd o b s e r v e f o r le a k b u b b le s . I f b u b b le s a p p e a r , re p lace
the m o d u la to r.
N O T E : D o not use a n y m e th o d o t h e r th a n h u m a n
lu n g p o w e r f o r a p p l y i n g a ir pre ssure , as p ressu res
o v e r 6 psi m a y d a m a g e the m o d u la to r.
D rive
N eutral
Park
LI
or
L2
R everse
150
150
145
138
132
12 6
121
116
150
150
150
150
150
150
150
150
244
233
222
212
203
194
186
178
Bellows Comparison Check
U s i n g a c o m p a r i s o n g a u g e , as s h o w n in F i g u r e 7 A -
0
2 ,0 0 0
4 ,0 0 0
6 ,0 0 0
8,0 0 0
10 ,0 0 0
12 ,0 0 0
14 ,0 0 0
Fig . 7 A - 7 C - O il
P re ssu re C h e ck
V acuum
Tube
- V e h ic le S t a t io n a r y ,
D is c o n n e c t e d
Drive, N eutral, Park
L I o r L2
Reverse
60
150
107
F ig . 7 A - 8 C - O il
Pre ssu re
Vacuu m
C heck
- V e h ic le S t a t io n a r y ,
T u b e C o n n e c te d
10 C, c o m p a r e the lo a d o f a k n o w n g o o d m o d u la t o r w ith
the a s s e m b l y in q u e stio n .
a.
In stall the m o d u la t o r that is k n o w n to
a c c e p t a b le o n e it h e r e n d o f the g a u g e ( F i g . 7 A - 1 1C).
b.
Install
the
m odulator
in
q u e s tio n
o p p o s it e end o f the g a u g e . ( F ig . 7 A - 1 2 C ) .
on
be
the
c.
H o l d i n g the m o d u l a t o r s in a h o r i z o n t a l p o sitio n ,
b rin g
them
to ge th er under pressure
u n til e it h e r
m o d u l a t o r s le e v e e n d j u s t to u c h e s the lin e in the c e n t e r
o f the g a u g e ( F i g . 7 A - 1 3 C ) . T h e g a p b e t w e e n the
o p p o s i t e m o d u l a t o r s lee ve en d a n d the g a u g e line s h o uld
then be 1 / 1 6 " o r less. I f the d is t a n c e is g r e a t e r t h a n this
a m o u n t , the m o d u l a t o r in q u e s ti o n sh o u ld be r e p la c e d .
Sleeve Alignment Check
R o ll the m a i n b o d y o f the m o d u l a t o r o n a flat
s u r f a c e a n d o b s e r v e the s le e v e f o r c o n c e n t r ic i t y to the
ca n . I f the s le e v e is c o n c e n t r i c a n d the p l u n g e r is fre e,
the m o d u l a t o r is a c c e p t a b l e .
O n c e the m o d u l a t o r a s s e m b l y passes all o f the a b o v e
tests, it is an a c c e p t a b l e p a r t a n d s h o u ld be re-used.
Fig.
7A12C
M o d u la t o r
B e llo w s - B a d
MANUAL LINKAGE
M a n u a l l i n k a g e a d j u s t m e n t a n d the a s s o c ia t e d
n e u t r a l s a f e t y sw itch a r e i m p o r t a n t f r o m a s a f e t y
s t a n d p o i n t . T h e n e u t r a l s a f e t y s w itch s h o u ld be a d ju s te d
so th a t the e n g i n e w ill start in the P a r k a n d N e u t r a l
p o s it io n s o n l y .
Fig. 7 A 1 3 C - - M o d u la to r B e llo w s ( G o o d )
W i t h the s e le c t o r le v e r in the P a r k p o sit io n , the
p a r k i n g p a w l s h o u l d f r e e l y e n g a g e a n d p r e v e n t the
v e h i c l e f r o m ro llin g . T h e p o in t e r o n the i n d ic a t o r
q u a d r a n t s h o uld line up p r o p e r l y w ith the r a n g e
i n d i c a t o r s in all r a n g e s .
TROUBLE DIAGNOSIS
Fig. 7 A 1 0 C - B e l l o w s C o m p a r is o n
Gauge
No Drive in Drive Range
(Install p re ss u re g a g e )
M O D U LATO R PART N UM BER!
IS LO C A T ED O N B A C K SID E I
O F THE ASSEM B LY
•
L o w oil lev e l - c h e c k f o r e x t e r n a l lea ks or
d e f e c t i v e v a c u u m m o d u l a t o r ( l e a k i n g d i a p h r a g m w ill
e v a c u a t e oil f r o m unit).
•
M a n u a l l i n k a g e m a l a d j u s t e d (co rre ct a l i g n m e n t
in m a n u a l le v e r s h i f t q u a d r a n t is e sse ntia l);
v a l v e d i s c o n n e c t e d f r o m m a n u a l le v e r pin.
•
Low
oil p re ss u re
P R E S S U R E b e lo w .
•
H O LD M O D U LA TO RS IN A H O R IZ O N T A L P O S IT IO N ,A S SH O W N ,
-
refer
to
LOW
m anual
LIN E
F o r w a r d clutch:
a. C l u t c h d o e s n o t a p p l y - p is t o n c r a c k e d ; seals
m is s in g , d a m a g e d ; clutch p la te s b u r n t (see B U R N E D
C L U T C H P L A T E S b elo w ).
BRIN G THEM S LO W L Y TO GETHER UNDER PRESSURE
rings
b.
P u m p f e e d c ir c u i t - t o - f o r w a r d c lu tch o il seal
m is s i n g o r b r o k e n o n p u m p c o v e r; leak o r
re s trictio n in f e e d circuits; p u m p - t o - c a s e g a s k e t m isp osit io n e d o r d a m a g e d . C l u t c h d r u m b a ll c h e c k stuck o r
m issin g .
•
R o l l e r C l u t c h - b r o k e n s p rin g s , d a m a g e d c a g e or
in s t a lle d b a c k w a r d s .
High or Low Oil Pressure
6.
V a c u u m Leak:
V a c u u m line d i s c o n n e c t e d .
b.
c.
L e a k o n line f r o m e n g i n e to m o d u l a t o r .
I m p r o p e r e n g in e v a c u u m .
d.
Leak
vacuum -operated
accessory
v a c u u m a d v a n c e , etc.).
•
M odulator:
a. S t u c k m o d u l a t o r v a l v e .
b.
W a t e r in m o d u la t o r .
c.
D a m a g e d , not o p e r a t i n g p r o p e r l y .
•
D e ten t System :
a.
D e t e n t sw itch a c tu a t e d ( p l u n g e r
s h o rt e d .
b.
D e t e n t w i r i n g s h o rte d .
D e t e n t s o l e n o i d loose.
f.
g.
D e ten t v a lv e bore p lu g d a m a g e d .
D e t e n t r e g u l a t o r v a l v e p in short.
•
•
stuck)
In c o r r e c t p re ss u re r e g u l a t o r v a l v e sp rin g .
T o o m a n y p re s s u r e r e g u l a t o r v a l v e s p ace rs.
d.
Pressure
or
in sta lle d
c.
•
•
Pu m p castin g bad.
•
D e fe c tiv e v a c u u m m o d u la to r assem bly.
Filter A ssem b ly:
a.
B l o c k e d o r restricted.
b.
"O "
R i n g sea l o n
i n ta k e
p ip e
-
leakin g,
dam aged,
•
cover.
•
Internal C ircuit Leaks:
a.
F o r w a r d clutch leak (p re s s u re low in D r i v e
r a n g e - p r e s s u r e n o r m a l in N e u t r a l a n d R e v e r s e ).
D i r e c t clutch le a k ( p re s s u re low in R e v e r s e ,
p r e s s u r e n o r m a l in all o t h e r r a n g e s ) .
V a l v e stick in g .
D r i v e n g e a r loose, d a m a g e d o r w o r n (c h e c k
Con trol valve:
c.
and/or
P u m p - t o - c a s e g a s k e t m i s p o s i t io n e d .
D e fe c tiv e or m ism atched pum p b o d y / p u m p
C h e c k p u m p o il s e a l rin gs.
G overnor:
1-2 s h if t v a l v e tra in stuck clo sed.
G o v e r n o r f e e d c h a n n e l s b lo c k e d ,
le a k in g ,
p ip e s o u t o f p o sit io n , g o v e r n o r s cre en p lu g g e d .
c. N o t e n o u g h s p a c e r s in p re ss u re re g u la to r.
d. G e a r c l e a r a n c e , d a m a g e d , w o r n , d r iv e g e a r
in s t a l l e d b a c k w a r d s .
C h e c k f o r w a r d c lu t c h seals.
C a s e - p o ro s ity .
a.
b.
P r e s s u r e r e g u l a t o r v a l v e s p r i n g too w e a k .
1.
D e t e n t v a l v e tra in stuck.
3-2 v a l v e stuck.
ge ar shows d a m a g e.
W r o n g filter a s s e m b l y .
2.
b.
f o r p in in c a s e a n d le n g t h o f p i n s h o w in g ); also c h e c k
o u tp u t s h a f t d r i v e g e a r f o r n icks o r r o u g h finish i f d r i v e n
V a l v e b o d y g a s k e ts l e a k in g , d a m a g e d , i n c o r
rectly in stalled.
•
Case:
a. I n t e r m e d i a t e clutch c u p p l u g l e a k i n g o r b lo w n
out.
O il P u m p :
a. P r e s s u r e r e g u l a t o r a n d / o r b o o s t v a l v e stuck.
b.
g a s k e ts
c.
a.
b.
L o w t r a n s m i s s i o n o il level.
e.
f.
S tick s o p e n .
C o n tro l valve:
a. V a l v e b o d y
First Speed Only, No 1-2 Shift
b a c k w a r d s or
P res s u re b o o st b u s h i n g b r o k e n or d e f e c t iv e .
b.
P o r o s i t y in i n ta k e b o re a re a.
u p s h ifts.
•
D e t e n t s o le n o id :
a.
L oose.
b. G a s k e t l e a k in g .
g r o m m e t om itted or d a m ag ed .
c. S p l i t or l e a k i n g in t a k e p ipe .
•
C ase A ssem bly:
•
D e t e n t s w itch s t i c k i n g o r d e f e c t i v e ( m a y stick in
c o ld or w e t w e a t h e r ) . C a n be d e te c te d b y p u llin g
c o n n e c t i o n at t r a n s m i s s i o n a n d o b t a i n i n g n o r m a l
b.
c.
d.
a c c u m u la t o r
1-2 Shift-Full Throttle Only
Low Line Pressure
•
front
L I ra n g e ).
O il Pum p:
a.
P res s u re r e g u l a t o r a n d / o r b o o s t v a l v e stuck.
f.
and
i n c o r r e c t ly in sta lled .
e.
d efective.
e.
servo
(h oses,
D e t e n t s o l e n o i d stuck o p en .
D e t e n t f e e d o rifice in s p a c e r p late b l o c k e d o r
b o o st v a l v e
rear
c.
L I - r e v e r s e c h e ck ball m i s p o s i t io n e d o r m i s s
i n g (this w ill ca u s e n o r e v e rs e a n d n o o v e r r u n b r a k i n g in
re stricted .
•
Check
b. C h e c k c a s e f o r in t e r m e d i a t e clutch c u p p lu g
leak o r b lo w n out.
a.
c.
d.
3.
a.
High Line Pressure
in
C h e c k c e n t e r s u p p o r t oil sea l rin gs.
C h e c k d ir e ct clutch o u t e r seal.
p isto n s a n d r in g s f o r d a m a g e o r m is s in g .
( R e f e r to O I L P R E S S U R E C E H C K S )
•
1.
2.
b.
P o r o s it y b e t w e e n c h a n n e ls .
c.
G overnor
feed
channel
b lo c k e d ;
governor
b o re sco re d o r w o r n , a l l o w i n g cross p re ssu re lea k .
•
In t e r m e d i a t e clutch:
a. C a s e c e n t e r s u p p o r t - oil
b r o k e n , d e f e c t i v e ; o rifice p l u g m is s in g .
b.
C lu tch
piston
s e a ls
rings
m issing,
m issin g ,
im p ro p erly
a s s e m b le d , cut.
First and Second Speeds Only, No 2-3 Shift
•
D e t e n t s o le n o id - stuck o p e n (de ten t s h ifts o n l y the 2-3 s h if t w o u l d o c c u r at v e r y h ig h speeds, b e in g
in te r p r e t e d as no 2-3 sh ift).
•
D e t e n t switch.
•
C o n tro l valve:
a.
2-3 v a l v e t ra in stuck.
b.
re c t ly in sta lle d .
•
V a l v e b o d y g a s k e ts l e a k i n g , d a m a g e d , i n c o r
• F o r w a r d a n d d ir e ct c lu tch es s l i p p i n g ( i f burnt,
see B U R N E D C L U T C H P L A T E b e lo w ); o il seal r i n g s on
D i r e c t clutch :
a.
d efective.
C enter
p u m p cover b roken or worn.
support
oil
r in g s
m is s in g ,
b ro k e n ,
b.
C lu tc h p isto n seals m issin g ,
im p rop erly
a s s e m b l e d , cut; p isto n b a ll c h e c k stuck o r m is s in g .
•
M a n u a l link age m alad ju sted .
•
Internal L in kage:
M a n u a l valve disconn ected or end broken.
b.
In s id e d e t e n t l e v e r p in b ro k e n .
•
P u m p A s s e m b l y - t r a n s m i s s io n lu b e
l e a k i n g i n to f o r w a r d c lu tch a p p l y p a s s a g e .
•
p re ss u re
B u r n e d p lates - c h e c k cause.
d o e sn ’t release
- w ill
a lso ca u s e
no
No Drive in Reverse or Slips in Reverse
(Install p re s s u r e g a u g e )
•
L o w fluid level.
•
M a n u a l lin k ag e m aladjusted.
• O i l p re s s u r e - r e f e r to L O W L I N E P R E S S U R E
above.
•
L o w fluid level.
O il p re ss u re - r e f e r to L O W
LIN E P R E S S U R E
C o n tro l valve:
a.
1-2 a c c u m u la t o r v a l v e t r a i n stickin g.
b.
P o r o s it y in v a l v e b o d y o r case.
c.
to rq u e d .
F o r w a r d C lu tc h :
b.
C lu tch
d r i v e in R e v e r s e .
•
•
F r o n t a c c u m u la t o r p isto n oil r i n g d a m a g e d or
m is s in g .
a.
a.
(Install p re ss u re g a u g e )
•
above.
Drive in Neutral
•
Slips 1-2 Shift
C o n tro l valve:
V a lv e
body
a ttachin g
bolts
not
p rop erly
•
R e a r a c c u m u l a t o r o il r in g m i s s in g o r d a m a g e d ;
c a se b o re d a m a g e d .
•
P u m p - t o - c a s e g a s k e t m is p o s it io n e d .
•
Case:
a.
I n t e r m e d i a t e c lu tch c u p p l u g le a k s e xce s s iv e ly .
b.
P o r o s it y b e tw e e n c h a n n e ls .
c.
R a i s e d r i d g e a r o u n d c a s e c e n t e r s u p p o r t bolt
(d o e s n ot a llo w c o n tr o l v a lv e a s s e m b l y to sea t p r o p e r ly ) .
•
I n t e r m e d i a t e clutch :
a.
P isto n seals m i s s i n g o r d a m a g e d ; clutch p lates
b u r n t (see B U R N E D C L U T C H P L A T E S b e lo w ).
a. V a l v e b o d y g a s k e t s l e a k i n g , d a m a g e d , i n c o r
re c t ly i n s t a l l e d
(O ther
m a lfu n ctio n s
m a y a lso
be
i n d ic a t e d ) .
b.
C e n t e r s u p p o r t - leak in f e e d c ir c u it (oil r in g s
d a m a g e d o r g r o o v e s d e fe c t i v e ) , e x c e s s iv e le a k b e tw e e n
to w e r a n d b u s h i n g , orifice b lee d p l u g h o le (.020 dia.)
b.
L o w r e v e rs e b a ll c h e c k m is s i n g f r o m case
(this w i ll a ls o ca u s e n o o v e r r u n b r a k i n g in L I R a n g e ) .
b lo c k e d , c e n t e r s u p p o r t bolt n ot s e a t e d p r o p e r l y in ca se.
c. 2-3 v a l v e t ra in stuck o p e n (this w ill a lso ca u se
1-3 u p s h i f t in D r i v e r a n g e ).
d.
R everse
case passages.
•
feed
passage
re s tricted ;
also c h e c k
R e a r s e r v o a n d a c c u m u la t o r :
a.
Rough 1-2 Shift
(Install p re ss u re g a u g e )
•
above.
•
S e r v o p i s t o n sea l r i n g d a m a g e d o r m is s in g .
b.
S h o r t b a n d a p p l y p in (this m a y also ca u s e n o
o v e r r u n b r a k i n g o r slips in o v e r r u n b r a k i n g - L I r a n g e ).
R e f e r to I N S T A L L A T I O N O F R E A R S E R V O A S S E M
B L Y f o r p i n s e le c t io n p r o c e d u r e .
c.
D e f e c t i v e r e a r s e r v o p is t o n o r b o re .
•
R e v e r s e o r low b a n d b urnt, loose l in in g ; a p p l y
p in o r a n c h o r p ins not e n g a g ed ; b a n d broken.
•
•
C on trol valve:
a.
1-2 a c c u m u la t o r v a l v e train.
b.
V a l v e b o d y - t o - c a s e bolts loose.
c.
W r o n g g a s k e ts o r o f f l o c a tio n , d a m a g e d .
Case:
a.
sea lin g .
b.
•
D i r e c t clutch:
a.
O il p re ss u re - r e f e r to H I G H L I N E P R E S S U R E
O u t e r seal d a m a g e d o r m is s in g .
b.
C l u t c h p la te s b u r n t (see B U R N E D C L U T C H
P L A T E S b e lo w ).
In term ed iate
clutch
b a ll
a.
O il r in g s d a m a g e d .
b.
c.
P isto n stuck.
B r o k e n o r m i s s in g sp rin g .
d.
B o re d a m a g e d .
In t e r m e d i a t e clutch
•
C e n te r support
d a m a g ed or worn.
Slips 2-3 Shift
o il
se a l
r in g s
or
grooves
Slips in all Ranges, Slips on Start
(In s ta ll p r e s s u r e g a u g e )
•
L o w flu id level.
•
above.
•
O i l p r e s s u re - r e f e r to L O W
C a s e - cross leaks, p o r o s ity .
- clutch
plates
burnt
(see
(Install p re ss u re g a u g e )
•
L o w fluid lev el.
•
above.
LIN E P R E S S U R E
not
P o r o s it y b e tw e e n c h a n n e ls .
B U R N E D C L U T C H P L A T E S belo w ).
-
or
R e a r s e r v o a c c u m u la t o r :
•
F o r w a r d c lu t c h - c lu tch d o e s not re le a s e (w ill also
c a u s e D r i v e in N e u t r a l ) .
•
m i s s in g
O il p re ss u re - r e f e r to L O W L I N E P R E S S U R E
•
C o n t r o l v a l v e - a c c u m u la t o r p isto n p in ( le a k at
s w e d g e end).
•
C a s e p o ro s ity .
•
•
D i r e c t clutch :
a.
P is to n seals l e a k i n g o r ball c h e c k leaks.
b. C e n t e r s u p p o r t oil seal r in g s
e x c e s s iv e le a k b e t w e e n to w e r a n d b u s h in g .
dam aged;
D e t e n t switch.
• D e t e n t s o l e n o i d stuck o p e n , loose, etc. (w ill ca u s e
late shifts).
•
C on trol valve:
Rough 2-3 Shift
(Install p re s s u r e g a u g e )
•
O il P r e s s u r e - r e f e r to H I G H L I N E P R E S S U R E
above.
•
F r o n t s e r v o a c c u m u la t o r :
a. S e r v o o r a c c u m u l a t o r oil r in g s o r b o re s
leaking.
b. S e r v o p is t o n c o c k e d o r stuck.
•
F r o n t b a n d b r o k e n , b u r n t (ch eck f o r cause), not
•
M a n u a l lin k ag e m aladjusted.
•
In terna l lin k a g e :
short,
im p rop erly
N O T E : Items a b o v e w i ll a lso ca u s e slips in R e v e r s e
OR
LOW
O IL
•
S o len o id in op erative, connections.
•
C o n t r o l v a l v e - d e t e n t v a l v e tra in stickin g.
burned,
rough
P a r k i n g p a w l r e t u rn s p r i n g m is s in g , b r o k e n o r
O il level low.
b.
P l u g g e d o r restricted filter.
c.
In tak e p i p e " O " r i n g d a m a g e d .
d.
In ta k e p i p e split, p o r o s i t y in case i n ta k e p i p e
e.
W a t e r in oil.
f.
P o r o s i t y o r v o i d s at t r a n s m i s s i o n ca se ( p u m p
g.
•
•
O i l P res s u re - r e f e r to
P R E S S U R E above.
H IGH
OR
LOW
a.
O IL
•
G overnor:
restricted
d a m a g e d or m is p o s i t i o n e d .
F e e d line s cre en p l u g g e d .
or
lea kin g;
P u m p - t o - c a s e g a s k e t o f f lo catio n .
Pump A ssem bly:
G ears
dam aged
or
defective;
in sta lled b a c k w a r d s .
(Install p re s s u r e g a u g e )
c.
loose,
bore.
Low or High Shift Points
holes
bracket
f a c e ) in ta k e port.
•
D e t e n t sw itch a d j u s tm e n ts , c o n n e c t i o n (sw itch
p l u n g e r a c t iv a t e d a p p r o x . 7 / 8 " at full throttle o p e n i n g ) .
Feed
pawl
d efective
Pum p C avitation :
a.
No Detent Downshifts
b.
P a r k i n g p a w l b ro k e n .
P arkin g
•
•
C o n t r o l v a l v e - 3-2 v a l v e stuck s p r in g m is s i n g or
broken.
V a l v e s t ic k in g .
p lu g
Park, Neutral and all Driving Ranges
No Part Throttle Downshift
a.
cup
CAUTION: B
efore checking transmission for
what is believed to be "transmission noise",
makesure that the noise is notfromthe water
pump, alternator, power steering, etc. These
components can be isolated by removing the
proper belt and running the engine no more
thantwominutes at onetime.
o r no R e v e r s e .
H IGH
clutch
Transmission Noisy
•
R e a r b a n d b r o k e n , b u r n t (ch eck f o r cause), n ot
e n g a g e d on a n c h o r p in s o r s e r v o pin.
•
b.
c.
d.
a p p l y p re ss u re .
to
spacer
in c o r r e c t l y h o o k e d .
R e a r servo:
a. O i l seal r in g , b o r e o r p isto n d a m a g e d ; l e a k in g
(I nsta ll p r e s s u r e g a u g e )
•
O il p re ss u re - r e f e r
P R E S S U R E above.
in t e r m e d i a t e
a. P a r k i n g b r a k e lev er a n d a c t u a t o r
(ch eck f o r c h a m f e r o n a c t u a t o r r o d sleeve).
c h e c k b a ll a re a .
p in
m i s p o s it i o n e d ;
e d g e s o r in c o r r e c t ly in sta lled .
•
C a s e a s s e m b l y - L I - r e v e r s e c h e c k ball m i s p o s i
tio n e d o r m i s s in g f r o m ca se; ca se d a m a g e d at L I - r e v e r s e
app ly
g a s k e ts
Won’t Hold in Park
No Engine Braking in LI Range - 1st Gear
band
plate
•
C a s e p o r o s i ty ;
le a k i n g , m issin g .
•
e n g a g e d o n a n c h o r p in a n d / o r s e r v o pin.
Spacer
p late orifice h o le s m i s s i n g o r b lo ck e d .
No Engine Braking in L2 Range - 2nd Gear
b.
Rear
assem bled.
3-2 v a l v e tra in (de ten t u p s h i f t s p o ssible ).
c.
1-2 s h i f t v a l v e tra in - 1-2 r e g u l a t o r v a l v e stuck
(this w o u ld c a u s e a co n s t a n t 1-2 s h i f t p o in t, re g a r d le s s o f
d.
F r o n t a c c u m u l a t o r s p r i n g m issin g , b ro k e n .
b. A c c u m u l a t o r p is t o n stuck.
•
D i r e c t c lu tch - a ir c h e c k f o r leak to o u t e r a r e a o f
c lu tch p is t o n o r ce n t e r p isto n seal.
•
D a m a g e d c e n t e r su p p o rt.
•
D e t e n t v a l v e train.
b.
throttle o p e n in g ) .
F r o n t s e r v o a c c u m u la t o r :
a.
a.
p ipes
b.
Crescent interference.
c.
O i l seal r i n g s d a m a g e d o r w o r n .
Converter:
a.
L o o s e f l y w h e e l - t o - c o n v e r t e r bolts.
b.
D a m a g e d c o n v e rt e r .
First, Second and/or Reverse Gears
P l a n e t a r y G e a r Set:
a.
G e a r s or thrust b e a r i n g s d a m a g e d .
d rivin g
gear
b.
F r o n t in te r n a l g e a r r i n g d a m a g e d .
During Acceleration - Any Gear
• T ran sm issio n
underbody.
•
or
cooler
lin e s
grounded
to
Squeal at Low Vehicle Speed
s h a ft
sea l
-
re q u ir e s
Burned Clutch Plates
•
a.
m is s in g .
C h e c k b a ll in c lu tch d r u m d a m a g e d , stuck or
b.
m is s in g .
C lu tch
c.
Low
S U R E above).
line
cracked,
p re ss u re
(see
seals
LOW
dam aged
L IN E
or
PRES
d.
M a n u a l v a l v e m i s p o s it i o n e d ( m a y also ca u se
fro n t b and failure).
e.
R e s tr i c t e d oil f e e d to f o r w a r d c lu tch (clutch
h o u s i n g to in n e r a n d o u t e r a r e a s not d rille d , restricted,
p o r o s i t y in p u m p . etc.).
f. T r a n s m i s s i o n c a s e v a l v e b o d y f a c e n ot flat o r
p o r o s i t y b e tw e e n c h a n n e ls .
g.
M anual
gro u n d properly.
valve
bent
and
center
la n d
n ot
h.
P u m p c o v e r oil seal r in g s m is s in g , b r o k e n o r
u n d e r s iz e , r i n g g r o o v e o v e r s iz e .
•
I n t e r m e d ia t e C lu tc h :
ble e d
d.
m is s in g .
I n t e r m e d ia t e clutch p isto n seals d a m a g e d o r
h. T r a n s m i s s i o n case v a l v e b o d y f a c e not flat or
p o r o s i t y b e tw e e n c h a n n e ls .
i. M a n u a l v a l v e b e n t a n d c e n t e r la n d n ot g r o u n d
properly.
•
F o r w a r d clutch:
p is t o n
1-2 a c c u m u la t o r v a l v e stuck in c o n tr o l v a l v e
e.
C e n t e r s u p p o r t bo lt loose.
f.
L o w line p re ssu re (see L O W L I N E P R E S
S U R E above).
g.
In t e r m e d ia t e clutch c u p p l u g in c a s e m issing.
M o t o r m o u n t s lo o se o r b r o k e n .
S p ee d o m ete r driven g e a r
lu brication or replacem ent.
c.
assem bly.
a.
m is s in g .
C o n stan t
o rifice
in
center
support
b.
m is s in g .
R e a r a c c u m u l a t o r p isto n oil r i n g d a m a g e d o r
D i r e c t C lu tc h :
a.
R e s tr icted orifice in v a c u u m line to m o d u l a t o r
( p o o r v a c u u m respo n se).
b. C h e c k ba ll in clutch p isto n d a m a g e d , stuck or
m issin g .
c.
D e f e c t i v e m o d u l a t o r bellow s.
d.
C e n t e r s u p p o r t bolt lo o se (bolt m a y be tight
in s u p p o r t b u t not h o l d i n g s u p p o r t tight to the ca se).
e.
C e n t e r s u p p o r t oil rin gs o r g r o o v e s d a m a g e d
o r m issing .
f. C lu tc h p isto n c r a c k e d , seals d a m a g e d or
m issing .
g.
F r o n t a n d re a r servo p istons a n d / o r seals
dam aged.
h.
3-2 v a l v e , 3-2 v a l v e s p r i n g o r 3-2 s p a c e r pin
i n sta lled in w r o n g lo c a tio n in 3-2 v a l v e train bore.
i. M a n u a l v a l v e be n t a n d ce n t e r la n d not g r o u n d
p r o p e r ly .
j.
T ransm issio n
ca se
valve
body
not
flat
or
p o r o s i t y b e tw e e n c h a n n e ls .
k.
I n t e r m e d ia t e ro lle r clutch in sta lle d b a c k w a r d s .
•
In a d d i t io n , bu r n e d clutch p lates ca n be c a u s ed
b y i n c o rre c t u s a g e o f clutch p lates. A l s o , a n t i - f r e e z e in
t ra n s m is s io n fluid ca n ca u s e s ev er e d a m a g e d , such as
la rg e p iece s o f c lu tch p late m a te r i a l p e e l i n g off.
MAINLINE PRESSURE
INTAKE PRESSURE
CONVERTER PRESSURE
GOVERNOR PRESSURE
MODULATOR PRESSURE
DETENT PRESSURE
1-2 ACCUMULATOR PRESSURE
: rev er se :
AUTOMATIC
Fig.
400
H yd rau lic
C ir c u it
TRANSMISSION
7A-14C--THM
GOVERNOR ASHMI1V
REVERSE
7A 33
SERVICE OPERATIONS
TRANSMISSION REPLACEMENT
NOTE:
4 .R e m o v e truck f r o m hoist.
I f n e c e s s a r y , the c a t a l y t i c c o n v e r t e r m a y
h a v e to be d i s c o n n e c t e d to p r o v i d e a d e q u a t e
c l e a r a n c e t'or t r a n s m i s s i o n r e m o v a l . T h i s p r o c e d u r e
w i ll i n c l u d e r e m o v a l o f the c o n v e r t e r s u p p o r t
bracket.
B e f o r e r a i s i n g the truck, d i s c o n n e c t the b a t t e r y and
r e le a s e the p a r k i n g b r a k e .
R a i s e truck o n hoist.
2.
R e m o v e p r o p e l l e r s h a ft .
D i s c o n n e c t s h i f t c o n tr o l lin k a g e .
5.
S u p p o r t t r a n s m i s s io n w i t h s u i t a b le t ra n s m is s io n
jack.
rear
m ount
fro m
7.
R e m o v e tw o bo lts at e a c h e n d
crossm e m b er and rem ove crossm em ber.
o f the
8.
R e m o v e con verter and pan.
9.
R e m o v e c o n v e r t e r to f l y w h e e l bolts.
Loosen
exhaust
p ipe
a p p r o x i m a t e l y 1/ 4 in ch, a n d
j a c k is b a r e l y s u p p o r t i n g it.
to
Model CL
1.
U s e a n o n - h a r d e n i n g s e a l e r on o u t s id e o f seal
b o d y ; a n d u s in g T o o l J-24057, d r i v e seal in p la ce .
m a n ifo ld
low er transm ission
R e -in s t a ll p r o p e l l e r s h a ft.
GOVERNOR
fram e
1. R e m o v e g o v e r n o r c o v e r a t t a c h i n g scre ws, co ve r,
a n d ga ske t.
2.
D i s c a r d g a s k e t.
3.
W i t h d r a w g o v e r n o r a s s e m b l y f r o m ca se.
Installation
bolts
until
In s t a lla tio n o f the g o v e r n o r a s s e m b l y is the r e ve rs e
o f the r e m o v a l . U s e a n ew g a s k e t u n d e r the g o v e r n o r
c o v e r. A d j u s t fluid level.
13.
U s e c o n v e r t e r h o l d i n g T o o l J-5384 w h e n
l o w e r i n g t r a n s m i s s io n o r k e e p r e a r o f t r a n s m is s i o n lo w e r
t h a n f r o n t so as n o t to lose c o n v e r t e r .
MODULATOR AND MODULATOR VALVE
Removal
1.
Rem ove
m o dulato r
assem bly
attach in g
screw
a n d r e tain er .
2. R e m o v e m o d u l a t o r a s s e m b l y f r o m case. D i s c a r d
" O " r i n g seal.
3.
R e m o v e m o d u l a t o r v a l v e f r o m ca se.
Installation
Installation
T h e in s t a l l a t i o n o f the t r a n s m i s s i o n is the r e v e rs e o f
t he r e m o v a l w i t h the f o l l o w i n g a d d i t i o n a l steps.
r o t a te s f r e e l y b y h a n d in this p o s it io n . T h e n , h a n d start
t i g h t e n f in g e r t i g h t
T h is
w i ll
insure
transm ission
b e f o r e t o r q u i n g to
p roper
converter
support
crossm em ber
to
t r a n s m i s s i o n a n d f r a m e w i t h t a p e r on s u p p o r t s l o p i n g
t o w a r d re a r.
A f t e r in s t a l l a t i o n o f t r a n s m is s i o n , c h e c k l i n k a g e
fo r p ro p er adjustm ent.
In s ta lla tio n o f the m o d u l a t o r a s s e m b l y a n d m o d u l a
tor v a l v e is the re v e r s e o f the r e m o v a l . U s e a n e w " O "
r i n g seal o n the m o d u l a t o r a s s e m b ly .
B e f o r e in s t a l l i n g the flex p late to c o n v e r t e r bolts,
m a k e c e r t a i n w i t h the flex p la t e th a t the w e l d nuts o n the
c o n v e r t e r as flush w it h the flex p la t e a n d the c o n v e r t e r
3.
R e -in s t a ll p r o p e l l e r s ha ft.
Removal
12.
R a i s e t r a n s m is s i o n to its n o r m a l p o sitio n ,
s u p p o r t e n g i n e w i t h j a c k a n d s lid e t r a n s m is s io n r e a r w a r d
f r o m e n g i n e a n d l o w e r it a w a y f r o m v e h ic le .
Install
U s e a n o n - h a r d e n i n g s e a le r on o u ts id e o f seal
fram e
11.
R e m o v e t r a n s m i s s i o n to e n g i n e m o u n t i n g bolts
a n d r e m o v e oil filler tu b e at tra n s m is s io n .
2.
1.
2.
4.
6.
D isco n n ect
crossm em ber.
All Models Except CL
2.
3.
D i s c o n n e c t s p e e d o m e t e r c a b le , e le c t r ic a l le a d to
c a s e c o n n e c t o r , v a c u u m lin e at m o d u l a t o r , a n d oil c o o l e r
p ip e s .
all bo lts a n d
sp ecification .
a l ig n m e n t .
R e m o v e p r o p e l l e r sha ft.
P r y seal o u t w it h screw d r iv e r.
b o d y ; a n d u s in g T o o l J-21359, d r iv e seal in p lace .
1.
1.
1.
2.
Installation
Removal
10.
REAR SEAL
Removal
A d j u s t fluid level.
PARKING LINKAGE-10, 20 SERIES
Removal
1.
R e m o v e b o t t o m p a n a n d oil filter.
2. U n t h r e a d
m a n u a l s h a ft.
jam
n ut
h o ld in g
d e te n t
le v e r
3.
R e m o v e m a n u a l s h a f t r e t a i n i n g p i n f r o m case.
4.
R e m o v e m a n u a l s h a f t a n d j a m n ut f r o m ca se.
NOTE:
to
D o n ot r e m o v e m a n u a l s h a f t sea l unless
re p l a c e m e n t is r e q u i r e d .
5.
R e m o v e p a r k i n g a c t u a t o r rod a n d d e te n t le v e r
assem bly.
6.
R e m o v e p a r k i n g p a w l b r a c k e t a t t a c h i n g screw s
a n d bracket.
7.
R e m o v e the g o v e r n o r p i p e s a n d m a n u a l v a l v e
Installation
I n s ta lla tio n o f c o n tr o l v a l v e b o d y is in r e ve rs e o f
r e m o v a l . See O v e r h a u l M a n u a l . A d j u s t fluid level.
R e m o v e p a r k i n g p a w l r e t u rn s p rin g .
NOTE:
6.
f r o m co n tr o l v a l v e b o d y .
T h e f o l l o w i n g steps s h o u ld be c o m p l e t e d
un less p a r t r e p l a c e m e n t is r e q u i r e d .
PRESSURE REGULATOR VALVE
8.
R e m o v e p a r k i n g p a w l s h a f t re ta in er .
9.
R e m o v e p a r k i n g p a w l s h a ft , c u p p l u g p a r k i n g
p a w l s h a f t , a n d p a r k i n g p a w l.
Removal
1.
Installation
I n s t a l l a t io n o f the p a r k i n g l i n k a g e is the r e v e rs e o f
th e r e m o v a l . U s e n e w seal a n d c u p p lu g , i f r e m o v e d , a n d
n ew b o t t o m p a n g a s k e t.
CONTROL VALVE BODY
Removal
R e m o v e b o t t o m p a n a n d filter.
2.
C o m p r e s s r e g u l a t o r b o o st v a l v e b u s h i n g a g a in s t
p re ss u re r e g u l a t o r s p r i n g a n d r e m o v e s n a p r i n g , u s in g
J-5403 pliers.
3.
Rem ove
regu lator
b o o st
valve
bu shin g
and
v a lv e .
4.
R e m o v e p r e s s u re r e g u l a t o r sp rin g.
5.
Rem ove
sprin g
retainer,
w asher
s p ace r(s )
is
p re se n t, a n d r e g u l a t o r v a lv e .
1.
R e m o v e b o t t o m p a n a n d filter.
2.
D isconnect
lea d
w ire
from
p re ss u re
switch
Installation
assem b ly.
N O T E : A solid ty p e p re ss u re r e g u l a t o r v a l v e must
3.
R e m o v e c o n tr o l v a l v e b o d y a t t a c h i n g screw s a n d
d e t e n t r o lle r s p r i n g a s s e m b l y .
o n l y be' used in a p u m p c o v e r w it h a s q ua re d-o ff'
N O T E : D o n o t r e m o v e s o l e n o i d a t t a c h i n g screws.
CAU TION: I f the transmission is in the vehicle,
the front servo parts may drop out as the
control valve assembly is removed.
4.
R e m o v e c o n tr o l v a l v e
b o d y assem bly and
g o v e r n o r p ip e s . I f c a r e is t a k e n in r e m o v i n g c o n tr o l v a l v e
b o d y the six (6) c h e c k b a lls w ill s t a y in p la c e a b o v e the
s p a c e r p late.
5.
R e m o v e the g o v e r n o r s c r e e n a s s e m b l y f r o m e n d
o f g o v e r n o r f e e d p ip e o r f r o m the g o v e r n o r f e e d p i p e
h o le in the c a s e ( F i g . 7 A - 1 5 C ) . C l e a n g o v e r n o r s cre en in
c l e a n s o l v e n t a n d a i r dry.
CAU TIO N : £>o not drop manual valve.
p re ss u re r e g u l a t o r b oss ( S e e F i g u r e 7 A - 1 6 C ) . A
p re ss u re r e g u l a t o r v a l v e w it h oil holes a n d orifice
c u p p l u g m a y b e used to s e r v ic e e it h e r ty p e p u m p .
In s ta lla tio n
o f the p re ss u re r e g u l a t o r v a l v e
is the
re ve rs e o f the r e m o v a l . I n s t a l l i n g n ew g a s k e t o n oil p a n
a n d a d j u s t in g fluid lev el.
OIL COOLER PIPES
I f r e p l a c e m e n t o f t ra n s m is s i o n steel t u b i n g c o o le r
p ip e s is r e q u ir e d , use o n l y d o u b l e w r a p p e d a n d b r a z e d
steel t u b in g m e e t i n g G M s p e c if ic a tio n 1 2 3 M o r its
e q u i v a l e n t . U n d e r n o c o n d i t io n use c o p p e r o r a l u m i n u m
t u b i n g to r e p l a c e steel t u b in g . T h o s m a t e r i a l s do n ot
h a v e s a t i s f a c t o r y f a t i q u e d u r a b i l i t y to w i t h s t a n d n o r m a l
v e h ic l e v ib r a t i o n s .
GOVERNOR SCREEN
ASSY.
GOVERNOR FEED
PIPE HOLE
PUMP
FOR
COVER
ID E N T IF IC A T IO N -
SQUARED
REG.
OFF
BOSS.
PRESSURE
Stell t u b i n g s h o u ld be f la r e d u s in g the upset ( d o u b le
l a p ) fla r e m e t h o d w h i c h is d e t a i l e d in S e c t i o n 5.
OTHER SERVICE OPERATIONS
2.
O il p a n a n d ga ske t.
3.
D o w n s h if t s o le n o id o r co n n e c to r .
4.
V a l v e b o d y s p a c e r plate, g a s k e t a n d c h e c k ba lls.
5.
F r o n t a c c u m u la t o r piston.
sin g le
6.
R e a r s e r v o a n d r e a r a c c u m u la t o r a s s e m b l y .
o p e r a t i o n s a n d n o t as p a r t o f a g e n e r a l o v e r h a u l sh o u ld ,
as a p r a c t i c a l m a tt e r , be p e r f o r m e d w ith the t r a n s m is s io n
7.
R e a r b a n d a p p l y c h e c k i n g w ith T o o l J-2 1370.
8.
F r o n t s e r v o a s s e m b ly .
9.
S p ee d o d riven gear.
The
fo llo w in g
operations
when
done
as
in the v e h i c l e . R e f e r to the " T r a n s m i s s i o n D i s a s s e m b l y
a n d R e a s s e m b l y " s ectio n o f the O v e r h a u l M a n u a l f o r
s e r v ic e p r o c e d u r e s .
1.
O i l filler p ip e a n d " O " r i n g seal.
10.
C a s e e x t e n s i o n o r ga ske t.
11.
F i l t e r a n d " O " rin g .
12.
P r e s s u r e s w itch a s s e m b ly .
S P E C IF IC A T IO N S
CBC 350
TH M 400
1 7 ft. lbs.
Pump C over to Pump B o d y .................................
Pump A ss e m b ly to Ca se ....................................18 -1/2 ft. lbs.
Valve B o d y and Support P l a t e ........................... 13 0 in. lbs.
Parking L o c k B r a c k e t .............................................
29 ft. lbs.
Oil Suctio n Screen ................................................ 40 in. lbs.
Oil Pan to C a s e .........................................................13 0 in. lbs.
E x ten sio n to Ca se ...................................................... 2 5 ft. lbs.
M o dula to r R etain er to C a s e ................................. 13 0 in. lbs.
Inner S electo r Lever to S h a f t .................................25 ft. lbs.
Detent Valv e A ctuatin g B r a c k e t ........................... 52 in. lbs.
Converter t o F ly w h ee l B o l t s ................................. 35 ft. lbs.
Under Pan to Transmission Case . . . . . . . . . 1 1 0 in. lbs.
Transmission Case to Engine ................................. 35 ft. lbs.
Oil C o o ler Pipe Connectors to Transmission
Case or R a d i a t o r ................................................ 1 2 5 in. lbs.
Oil C o o ler Pipe to Co n necto rs ........................... 10 ft. lbs.
D etent Cable t o Transm issio n ................................. 75 in. lbs.
Detent Cable to C a r b ................................................ 1 1 2 in. lbs.
Pump Cover B o l t s ...................................................... 18 ft. lbs.
Parking Pawl Bracket Bolts....................................... 18 ft.' lbs.
Center Support B o l t ................................................... 23 ft. lbs.
Pump to Case A tt achin g B o l t s .............................. 18 ft. lbs.
Exten sion Housing to Case A tta chin g B o l t s . . . 23 ft. lbs.
Rear Servo Cover B o l t s .............................................18 ft. lbs.
De tent So lenoid Bolts ............................................. 7 ft. lbs.
Con trol Valve B o d y B o l t s .......................................
8 ft. lbs.
Bo tto m Pan A ttaching S c r e w s .............................. 12 ft. lbs.
Modulator Retainer B o l t .......................................... 18 ft. lbs.
Govern or Cover B o l t s ................................................18 ft. lbs.
Manual Lever to Manual Shaft N u t ..................... 8 ft. lbs.
Manual Shaft to Inside D e ten t L e v e r ............... 18 ft. lbs.
Lin kage Swivel Clamp N u t .................................... 43 ft. lbs.
Converter Dust Shield S c r e w s ................................. 93 ft. lbs.
Transmission to Engine Mounting B o l t s ............ 35 ft. lbs.
Converter to F ly w h e e l B o l t s ................................. 35 ft. lbs.
Rear M o un t to Transmission B o l t s ..................... 40 ft. lbs.
Rear M ount to Crossmember B o l t ........................ 40 ft. lbs.
Crossmember M ounting B o l t s .................................25 ft. lbs.
Oil C o o ler L i n e ............................................................10 ft. lbs.
Line Pressure T a k e - O ff P l u g .................................... 13 ft. lbs.
Strainer Retainer B o lt ............................................. 10 ft. lbs.
Oil C ooler Pipe Connectors to Transmission
Case or Radiator ................................................125 in. lbs.
Oil C ooler Pipe to C o n n e c t o r ................................. 10 in. lbs.
Downshift Sw itch to B r a c k e t ................................. 22 in. lbs.
S P E C IA L T O O L S
1. J-8763-02
2. J 3289-20
3. J-8092
4. J-21465-13
5. J-23062-3
6. J-23062-7
7. J-21465-15
8.
9.
10.
11.
J-23329
J-9534-01
J-23327
J-23062-2
12. J 23062-1
13. J-21424-9
Transmission Holding Fixture
(Used with J-3289-20 Base)
Transmission Holding Fixture
Base
Driver Handle (Threaded type)
Driver Handle Extension (Used with J-8092)
Sun Gear and Reaction Carrier
Bushing
Output Shaft Bushing Installer
Stator Shaft Front Bushing
Remover (Used with J-8092)
Direct Clutch Bushing Installer
Output Shaft Bushing Remover
Clutch Spring Compressor
Stator Shaft Rear Bushing
Installer (Both Rear)
Case Bushing Remover and Installer
Extension Housing Bushing Remover and
Installer (Used with J-8092)
14. J-21424-7
15. J-23062-5
16. J-5154 or
J-21426
17. J-21359
18. J-7004
19. J 21885
20. J-23069
21. J-2619-01
Stator Shaft Front Bushing
Installer (Used with J-8092)
Input Ring Gear Bushing
Remover and Installer
Extension Housing Oil Seal
Installer
Pump Oil Seal Installer
Slide Hammers (Pair) (Ear
Pump Body removal) (3/8" x 16 tread)
2-3 Accumulator Piston
Compressor
Intermediate Accumulator Cover
Remover arid Installer
Slide Hammer (5/8'' x 18
with 1/2" x 13 Adapter)
Not Illustrated
J-21369
J-8001
Converter Pressure Check
Fixture
Dial Indicator Set
(.001" Increments, .001" Travel)
17
1.
2.
3
4
J - 6 1 16-01
J-80 9 2
J -21359
J-21364
5.
J -2 6 1 9
6.
7.
8.
J-5154
J-6585
J-9539
9.
10.
1 1.
12.
13.
J-5 5 90
J-21867
J-2 1 3 7 0 - 6
J - 2 1370-5
J-2 1795-1
Rear Unit Holding Fixture
Driver Handle
Pump Oil Seal Installer
Holding Fixture Ad ap ter (Used
with J - 6 1 1 6 -0 1 Fixture)
Slide H am m er (Used with
2 6 1 9 - 4 Ad ap ter
and Remover Tools J - 2 1 4 6 5 - 0 1 )
Extension Oil Seal Installer
Slide H am m er Weights
Slide Ha mm er Bolts ( 3 / 8 ' - 16
Threads)
Speedo Gear Installer
Pressure Gauge and Hose
Rear Band Apply Fixture
Rear Band Apply Pin
Gear Unit Assembly Holding
Tool
18
19
14.
15.
16.
17.
18.
19.
20.
21
22.
23
24.
25.
26.
27.
28.
29
20
J-2 1 7 9 5 - 2
J -5384
J-2 1 4 6 5 -0 1
J - 2 1465-5
J - 2 1465-3
J - 2 1465-2
J - 2 1 4 6 5-1
J-2 1 4 6 5 - 1 7
J -2 1465-8
J - 2 14 6 5 -1 3
J - 2 1465-6
J -2 1465-15
J -2 1465-16
J -2 1465-9
J -2 1465-10
J-22182
21
22
Part of Above Holding Tool
Converter Holding Strap
Bushing Tool Set
Part of Bushing Tool Set
Part of Bushing Tool Set
Part of Bushing Tool Set
Part of Bushing Tool Set
Part of Bushing Tool Set
Part of Bushing Tool Set
Part of Bushing Tool Set
Part of Bushing Tool Set
Part of Bushing Tool Set
Part of Bushing Tool Set
Part of Bushing Tool Set
Part of Bushing Tool Set
Ext. Bushing Rem. and Inst.
(Not Illustrated)
1.
2.
3.
4.
J-8763
J-3289-14
J-21427-1
J-9539
5.
6.
7.
8.
J-8105
J 22269-01
J-21369
J-21362
9. J 21363
10. J-21409
Transmission Holding Fixture
Holding Fixture Base
Speedo Gear Remover
Side Hammer Bolts (3/8” - 16
Threads)
Speedo Gear Remover Puller
Accumulator Piston Remover and Installer
Converter Pressure Check Fixture
Seal Protector - Forward and
Direct Clutch - Inner
Seal Protector - Intermediate
Clutch - Inner
Seal Protector - Forward Clutch - Outer
11. J 21664
12.
13.
14.
15.
16.
Not
J-4670
J-8059
J 5586
J-5403
J-1313
11lustrated
J-24684
J-24675
Clutch Spring Compressor
Adapter Ring
Clutch Spring Compressor
Snap Ring Pliers
Snap Ring Pliers
Snap Ring Pliers
Torque Wrench 0-140 Ft. Lbs.
Pressure Regulator
Valve Compressor
Accumulator Piston Adapter
(Used with J-22269 01)
SECTION 7B
M A N U A L TR A N S M IS S IO N
INDEX
G e n e r a l D escrip tion
C o m p o n e n t Parts R e p l a c e m e n t
3 - S p e e d 7 6 m m S a g i n a w .................................................... 7B-1
T r a n s m i s s i o n s ........................................................................... 7 B - 1 7
R e p l a c e m e n t ........................................................................ 7 B - 1 7
A l i g n m e n t ............................................................................. 7 B - 19
3 - S p e e d 7 7 m m T r e m a c ..................................................... 7B-1
3 - S p e e d 8 3 m m M u n c i e ..................................................... 7B-I
4 - S p e e d 1 1 7 m m M u n c i e ................................................... 7B-1
M a in te n a n ce and A djustm ents
T r a n s m i s s i o n L i n k a g e ........................................................ 7B -10
T r a n s f e r C a s e L i n k a g e ..................................................... 7B-10
D iagn osis
Free
Spin
Sh ift
Sh ift
P e d a l T r a v e l ................................................................
D o w n T i m e ..................................................................
L i n k a g e ...........................................................................
E f f o r t ................................................................................
7 B - 14
7 B - 14
7B-14
7 B - 14
O il S e a l ..................................................................................
S p e e d o G e a r .......................................................................
Sid e C o v e r ...........................................................................
S h i f t C o n t r o l L e v e r .......................................................
T r a n s f e r C a s e .........................................................................
R e m o v a l .................................................................................
In s t a l l a ti o n ............................................................................
S p e c i f i c a t i o n s .................................................................................
S p e c ia l T o o l s .................................................................................
7B-20
7B-21
7B-21
7B-22
7B-22
7B-22
7B-22
7B-24
7B -25
GENERAL DESCRIPTION
THREE-SPEED TRANSMISSIONS
3-Speed 76 mm Saginaw
3-Speed 77mm Tremac
3-Speed 83mm H.D. Muncie
T h e t ra n s m is s io n s are f u lly s y n c h r o n i z e d in all
f o r w a r d speeds; h o w e v e r , re ve rse g e a r is not. T h e
s y n c h r o n i z e r a ss e m b lie s co n sist o f a hub, sle eve, two key
s p rin g s a n d three s y n c h r o n i z e r keys. T h e s n y c h r o n i z e r
h u b s a re sp lin e d to the m a i n s h a f t a n d re t a in e d b y sn a p
rin gs.
T h e th ree sp ee d s y n c h r o m e s h t ra n s m is s io n s (F igs.
7B -1 t h r o u g h 7 B - 5 ) a re r e p r e s e n ta t iv e o f a c o n s t a n t - m e s h
t r a n s m is s io n d e s ig n . F u n d a m e n t a l c o m p o n e n t s o f these
un its a re the c a se, w h i c h h o u s e s the g e a r s a nd s h a ft ; the
co n tr o l c o v e r , w h i c h h ouses the s h i f t e r m e c h a n i s m ; a n d
the v a r io u s s h a ft s a n d g e a r s . T h e in p u t s h a ft has an
in te g r a l
m ain
d r iv e
gear
and
ro tates w ith
the clutch
d r i v e n p late; tha t is, the s h a f t ro ta te s all the tim e the
clutch is e n g a g e d and the e n g i n e is r u n n in g . T h e in p u t
s h a f t is s u p p o r t e d in the c a se b y a ball b e a r i n g a n d at
the f r o n t e n d b y an oil i m p r e g n a t e d b u s h i n g m o u n t e d in
the e n g i n e
cran ksh aft.
The
drive
g e a r is in co n sta n t
m e s h w i t h the c o u n t e r s h a f t d r i v e g e a r . S in c e all g e a r s in
the c o u n t e r s h a f t cluster are i n te g r a l to the s h a ft , th e y
a lso r o ta te at the tim e the c lutch is e n g a g e d . T h e
c o u n t e r g e a r is c a r r i e d o n r o lle r b e a r i n g s at b o th e n d s
a n d thrust is a b s o r b e d b y thrust w a s h e r s lo c a te d b e tw ee n
the
countergear
and
thrust
bosses
in
the
case.
These
a s s e m b lie s
perm it
gears
to
be
selected
w i th o u t c i a s h i n g . b y s y n c h r o n i z i n g the sp ee d s o f m a t i n g
p arts b e fo r e t h e y e n g a g e .
F o u r o f the t ra n s m is s io n g e a r s a re r i g i d l y c o n n e c te d
to the c o u n t e r g e a r . T h e s e are the d r iv e n g e a r , sec o n d s p ee d g e a r , first-speed g e a r a n d re v e rs e g e a r . T h e e n g in e
d r iv e n
clutch
gear
d r iv e s
the
countergear
through
a
co n sta n t m e sh c o u n t e r s h a f t d r iv e n g e a r . T h e c o u n t e r g e a r
ro tates in a d ir e c tio n o p p o s it e , o r c o u n ter, to the ro ta tio n
of
the
c lutch
coun tergear
gear.
rem ain
Forw ard
in
sp ee d
constant
gears
m esh
on
w ith
the
tw o
n o n s l i d i n g m a i n s h a f t g e a r s g i v i n g first a nd s ec o n d speed.
T hird
s p eed
is
a
d ir e c t
d r iv e
w ith
e n g a g e d d ir e c t ly to the m a i n s h a f t .
the
clutch
gear
F o r w a r d g e a r s are
e n g a g e d t h r o u g h t w o s l i d i n g s y n c h r o n i z e r s le e v e s
m o u n t e d o n the m a i n s h a f t . E n g a g e m e n t o f the co n sta n t
m e sh m a i n s h a f t g e a r s to the m a i n s h a f t is a c c o m p li s h e d
t h r o u g h b lo c k e r r i n g - t y p e s y n c h ro n iz e rs .
The
N O T E : T h e M u n c i e un it is s i m i l a r to the S a g i n a w
t r a n s m is s io n m a i n s h a f t is h e ld in line w i t h the in p u t
s h a f t b y a p ilo t b e a r i n g at its f r o n t e n d . w h i c h allo w s it
d e s ig n but d iffers in that it has l a r g e r b e arin g s,
to ro ta te o r c o m e to rest i n d e p e n d e n t l y o f the in p u t
sh a ft . It is c a r r i e d at the re a r b y a b a ll b e a r i n g m o u n t e d
in the f r o n t f a c e o f the e x t e n s io n h o u s in g.
H e lic a l g e a r s are in c o r p o r a t e d th r o u g h o u t, i n c l u d i n g
re v e rs e
gear.
in d ep en d ently
The
on
m a in sh a ft gears
the
m ainsh aft
are
and
fre e
a re
g ears, in p u t s h a f t a n d m a i n s h a f t .
FOUR-SPEED TRANSMISSION
4-Speed 117mm Muncie
to ro ta te
in co n sta n t
m e s h w i t h the c o u n t e r s h a f t g e a r s . T h e re v e rs e id le r g e a r
T h e M u n c i e M o d e l C H 465 truck t ra n s m is s io n (F igs.
7B-6
and
engages
7B -7)
w ith
uses
the
a c o n sta n t
s ec o n d
s p ee d
m e sh
first g e a r
synch ronizer
that
sleeve.
is c a r r i e d o n a b u s h in g , finish b o r e d in p la c e , a n d thrust
S e c o n d , third a n d f o u r t h g e a r s a re s y n c h r o n iz e d . T h e
is t a k e n o n the thrust bosses o f the case.
clutch g e a r is s u p p o r t e d b y a h e a v y d u ty ball b e a r in g .
T h e f o r w a r d e n d o f the m a i n s h a f t is s u p p o r t e d b y a
lo o se c o l l a r - t y p e b e a r i n g i n sid e the c lu tch g e a r , w h i l e
t h e r e a r is c a r r i e d o n a b a ll b e a r i n g in the case. E n d p l a y
is
taken
up
by
the
rear
flange
retain ing
nut.
The
c o u n t e r g e a r is s u p p o r t e d at the r e a r b y a s in g le ro w ball
b e a r i n g w h i c h ta k e s the thrust load, a n d b y a ro lle r
b e a r i n g at the f r o n t . I n c o r p o r a t e d in the c o v e r is a ball
p in t y p e i n t e r l o c k w h i c h p r e v e n t s s im u l t a n e o u s e n g a g e
m e n t o f two g e a r s . A s o n e r o d is m o v e d , it p u s h e s a ball
o u t that e n g a g e s
m ovem ent.
the o t h e r tw o ro ds to p r e v e n t
their
G earsh ift
lo cate d
e it h e r
fl o o r b o a r d .
le v e r s
on
on
the
manual
s t e e r in g
t r a n s m is s io n s
colum n
or
on
are
the
R e g a r d l e s s o f lo c a t io n , the l e v e r p e r f o r m s
two o p e r a t i o n s : It selects the g e a r a s s e m b l y to be m o v e d ,
a n d m o v e s it e it h e r f o r w a r d o r b a c k w a r d in to the d e sired
gear
p o sitio n .
The
t r a n s m is s io n
a c tio n
is
the
sam e
w h e t h e r a f l o o r - t y p e s h if t le v e r o r a s t e e r in g c o l u m n s h ift
lev er
is
used.
W hen
the
shift
le v e r
is
m oved,
m o v e m e n t is c a r r ie d b y l i n k a g e to the tra n s m is s io n .
the
3
30
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
4
5 6
7
8
9
1 0 1 1 1 2 1 3
1 4 1 5
16
31
Clutch Gear
Bearing Retainer
Pilot Bearings
Case
3rd Speed Blocker Ring
2-3 Synch. Snap Ring
2-3 Synch. Hub
2nd Speed Blocker Ring
2nd Speed Gear
1st Speed Gear
1st Speed Blocker Ring
1st Speed Synch. Hub
1st Speed Synch. Snap Ring
Reverse Gear
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
Reverse Gear Thrust and Spring Washers
Snap Ring—Bearing to Mainshaft
Extension
Vent
Speedometer Drive Gear and Clip
Mainshaft
Rear Oil Seal
Retainer Oil Seal
Snap Ring—Bearing to Gear
Clutch Gear Bearing
Snap Ring—Bearing to Case
Thrust Washer—Front
Thrust Washer—Rear
Fig. 7B-1-3-Speed 76mm, Cross-Section
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
Snap Ring—Bearing to Extension
Rear Bearing
Countegear Roller Bearings
Anti-Lash Plate Assembly
Magnet
2-3 Synch. Sleeve
Countergear
Countershaft
Reverse Idler Shaft
1st Speed Synch. Sleeve
" E " Ring
Reverse Idler Gear
Woodruff Key
19.
3 rd S p e e d B l o c k e r
1.
T h ru s t W a s h e r • Fro n t
2
B e a r in g W a s h e r
3
N e e d le B e a r in g s
20
"E "
4.
C o u n te rg e a r
2 1.
R e v e r s e Id le r G e a r
5
N e e d le B e a r in g s
22
R e v e r s e Id le r S h a f t
6
B e a r in g W a h s e r
23
W o o d ru ff K ey
7
T h ru st W a s h e r • R ear
24
8.
C o u n te r S h a ft
9
W o o d ru ff K ey
10
B e a r i n g R e t a in e r
1 1.
G asket
12.
O il S e a l
13.
S n a p R in g - B e a r in g
25
26
27
S n a p R in g ■ B e a r in g
R in g
34.
28
1-2 S y n c h r o n iz e r
47
G asket
4 8.
2-3 S h if t F o rk
49
S le e v e
35
S n a p R in g - H u b to
S n a p R in g - H u b to
36
R e v e rse G e a r
S h a ft
37.
T h ru st W a s h e r
1st a n d R e v e r s e S h if t
F o rk
50
Sh a ft
2-3 S h if t e r S h a f t
A s s e m b ly
51.
1st a n d R e v e r s e
S h if t e r S h a f t
2-3 S y n c h r o n iz e r
38
S p r in g W a s h e r
S le e v e
39
R e a r B e a r in g
5 2.
" 0 " R in g S e a l
S y n c h r o n iz e r K e y
40.
S n a p R in g - B e a r in g
53
"E "
to S h a f t
54
S p r in g
S p e e d o m e t e r D riv e
55
2-3 S y n c h r o n iz e r H u b
41.
2 n d S p e e d B lo c k e r
42
R e t a in in g C lip
R in g
43
G asket
44.
R in g
2 n d a n d 3 rd D e te n t
Cam
56
1 st a n d R e v e r s e
D e te n t C a m
S n a p R in g - R e a r
57
S id e C o v e r
B e a r in g to E x te n s io n
58
T C S S w itc h and
15.
D r iv e G e a r B e a r in g
29
2nd S p e e d G ear
16
C ase
30
M a in s h a f t
17.
D r iv e G e a r
3 1.
1st S p e e d G e a r
45.
E x te n s io n
18
P ilo t B e a r i n g s
32
1st S p e e d B l o c k e r
46
O il S e a l
Ring
A s s e m b ly
Gear
A s s e m b ly
to G e a r
1-2 S y n c h r o n iz e r H u b
A s s e m b ly
S p r in g
to C a s e
14
33
R in g
G asket
59
L ip S e a l
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
MAINSHAFT ROLLER BEARINGS
2ND & 3RD SYNCHRONIZER RETAINING RING
SYNCHRONIZER BLOCKER RINGS
2ND & 3RD SYNCHRONIZER SPRING
2ND & 3RD SYNCHRONIZER SLEEVE
2ND & 3RD SYNCHRONIZER KEYS
2ND & 3RD SYNCHRONIZER HUB
SECOND SPEED GEAR
1ST SPEED GEAR RETAINING RING
1ST SPEED GEAR TABBED WASHER
1ST SPEED GEAR
REVERSE SYNCHRONIZER SPRING
1ST & REVERSE SYNCHRONIZER SLEEVE & GEAR
REVERSE SYNCHRONIZER KEYS
1ST & REVERSE SYNCHRONIZER HUB
1ST & REVERSE SYNCHRONIZER RETAINING RING
REAR BEARING RETAINING RING
TRANSMISSION MAINSHAFT
REVERSE SYNCHRONIZER ASSEMBLY
ACCESS COVER BOLTS
ACCESS COVER
ACCESS COVER GASKET
BEARING RETAINER - TO CASE BOLTS
BEARING RETAINER - CLUTCH GEAR
GASKET - CLUTCH GEAR BEARING RETAINER
SEAL ASSEMBLY - CLUTCH GEAR BEARING RETAINER
CLUTCH GEAR BEARING RETAINING RING
CLUTCH GEAR BEARING LOCK RING
CLUTCH GEAR BEARING ASSEMBLY
CLUTCH GEAR
EXPANSION PLUG
FILLER PLUG
TRANSMISSION CASE MAGNET
CASE
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
EXTENSION HOUSING TO CASE GASKET
SPEEDOMETER DRIVER GEAR RETAINING CLIP
TRANSMISSION REAR BEARING LOCK RING
MAINSHAFT BEARING ASSEMBLY
SPEEDOMETER DRIVE GEAR
EXTENSION TO CASE WASHER
EXTENSION TO CASE BOLT
TRANSMISSION EXTENSION VENTILATOR ASSEMBLY
EXTENSION HOUSING ASSEMBLY
EXTENSION HOUSING BUSHING
EXTENSION HOUSING OIL SEAL ASSEMBLY
COUNTERGEAR THRUST WASHER
COUNTERGEAR SPACER
COUNTERGEAR ROLLET BEARINGS
COUNTERGEAR SHAFT
COUNTERGEAR SPRING PIN
COUNTERGEAR
2ND & 3RD SHIFTER FORK
SHIFT FORK LOCKING SCREW
1ST & 2ND SHIFTER INTERLOCK SPRING
SHIFTER INTERLOCK PIN
1ST & REVERSE SHIFT RAIL
1ST & REVERSE SHIFT FORK
2ND & 3RD SHIFTER INTERLOCK SPRING
2ND & 3RD SHIFT RAIL
REVERSE IDLER GEAR THRUST WASHER
REVERSE IDLER GEAR SHAFT
SPRING PIN IDLER GEAR SHAFT
REVERSE IDLER GEAR BUSHING
REVERSE IDLER GEAR
REVERSE IDLER GEAR ASSEMBLY
SEAL TRANSMISSION SHIFTER
TRANSMISSION SHIFTER SHAFT & LEVER ASSEMBLY
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Clutch Gear
Clutch Gear Bearing Retainer
3rd Speed Synchronizer Ring
2nd-3rd Speed Clutch Assy.
2nd Speed Synchronizer Ring
2nd Speed Gear
1st Speed Gear
1st Speed Synchronizer Ring
1st—Reverse Clutch Assy.
Reverse Gear
11.
12.
13.
14.
15.
16.
17.
18.
19.
2 0.
Vent
S p e e d o m e t e r Gear an d C li p
Rear E x t e n s i o n Seal
Rear E x t e n s i o n
Rear B e a r i n g - t o - S h a f t Sn ap Rin g
Rear B e a ri n g - t o - e x t e n s i o n Sn ap R in g
C ountergear W o o d r u f f Key
T h r u s t Washer
Reverse I dle r S h a f t W o o d r u f f K e y
Reverse I dle r Gear
Fig. 7B-4 3-Speed 83mm, Cross-Section
21.
22.
23.
24.
25.
26.
27.
28.
29.
Reverse Idler Shaft
Countergear Bearings
Countergear
Case Magnet
Anti-Lash Plate Assy.
Thrust Washer
Clutch Gear Bearing
Snap Ring
Clutch Gear Retainer Lip Seal
1 Bearing Retainer
2 Bolt and Lock
Washer
3 Gasket
4 Oil Seal
5 Snap Ring
(Beanng-to-Mam
Drive Gear)
6 Main Drive Gear
Bearing
7 Snap Ring Bearing
8 Oil Shnger
9 Case
1
10 Gasket
1 1 Snap Ring (Rear
Bearing-to-Extension)
12 Extension
13 Extension Bushing
14 Oil Seal
15 Thrust Washer
16 Bearing Washer
17 Needle Bearings
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
Countergear
Countershaft
Woodruff Key
Bolt
(Extension-to-Case)
Reverse Gear
Thrust Washer
Rear Bearing
Snap Ring
Speedometer Drive
Gear
Retainer Clip
Reverse Idler Gear
Reverse Idler
Bushing
Reverse Idler Shaft
Woodruff Key
1st Speed Gear
1st Speed Blocker
Ring
Syncrhonizer Key
Spring
35
36
Synchronizer Keys
1st and Reverse
Synchronizer Hub
Assembly
37 Snap Ring
38
1st and Reverse
Synchronizer Collar
39 Main Drive Gear
40 Pilot Bearings
4 1 3rd Speed Blocker
Ring
42 2nd and 3rd
Synchronizer Collar
43 Snap Ring
44 Synchronizer Key
Spring
45 Synchronizer Keys
46 2nd and 3rd
Synchronizer Hub
47 2nd Speed Blocker
Ring
48 2nd Speed Gear
49 Mainshaft
50
51
Gasket
2nd and 3rd Shifter
Fork
52 1st and Reverse
Shifter Fork
53 2-3 Shifter Shaft
Assembly
54 1st and Reverse
Shifter Shaft
Assembly
55 Spring
56 O-Ring Seal
57. 1st and Reverse
Detent Cam
58 2nd and 3rd Detent
Cam
59 Side Cover
60 Bolt and Lock
Washer
61 TCS Switch and
Gasket
62 Lip Seal
K” MODELS
1
2
Main Drive Gear
Drive Gear Bearing
Retainer
3 Snap Ring-Outer
4. 3rd and 4th
Synchronizer Ring
5 3rd and 4th
Synchronizer Collar
6 3rd and 4th Shift
Fork
7 3rd and 4th Speed
Synchronizer Ring
8 3rd Speed G#ar
9 2nd Speed Gear
10. 1st and 2nd
Synchronizer
Assembly
11
12
13.
14.
15
Reverse Driven Gear
Poppet Spring
Poppet Ball
Shift Rail
1st and 2nd Shift
Fork
16 1st Speed Gear
17. Thrust Washer
18 Bearing Snap Ring
19. Speedometer Drive
Gear
20 Output Yoke
21 Flange Nut
22 Rear Bearing
Retainer Oil Seal
23 Rear Bearing
Retainer
24
25
26
27
28
29
30
31
32
33
34
35
36
Mainshaft Rear
Bearing
Rear Bearing Snap
Ring
Snap Ring
Countershaft
Countershaft Rear
Bearing
Bearing Snap Ring
Reverse Idler Gear
Reverse Idler Shaft
Case Magnet
Snap Ring
Snap Ring
Spacer
Countergear
37
38
39.
40.
41
42.
43
44
45.
46
47.
Thrust Washer
Snap Ring
Front Countershaft
Bearing
Countergear Front
Cover
Pilot Bearing Rollers
Clutch Gear Oil
Slinger
Snap Ring
3rd Speed Gear
Bushing
Thrust Washer
2nd Speed Gear
Bushing
1st Speed Gear
Bushing
(3C
1.
2.
3.
4.
5.
6.
7.
8.
8a.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
Bearing Retainer
Gasket
Bearing Retaining
Nut
Bearing Snap Ring
Main Drive Gear
Bearing
Transmission Case
Rear Bearing Retainer
Gasket
Main Drive Gear
Oil Slinger
Bearing Rollers (17)
and Cage
Snap Ring
Third and Fourth
Speed Clutch Sliding
Sleeve
Fourth Speed Gear
Synchronizing Ring
Third Speed
Synchronizing Ring
Third Speed Gear
Mainshaft
Second Speed Gear
Second Speed Gear
Synchronizing Ring
First and Second
Speed Clutch
Assembly
Clutch Key Spring
Clutch Flub
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
Clutch Keys
* “H,'
First and Second
Speed Clutch Sliding v
Sleeve
First Speed Gear
Synchronizing Ring
First Speed Gear
First Speed Gear
Sleeve
Rear Bearing Snap
Ring
Rear Bearing
Rear Bearing
Retainer
Selective Fit Snap
Ring
Reverse Gear
Speedometer Drive
Gear
Rear Bearing
Retainer to]
Case Extension-Gasket
Case Extension
Extension Bushing
Rear Oil Seal
Reverse Idler Front
Thrust Washer
(Tanged)
Reverse Idler Gear
(Front)
Reverse Idler Gear
(Rear)
J *
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
57a.
58.
59.
60.
Flat Thrust Washer
Reverse Idler Shaft
Reverse Idler Shaft
Roll Pin
Reverse Shifter Shaft
Lock Pin
Reverse Shifter Shaft
Lip Seal
Reverse Shift Fork
Reverse Shifter Shaft
and Detent Plate
Reverse Shifter Lever
Reverse Shifter Shaft
Detent Ball
Reverse Shifter Shaft
Ball Detent Spring
Speedometer Driven
Gear and Fitting
Retainer and Bolt
"O" Ring Seal
Tanged Washer
Spacer
Bearing Rollers (28)
Spacer
Bearing Rollers (28)
Countergear
Damper Plate
Countergear Roller
Spacer
Bearing Rollers (28)
Spacer
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
Bearing Rollers (28)
Spacer
Tanged Washer
Countershaft
Gasket
Detent Cams Retainer
Ring
Forward Speed Shift
Forks
First and Second
Speed Gear Shifter
Shaft and Detent
Plate
Third and Fourth
Speed Gear Shifter
Shaft and Detent
Plate
Detent Cams
Detent Cam Spring
Lip Seals
Transmission Side
Cover
Headed Cam Pin
Third and Fourth
Speed Shifter Lever
First and Second
Speed Shifter Lever
TCS Switch and
Gasket.
Lever Attaching Bolts
MAINTENANCE AND ADJUSTMENTS
TRANSMISSION LINKAGE ADJUSTMENT
4.
3-Speed Column Shift
in all p o sitio n s.
(Figs. 7B-8, 7B-9, and 7B-10)
N O T E : I f m a s t j a c k e t lo w e r d a s h c l a m p h a s been
In c a s e s w h e r e g e a r s h i f t l i n k a g e h a s b e e n d i s c o n
nected
or
rem oved,
proper
adjustm ent
sequence
is
im portant.
1.
R e m o v e g a u g e a n d m o v e s ele cto r le v e r th r o u g h
all p o sitio n s to c h e c k a d j u s tm e n t a n d in su re o v e r - t r a v e l
d i s t u r b e d at its m o u n t i n g o n d a s h , its a d j u s t m e n t to
the
steering
m ainshaft
should
be
checked
as
o u t lin e d in S e c t io n 3 B o f this m a n u a l .
S e t b o t h s h i f t e r le v e r s in n e u tr a l p o sitio n . Install
c o n tr o l r o d s to bo th s e c o n d a n d th ird s h i f t e r le v e r a n d
TRANSFER CASE SHIFT CONTROL
first a n d r e v e rs e s h i f t e r lev er.
2.
A l i g n both s h i f t e r tube le v e r s o n m ast j a c k e t in
the n e u t r a l p o sit io n . Install g a u g e ( 3 / 1 6 to 7/ 3 2 in.) in
h o le s o f le v e r s so that g e a r s h i f t c o n tr o l le v e r is in n e u t r a l
p o s it io n .
3. C o n n e c t c o n tr o l r o d s to tu b e levers m a k i n g sure
c l a m p s a re p r o p e r l y a d j u s te d so that tube levers a n d
t r a n s m i s s i o n s h i f t e r lev ers r e m a i n in t h e ir n e u t r a l
p o s i t i o n s w h i l e t i g h t e n in g .
LINKAGE ADJUSTMENT
Model 203 (Full-Time) Transfer Case
(Fig. 7B-11)
R efer
to F i g .
7B-11
for
illu s t r a tio n
2 N D & 3RD LEVER
1ST & REV
LEVER
2 N D & 3RD
LEVER
1ST & REV
LEVER
of
co n tr o ls a n d l i n k a g e a d j u s tm e n t p r o c e d u r e s
M o d e l 203 ( F u l l T i m e ) T r a n s f e r C a s e .
1ST-REVERSE
C O N TR O L ROD
2N D -3R D
C O N TR O L ROD
the
for
s h ift
the
VIEW
B
FLAT
tO % 2
IvEwfDl ( /l6GAGE
G
T R A N S F E R CASE C O N T R O L
L IN K A G E ADJUSTM ENT
1. A lig n gage holes in Levers (A ) & (B)
LOCK
w ith gage hole in S h ifte r Asm & insert
Gage Pin (J). This p ositio n s Levers
(A ) & (B) in " N E U T R A L " .
2. P osition A rm s (F) & (G) in a straight
dow n 6 o 'c lo c k (neutral) p o s itio n .
3. W ith Swivel (E) & L o c k Nuts (D)
loosely assembled to Rod (C ), ro ta te
Swivel (E) u n til ends o f Rod (C) w ill
sim ulta n e ou sly enter Lever (B) & A rm
(F ).
4. Lock in place w ith Retainers ( K ) .
5. T ig h te n L ock Nuts (D) against Swivel
(E) (being ca refu l n o t to change p osition
o f A rm ( F )) to specified to rq u e . See
V ie w A .
6. Repeat steps 3, 4 & 5 fo r Rod ( H ) to
Lever (A ) & A rm (G).
7. Remove Gage Pin (J).
DIAGNOSIS
Preliminary Inspection
T r a n s m i s s i o n c o n tr o l levers s h o u ld be c h e c k e d f o r w e a r
B e f o r e a t t e m p t i n g to r e p a i r the clutch , t r a n s m is s io n
o r r e l a t e d l i n k a g e s f o r a n y r e a s o n o t h e r t h a n an o b v i o u s
failu re,
the
i d e n t if i e d .
p ro b lem
A
large
and
p ro b ab le
percentage
of
cause
clutch
s h o u ld
and
be
m anual
t r a n s m is s i o n
pro blem s
are
m an ifested
by shifting
d ifficulties s uch as h i g h s h i f t effort, g e a r cla s h a n d
g r i n d i n g o r t ra n s m i s s io n b l o c k o u t . W h e n a n y o f these
p r o b l e m s o c c u r a c a r e f u l a n a l y s i s o f th e se difficulties
s h o u l d b e a c c o m p l i s h e d , a n d the f o l l o w i n g c h e c k s a n d
a d j u s t m e n t s p e r f o r m e d in the p r e s e n te d s e q u e n c e b e f o r e
r e m o v i n g the c lu t c h o r t r a n s m is s i o n f o r re p a ir s.
Clutch Free Pedal Travel
1. T h e c lu tch f r e e p e d a l tra v e l a d j u s t m e n t s h o u ld
be m a d e as o u t l i n e d in S e c t i o n 7 C .
2. C h e c k c lu tch l i n k a g e f o r lost m o t i o n c a u s e d b y
lo o se o r w o r n s w iv els, d e fle c t i o n o f m o u n t i n g b ra c k e t s o r
d a m a g e d c o r d o n s h a ft .
the
e n g in e
D isen g ag e
the
1.
R e m o v e the s h if t ro ds at the t r a n s m is s io n a n d
a l ig n the s leeve, b l o c k e r r i n g a n d g e a r b y s h i f t i n g in to
the o f f e n d i n g g e a r a n d the n b a ck i n to n eu tral.
2.
C h e c k the to r q u e r e q u i r e d to s h if t i n to g e a r w ith
an in ch p o u n d to rq u e w r e n c h on the s h if t le v e r a t t a c h i n g
3.
va lu e .
C l e a n levers, l u b r ic a t e a n d re ch e ck the to rq u e
N O T E : I f at this p o in t in the p r o c e d u r e , it is f o u n d
that h i g h s h i f t effo rt o r g e a r c l a s h i n g still exists, an
a n t i - c h a t t e r l u b r ic a n t (p o s i tr a c ti o n a d d i t i v e ) should
be used. T h e l u b r i c a n t is a v a i l a b l e in p la s t ic bottle
the filler plug.
at
a
norm al
id l e
w ith
t r a n s m i s s i o n in n e u t r a l a n d c lu tch e n g a g e d .
2.
Transmission Shift Effort Checking
Procedures
a n d c a n be s q u ir t e d in to the t r a n s m is s io n t h r o u g h
Clutch Spin Down Time
Run
TRANSMISSION SHIFT EFFORT
bolt. I f m o r e t h a n the sp ecified to r q u e ( F i g . 7 B - 1 2 ) is
re q u ir e d , the t r a n s m i s s i o n s h if t l e v e r s h o u ld be c h e c k e d
fo r rust o r d ir t b i n d i n g the lever.
CLUTCH ADJUSTMENT
1.
a n d r e p a i r e d o r r e p l a c e d as n e c e s sa ry .
c lu tch , w a i t
n in e
s e co n d s
and
Transmission Internal Problems Related to
Shift Effort
s h i f t the t r a n s m is s i o n to re v e rs e . N o g r i n d i n g n oise
s h o u l d be h e a r d . A g r i n d i n g n o is e in d ic a t e s i n c o rre c t
W h e n the a b o v e p r o c e d u r e s h a v e b e e n c h e c k e d a n d
the p r o b l e m still exists, the t ra n s m is s io n w ill h a v e to be
c lu tch a d j u s tm e n t, lost m o t i o n clutch m i s a l i g n m e n t , o r
r e m o v e d a n d d i s a s s e m b l e d f o r f u r t h e r d ia g n o s i s . T h e r e
are three b a s ic t y p e s o f t r a n s m is s i o n i n t e r n a l p r o b l e m s
i n t e r n a l p r o b l e m s such as f a i l e d d a m p e r s , f a c in g s ,
c u s h i o n s p r in g s , d i a p h r a g m s p r i n g fingers, p re s s u r e p la te
d r i v e s tra ps, etc.
SHIFT LINKAGE ADJUSTMENT
ru nn in g)
R e m o v e the s h if t c o n t r o l ro ds f r o m the c o l u m n
2. C h e c k s h if t effo rt at the s h i f t c o n tr o l le v e r k n o b .
( E f f o r t s h o u l d n o t e x c e e d 2 lbs. w i t h t ra n s m is s i o n l i n k a g e
rem oved.)
3.
If
bin din g
p rocedure for
S e c t i o n 3B.
the
is
felt,
s t e e r in g
refer
co lum n
to
the
low er
the s y n c h r o n i z e r s lee ve
and
h u b s s h o u ld
be
c h e c k e d f o r a t igh t fit. W i t h the t h r e e s y n c h r o n i z e r keys
r e m o v e d , the s lee ve s h o u ld be lo o se on the hu b. I f the
h u b a n d s lee ve a re
synch ron izer assem bly.
n ot
a
lo o se
fit,
replace
the
adjustm ent
2.
B lo c k o u t - T h e le v e r m o v e s f r e e l y until the
s y n c h r o n i z e r is e n g a g e d . S y n c h r o n i z a t i o n s h o u ld be
bearing
h e a r d to tak e p la ce , b u t the g e a r w ill n ot e n g a g e . W h e n
4.
L u b r i c a t e all ro d a n d sw iv el c o n n e c t io n s
r e c h e c k s h i f t e ffo rt a f t e r i n s t a lla t io n .
in
it d o e s e n g a g e , a d o u b l e b u m p is g e n e r a l l y felt in the
and
5. I f s h i f t l i n k a g e is f r e e f r o m b i n d i n g , the c o l u m n
le v e r s s h o u l d be c h e c k e d f o r e n d p la y . A .0 05" fe e l e r
g a u g e s h o u l d fit b e t w e e n the lev ers a n d c o n tr o l lever.
6.
control
1.
H a r d S h i f t i n g - T h e effo rt to s h i f t is excessive,
but the g e a r s e n g a g e . T h e lev er m o v e s w i t h e x ce s s iv e
effo rt t h r o u g h o u t the e n t ire t ra ve l r a n g e . I f the static
s h i f t effo rt is h i g h , (clu tch d e p r e s s e d , e n g in e not
Steering Column Shift Control
1.
lev ers.
re fle c te d b y s h i f t i n g effort.
C o n n e c t c o n tr o l r o d s a n d c h e ck s t e e r in g c o l u m n
le v e r s f o r a l ig n m e n t . In n e u t r a l, the c o l u m n
c o n t r o l l e v e r t a n g s s h o u ld lin e up w ith the slot in the
m a i n c o n t r o l lever.
Floor Shift Control
A l l s w iv els, ro d s a n d m o u n t i n g s s h o u ld be c h e c k e d
f o r lost m o t i o n a n d r e p a i r e d o r r e p l a c e d as n e c e s sa ry .
lever. T h e s y n c h r o n i z e d b l o c k e r r i n g ca n be d a m a g e d b y
e x c e s s iv e
force
on
gear
cones
that
are
f in is h e d
im p r o p e r l y . T h e b l o c k e r r i n g m a t e r i a l m a y stick to the
Shift T orque
In. Lbs.
3-Saginaw
3-Muncie
50
60
s y n c h r o n i z e r g e a r c o n e c a u s i n g it to be a y e l l o w is h bra ss
s light, the l o a d w ill b u ild up on the s h if t le v e r a n d the n
c o lo r,
fall o f f r a p i d l y f o l l o w e d b y the g r a t i n g so un d.
I f the t ra n s m i s s i o n h a s b e e n c la s h i n g ,
in
s tre ak s ,
w hich
results
in
hard
s h ifts
when
p r e s e n t. T h e g e a r c o n e s h o u ld be a b r i g h t s i l v e r co lo r.
P o lis h the g e a r c o n e w i t h 400 g r it p a p e r to a b r ig h t s i l v e r
w h e n this c o n d i t i o n is p re se n t. T h e b l o c k e r r in g s s h o u ld
b e r e p l a c e d i f the t h r e a d is d a m a g e d o r w o r n .
3.
C l a s h - G e a r clash is a s o u n d w h i c h s o m e t i m e s
o c c u r s w h e n the s le e v e a n d g e a r c h a m f e r s c o n ta c t e a c h
o t h e r in the u n s y n c h r o n i z e d state. T h e c h a r a c t e r i s ti c s o f
clash
are
a
gratin g
or
lo ud
buzzin g
sound
from
the
t r a n s m i s s i o n . T h e s h i f t le v e r l o a d w ill be lo w e r, b u t a
v i b r a t i o n s h o u l d b e felt. T h e n o is e (cla sh ) c a n be f o r a
sh o r t i n s t a n t o r l o n g e n o u g h to k e e p the g e a r f r o m b e i n g
e n g a g e d . T h is condition
hard
sh iftin g
or reported
s h o u ld
not be c o n f u s e d w i t h
as such . H a r d
shifting
and
c l a s h a r e d i r e c t l y o p p o s it e c o n d itio n s . W h e n the cla s h is
the s lee ve
e n d s s h o u ld be e x a m i n e d f o r c h i p p i n g a n d burrs. I f the
slee ve s a re d a m a g e d , the s y n c h r o n i z e r a s s e m b l i e s a n d
b l o c k e r r in g s s h o u l d be r e p l a c e d . S y n c h r o n i z e r s le e v e
e n d s s h o u ld h a v e a n a n g u l a r s u r fa c e . T h e s u r fa c e s
s h o u ld be e v e n f r o m side to side a n d the ra d i i i n d i c a t e d
sh o uld
be
very
s m a ll.
Any
ch ip p in g
w ill
r e q u ir e
synch ron izer replacem ent.
C h e c k the s y n c h r o n i z e r lo ad . W h e n the keys are
in sta lled , the s p r i n g e n d s o n o n e side o f the h u b sh o u ld
be h o o k e d in o n e k e y a n d the s p r in g on the o p p o s i t e side
o f the s y n c h r o n i z e r s h o u ld n ot be h o o k e d o n the s a m e
ke y . A d e fin ite lo a d s h o u ld b e f e l t w h e n the s lee ve is
m o v e d o n the h u b s w i t h the k e y s a n d s p r i n g s in p r o p e r
p o sitio n .
SHIFTING DIFFICULTY DIAGNOSIS
High Shift Effort-Column Shift
(E ffort exceeds 2 ft. lbs. at
lever kn o b with transmission
linkage disconnected.)
High Shift E ffort-Floor Shift
(crossover from lst-2nd to 3rd4th position cannot be a c c o m
plished w ith out o ffset or step)
C O R R E C T IO N
PROBABLE CAUSE
C O N D I T IO N
Binding o f column levers
Adjust column mechanism per Section 9,
Steering o f the Chassis Service Manual
Clean and lubricate all rod and swivel
connections.
Lever end play exceeds .005 in.
Adjust levers
Misalignment o f column control levers.
Adjust levers
Improper linkage Adjustm ent
Adjust linkage
Lost motion due to damaged or worn
swivels, rods, grommets or mountings.
Repair or replace defective components.
Loose lever attaching bolts
Tighten bolts and check levers for correct
fit on shifter shafts.
Binding
Clean and Adjust linkage
S t if f shift lever boot
Replace bo o t
Gear Clash and binding
Improper linkage Adjustment
Adjust Shift linkage
Lost motion
Loose or worn swivels and grommets.
Deflection o f Mounting Brackets.
Loose shift levers.
Damaged Cordon Shaft
Replace defective parts
MANUAL TRANSMISSION DIAGNOSIS
C O N D IT IO N
Slips out o f High Gear
PROBABLE CAUSE
CO RRECTIO N
a. Transmission loose on clutch housing
b. Shift rods interfere with engine
mounts or clutch throw-out lever
c. Shift linkage does not w ork freely;
binds
d. Damaged mainshaft pilot bearing
e. Main drive gear retainer broken or
loose
f. Dirt between transmission case and
and clutch housing
g. Misalignment o f transmission
a. Tighten mounting bolts
b. Replace or bend levers and rods to
eliminate interference
c. Adjust and free up shift linkage
h. Stiff shift lever seal
i. Pilot bearing loose in crankshaft
j. Worn or improperly adjusted linkage
Noisy in All Gears
d. Replace pilot bearing
e. Tighten or replace main drive gear
f.
Clean mating surfaces
g. Refer to T R A N S M IS S IO N
ALIGNM ENT
h. Replace seal
i. See Section 6 for brg. fits
j. Adjust or replace linkage as required
a. Insufficient lubricant
b. Worn countergear bearings
c. Worn or damaged main drive gear and
countergear
d. Damaged main drive gear or main
shaft bearings
e. Worn or damaged countergear anti
lash plate
a. Fill to correct level
b. Replace countergear bearings and shaft
c. Replace worn or damaged gears
Noisy in High Gear
a. Damaged main drive gear bearing
b. Damaged mainshaft bearing
c. Damaged high speed gear synchronizer
a. Replace damaged bearing
b. Replace damaged bearing
c. Replace synchronizer
Noisy in Neutral w ith Engine
Running
a. Damaged main drive gear bearing
b. Damaged or loose mainshaft pilot
bearing
c. Worn or damaged countergear anti
lash plate
d. Worn countergear bearings
a. Replace damaged bearing
b. Replace pilot bearings. See Section 6
for bearing fits
c. Replace countergear
Noisy in all Reduction Gears
a. Insufficient lubricant
b. Worn or damaged main drive gear or
countergear
a. Fill to correct level
b. Replace faulty or damaged gears
Noisy in Seco nd O nly
a. Damaged or worn second-speed
constant mesh gears
b. Worn or damaged countergear
bearings
c. Damaged or worn second-speed
synchronizer
a. Replace damaged gears
Noisy in
Speed)
Third
O nly
(F o ur
rear
a. Damaged or worn third-speed constant
mesh gears
b. Worn or damaged countergear bearings
d. Replace damaged bearings
drive gear
e. Replace countergear
or main
d. Replace countergear bearings and shaft
b. Replace countergear bearings and shaft
c. Replace synchronizer
a. Replace damaged gears
b. Replace damaged countergear bearings
and shaft
MANUAL TRANSMISSION DIAGNOSIS (CONT'D.)
CO R R EC TIO N
PROBABLE CAUSE
C O N D IT IO N
a. Worn or damaged reverse idler gear or
idler bushing
b. Worn or damaged reverse gear on
mainshaft
c. Damaged or worn reverse countergear
d. Damaged Shift mechanism
a. Replace
Excessive Backlash in all
Reduction Gears
a. Worn countergear bearings
b. Excessive end play in countergear
a. Replace bearings
b. Replace countergear
Main Drive Gear Bearing
Retainer Burned or Scored
by Input Shaft
a. Loose or damaged mainshaft
bearing
b. Misalignment o f transmission
a. Replace bearing. See Section 6 for
bearing fit
b. Align transmission
Leaks Lubricant
a. Excessive amount o f lubricant in
transmission
b. Loose o r 1, broken main drive gear
bearing retainer
c. Main drive gear bearing retainer gasket
damaged
d. Side cover loose or gasket damaged
e. Rear bearing retainer oil seal leaks
f. Countershaft loose in case
g. Shift lever seals leak
Noisy in Reverse Only
pilot
reverse
b. Replace reverse gear
c. Replace countergear assembly
d. Inspect linkage and adjust or replace
damaged parts
b. Tighten or replace retainer
c. Replace gasket
d.
e.
f.
g.
Tighten
Replace
Replace
Replace
cover or replace gasket
seal
case
seal
COMPONENT PARTS REPLACEMENT
TRANSMISSION REPLACEMENT
3-Speed Transmission
(Except K Series)
Removal
1.
R a i s e v e h i c l e o n s u it a b l e
l u b r i c a n t f r o m t r a n s m is s io n .
2.
D isco n n ect
speedom eter
ho ist
c a b le ,
and
d rain
back-up
lam p
a n d T C S s w itch at t r a n s m is s i o n .
3.
R e m o v e s h i f t co n tr o ls f r o m tra n s m is s io n .
N O T E : O n v e h i c l e e q u i p p e d w ith M u n c i e 4 - S p e e d
t r a n s m i s s i o n , r e m o v e the g e a r s h i f t le v e r u s i n g T o o l
J -8109 as s h o w n in F i g u r e 7 B - 1 7 . Press d o w n fir m ly
and
rotate
tool
cou n terclo ck w ise
to
release
g e a r s h i f t lev er .
Place
clean
lin t - f r e e
c lo th
or
other
s u it a b le
c o v e r i n g o v e r o p e n i n g o n t r a n s m i s s io n to p r e v e n t
e n t r y o f d ir t o f f o r e i g n m a te ria l.
thrust washers
a. Drain to correct level
Fig. 7B15--Manual Transmission Diagnosis Chart B
INDEX
idler gear assembly
g r e a s e to the m a i n d r iv e g e a r b e a r i n g r e t a in e r and
s p lin e d p o r t io n o f t r a n s m is s io n m a i n d r iv e g e a r s h a f t to
assu re
free
m ovem ent
of
clutch
and
t ra n s m is s io n
c o m p o n e n t s d u r i n g a ss e m b ly .
CAUTION: Do not apply an excessive amount
o f grease in the above areas, as under normal
operation this grease could be thrown onto
clutch facings resulting in clutch problems.
2.
Sh ift
the
t ra n s m is s io n
in to
t ra n s m is s io n on d o l l y o r j a c k a n d
h ig h
gear.
M ount
m o v e i n to p o sitio n
u n d e r the ve h ic le .
CAUTION: A void springing the clutch when the
transmission is being installed to the engine.
Do not force the transmission into the clutch
disc hub. Do not let the transmission hang
unsupported in the splined portion o f the clutch
disc.
3. In stall f l y w h e e l h o u s in g - t o - t r a n s m i s s i o n m o u n t
in g bolts a n d w a s h e r s . T i g h t e n bolts to sp ecifica tio n s.
Fig. 7B 17 Removing Gearshift Lever
4.
D iscon n ect
parkin g
brake
le v e r
and
co n tro ls
( w h e n us e d ) a n d b a c k up l a m p s w itch w ire .
5.
D i s c o n n e c t p r o p e l l e r s h a f t f r o m t r a n s m i s s i o n as
d e s c r i b e d in S e c t i o n 4 -A .
6.
P o s it i o n
veh icle
and
tra n s m is s i o n .
7.
a
adjust
V isu a lly
m e n t,
lin e s
s u i t a b le
or
to
in sp e ct
brackets
dolly
carry
or ja c k
the
w eigh t
to d e t e r m i n e
must
be
under
of
i f other
rem oved
to
the
equ ip
perm it
Be sure to support the clutch
release bearing and support assembly during
removal o f the transmission main drive gear
from the flywheel housing. This will prevent the
release bearing from falling out o f the flywheel
housing when the transmission is removed.
CAU TION :
from
the e n g in e ,
u s in g c a r e
to k e e p the t ra n s m is s io n
m a i n d r i v e g e a r s h a f t in a l i g n m e n t w ith the clutch disc
h u b . S e e F i g . 7 B - 16 .
10.
W h e n the t r a n s m i s s i o n is f r e e f r o m the e n g in e ,
l o w e r the t ra n s m is s i o n a n d m o v e f r o m u n d e r the v e h ic le .
11.
I f d e sir e d , a c a r e f u l c h e c k o f clutch c o m p o
n e n ts s h o u ld be m a d e a f t e r the t r a n s m is s io n has be en
r e m o v e d . I f the clutch r e q u i r e s re p a ir , r e f e r to S e c t io n
7 C b e f o r e t r a n s m i s s io n is r e in s t a l l e d in the v e h ic le .
A p p ly
Install c r o s s m e m b e r .
6.
Connect
propeller
shaft
to
t r a n s m is s io n
as
Connect
p arkin g
brake
lever
and
c o n tr o l
(if
8.
Install f l y w h e e l h o u s in g u n d e r p a n . T i g h t e n c a p
screw s firm ly.
9.
Reconnect
sp eedom eter
cable
to
adapter
at
t ra n s m is s io n , c o n n e c t b a c k - u p l a m p switch w i r e a n d T C S
switch .
10.
R e in s t a ll s h if t c o n tr o ls o n t ra n s m is s io n .
NOTE:
O n v e h ic l e e q u i p p e d w ith 3 -s p e e d t r a n s
m issio n , r e c o n n e c t s h i f t levers to t r a n s m is s io n side
c o v e r. O n v e h i c l e e q u i p p e d w i t h M u n c i e 4 -S p e e d
tra n s m is s io n , in sta ll g e a r s h i f t lever u s in g T o o l
J-8109 as s h o w n in F i g u r e 7 B - 1 7 . Press d o w n firm ly
and
ro ta te
c l o c k w is e
to
in sta ll
gearshift
lever.
Install t r a n s m is s io n f lo o r p a n c o v e r a n d f lo o r m a t.
11.
I f o t h e r e q u i p m e n t (e x h a u s t p ip e ,
b ra ck ets , etc.) w a s r e m o v e d , re in sta ll these parts.
support
12.
R e fill t r a n s m i s s i o n w i t h l u b r i c a n t
m e n d e d in S e c t i o n 0-B o f this m a n u a l .
recom
13.
If
necessary,
a d ju s t
c lu t c h
or
t r a n s m is s io n
c o n tr o l l i n k a g e to a c h i e v e p r o p e r t r a n s m i s s io n o p e r a t io n .
3-Speed Transmission
"K" Series
Replacement
nect
1.
R a is e v e h i c l e o n hoist.
2.
D rain
t r a n s f e r c a s e a n d t r a n s m is s i o n . D i s c o n
the s p e e d o m e t e r
c a b le
from
speedom eter
driven
g e a r fitting, a n d T C S switch co n n e c t io n s .
I n s t a l l a tio n
1.
5.
7.
3-Speed Transmission
(Except K Series)
d r i v e g e a r s h a ft
used). A d j u s t b r a k e s as o u t lin e d in S e c t io n 5.
CAU TION :
M o v e the t ra n s m i s s io n a s s e m b l y s t r a i g h t a w a y
m ain
d e s c r ib e d in S e c t io n 4 A . R e m o v e t ra n s m i s s i o n j a c k .
m is s i o n - t o - f l y w h e e l h o u s i n g m o u n t i n g bolts.
9.
the t r a n s m is s io n
clutch disc splines.
R e m o v e f l y w h e e l h o u s i n g u n d e r p a n a n d trans-
When removing the transmission,
do not allow the weight o f the transmission to
hang on the clutch disc hub, as the disc may
become distorted, seriously affecting clutch
operation.
A lign
c o m p a n i o n f l a n g e o r o u t p u t y o k e . M o v e the t ra n s m is s io n
f o r w a r d , g u i d i n g the m a i n d r i v e g e a r s h a f t i n to the
the
r e m o v a l o f th e t r a n s m is s i o n . R e m o v e c r o s s m e m b e r .
8.
4.
w ith the clutch d is c h u b b y r o t a t in g the t ra n s m is s io n
a
lig h t
coatin g
of
h ig h
t e m p e r a tu r e
3. D i s c o n n e c t p r o p e l l e r s h a ft s f r o n t U - j o i n t y o k e
at case, a n d tie up o u t o f w a y .
4.
Rem ove
holt
holdin g
the
s h if t
lev er
co n tr o l
a s s e m b l y to the a d a p t e r a s s e m b l y . Push a s s e m b l y to o n e
s id e a n d tie up o u t o f w a y .
5.
S u p p o r t t r a n s f e r ca se in a s u it a b le
R e m o v e bo lts a t t a c h i n g t r a n s f e r c a s e to a d a p t e r .
c r a d le .
the s h i f t e r
9.
R e m o v e the 2 top t ra n s m i s s i o n to clutch h o u s i n g
c a p s cre w s a n d in sert 2 t r a n s m is s i o n g u i d e p ins, T o o l
J-l 126 in these holes.
10.
R e m o v e flyw heel u n d er pan. R e m o v e
l o w e r t ra n s m i s s i o n - t o - c l u t c h h o u s i n g c a p screws.
S lid e
the t ra n s m i s s i o n
and
11.
D i s c o n n e c t f r o n t p r o p s h a f t f r o m t r a n s f e r ca se
a n d tie up a w a y f r o m w o r k area.
the
2
NOTE:
prevent
w ill
support
dam age
to
the
the
transm ission
clutch
dis c
and
through
sp rin ging.
12.
Rem ove
the t r a n s m i s s i o n a n d a d a p t e r as an
a s s e m b l y f r o m u n d e r the b o d y .
R e m o v e a d a p t e r f r o m tra n s m is s io n .
14.
T o install, r e v e rs e r e m o v a l p r o c e d u r e .
13.
atta ch in g
2.
R em ove
com partm ent.
s cre w s
from
transfer
ca se
Rem ove
flo or
mat
or
crossm em ber
bolts
and
t r a n s m is s io n
to
flyw heel
housing
17.
S l i d e t r a n s m i s s io n r e a r w a r d until m a i n d r iv e
g e a r cle a r s the c lu tch a s s e m b l y a n d lo w e r a s s e m b l y f r o m
v e h ic le .
4-Speed Transmission
K Series
P o s itio n
t r a n s m is s io n ,
w it h
transfer
case
at
to the f l y w h e e l h o u s in g . In stall bolts a t t a c h i n g
Install
flyw heel
h ousin g
cover
and
attachin g
in g
P o s it io n f r a m e c r o s s m e m b e r a n d in sta ll r e t a i n
bolts.
Install
bo lts r e t a i n i n g
crossm em ber and
t r a n s f e r ca se
adapter
assem b ly
to f r a m e r a il
to
b ra ck et.
T o r q u e all bolts to sp e c ific a tio n .
carp etin g
from
4.
T o r q u e f r o n t a n d r e a r t r a n s f e r ca se y o k e lock
nuts to sp e cifica tio n s .
atta ch in g
s cre w s
from
t r a n s m is s io n
s h i f t l e v e r b o o t re t a in e r . S l i d e b o o t a n d r e t a i n e r up le v e r
a n d r e m o v e t r a n s m i s s io n s h i f t l e v e r u s in g T o o l J-8109 as
s h o w n in F i g u r e 7 B - 1 7 .
If necessary,
rem ove
center
f lo o r o utlet
from
h e a t e r d i s t r i b u t o r duct. I f e q u i p p e d w ith a c e n t e r c o n so le ,
r e m o v e c o n s o l e b e f o r e p r o c e e d i n g to n ext step.
Rem ove
t r a n s m is s i o n
flo o r
cover
5.
vehicle.
6.
shift
le v e r
link
assem bly
7.
and
support
v e h ic l e
on
hoist.
switch
Support
t r a n s m i s s io n a s s e m b lie s .
speedom eter
cable
from
t ra n s m i s s io n
and
t r a n s f e r ca se
to p r o p e r
Install
t r a n s f e r ca se s h i f t
le v e r a s s e m b l y
and
a t t a c h i n g bolt. C o n n e c t s h i f t le v e r link to s h i f t ra il bar.
9.
bolts.
In stall
transm ission
flo o r c o v e r
and
attachin g
Install h e a t e r d i s t r i b u t o r d uct c e n t e r outlet.
NOTE:
On
m odels
w ith
center
c o n so le ,
install
c o n so le a n d r e t a i n i n g bolts.
11.
Install
f lo o r
m a t,
transfer
ca se
shift
le v e r
r e t a in e r a n d a t t a c h i n g screws.
e n g i n e w it h s u i t a b l e f lo o r s ta n d . D r a i n t r a n s f e r ca se a n d
D isco n n ect
F ill
lev el w i t h l u b r ic a n t s p e c ifie d in S e c t i o n 0-B.
from
t r a n s f e r ca se s h if t ra il c o n n e c t i n g ro d . R e m o v e s h i f t
le v e r a t t a c h i n g bo lt a n d s h i f t l e v e r c o n tr o l f r o m a d a p t e r .
7.
D iscon nect back-up lam p w irin g from
a n d r e m o v e a t t a c h i n g c l a m p f r o m top c o v e r bo lt.
C o n n e c t the s p e e d o m e t e r c a b le , b a c k - u p l a m p
w i r i n g a n d T C S sw itches.
10.
D isconnect
Install f r o n t a n d re a r p r o p s h a f t s to t r a n s f e r case
o u tp u t y o ke s.
8.
a ttachin g
s cre w s a n d c o v e r . R o t a t e c o v e r a p p r o x i m a t e l y 90° to
c l e a r t r a n s f e r ca se s h if t le v e r w h i l e l i f t i n g c o v e r f r o m
9.
to
NOTE:
R e m o v e u p p e r bo lts first a n d install
t r a n s m is s io n g u i d e p in s J-l 126 U s e o f the g u i d e
p in s w ill p r e v e n t d a m a g e to the c lu tch a s s e m b l y .
3.
Rem ove
R aise
fram e
bolts. O n V-8 m o d e ls, in sta ll e x h a u s t c r o s s o v e r p ip e .
s h i f t l e v e r b o o t r e t a i n e r a n d r e m o v e re ta in er .
8.
Rem ove
16.
Rem ove
a t t a c h i n g bolts.
2.
Series
Removal
6.
S u p p o r t t r a n s m is s io n a n d t r a n s f e r c a s e a s s e m
t r a n s m i s s io n to f l y w h e e l h o u s in g .
K
5.
t ra n s m is s i o n
to c l e a r f r a m e rails.
15.
R e m o v e fly w h e e l h o u s i n g c o v e r . O n V -8 e n g i n e
m o d e ls, r e m o v e e x h a u s t c r o s s o v e r p ip e .
1.
4-Speed Transmission
4.
rem ove
rem o ve cro ssm e m b er fro m vehicle. R otate crossm em b er
tached
3.
and
Installation
13.
1.
tabs
b l y w ith s u it a b le f lo o r stand.
adap ter assem bly
T h e use o f the 2 g u i d e pins d u r i n g this
lock
c a s e - t o - f r a m e b r a c k e t a t t a c h i n g bo lts.
s t r a i g h t b a c k o n g u i d e p i n s u n til the c lu tch g e a r is f r e e
o f s p lin e s in the c lu t c h disc.
o p eratio n
Open
m o u n t - t o - f r a m e c r o s s m e m b e r bolts. A l s o r e m o v e t r a n s f e r
14.
8. S u p p o r t r e a r p o r t i o n o f e n g in e . R e m o v e two (2)
a d a p t e r m o u n t bolts.
11 .
D i s c o n n e c t p r o p s h a f t at r e a r o f t r a n s f e r ca se
12.
6.
R e m o v e bolts a t t a c h i n g t r a n s f e r case to f r a m e
b r a c k e t at r i g h t sid e o f c a s e a n d r e m o v e c a s e f r o m
adapter.
7.
D i s c o n n e c t s h i f t c o n t r o l ro d s f r o m
le v e r s at the t r a n s m is s io n .
10.
a n d tie up a w a y f r o m w o r k a re a.
12.
Install t ra n s m i s s i o n s h if t lever.
TRANSMISSION ALIGNMENT
transfer
In s o m e in s t a n c e s w h e r e " e x c e s s i v e " g e a r w h i n e o r
case. D i s c o n n e c t b a c k - u p l a m p s w itch w i r i n g a n d T C S
h i g h g e a r h o p out, p a r t i c u l a r l y at 50 M P H a n d up, are
sw itch .
encountered;
a n d a f t e r all o t h e r p r o b a b l e c a u s e s h a v e
b e e n c h e c k e d , an a l i g n m e n t c h e c k o f the t r a n s m is s io n
a n d clutch h o u s i n g m a y be h e l p f u l .
NOTE:
A s p e c ia l tool, o n w h i c h a d ia l in d i c a t o r is m o u n t e d ,
is n e c e s s a r y to c h e c k the t r a n s m is s io n c a s e r e a r b o re
a l ig n m e n t . T h i s tool m a y b e m a d e f r o m a n ew o r g o o d
used clutch g e a r w h i c h has a g o o d b e a r i n g s u r f a c e o n the
crankshaft
lo catio n .
p ilot
end
and
at
the
front
m ain
bearing
the c lu t c h g e a r s h o u l d b e g r o u n d o f f so the s h a f t m a y be
ro t a t e d in a c lu tch d is c h u b w i t h o u t i n t e r f e r e n c e w h e n
a s s e m b l e d in the ca r. W e l d a p ie c e o f 1 / 4 " ro d in the
m a i n s h a f t p ilo t b o r e l o n g e n o u g h to e x t e n d out the case
clutch
h o u s in g
s h o u ld
then
be
lo ca tio n .
7.
Inspect the e x t e r n a l c l u t c h in g teeth o f the clutch
g e a r a n d s e c o n d s p e e d g e a r . In spect the s e c o n d a n d third
sp e e d clutch i n te r n a l c l u t c h in g teeth. If the teeth are
worn
T h e s p lin e s o n the c lu tch g e a r s h a f t a n d the tee th o n
The
s t a m p e d , s h o w i n g the p o s i t io n w h e r e s h im s a re to
be in sta lled a n d the t h ick n e ss o f s h i m s at each
or
t a p e re d ,
even
slightly ,
the
gears
sh o u ld
be
re p l a c e d . R e a s s e m b l e the tra n s m is s io n .
8.
Install the t ra n s m is s io n a s s e m b l y to the clutch
h o u s in g , u s in g the c o rr e c t n u m b e r o f s h im s at the p r o p e r
lo c a t io n s as p r e v i o u s l y d e t e r m in e d . S h i m s a re a v a i l a b l e
re a r b o re . A s s e m b l e a g o o d b e a r i n g on the clutch g e a r
b y un it p a r t n u m b e r w ith e a c h u n it c o n s is t in g o f the
f o l l o w i n g s him s:
s h a f t a n d s ecu re it w i t h the clutch g e a r b e a r i n g s n a p
4 — .002" s h im s I d e n tif ic a t io n —tw o c o r n e r s cut off.
rin g . A t t a c h a s u i t a b l e d ia l i n d i c a t o r to the rod.
2 — .0 05" s h i m s Id e n ti f i c a t i o n —o n e c o r n e r cut off.
1— .0 1 0 " s h im s I d e n tif ic a t io n —all c o r n e r s s q u a re .
1.
R e m o v e the t ra n s m is s i o n f r o m the v e h i c l e a n d
c o m p l e t e l y d is a s s e m b l e , e x c e p t f o r the r e v e rs e id le r g e a r .
N O T E : In a n y ca se w h e r e the clutch g e a r p ilo t o r
p ilo t b e a r i n g is e x c e s s iv e l y lo o se o r w o r n , the p ilo t
b e a r i n g s h o u ld b e r e p l a c e d b e f o r e c h e c k i n g the
t r a n s m is s i o n c a s e r e a r b o r e a l ig n m e n t b y the d ia l
i n d i c a t o r m e th o d .
2. C a r e f u l l y install the s p e c ia l tool w ith the dial
i n d i c a t o r in the t r a n s m i s s io n ca se w ith the f a c e o f the
i n d i c a t o r to the r e a r o f the ca se a n d w it h the t r a c i n g
f in g e r c o n t a c t i n g the l . D . o f the c a s e re a r b o re . S e c u r e in
p l a c e w i t h a c lu tch g e a r b e a r i n g re ta in e r .
3.
A ssem ble
the
h o u s i n g a n d t ig h t e n
bolts s ecu re ly.
t r a n s m is s i o n
the
fo u r
case
to
t ra n s m i s s i o n
the
clutch
N O T E : T h e s e s p ecia l sh im s h a v e a t a b o n o n e end
f o r e a s e o f in st a lla t io n . D o n ot slot the s h im s f o r
the p e r m a n e n t in sta llatio n .
REAR OIL SEAL REPLACEMENT
1.
2.
D r a i n l u b r i c a n t f r o m tra n s m is s io n .
D i s c o n n e c t p r o p e l l e r s h a f t f r o m t r a n s m i s s io n as
d e s c r i b e d in S e c t io n 4 A .
3.
O n 3 -s p e e d tra n s m is s io n s , p e r f o r m the f o l lo w i n g
r e p l a c e m e n t p r o c e d u re s :
a.
Rem ove
slip
t r a n s m is s io n m a i n s h a f t .
b.
m ou n ting
jo in t
yoke
fro m
rear
of
P r y seal o u t o f e x t e n s io n h o u s in g o r r e m o v e
oil seal us in g oil sea l r e m o v e r (J-5859) a n d s lid e h a m m e r
(J-2 6 I9 ) as s h o w n in F i g u r e 7B -18.
N O T E : Be sure to c l e a n o f f a n y p a in t o r o t h e r
f o r e i g n m a t e r i a l on the m a t i n g f a c e s o f the clutch
sealing
h o u s in g a n d t r a n s m i s s io n as a n y f o r e i g n m a te r ia l
h o u s i n g oil sea l i n st a lle r (J-5 154).
o n these f a c e s w ill c h a n g e a l ig n m e n t ; also, c h e ck
c a r e f u l l y f o r d i n g s o r b u r r s on these m a t i n g
s u r f a c e s a n d r e m o v e c a r e f u l l y as nece ssa ry .
4.
D i a l i n d i c a t e the t r a n s m i s s io n c a s e r e a r b o re
a n d r e c o r d the in d i c a t o r r e a d i n g s in the 12, 3, 6 a n d 9
o ’c l o c k p o sitio n s.
c.
d.
Install slip j o i n t y o k e o n re a r o f t ra n s m is s io n
m a in s h a f t .
4.
O n M u n c i e 4 -s p e e d t ra n s m is s io n s , p e r f o r m the
fo l lo w i n g :
a.
R e m o v e p a r k i n g b r a k e f r o m re a r o f t r a n s m is
sion as d e s c r i b e d in S e c t i o n 5.
b.
D iscon nect
speedom eter
N O T E : It is b e st to s tar t the r e a d i n g at the 3, 6, 9
s p e e d o m e t e r d r iv e n g e a r f r o m
o r 12 o ’c l o c k p o s it io n clo s es t to the p o in t w h e r e the
ca p.
i n d i c a t o r p l u n g e r r e a c h e s its m a x i m u m o u t w a r d
tra v e l. S e t the d ia l i n d i c a t o r at " 0 " at this lo c a t io n
a n d th e n re co rd the 3, 6, 9 a n d 12 o ’c lo ck r e a d in g s
in ro t a tio n .
5.
In stall t e m p o r a r y slo tted s h im s b e tw e e n
t r a n s m i s s i o n ca se a n d the c lu t c h h o u s i n g in
the
the
q u a n t i t i e s a n d at the b o lt l o c a t io n s as n e c e s s a r y to b r i n g
m i s a l i g n m e n t at the t r a n s m i s s i o n ca se r e a r b o re
to a
m i x i m u m o f .00 5" in d i c a t o r r e a d i n g in e i t h e r the v e r t i c a l
o r h o r i z o n t a l d ir e c t io n .
E X A M P L E : I f the m a x i m u m i n d i c a t o r r e a d i n g is at
t h e 12 o ’c l o c k p o s it io n , p u t s h i m s on the two b o t to m
bo lts.
6.
been
C o a t o u t e r d i a m e t e r o f n ew o il seal w ith
c e m e n t . Install n ew oil seal u s in g e x te n s io n
A fter
the
d eterm in ed
m a y be r e m o v e d .
p o sit io n
and
and
recorded
quanity
the
of
s h im s
t r a n s m is s io n
has
case
c.
cable
and
rem ove
m a in sh a ft rear bearing
U s i n g f l a n g e or y o k e h o l d i n g tool, r e m o v e the
o u t p u t y o k e o r c o m p a n i o n f l a n g e nut. Pull o u t p u t y o k e o r
in to h o u s i n g un til lock p la t e ca n be in se rte d in g r o o v e
c o m p a n i o n f l a n g e nut o f f the m a i n s h a f t .
a n d a tt a c h e d to h o u s in g .
d.
Rem ove
m ainshaft
rear
b earin g
cap
and
rear
b earing
cap.
n ew
oil
w ith
g a s k e t. D i s c a r d g a s k e t.
e.
Rem ove
o il
seal
fro m
TRANSMISSION SIDE COVER
Replacement/Repair (Fig. 7B-20)
D i s c a r d oil seal.
f.
Coat
outer
d iam eter
of
seal
s e a l i n g c e m e n t . Install oil sea l in re a r b e a r i n g c u p u s in g
a s u it a b l e in sta ller . D r i v e sea l flush w ith o u t s id e o f re a r
bearin g
ca p .
bein g
carefu l
n ot
to
dam age
seal.
Use
In s t a lle r J-22834 w i t h A d a p t e r J -228 34-l as r e q u i r e d , as
s h o w n in F ig . 7 B - 1 9 .
T i g h t e n c a p s cre w s firm ly.
h.
In stall o u t p u t y o k e o r c o m p a n i o n f l a n g e o r
m a i n s h a f t . U s i n g a f l a n g e o r y o k e h o k d i n g tool install
r e t a i n i n g nut. T o r q u e the r e t a i n i n g n ut to s p ecifica tio n .
In stall s p e e d o m e t e r d r i v e n g e a r , then c o n n e c t
Reconnect
c o n tr o l
ro ds
from
levers,
back-up
2.
S h i f t t ra n s m i s s i o n in to n eu tr a l d e te n t p o s it io n s
R e m o v e the o u t e r s h i f t e r levers.
4.
R e m o ve both shift forks from sh ifter sh aft
a ss e m b lie s . R e m o v e b o t h s h if t e r s h a f t a s s e m b l ie s f r o m
co v e r. S e a ls a r o u n d s h i f t e r s h a ft m a y n o w be p r i e d o u t i f
r e p l a c e m e n t is r e q u i r e d b e c a u s e o f d a m a g e .
5.
R e m o v e d e t e n t c a m s p r i n g a n d p iv o t r e t a in e r
" C " rin g . R e m o v e bo th d e te n t c a m s .
6.
W i t h d e te n t s p r i n g t a n g p r o j e c t i n g up o v e r the
2 nd a n d 3rd s h i f t e r s h a f t c o v e r o p e n i n g , install the first
s p e e d o m e t e r c a b le .
5.
D isconnect
b e fo re re m o v in g cover. R e m o ve co ver a ssem bly fro m
t r a n s m is s io n c a s e c a r e f u l l y a n d a llo w oil to d r a in .
3.
g.
C l e a n all g a s k e t s u r fa c e s , then install the re a r
b e a r i n g c a p w i t h a new g a s k e t on the tra n s m is s io n .
i.
1.
la m p w i r i n g a n d T C S switch.
p rop eller
sh aft
to
t r a n s m is s io n
as
d e s c r i b e d in S e c t i o n 4 A .
a n d reve rse d e te n t c a m o n t o the d e te n t c a m p iv o t pin.
W i t h the d e te n t s p r i n g t a n g p r o j e c t i n g u p o v e r the first
a n d r e v e rs e s h i f t e r s h a f t c o v e r h o le install the 2 nd a n d
6.
Refill t r a n s m is s i o n w i t h l u b r ic a n t r e c o m m e n d e d
in S e c t i o n 0-B.
3rd d e t e n t c a m .
7.
Install d e te n t c a m r e t a i n i n g " C "
r i n g to p iv o t
s h a ft , a n d h o o k s p r i n g in to d e te n t c a m n otch es.
SPEEDOMETER DRIVEN GEAR
REPLACEMENT
8.
Install bo th s h i f t e r s h a f t a s s e m b l ie s in c o v e r
b e i n g c a r e f u l not to d a m a g e seals. Install bo th s h i f t f o rk s
to s h i f t e r s h a f t a s s e m b lie s , l if t i n g up on d e te n t c a m to
D i s c o n n e c t s p e e d o m e t e r c a b l e , r e m o v e lock p la t e to
ho usin g
b o lt a n d
lock w a s h e r a n d r e m o v e
lock p late.
Insert scre w d r i v e r in lock p l a t e slot in fitting a n d p r y
fitting, g e a r a n d s h a f t f r o m h o u s i n g . P r y " O " r i n g f r o m
a llo w f o r k s to f u l l y s e a t in to p o sitio n .
9.
Install
outer
shifter
levers,
flat w a s h e r s ,
lock
w a s h e r s a n d bolts.
10.
S h i f t s h i f t e r lev ers in to n e u t r a l d e te n t (center)
g r o o v e in fitting.
p o s it io n a n d slide c o v e r in to p la c e m a k i n g sure the s h if t
In stall n e w " O " r i n g in g r o o v e in fitting, co a t " O "
r i n g a n d d r i v e n g e a r s h a f t w it h t r a n s m is s io n l u b r i c a n t
f o r k s a re a l ig n e d w i t h th e ir re s p e c t iv e m a i n s h a f t clutch
s lid in g sleeves.
a n d i n s e r t s h a ft .
H o l d the a s s e m b l y so slot in fitting is t o w a r d lock
p l a t e b o ss o n h o u s i n g a n d install in h o u s in g . Pu sh fitting
D ET EN T C A M
DETENT SPRING
DETENT CAM
J -2 2 8 3 4 -2
J -2 2 8 3 4 -l
NOTE
2-3 SHIFT
FORK
P A R K IN G
BR A KE M O U N T I N G
FLANGE
J -2 2 8 3 4 -2
O N LY
1ST & REV.
SHIFTER SHAFT
SHIFT FORK
2-3 SHIFTER SHAFT
DETENT CAM
RETAINER RING
11 .
In stall c o v e r a t t a c h i n g bo lts a n d t i g h t e n e v e n l y
to s p e c if ie d
w iring.
12.
to rq u e .
In stall
TCS
sw itch
and
connect
6.
D is c o n n e c t s h i f t le v e r rod f r o m s h i f t ra il link.
O n full tim e 4 w h e e l d r iv e m o d e ls, d is c o n n e c t s h if t levers
at t r a n s f e r ca se.
R e m o v e filler p l u g a n d a d d l u b r i c a n t s p ecified
7.
S u p p o r t t r a n s f e r ca se a n d r e m o v e bolts a t t a c h
in S e c t i o n 0 -B to lev el o f filler p l u g hole.
i n g t r a n s f e r c a s e to t r a n s m i s s io n a d a p t e r .
8.
M o v e t r a n s f e r ca se to r e a r un til
TRANSMISSION FLOOR SHIFT CONTROL
LEVER REPLACEMENT
c le a r s a d a p t e r a n d l o w e r a s s e m b l y f r o m v e h ic l e .
1.
O n K - S e r i e s m o d e l s r e m o v e t r a n s f e r ca se s h if t
input
Installation
1.
Support
transfer
case
in
s u it a b le
stan d
le v e r b o o t r e t a i n e r a t t a c h i n g s cre w s a n d r e t a in e r f r o m
p o s it io n
c o m p a r t m e n t floor.
a t t a c h i n g c a s e to a d a p t e r a n d to r q u e to 45 ft. lbs.
2.
R e m o v e f l o o r c o v e r i n g f r o m v e h ic le .
3.
R e m o v e t r a n s m i s s i o n s h i f t lev er b o o t r e t a in e r
a t t a c h i n g screws.
4. S l i d e b o o t a n d r e t a i n e r u p on s h i f t le v e r a n d
r e m o v e the t r a n s m is s i o n s h i f t le v e r u s in g T o o l J-8109 as
s h o w n in F i g u r e 7 B - 1 7 .
5.
T o in stall, r e v e rs e r e m o v a l p r o c e d u r e S tep s 1-4.
TRANSFER CASE REPLACEMENT
and
2.
D iscon nect
a n d T C S switch.
support
veh icle
speedom eter
on
ca b le ,
hoist.
D rain
back-up
lam p
3.
R e m o v e s k id p l a t e a n d c r o s s m e m b e r s u p p o r ts as
necessary.
4.
D isco n n ect rear p ro p sh a ft from
t r a n s f e r case
a n d tie up a w a y f r o m w o r k a re a.
5.
D i s c o n n e c t f r o n t p r o p s h a f t f r o m t r a n s f e r case
a n d tie up s h a f t a w a y f r o m w o r k a re a.
ca se
to
transm ission
adapter.
In stall
and
bolts
2.
R e m o v e s ta n d as r e q u i r e d a n d in sta ll bolts
a t t a c h i n g t r a n s f e r ca se to f r a m e rail. B e n d lock tabs
a f t e r a ss e m b ly .
3.
Install
con necting
ro d
to
s h if t
ra il
link
or
c o n n e c t s h if t lev ers to t r a n s f e r ca se, as a p p l i c a b le .
4.
C o n n e c t f r o n t p r o p s h a f t to t r a n s f e r case fro n t
o u t p u t s h a ft.
5.
C o n n e c t r e a r p r o p s h a ft to t r a n s f e r case re a r
o u t p u t s h a ft.
6.
Install c r o s s m e m b e r s u p p o r t a n d skid p la te, i f
Removal (Fig. 7B-21)
1.
Raise
t r a n s f e r case.
s h a ft
re m o v e d .
7.
C o n n e c t s p e e d o m e t e r c a b le , b a c k - u p l a m p a n d
T C S switch .
8.
Fill t r a n s f e r case to p r o p e r level w i t h lu b r ic a n t
s p ecified in section 0-B.
9.
L o w e r a n d r e m o v e v e h ic l e f r o m hoist.
CAUTION: Check ami tighten all bolts to
specified torques.
N O T E : B e f o r e c o n n e c t i n g p r o p s h a ft s to c o m p a n
io n f l a n g e s be sure lo ckn u ts a re t o rq u e d to
s p ecifica tio n s.
VIEW
B
WITH "AUTOMATIC
TRANSMISSION
VIEW
WITH "MANUAL"
TRANSMISSION
A
SPECIFICATIONS
THREE SPEED SAGINAW (76mm)
THREE SPEED TREMEC (77mm)
Clutch Gear Retainer to Case B o l t s ..................
Side C over to Case B o l t s .......................................
Extension to Case B o l t s ..........................................
Shift Lever to Shifter Shaft B o l t s .....................
Lubrica tion Filler P l u g ..........................................
Transmission Case to C lu tch Housing Bolts .
15 ft. lbs.
15 ft. lbs.
45 ft. lbs.
25 ft. lbs.
13 ft. lbs.
75 ft. lbs.
Crossmember to Frame N u t s ..............................
Crossm ember to Mount Bolts ...........................
25
40
18
20
2-3 Cross Over Shaft Bracket Retaining Nut .
1-Rev. Swivel Attaching B o l t ..............................
M ount to Transmission B o l t ..............................
ft.
ft.
ft.
ft.
50 ft.
lbs.
lbs.
lbs.
lbs.
lbs.
Clutch Gear Retainer to Case B o l t s ..................
T op Cover to Case Bolts ......................................
Extension to Case B o l t s .........................................
Shift Lever to Shifter Shaft Bolts ....................
Lubrication f’ iller Plug .........................................
Transmission Case to Clutch Housing Bolts . .
Crossmember to Frame N u t s ...............................
Crossmember to Mount Bolts ............................
2-3 Cross Over Shaft Bracket Retaining Nut .
1- Rev. Swivel A ttaching Bolt ............................
Mount to Transmission Bolt ...............................
35 ft. lbs.
30 ft. lbs.
45 ft. lbs.
25 ft. lbs.
15 ft lbs.
75 ft lbs.
25 ft. lbs.
40 ft. lbs.
18 ft lbs.
20 ft lbs.
50 ft lbs.
THREE SPEED MUNCIE (83mm)
Clutch Gear Retainer to Case B o l t s ..................
Side C o v er to Case Bolts
....................................
Extension to Case B o l t s .......................................
Shaft Lever to Shifter Shaft B o l t s ..................
Lubrication Filler P lu g s ..........................................
15
15
45
25
13
ft.
ft.
ft
ft.
ft.
lbs.
lbs.
lbs.
lbs.
lbs.
Transmission Case to C lu tch Housing Bolts . .
Crossm ember to Frame N u t s ..............................
Crossm ember to Mount Bolts..............................
Transmission Drain P l u g .......................................
2-3 Cross Over Shaft Bracket Retaining Nut.
75
25
40
30
18
ft.
ft.
ft.
ft.
ft.
lbs.
lbs.
lbs.
lbs.
lbs.
1-Rev. Swivel Attaching B o l t ..............................
M ount to Transmission Bolt ..............................
20 ft. lbs.
50 ft. lbs.
FOUR-SPEED (MUNCIE CH465) 117mm
Clutch Gear Bearing Retainer to Case Bolts ......................................................................................................................................25 ft. lbs.
Cover to Case B o l t s .................................................................................................................................................................................. ...20 ft. lbs.
E xtension and Retain er to Case B o l t s - ( U p p e r ) ................................................................................................................................20 ft. lbs.
—( L o w e r ) ................................................................................................................................ 30 ft. lbs.
L ubrication Filler P l u g ............................................................................................................................................................................ ...30 ft. lbs.
Shift Lever to Shifter Shaft N u t .......................................................................................................................................................... ...20 ft. lbs.
Mount-To-Transmission Bolts
............................................................................................................................................................. ...32 ft. lbs.
SPECIAL TOOLS
7
1.
J
T r a n s m i s s i o n G u i d e Pi ns
6. J - 2 2 2 8
R e a r B e a r i n g Press Plat es
2.
J 8059
1126
R e t a i n e r S n a p R i n g Pl ie rs
7. J 5 5 9 0
C lu t c h Gear B e a rin g In sta lle r
3.
J 22246
C ou n te rg ea r L o a d in g T o o l
8. J 9 7 7 2
C lu t c h Gear B e a rin g In sta lle r
4.
J 5778
E x te n s io n B u sh in g R em o v e r and
9. J 2 3 0 9 6
C l u t c h G e a r R e t a i n e r Seal I n s t a l l e r
5.
J-5154
E x t e n s i o n Seal I n s t a l l e r
In s ta lle r
3
Q
)
lO
11 A
C ountergear Rear Bearing Remover
8
2 J-8433-1
1
J-22832
Bearing Puller
9. J 22874-5
3. J-22872
C lutch Gear B earing Remover and In sta lle r
10
J 22874 2
C ou n te rsh aft S upport Tool
4. J 22833
Front Bearing R etainer Seal In sta lle r
11
J 22834 2
Rear B earing R etain e r Seal In s ta lle r
5. J-22873
2nd Speed Bushing In sta lle r
1 la
6. J-22875
3rd Speed Bushing In sta lle r
12
7. J-22830
Snap Ring Insta lle r
J 22874 1
Bearing In sta lle r
M a in s h a ft S upport Tool
J 22834 1 A dapter
J 23070
M a in s h a ft Rear B earing Lock N u t In s ta lle r
fit
@
10
1.
2.
3.
4.
J —2 3 4 3 2 —1
J-23432
J-8092
J-23429
S n a p Ri ng Pi ck s
S n ap Ri ng Pliers
H a ndle
In te r m e d ia te Sh aft
5.
6.
J-22836
J-21359
F r o n t O u t p u t S h a f t B e a r i n g R e t a i n e r S e al I n s t a l l e r
Rear O u t p u t S h a f t B e a r i n g R e t a i n e r S e al I n s t a l l e r
Re m o v e r a n d
In sta lle r
9.
10.
1. J 22836 - Front Output Shaft Bearing Retainer Seal
Installer
J 22388 - Rear Output Shaft Seal Installer
J-21359 - Input gear Bearing Retainer Seal Installer
J 24745 - Cluster Gear Loading Tool
J-8614-1 - Compan on Flange Remover
2.
3.
4.
5.
J —234 31
Rear O u t p u t
J-7137
Remover and In s ta lle r
A d a p te r Seal In sta lle r
Shaft
J-9276-2
Inte rm e d ia te G e a r
J —2 2 8 7 5
Rear O u t p u t
H o u s in g
Bearing
Bearing
Cup
In s ta lle r
S h a f t Rear B e a r i n g
In sta ile r
r
SECTION 7C
CLUTCH
INDEX
G e n e r a l D e s c r i p t i o n ................................................................. 7 C - 1
C l u t c h S y s t e m s ....................................................................... 7 C - I
D iap h ragm
T y p e .............................................................. 7 C - I
C o m p o n e n t Parts R e p l a c e m e n t ......................................... 7 C - 1 2
P r e l i m i n a r y I n s p e c t i o n ...................................................... 7 C - 1 2
C lu tc h D is c a n d Pressure P l a t e .................................. 7 C - 1 2
D i a p h r a g m T y p e ............................................................. 7 C - 1 2
C o i l S p r i n g T y p e ............................................................ 7 C - 2
C l u t c h C o n t r o l s ...................................................................... 7 C - 4
M a i n t e n a n c e a n d A d j u s t m e n t s ......................................... 7 C - 9
I n s p e c t i o n .................................................................................. 7 C - 9
F r e e P e d a l A d j u s t m e n t ..................................................... 7 C - 9
C o i l S p r i n g T y p e ............................................................
P e d a l .............................................................................................
C r o s s - S h a f t ...............................................................................
S p e c ia l T o o l s ................................................................................
7C -I3
7C -13
7C -14
7C -16
D i a g n o s i s ........................................................................................ 7 C - 1 1
GENERAL DESCRIPTION
produces
CLUTCH SYSTEMS
heat. T h e m o s t c o m m o n l y
used
l a d i n g s a re
DIAPHRAGM SPRING CLUTCH
m a d e o f co tto n a n d asb e s to s fibers w o v e n o r m o ld e d
to g e th e r a n d i m p r e g n a t e d w i t h re sin or s i m i l a r b i n d i n g
Principal Components
a gen ts . V e r y o f te n , c o p p e r w ir e s a re w o v e n , o r p ressed
in to m a t e r i a l to g i v e it a d d i t i o n a l strength .
In o r d e r to m a k e clutch e n g a g e m e n t as s m o o th as
T h e p rin c ip a l p arts o f a d i a p h r a g m - t y p e clutch
system are: the d r i v i n g m e m b e r s , a tta c h e d to the e n g in e
p o ss ib le a n d e l i m in a t e c h a tter, the steel s e g m e n ts
a tt a c h e d to the s p lin e d h u b are s lig h t ly w a v e d , w h ic h
causes
the
c o n ta c t
p re ss u re
on
the
facin gs
to
rise
a n d t u r n in g w i t h it; the d r i v e n m e m b e r s a tta c h e d to the
t ra n s m is s io n a n d t u r n in g w i t h it; the o p e r a t i n g m e m b e r s
g r a d u a l l y as the w a v e d s p rin g s flatten out.
w h ic h
a b s o r b the t o r s io n a l v i b r a t i o n o f the c r a n k s h a f t w h i c h
w o u l d be t ra n s m itte d to the p o w e r train unless it w e r e
in c lu d e
the
spring
o r s p r in g s
and
the
li n k a g e
r e q u ir e d to a p p l y a n d re lea se the p re ssu re w h i c h holds
the d r i v i n g a n d d r i v e n m e m b e r s in c o n ta c t w i t h e ac h
o ther. F i g u r e 7 C - 1 sho w s a clutch c u t a w a y so o p e r a t i n g
m e m b e r s c a n be seen.
T h e c lutch disc is p r o v i d e d w i t h a fle x ib le c e n t e r to
e li m in a t e d . T h e fle x ib le c e n t e r ta k e s the f o r m o f steel
c o m p r e s s i o n s p r in g s p la c e d b e tw e e n the h u b a n d the
stee l p la t e . T h e s p r in g s p e r m i t the disc to ro ta te s lig h tly
w i t h r e l a t i o n to its h u b until the sp rin g s a re c o m p r e s s e d
Driving Members
and
r e la t iv e
m o t io n
stops.
Then
the
d isc c a n
rotate
T h e d r i v i n g m e m b e r s o f a c lutch usu a lly consist o f
s l ig h t ly b a c k w a r d as the s p rin g s d e c o m p r e s s . T h i s sligh t
tw o n o d u l a r iro n p lates o r flat s u r fa c e s m a c h i n e d to a
b a c k w a r d a n d f o r w a r d r o t a tio n p e r m it te d b y the sp rin g s
a llo w s the c lu tc h s h a f t to r o ta te at a m o r e u n i f o r m rate
sm ooth
f in is h .
N o d u lar
c o n ta i n s e n o u g h
when
the d r i v i n g
grap hite
iron
is
desirable
because
it
to p r o v i d e s o m e l u b r ic a t io n
m e m b e r is s l i p p i n g d u r i n g e n g a g e
t h a n th e c r a n k s h a f t ,
t h e r e b y e l i m i n a t i n g s o m e o f the
t o r s io n a l v i b r a t i o n f r o m the c r a n k s h a f t a n d p r e v e n t i n g
m ent. O n e o f th ese s u r fa c e s is u s u a lly the re a r f a c e o f
the
the e n g i n e fly w h e el, a n d the o t h e r is a c o m p a r a t i v e l y
h e a v y flat r i n g w ith o n e s id e m a c h i n e d . T h is p a r t is
tra n s m is s io n .
vibration
from
b e in g
carried
back
through
the
k n o w n as the p re ss u re p late. It is fitted in to a steel co ve r,
Operating Members
w h i c h a lso c o n ta in s s o m e o f the o p e r a t i n g m e m b e r s , a n d
is b o lted to the fly w h e e l.
T h e d r i v i n g a n d d r iv e n m e m b e r s are held in c o n ta c t
b y s p r i n g p ressu re. T h i s p re ssu re m a y be e x e r t e d b y a
o n e - p i e c e c o n ic a l or d i a p h r a g m s p rin g. In the d i a p h r a g m
d e s i g n clutch, the th r o w o u t b e a r i n g m o v e s f o r w a r d
Driven Members
T h e d r i v e n m e m b e r is the c lutch disc w ith a s p lin e d
a g a i n s t the s p r i n g fingers f o r c i n g the d i a p h r a g m s p r in g
h u b w h i c h is f r e e to s lid e l e n g t h w is e a l o n g the sp lin es o f
the c lutch s h a ft , but w h i c h d r iv e s the s h a f t t h r o u g h these
to p i v o t a r o u n d the p i v o t rin g , d i s h i n g the fingers t o w a rd
s a m e sp lin e s. G r o o v e s o n b o th sid es o f the c lutch disc
lifts
l i n i n g p r e v e n t s t ic k in g o f the p la te to the fly w h e e l a n d
th r o u g h a series o f r e t r a c t i n g s p rin g s p la c e d a r o u n d the
p re ss u re p late. S u i t a b l e f r i c t i o n a l f a c i n g s a re a tta c h e d to
o u te r c i r c u m f e r e n c e o f the p re ssu re plate.
the fly w h e e l. T h e o u te r c i r c u m f e r e n c e o f the s p r i n g n o w
th e
p re ss u re
p la t e
away
from
the
d r iv e n
disc,
e a c h s id e o f the c lu tc h disc b y m e a n s o f brass rivets.
NOTE:
T hese
d e s ig n a re the flat fin g er ty pe and the b e n t fing er
facin gs
m ust
be
heat
re sistan t
since
fr ic t io n
T w o v a r ia t i o n s o f the d i a p h r a g m
s p rin g
D R IV E N
PLA TE A S S Y .
P R E S S U R E PLA TE
AND
C LUTCH
COVER
ASSY.
H O U S IN G
COVER
THROW OUT
CLUTCH
BRG.
FO RK
CLUTCH
H O U S IN G
CLUTCH
FO RK
BALL S T U D
Fig. 7C-1 Clutch System Components
ty p e ( F i g . 7 C - 2 ) . T h e in t e g r a l re le a s e fin g er s in the
be n t
f in g e r
centrifugal
d e s ig n
b oost
are
bent
to aid
q u ic k
back
to
gain
a
re-engagem ent
at
Clutch Spring Operation
In d i a p h r a g m
spring
type
clu tch es,
a d iap h ragm
s p r i n g is used i n s t e a d o f coil s p rin g s . It is a c o n i c a l p ie c e
h ig h e n g in e sp eeds.
o f s p r in g steel p u n c h e d to g i v e it g r e a t e r f le x ib ility . T h e
T h e t h r o w - o u t (clu tch re lea s e) h e a r i n g is a ballthrust b e a r i n g c o n t a i n e d in the clutch h o u s in g , m o u n t e d
d i a p h r a g m is p o s it io n e d b e tw e e n the c o v e r a n d the
pre ssu re p l a t e so that the d i a p h r a g m s p r i n g is n e a r l y flat
w h e n the clutch is in the e n g a g e d p o sitio n . T h e a c tio n o f
o n a slee ve a t t a c h e d to the f r o n t o f the t r a n s m is s i o n ca se.
T h e t h r o w -o u t b e a r i n g i s m o v e d b y the c lu tch f o r k to
c o n ta c t the re le a s e lev ers a n d m o v e the p re ss u re p late to
this ty p e o f s p r i n g is s i m i l a r to th a t o f the b o t t o m o f an
o r d i n a r y o il can. T h e p re ssu re o f the o u t e r rim o f the
the rea r, thus s e p a r a t i n g the cllu tch d r i v i n g m e m b e r s
is p as s ed . T h e o u t e r rim o f the d i a p h r a g m is s ecu re d to
fro m
is
the p re ss u re p la t e a n d is p i v o t e d o n r i n g s a p p r o x i m a t e l y
d e p r e s s e d b y the d r i v e r . A e re tu rn s p r i n g p r e l o a d s clutch
l in k a g e , r e m o v i n g lo o se n e s s due to w e a r , k e e p i n g
the
the p re ssu re at the i n n e r section w ill ca u se the o u t e r rim
the
driven
m em ber
when
the
clutch
pedal
s p r in g o n the p re ss u re p late d e c r e a s e s as the flat p o s it io n
1 in ch in f r o m the o u t e r e d g e so that the a p p l i c a t i o n o f
b e a r i n g c l e a r o f the s p r in g fingers. T h e c lu tch f r e e p e d a l
to m o v e a w a y f r o m the fly w h e e l a n d d r a w the p re ss u re
tra v e l, t h e r e f o r e , w i l l in c r e a s e w i t h
and
p l a t e aw'ay f r o m the c lu tch disc, r e l e a s i n g o r d i s e n g a g i n g
d e c r e a s e w it h d r i v e n d isc w e a r . T h e fre e tra ve l felt at the
the clutch. W h e n the p re ss u re is r e l e a s e d f r o m the in n e r
c l u t c h p e d a l is t h r o w o u t b e a r i n g lash.
section , the o il- c a n a c tio n o f the d i a p h r a g m ca u s es the
linkage w e a r
i n n e r s ectio n to m o v e out, a n d the m o v e m e n t o f the
o u t e r r im f o r c e s the p re ss u re p l a t e a g a in s t the clutch
disc, thus e n g a g i n g the clutch.
N O T E : T h e c lu t c h r e le a s e b e a r i n g used w i t h the
b e n t fin g er d e s i g n
is o f s h o r t e r le n g t h
t h a n the
re le a s e b e a r i n g u s e d w i t h the flat f in g e r d e s i g n
clutch. D o n o t in t e r c h a n g e the two b e a r in g s . T h e
lo n g e r b e a r i n g , i f used w it h the b e n t f in g e r s p r i n g
clutch, w ill ca u s e i n a b i l i t y to o b t a i n p r o p e r
freep ed al
w e a r.
t r a v e l r e s u lt in g
in
slippage
and
r a p id
COIL SPRING CLUTCH
T h e co il s p r i n g s in g le p late c lu tch ( F i g . 7 C - 4 ) is a
d r y disc t y p e a n d n o a d j u s tm e n t f o r w e a r is p r o v i d e d in
the clutch itself. A n i n d i v i d u a l a d j u s t m e n t is p r o v i d e d
f o r lo c a t i n g e a c h le v e r in m a n u f a c t u r i n g b u t the
a d j u s t i n g n ut is lo c k e d
in p la c e
a n d s h o u ld n e v e r be
FLAT FINGER
BENT
1. Flywheel
2. Dowel-hole
3. Pilot Bushing
4. Driven Disc
F IN G E R
5. Pressure Plate
6. Diaphragm Spring
7. Cover
8. Throwout Bearing
9.
10.
Fork
Retracting Spring
FRICTION
RING
DRIVE
WASHER
FACINGS
FLANGE
STOP PIN
TORSIONAL
COIL SPRINGS
CUSHION SPRINGS
Fig. 7C-3--Clutch Disc
d is t u r b e d , un less the c lu tch a s s e m b l y is d i s m a n t l e d f o r
r e p l a c e m e n t o f parts.
W h e n the clutch p e d a l is d e p r e s s e d the t h r o w -o u t
b e a r i n g is m o v e d t o w a r d the fly w h e e l a n d co n ta c t s the
i n n e r e n d s o f the re lea s e levers, (item 1 in F ig . 7 C - 5 ) .
E a c h re le a s e le v e r is p i v o t e d o n a f l o a t i n g p in w h i c h
r e m a i n s s t a t i o n a r y in the le v e r a n d rolls a cro ss a short
flat p o r t i o n o f the e n l a r g e d h o le in the e y e b o l t (item 2).
T h e o u t e r e n d o f e a c h r e l e a s e l e v e r e n g a g e s the p re ss u re
p l a t e lu g b y m e a n s o f a strut (3), w h i c h p r o v i d e s k n i f e e d g e c o n t a c t b e t w e e n the o u t e r e n d o f the le v e r a n d the
lug. T h e o u t e r e n d s o f the e y e b o l t s e x t e n d t h r o u g h holes
in the s t a m p e d c o v e r (4), a n d a re fitted w it h a d j u s t i n g
n uts (5) to c o r r e c t l y p o sit io n the lev ers.
1.
2.
3.
4.
5.
6.
W h e n the c lu t c h s y ste m is f u l l y e n g a g e d , the clutch
d is c is
fir m ly c l a m p e d
b etw een
the
flyw heel
and
the
p r e s s u r e p l a t e b y the p re ss u re o f the s p r in g s . W h e n the
d r i v e r d i s e n g a g e s the clutch b y d e p r e s s i n g the p e d a l , the
7.
8.
9.
10.
11.
Release Lever
Eyebolt
Strut
Cover
Adjustment Nut
Coil Spring
Drive Disc
Pressure Plate
Anti-Rattle Spring
Throwout Bearing
Flywheel
r e l e a s e f o r k is m o v e d o n its p i v o t , a n d the p re ss u re is
a p p l i e d to the t h r o w - o u t b e a r i n g . T h e r o t a t i n g ra c e o f
the t h r o w - o u t b e a r i n g p re sse s a g a i n s t the clutch re lea s e
le v e r s a n d
m o v e s t h e m o n their p i v o t p in s . T h e o u t e r
e n d s o f the re le a s e levers, b e i n g f a s t e n e d to the co v e r,
m o v e the p re ss u re p la t e to the rear, c o m p r e s s i n g the
c lu t c h s p r i n g s a n d a l l o w i n g d r i v i n g m e m b e r s to ro ta te
i n d e p e n d e n t l y o f the d r i v e n m e m b e r . T h e re le a s e fo rk
m o v e s o n l y o n its p iv o t , w h i c h co n ta c t s the c lu tch f o r k
b a l l stud. A l l p arts o f the clutch sy ste m , e x c e p t the throw ou t b e a r i n g a n d co lla r , ro t a te w i t h the f l y w h e e l w h e n the
Fig. 7C-4--Cross-Section View of Coil Spring Type
push
rod,
r o u te d
v e r t ic a l l y ,
i n sid e
the
cab,
from
the
p e d a l le v e r d o w n t h r o u g h two b o o ts o n the toe p a n , to
the c r o s s - s h a f t lever. W h e n the c lu t c h p e d a l is d e p r es s ed ,
the
pedal
push
rod
moves
rotatin g
the
cr o s s -s h a ft,
p u s h i n g the f o r k p u s h rod r e a r w a r d , a n d p i v o t i n g the
c l u t c h is e n g a g e d .
W h e n the c lu tch is d i s e n g a g e d , the re le a s e b e a r i n g
ro t a te s w i t h the f l y w h e e l , but the d r i v e n p la te a n d the
clutch
fo rk
to m o v e
the t h r o w o u t b e a r i n g a g a i n s t the
c lu tch re le a s e fin g ers a n d re l e a s i n g the clutch.
The
clu t c h s h a f t ro ta te as d ic t a te d b y the t ra n s m i s s io n g e a r
clutch
op erating
co n tr o ls
for
"G "
and
"P"
r a n g e a n d v e h i c l e s p ee d .
m o d e l s a re a m e c h a n i c a l t y p e s i m i l a r to the C - K m o d e ls.
CLUTCH CONTROLS
v e r t i c a l l y f r o m the clutch p e d a l le v e r d o w n t h r o u g h the
On " G "
T h e c lu tch o p e r a t i n g co n tr o ls f o r C - K
tru cks (F ig .
m o d e ls ( F i g . 7 C - 7 ) a p e d a l pull r o d is r o u te d
t o e -p a n e l to the cross s h a ft . W h e n the p e d a l is d e p r e s s e d ,
7 C - 6 ) a re a m e c h a n i c a l t y p e c o n s i s t in g o f a p e n d a n t type
the
p e d a l , r e t u r n s p r i n g , p e d a l p u s h rod, cr o s s -s h a ft, f o r k
p u s h i n g the c lu tch f o r k r o d r e a r w a r d a n d p i v o t i n g the
pedal
p ull
rod
moves,
rotatin g
the
cross
s h a ft,
clutch fo r k . T h i s a c tio n m o v e s the t h r o w o u t b e a r i n g
a g a i n s t the clutch re le a s e fingers, r e l e a s i n g the clutch.
" P " m o d e l c o n tr o ls ( F i g . 7 C - 8 ) h a v e an u p p e r pull
rod c o n n e c t e d f r o m the c lu tch p e d a l s h a f t to a bell c r a n k
a n d a lo w e r pulll r o d f r o m the bell c r a n k to the cross
s h a ft . W h e n
the p e d a l is d e p r e s s e d , the p u ll ro ds are
m o v e d r o t a t in g the cross s h a f t a n d p u s h i n g the clutch
f o r k r e a r w a r d , thus s u b s e q u e n t ly
re le a s e m e c h a n i s m .
Fig. 7 C - 5 ~ R e l e a s e Lev er , C o i l S p r i n g T y p e
activatin g
the clutch
VIEW
D
1-6 ENGINE
VI EW
V -8 ENGINE
MAINTENANCE AND ADJUSTMENTS
CLUTCH LINKAG E IN S P E C TIO N
There are several things which affect good clutch
operations. Therefore, it is necessary, before p erform ing
any m ajor clutch operations, to make prelim inary
inspections to determ ine w hether trouble is actually in
the clutch.
Check the clutch linkage to be sure the clutch
releases fully as follows:
1. With engine running, hold the clutch pedal
approxim ately 1 /2 " from floor mat and move shift lever
between first and reverse several times. If this can be
done smoothly, the clutch is fully releasing. If shift is not
smooth, clutch is not fully releasing and adjustment is
necessary.
2. Check clutch pedal bushings for sticking or
excessive wear.
3. Check fork for p rop er installation on ball stud.
Lack o f lubrication on fork can cause fork to be pulled
off the ball.
4. Check for bent, cracked or dam aged cross shaft
levers or support bracket.
5. Loose or dam aged engine mounts may allow the
engine to shift its position causing a bind on clutch
linkage at the cross shaft. Check to be sure there is some
clearance between cross shaft, both m ount brackets, and
ball studs.
6. Check throw out bearing end clearance between
spring fingers and front bearing retainer on the
transmission. If no clearance exists, fork may be
im properly installed on ball stud or clutch disc may be
worn out.
CLUTCH FREE PEDAL TRAVEL
ADJU STM EN T
Only one adjustment is necessary to compensate for
all no rm al clutch wear. The clutch pedal should have free
travel (measured at clutch pedal pad) before the
throwout bearing engages the clutch d iaph ragm spring
or levers. Lash is required to prevent clutch slippage
which would occur if the bearing was held against the
fingers or to prevent the bearing from running
continually. A clutch that has been slipping prior to free
play adjustm ent m ay still slip right after the new
adjustm ent due to previous heat damage.
C, K and P Models (E xcept P30 W /J 7 6 )
1. Disconnect return spring at clutch fork.
2. Rotate clutch lever an d shaft assembly until
clutch pedal is firmly against ru bb er bum per on brake
pedal bracket.
3. Push outer end o f clutch fork rearward until
throwout bearin g lightly contacts pressure plate fingers
or levers.
4. Loosen lock nut an d adjust rod length so that
swivel slips freely into gauge hole. Increase pushrod
length until all lash is removed from system.
5. Remove swivel from gauge hole and insert into
lower hole on lever. Install two washers and cotter pin.
Tighten lock nut being careful not to change rod length.
6. Reinstall return spring and check pedal free
travel. Pedal travel should be 1 3 / 8 " to 1 5 / 8 " on "C -K "
models and 1 1/4" to 1 1/2 " on "P " models.
P-30 Models W /J 7 6 (Fig. 7 C -1 0)
1. Disconnect clutch fork return spring.
2. Loosen nut " G " at swivel.
3. Move the clutch fork rod against fork to
eliminate all clearance between throwout bearing and
clutch fingers.
4. Rotate shaft lever until clutch pedal contacts the
bum per mounted on the brake pedal bracket.
5. Rotate the fork rod until a clearance of
approximately 1/4" to 5 /1 6 " (.29) is obtained between
the shoulder on the fork rod and the adjustm ent nut.
6. Tighten nut " G " against swivel and install
clutch return spring.
7. Check free pedal clearance at pedal. Pedal
clearance should be 1 3 / 8 " to 1 5 /8 " . Readjust as
required.
CROSS SHAFT LEVER
Fig. 7C-1 1 -G -Truck F r e e
P e d a l T ru ck
G-Models (Fig. 7 C -1 1)
1. Disconnect clutch fork return spring at fork.
2. Loosen nut " A " and back off from swivel
approxim ately 1/2 inch.
3. Hold clutch fork push rod against fork to move
throwout bearing against clutch fingers (push rod will
slide through swivel at cross-shaft).
4. Adjust nut "B " to obtain approximately 1/4"
clearance between nut "B " and swivel.
5. Release push rod. connect return spring and
tighten nut " A " to lock swivel against nut "B".
6. Check free pedal clearance at pedal (l 1/4" to 1
1/2" is proper clearance). Readjust if necessary.
IN S U F F IC IE N T CLUTCH RELEASE
W here complaints of first or reverse gear clash due
to insufficient clutch release are encountered, the
following may be helpful. Cut off the existing clutch
pedal stop bum per to a height of 3 /8 " . Since shortening
the bum per increases the lash and not the usable stroke,
the lash must be reduced to specifications in order to
gain the additional stroke benefit.
DIAGNOSIS
CLUTCH TROUBLE DIAGNOSIS
C O N D IT IO N
P R O B A B L E C A U SE
Fails to R elease (P edal p ressed
to flo o r-sh ift lever does n o t
m ove freely in an d o u t o f
reverse gear
a.
b.
c.
d.
e.
f.
Im p ro p e r linkage A d ju stm e n t
Im p ro p e r pedal travel
L oose linkage
F a u lty p ilo t b earin g
F a u lty d riven disc
F o rk o f f ball stu d
g. C lu tc h disc h u b b in d in g on c lu tc h
gear spline
h. C lu tc h disc w a rp e d or b e n t
C O R R E C T IO N
a.
b.
c.
d.
e.
f.
A d ju st L inkage
T rim b u m p e r s to p an d a d ju s t linkage
R eplace as necessary
R ep lace b earin g
R eplace disc
In sta ll p ro p e rly a n d * lu b ric a te fingers
a t th ro w -o u t b e arin g w ith w heel
bearin g grease.
g. R e p air o r replace c lu tc h g ear a n d /o r
disc.
h. R eplace disc (ru n -o u t sh o u ld n o t
ex cee d .0 2 0 " ) .
*V ery lig h tly lu b ric a te fingers
S lipping
a. Im p ro p e r A d ju stm e n t (n o lash)
b . Oil S o ak ed driven disc
c. W orn facing o r facing to rn fro m disc.
d. W arped p ressu re p la te o r flyw heel
e. W eak d iap h rag m spring
f.
D riven p la te n o t se a te d in
g. D riven p la te o v e rh e a te d
G rab b in g (C h a tte rin g )
a. Oil on facing. B u rn ed or glazed
facings.
b . W orn splines on c lu tc h gear.
c. L oose engine m o u n tin g s.
d. W arped p ressure p late o r fly w h eel.
e. B u rn ed o r sm e ared resin on flyw heel
o r pressure p la te .
R attlin g -T ran sm issio n Click
T h ro w -O u t B earing N oise w ith
C lu tc h F ully E ngaged
N oisy
H ard P edal E ffo rt
F lo o r
W hen
b.
c.
d.
e.
new
disc
an d
c o rre c t leak .
R eplace tran sm issio n c lu tc h gear.
T ig h ten o r replace m o u n tin g s.
R eplace p ressure p late o r flyw heel.
S an d o f f i f su p e rficial, rep lace b u rn e d
o r h e a t c h e c k e d p a rts.
a. R eplace p ressu re p la te .
b. C h e ck ball stu d a n d retain in g .
a. Im p ro p e r a d ju s tm e n t. N o L ash.
b. T h ro w -o u t b earin g b in d in g on tra n s
m ission b earin g re ta in e r.
c. In su ffic ie n t te n s io n b e tw e e n c lu tc h
fo rk spring an d b all stu d .
d. F o rk im p ro p e rly in sta lle d .
e. W eak linkage r e tu rn spring.
a. A d ju st lin k ag e.
b. C lea n , re lu b ric a te , ch eck
n ick s, e tc .
c. R eplace fo rk .
a. W orn th ro w -o u t bearing.
b . F o rk o f f ball s tu d (h eav y clicking).
on
a. In sta ll
a. W eak re tra c tin g springs.
b. T h ro w -o u t fo rk loose o n ball stu d or
in b earin g groove.
c. Oil in driven p la te d a m p er.
d. D riven p la te d a m p e r spring failu re.
c. P ilo t
Pedal S tays
D isengaged
a. A d ju st linkage to spec.
b. In stall new disc an d c o rre c t leak at its
so u rce
c. R ep lace disc
d. R ep lace pressure p la te or fly w h eel
e. R e p la ce p ressu re p la te (B e sure lash is
c h e c k e d b e fo re rep lacin g p la te .)
f. M ake 30 to 4 0 n o rm a l sta rts
C A U T IO N : Do N o t O verheat
g. A llow to co o l — c h e c k lash
B earing
a. B ind in
loose
linkage
in
c ra n k sh a ft.
or release bearing.
c. R ep lace d riven disc.
d. R eplace driven disc.
fo r b u rrs,
d. In sta ll p ro p e rly .
e. R ep lace spring.
a. R eplace b earin g .
b. In sta ll p ro p e rly an d lu b ric a te
fingers a t bearing.
c. See S ectio n 6 fo r b earin g fits.
fo rk
b. Springs w eak in p ressu re p la te .
c. Springs being over trav eled .
a. L u b ric a te a n d free u p linkage an d
release b earin g .
b . R e p la ce p ressu re p la te .
c. A d ju st linkage to get p ro p e r lash , be
su re p ro p e r p e d a l sto p (b u m p e r) is
in sta lle d .
a. B ind in linkage.
b . D riven p late w o rn .
a. L u b ric a te an d free u p linkage.
b. R ep lace d riven p la te .
COMPONENT PARTS REPLACEMENT
P R E L IM IN A R Y IN S P E C TIO N
There are m a n y things which affect good clutch
operation. T herefore, it is necessary, before perform ing
any m ajor clutch operations, to make a preliminary
inspection to determ ine w hether or not the trouble is
actually in the clutch.
1. Check the clutch pedal and make sure that the
pedal has proper free travel, as described in "M a in te
nance and Adjustments".
2. Check the clutch pedal bushing for wear and for
sticking on the shaft or loose mountings.
3. Lubricate the pedal linkage.
4. Tighten all front and rear engine mounting
bolts.
CLUTCH DISC AND PRESSURE PLATE
(D IA P H R A G M TYPE)
Removal fro m Vehicle
1. Remove transmission as outlined in Section 7B.
2. Disconnect clutch fork push rod an d pull back
sorine.
3. Remove clutch and flywheel housing.
4. Remove clutch fork by pressing it away from its
ball m ounting with a screwdriver, until the fork snaps
loose from the ball or remove ball stud from rear o f
clutch housing. Remove throwout bearing from clutch
fork.
N OTE: The retainer may be removed from the
fork by prying out with a small screwdriver.
5. Install Tool J-5824 or a used clutch drive gear to
support the clutch assembly during removal.
N OTE: Before removing clutch from flywheel,
mark the flywheel, clutch cover and one pressure
plate lug, so that these parts may be assembled in
their same relative positions, as they were balanced
as an assembly.
6. Loosen the clutch attaching bolts one turn at a
time to prevent distortion o f clutch cover until
d ia p h ra g m spring is released.
7. Remove clutch pilot tool and remove clutch
assembly from vehicle.
N O TE : The flywheel should be inspected for
cracks, heat checking, flatness and other defects.
Installation to Vehicle
1. Install the pressure plate in the cover assembly
lining up the notch m ark on pressure plate with notch
mark on flange o f cover.
2. Install pressure plate retracting springs, lockwashers and drive strap to pressure plate bolts. Tighten
to l l ft. lbs. torque. The clutch is now ready to be
installed.
3. H and crank the engine until " X " m ark on
flywheel is at the bottom.
4. Install clutch disc, pressure plate and cover
assembly and support them with Tool J-5824 or a used
clutch drive gear.
5. Turn clutch assembly until "X " mark or painted
white letter on clutch cover flange lines up with " X "
mark on flywheel.
6. Install attaching bolts and tighten each one a
turn at a time to prevent distorting the cover as the
spring pressure is taken up.
7. Remove clutch pilot tool.
8. Pack clutch fork ball seat with a small am ount
of high melting point grease. On " P " models with J76,
install a new retainer in the groove o f the clutch fork if
the old retainer is worn or dam aged.
N O TE : Install retainer with high side up, away
from bottom of the ball socket and with open end
o f retainer on the horizontal.
C A U TIO N : Be careful not to use too much
lubricant. Excessive lubricant may get on
d u tch fingers and cause slippage.
9. Replace clutch fork ball if removed from the
clutch housing and snap clutch fork onto the ball.
10. Pack lubricant in the recess on the inside of the
throwout b earing collar and coat the throwout fork
groove with a small am ount o f graphite grease, as shown
in Figure 7C-13.
11. Install throwout bearing assembly to the
throwout fork. Install clutch and flywheel housing to
engine.
12. Assemble transmission as outlined in Section
7B.
13. Align push rod to clutch fork and attach return
spring to clutch fork.
14. Adjust clutch linkage as described in "M a in te
nance and Adjustments."
CLUTCH DISC AND PRESSURE PLATE
(COIL SPRING TYPE)
Removal From Vehicle
1. Remove transmission as outlined in Section 7B.
2. Disconnect clutch fork push rod and pull back
spring.
3. Remove clutch and flywheel housing.
4. Remove clutch fork by pressing it away from its
ball mounting with a screwdriver, until the fork snaps
loose from the ball or remove ball stud from rear of
clutch housing. Remove throwout bearing from clutch
fork.
NOTE: The retainer may be removed from the
fork by prying out with a small screwdriver.
5. Install Tool J-5824 or a used clutch drive gear to
support the clutch assembly during removal.
N O T E : Before removing clutch from flywheel,
m ark the flywheel, clutch cover and one pressure
plate lug, so that these parts may be assembled in
their same relative positions, as they were balanced
as an assembly.
6. Loosen the holding screws a turn or two at a
time to avoid bending rim o f cover. It is advantageous to
place wood or metal spacers (approxim ately 3 /8 thick)
between the clutch levers and the cover to hold the levers
down as the holding screws are removed or when clutch
is removed from engine. W hen removing driven plate be
sure to m ark flywheel side.
7. Remove clutch pilot tool and remove clutch
assembly from vehicle.
N O T E : Inspect flywheel for heat defects, cracks,
flatness, or other defects.
Installation To Vehicle
1. Assemble driven plate and clutch cover assem
bly to flywheel in accordance with m arking on driven
plate for flywheel side. Use Tool J-5824 or a dum m y
sh aft to support assembly.
2. Line up the clutch assembly with " X " mark or
painted white letter with " X " mark on flywheel, before
tightening cover holding screws.
3. Tighten holding screws, a turn at a time, before
rem oving d u m m y shaft.
4. Remove clutch pilot tool.
5. Pack clutch fork ball seat with a small am ount
o f high melting point grease and install a new retainer
in the groove o f the clutch fork if the oid retainer is
w orn or dam aged.
N OTE: Install retainer with high side up, away
from bottom o f the ball socket and with open end
o f retainer on the horizontal.
C A U T IO N : Be careful not to use too much
lubricant. Excessive lubricant m ay get on
clutch fingers and cause slippage.
6. Replace clutch fork ball if removed from the
clutch housing and snap clutch fork onto the ball.
7. Pack lubricant in the recess on the insde of the
throwout bearing collar and coat the throwout fork
groove with a small am ount o f graphite grease, as shown
in Figure 7C-13.
8. Install throwout b e a rin g assembly to the
throwout fork. Install clutch and flywheel housing to
engine.
9. Assemble transmission as outlined in Section 7B.
10. Align push rod to clutch fork and attach return
spring to clutch fork.
11. Adjust clutch linkage as described in " M a in te
nance and Adjustments."
CLUTCH PEDAL ARM , PUSH ROD OR
B U S H IN G R E P LA C E M E N T (Fig. 7 C -14)
C-K Models
Removal
1. Disconnect battery negative ground cable at the
battery terminal.
2. Disconnect clutch push rod at the cross shaft
under the vehicle.
3. Remove steering column covers. Remove screws
retaining push rod boots to bulkhead.
4. Remove air conditioning duct from lower left
side o f instrument cluster is so equipped. (Refer to
Section 1A).
CA U T IO N : M aintain pressure on lower arm.
When lower attaching bolt is removed upper
section will snap upward.
5. Disconnect clutch neutral start switch from
pedal arm.
6. Remove bolts attaching lower section o f clutch
pedal arm to the upper arm.
7. Remove lower arm and push rod from vehicle.
8. Remove pedal return spring.
9. Remove pedal pivot shaft retaining nut and
pivot shaft. Insert a dum m y shaft or rod through the
support to hold the brake pedal components in place.
10. Remove the clutch pedal assembly from the
support assembly.
11. Remove pedal bushings an d spacer from pedal
arm. Check pedal bum per for wear and replace as
required.
Installation
Inspection
1. Install new bushings and spacer in pedal arm.
C om ponents should be lubricated prior to assembly.
2. Position clutch pedal upper arm in support
bracket and install pivot bolt through support and pedal
arms.
1. Check clutch pedal bushings for excessive w ear
and replace as necessary.
N OTE: Bolt must be installed in direction shown in
Figure 7C-14 in order to clear return spring.
3. Install pivot bolt retaining nut and torque to
specifications.
4. Install p.ull back spring to support and pedal
arm.
Installation
NOTE: If previously removed connect pedal push
rod to clutch pedal arm.
5. Position lower pedal arm to upper arm and
install upper attaching bolt. Push down on pedal and
install lower bolt. Torque to specifications.
6. Install clutch neutral start switch.
7. Install air conditioning duct.
8. Install steering column covers. Install screws
retaining push rod boots to bulk head.
9. Check operation o f clutch assembly and adjust
clutch as required.
G
and
P
Models
(Fig. 7C -14)
Removal
1. Apply parking brake firmly. Disconnect neutral
start switch from pedal arm.
2. Remove bolt at clutch pedal push rod lever, then
remove lever from pedal shaft.
3. Hold pedal pad with one hand and slide clutch
pedal and shaft assembly outboard enough to clear pedal
stop. Insert a d um m y shaft or rod through support and
brake pedal assembly to hold components in place while
rem oving clutch pedal shaft. Allow return spring (or
center spring) to pull pedal up high enough to unhook
spring from pedal arm.
4. Remove pedal and shaft assembly from support
bracket.
2. Check clutch pedal s h a ft fo r w e a r
alignment. Straighten or replace as necessary.
N O T E : Use new sh a ft
Lubricate with petrolatum.
bush in g
if
and
needed.
1. Slide one pedal shaft bushing over shaft, install
shaft in support enough to still clear pedal bu m per stop,
hook pedal return (or overcenter) spring to pedal, then
rotate pedal forward of bu m p er stop; slide shaft into
position in support and release pedal against bum per
stop.
2. Install clutch pedal shaft bushing over pedal
shaft end and into place in sleeve.
3. Assemble pedal push rod lever over pedal shaft
and install bolts, washers, and nut.
4. Connect neutral start switch to pedal arm.
5. Adjust clutch pedal free travel as needed.
CLUTCH CROSS-SHAFT R EPLA C EM EN T
(Figs. 7C-6, 7C-7, 7C-8)
1. Disconnect clutch fork return spring at fork.
2. Disconnect pedal push rod at cross-shaft lever
and allow clutch fork push rod to hang free from lower
lever.
3. On C-K models, remove ball stud retaining nut,
at frame end and slide shaft toward engine. Then lift
cross-shaft up to clear bracket and remove shaft from
the engine ball stud. On G models, remove frome
bracket retaining bolts, then remove shaft from engine
ball stud.
4. REmove clutch fork push rod from cross-shaft
lever.
5. Reverse removal procedure to install.
SPECIAL TOOLS
1.
2.
3.
4.
5.
J-6456 Height Gauge
J-1048 Gauge Plate
J- 1522 Pilot Bearing Driver
J-23720 Clutch Pilot Tool
J-1448 Pilot Bearing Puller
SECTION 8
ELECTRICAL—BODY AND CHASSIS
C O N TE N TS
Lighting S ystem ....................................................................
G eneral D e s c rip tio n ..........................................................
D ia g n o sis...............................................................................
On-Vehicle Service.............................................................
M aintenance and A d ju stm e n ts...................................
H e adlam p A d ju s tm e n t...............................................
C om ponent Part R ep lacem en t....................................
Sealed Beam U n i t .........................................................
Parking L am p B u l b .....................................................
Parking L a m p H o u sin g ...............................................
Front Side M a r k e r ........................................................
Rear Side M a rk e r..........................................................
Tail, Stop and Backup L a m p s .................................
Directional Signal L a m p s ...........................................
Clearance, License Plate and Identification
L a m p s..................................................................................
Light S w itch .....................................................................
H eadlam p Beam Selector Switch.............................
Stoplam p Switch.............................................................
Instruments. Gauges and C o n tro ls ................................
G en eral D e sc rip tio n ..........................................................
D ia g n o sis................................................................................
On-Vehicle Service.............................................................
C om ponent Part R ep lacem en t....................................
N eutral Start S w itc h ....................................................
Backing L a m p Switch...................................................
W indshield W ip e r /W i p e r /W a s h e r Switch............
Ignition Switch................................................................
Instrument C lu s te r.........................................................
Indicator and Illuminating B ulbs............................
Lam inated (Printed) Circuit.......................................
S p e e d o m e te r .....................................................................
Speedom eter Cable C o r e ............................................
Fuel G a u g e .......................................................................
T em perature G a u g e .............. ........................................
T e m p e ratu re Sending U n i t ........................................
Oil Pressure G a u g e .......................................................
8-2
8-2
8-3
8-9
8-9
8-9
8-I0
8 - 10
8 - 10
8-10
8 - 10
8-10
8 - 1I
8 - 11
8 - 1I
8 - 11
8 - 11
8-ll
8 - 15
8 - 15
8-16
8-20
8-20
8-20
8-21
8-21
8-22
8-22
8-22
8-22
8-24
8-25
8-25
8-25
8-25
8-25
Oil Pressure Sending U n i t ........................................ ..8-26
V o ltm eter.............................................................................8-26
Directional Signal Sw itch.............................................8-26
Windshield W iper and W asher (C-K and G
M o d e ls).................................................................................... ..8-26
G eneral D e sc rip tio n ............................................................8-26
Electrical C ircuits............................................................. ..8-27
D iag n o sis............................................................................... ..8-30
W iper - On V eh icle....................................................... ..8-30
W iper - Off Vehicle.........................................................8-30
On Vehicle Service............................................................ .8-39
Com ponent Part R ep la c e m e nt.................................... .8-39
Wiper M o to r ................................................................... .8-39
Unit R e p a ir .......................................................................... .8-39
W ip e r /W a s h e r D isa sse m b ly ..........................................8-39
Motor D isassem bly...........................................................8-40
Motor A ssem b ly............................................................... .8-43
W iper A djustm ents...........................................................8-43
W asher P u m p ................................................................... .8-43
Windshield W iper and W asher (P M odels)...............8-45
G eneral D e sc rip tio n ...........................................................8-45
D ia g n o sis............................................................................... .8-47
W iper - On V ehicle.........................................................8-47
Unit R e p a i r .......................................................................... .8-52
W iper M o to r .......................................................................8-52
Windshield W a s h e r ..........................................................8-53
Circuit Pro te ctio n ................................................................. .8-56
G eneral D esc rip tio n ...........................................................8-56
Circuit B r e a k e r ................................................................. .8-56
Fuse .......................................................................................8-56
Fusible L in k ........................................................................8-57
D iagn osis............................................................................... .8-57
On-Vehicle Service............................................................. .8-58
Com ponent Part R eplacem ent.................................... .8-58
H eadlam p W arning Buzzer.............................................. .8-58
Seat Belt W arning S y s te m ............................................... .£-58
Specifications...........................................................................g_(,i
LIGHTING SYSTEM
GENERAL DESCRIPTION
The lighting system includes the m ain light switch;
stop light, d im m e r and backing lam p switches; head and
park in g lamps; stop, tail, side marker, clearance and
identification lamps; instrument illumination, directional
signal and indicator lamps and the necessary wiring to
complete the various circuits.
A bulkhead fuse panel (fig. 8-1) provides convenient
power taps and fuse clips for the appropriate circuits.
The engine wiring harness and forward lam p harness
connectors are bolted to the fuse panel.
All wiring systems not protected by a fuse or circuit
breaker incorporate a fusible link which provides
increased overload protection. The starting motor circuit
is the exception.
Composite wiring diagram s are available in a
separate manual. The standardized color code is common
to all wiring harnesses. The wire covering color
designates a particular circuit usage.
TRAFFIC H A Z A R D FLASHER
0 F U S E -H E A T E R & IG N A C C
[BlR EC E P T A C LE -H E A TE R
[A]F U S E - H E A T E R /A IR C O N D
(C jR E C E P T A C L E -IG N A C C
[B]F U S E - AC C E S S O R Y
[0 R E C E P T A C L E -R A D IO U 6 3
0 3 RECEPTACLE - C 6 2
[TJFU S E-IN ST PNL LA M P S
03 RECEPTACLE
[^ R E C E P T A C L E - INST PNL LAM PS
OS FUSE - PA NE L LIGHTS
0 F U S E - B / U LA M P S, R A D IO U 63
[□ R E C E P T A C L E - A C C E S S O R Y LA M P S
- N L 2 /A 3 3 /U 1 6
E D f u s e - c l u s t e r FEED
^ R E C E P T A C L E - ( N O T USED)
[U O U T IE T -D IR SIG FLASHER
Q llF U S E - CLUSTER FEED
[K ] FUSE-IDLE STO P.TC S
□
d lF U S E - W /S H IE L D W IPER
0 F U S E - W /S H IE L D W IPER
FUSE - B / U LA M P S
0 R E C E P T A C L E -W /S H IE L D W IPER
[□ F U S E - R A D IO & TCS
[N] RECEPTACLE-TCS
0R EC E PTA C LE -
[P ] FU SE-TAIL, PARK STOP, D O M E LA M P S
03)FUSE - TRAFFIC H A Z A R D
T P 2 /M 4 0
0 F U S E -T R A F F IC H A Z A R D
[□ F U S E - T A IL,S TO P , CTSYLAM PS
E lO U T L E T -TR AFFIC H A Z A R D FLASHER
(^R E C E P T A C L E - C 9 1 / U F 2 / U 3 5 / U 3 7
G D R E C E P T A C LE -C IG LIGHTER
____ _______ _____ G, SERIES
DIR S IG N A L FLASHER
C -K SERIES
Fig. 8-l--Fuse Panel
DIAGNOSIS
HEADLAMP DIAGNOSIS
Condition
One headlamp inoperative
or intermittent
Possible Cause
1. Loose connection
2. Defective Sealed Beam
One or more headlights
are dim.
1. Open ground connection
at headlight
2. Black ground wire
mislocated in headlight
connector (type 2
sealed beam)
C orrection
1. Secure connections to sealed
beam including ground.
(Black Wire)
2. Replace sealed beam
1. Repair black wire connection
between sealed beam and body
ground.
2. Relocate black wire in connector
One or more headlights
short life
1. Voltage regulator
misadjusted
1. Readjust regulator to
specifications.
All headlights inoperative
or intermittent
1. Loose connection
1. Check and secure connections
at dimmer switch and light
switch.
2. Defective dimmer
switch
2. Check voltage at dimmer switch
with test lamp. If test lamp
bulb lights only at light blue
wire terminal, replace dimmer
switch.
3. Check light blue wire with test
lamp. If bulb lights at light
switch light blue wire terminal
but not at dimmer switch, repair
open wire.
4. Check red wire terminal at light
switch with test lamp. If lamp
does not light, repair open red
wire circuit to battery, (possible
open fusible link)
3. Open wiring - light
switch to dimmer
switch
4. Open wiring - light switch
to battery
5. Shorted ground circuit
5. If, after a few minutes operation,
headlights flicker “O N ” and
“O F F ” and or a thumping noise
can be heard from the light
switch (circuit breaker opening
and closing), repair short to
ground in circuit between
light switch and headlights. After
repairing short, check for
headlight flickering after one
minute operation. If flickering
occurs, the circuit breaker has
been damaged and light switch
must be replaced.
6. Defective light switch
6. Check red and white wire
terminals at light switch with
test lamp. If bulb lights at read
wire terminal but not at light
blue terminal, replace light
switch.
Upper or lower beam
will not light or
intermittent
1. Open connection or
defective dimmer switch
1. Check dimmer switch terminals
with test lamp. If bulb lights
at light blue or tan wire terminals,
repair open wiring between dimmer
switch and headlights. If bulb
will not light at one of these
terminals, replace dimmer switch.
2. Short circuit to ground
2. Follow diagnosis above (All
headlights inoperative or
intermittent)
SIDE M A R K E R L A M P D IA G N O S IS
C o n d itio n
One lamp inoperative
Front or rear lamps
inoperative
All lamps inoperative
P o s s ib le C a u s e
C o r re c tio n
1. Turn signal bulb burnt
out (Front lamp)
1. Switch turn signals on. If signal
bulb does not light, replace bulb.
(Bulb filament provides ground
path for marker lamp bulb
through the light blue or dark
blue/white strip wires).
2. Side marker bulb
burnt out
2. Replace bulb.
3. Loose connection or
open in wiring
3. Usiftg test lamp, check brown
wire terminal at bulb socket.
If test lamp lights, repair open
ground circuit. If lamp
does not light, repair open
brown wire circuit.
1. Loose connection or
open ground connection
1. If associated tail or park lamps
do not operate, secure all
connectors in brown wire
circuit. If park and turn
lamps operate, repair open
ground connections.
2. Multiple bulbs burnt
out
2. Replace burnt out bulbs.
1. Blown fuse
1. If park and tail lamps do not
operate, replace blown fuse.
If new fuse blows, check for short
to ground between fuse panel
and lamps.
2. Secure connector to light switch.
2. Loose connection
3. Open in wiring
3. Check tail light fuse with
test lamp. If test lamp lights,
repair open wiring between fuse
and light switch. If not, repair
open wiring between fuse and
battery. (Possible open fusible
link).
4. Defective light switch
4. Check light switch with test
lamp. If test lamp lights at
terminal No. 5 but not at
terminal No. 4, replace
light switch.
T A IL , PARK A N D LICENSE L A M P D IA G N O S IS
C o n d itio n
One side inoperative
Both sides inoperative
P o s s ib le C a u s e
C o r re c tio n
1. Bulb burnt out
1. Replace bulb
2. Open ground connection
at bulb socket or
ground wire terminal
2. Jumper bulb base socket
connection to ground. If
lamp lights, repair open
ground circuit.
1. Tail lamp fuse
blown
1. Replace fuse. If new fuse
blows, repair short to
ground in brown wire circuit
between fuse panel through
light switch to lamps.
2. Loose connection
2. Secure connector at light
switch.
3. Open wiring
3. Using test light, check circuit
on both sides of fuse. If lamp
does not light on either side,
repair open circuit between
fuse panel and battery.
(possible open fusible link).
If test lamp lights at light
switch brown wire terminal,
repair open wiring between
light switch and lamps.
4. Multiple bulb
4. If test lamp lights at lamp
burnout
5. Defective light switch
socket brown wire terminal,
replace bulbs.
5. If test lamp lights at light switch
terminal No. 4 (Brown/white
wire) but not at terminal No. 5
(Brown wire), replace defective
light switch.
TUR N S IG N A L A N D H A Z A R D W A R N IN G L A M P
C o n d itio n
T u rn signals inoperative
one side
T u r n signals inoperative
P o s s ib le C a u s e
C o r re c tio n
1. Bulb(s) b u rn t out
(F la sh e r can n o t be
h e a rd )
T u r n h a z a rd w a rn in g system on.
I f one o r m o re bulbs are
inoperative replace necessary
bulbs.
2. O pe n wiring or
g ro u n d c o n n e c tio r
T u r n H azard w a rn in g system on.
If o n e o r m o re b u lb s are
in o p era tiv e , use test la m p an d
check circu it a t la m p so c k e t. If
test la m p lights, re p a ir o p e n
g r o u n d c o n n e c tio n . I f n o t,
re p air o p e n wiring b e tw e e n
b u lb so c k e t an d tu rn signal
switch.
3. I m p ro p e r bulb or
defective tu rn signal
switch.
3. T u r n h a z a rd w arning system on.
I f all front a n d rear lamps
operate, check for im p ro p e r
bulb (1034 instead o f 1157).
I f bulbs are O K , replace defective
tu rn signal switch.
4. Short to ground.
(F la sh er can be heard,
no bulbs operate)
4. L ocate a n d repair sh ort to
g ro u n d by disconnecting
front a n d rear circuits
separately.
1. Blow n tu rn signal
fuse
1. T u r n h a z a rd w arning system
on. If all lam ps operate, replace
blow n fuse. If new fuse blows,
rep air short to gro u n d between
fuse a n d lamps.
2. Defective flasher
(L ocated behind
in stru m e n t panel near
steering colum n)
2. If tu rn signal fuse is O K and
h a z a r d w arn in g system will
op erate lamps, replace defective
tu rn signal flasher.
3. Loose connection
3. Secure steering c o lu m n connector.
I f necessary, check purple wire
term inals in c o n n e c to r with
test lamp. If test la m p lights only
on one side o f connector, clean or
tighten c o n n e c to r contacts.
H azard warning lamps
inoperative
1. Blown stop-hazard
fuse
1. Switch turn signals on. If lamps
operate, replace stop-hazard
fuse if blown. If new fuse blows,
repair short to ground. (Could be
in stop light circuit).
2. Defective hazard
warning flasher. (Located
on fuse panel).
2. If stop-hazard fuse is O K,
switch turn signals on. If
lamps operate, replace
defective hazard flasher.
3. Open in wiring or
defective turn signal
switch.
3. Using test lamp, check brown
wire in turn signal steering
column connector. If lamp
does not light on either side of
connector, repair open circuit
between flasher and connector.
If lamp lights only on feed side
of connector, clean connector
contacts, If lamp lights on both
sides of connector, replace
defective turn signal switch
assembly.
BACK-UP LAM P
C o n d itio n
One lam p inoperative or
interm ittent
Both lamps inoperative
or intermittent.
P ossib le C au se
C o rre c tio n
1. Loose or burnt out
bulb
1. Secure or replace bulb.
2. Loose connection
2. Tighten connectors.
3. Open ground
connections
3. Repair bulb ground circuit.
1. Neutral start switch
misadjusted (Open when
shift lever is in reverse
position)
1. Readjust neutral start switch.
2. Loose connection or
open circuit
2. Secure all connectors. If OK,
check continuity of circuit from
fuse to lamps with test lamp. If
lam p does not light on either side
o f fuse, correct open circuit from
battery to fuse.
3. Blown fuse
3. Replace fuse. If new fuse blows,
repair short to ground in circuit
from fuse through neutral start
switch to back-up lamps.
4. Defective neutral
start switch
4. W ith ignition on, check switch
terminals in back-up position with
test lamp. If lam p lights at pink
wire terminal but not at light
green wire terminal, replace
neutral start switch.
5. Defective ignition
switch
5. If test lam p lights at ignition
switch battery terminal but not
at o utput terminal, replace
ignition switch.
L a m p will not tu r n off
1. N e u tra l start switch
m isadjusted (closed
w hen shift lever is not
in reverse position)
1 R e a d ju st ne u tra l s ta rt sw itch
STO P LIG HTS
C o n d itio n
P o s s ib le C a u s e
C o r re c tio n
O n e bulb inoperative
1. Bulb b u rn t out.
1. R eplace bulb.
O n e side inoperative
1. Loose connection,
open wiring or defective
bulbs
1. T u r n o n d ire c tio n a l signal. If
la m p d o e s n o t o p e r a te , c h ec k
bulbs. If b u lb s are O K , secure all
c o n n e c tio n s . If la m p still does
n o t o p e r a te , use te s t la m p and
c h eck fo r o p e n wiring.
2. Defective directional
signal switch or
cancelling cam
2. If la m p will o perate by tu rn in g
direction al signal on, the switch
is not centering p roperly du ring
cancelling operation. Replace
defective cancelling cam or
directional signal switch.
1. S to p -h a z ard fuse
blown
1. R eplace fuse. If new fuse blows,
r e p a ir sh ort to g ro u n d in circuit
between fuse a n d lamps.
2. S to p -sw itc h m isa d ju s te d
o r defective
2. With b ra k e p ed al d e p re ss e d , c h eck
w h ite wire te r m in a l in steerin g
c o lu m n c o n n e c t o r w ith test
la m p . If la m p d o e s n o t light,
c h e c k s to p sw itc h fo r p r o p e r
a d ju s tm e n t. If a d j u s t m e n t is
O K , replace s to p sw itch.
1. Stop switch
m isadjusted o r defective.
1. R eadjust switch. I f switch
still m alfunctions, replace.
All inoperative
Will not tu rn off
ON-VEHICLE SERVICE
MAINTENANCE AND
ADJUSTMENTS
M aintenance of the lighting units and wiring system
consists o f an occasional check to see that all wiring
connections are tight and clean, that the lighting units
are securely mounted to provide good ground and that
the h eadlam ps are properly adjusted. Loose or corroded
connections m ay cause a discharged battery, difficult
starting, dim lights, and possible d am age to the
generator. W ire harnesses must be replaced if insulation
becomes burned, cracked, or deteriorated. W henever it is
necessary to splice a wire or repair one that is broken,
always use solder to bond the splice. Always use rosin
flux solder on electrical connections. Use insulating tape
to cover all splices or bare wires.
W h en replacing wires, it is im portant that the
correct size be used. N ever replace a wire with one o f a
smaller size. Fusible links in the wiring are four gauge
sizes smaller than the cable it is designed to protect. The
links are marked on the insulation with wire gauge size
because o f the heavy insulation which makes the link
a p p e a r a heavier gauge than it actually is.
Each harness and wire must be held securely in
place by clips or other holding devices to prevent chafing
or w earing away the insulation due to vibration.
By referrin g to the wiring diag ram manual, circuits
m ay be tested for continuous circuit or shorts with a
conventional test lamp or low reading voltmeter.
whenever a sealed beam unit is replaced and after
repairs o f the front end sheet metal assembly.
Regardless of the method used for checking
h eadlam p aim, the truck must be at norm al weight, that
is with gas, oil, w ater and spare tire. Tires must be
inflated to specified pressures.
Some states have special requirem ents for h eadlam p
aiming adjustment and these requirem ents must be
known and followed.
Horizontal and vertical aiming o f each sealed beam
is proveded by two adjusting screws visible through the
bezel which move the m ounting ring against the tension
o f the coil spring (fig. 8-2).
There is no adjustm ent for focus since the sealed
beam unit is set for focus during m anufacturing
assembly.
H E A D LA M P A D J U S T M E N T (Fig. 8-2)
T he headlam ps must be properly aimed to obtain
m axim um road illumination. W hen using mechanical
h ea d la m p aimers, follow m anufacturers instructions.
T he headlam ps must be checked for proper aim
VERTICAL
AIM SCREW
HORIZONTAL
A I M SCREW
R i g h t side s h o w n , left
side is s i m i l a r .
Fig. 8-3- Front Lighting (C-K Models)
COMPONENT PART
REPLACEMENT
7.
To install, reverse removal steps.
Left Side
1. Remove two screws and parking lamp lens.
2. Disconnect wiring harness at connector.
3. Remove housing stud nuts and remove housing
with pigtail.
4. To install, reverse removal steps.
SEALED BEAM U N IT
Replacement (Figs. 8-3 and 8-4)
1.
2.
Remove bezel retaining screws and bezel.
Remove retaining ring.
FRO NT SIDE MARKER LAM P BULB A N D /
OR H O USING
All Models
Replacement
N O T E: Do not disturb adjusting screw setting.
3. Disconnect wiring harness connector located at
rear of' unit in engine com partm ent and remove sealed
beam unit.
4. Attach wiring harness connector to unit.
5. Position new sealed b eam unit in mounting ring
and install retaining ring.
N O T E: The num ber molded into lens face must be
at top.
6. Install retaining ring then check operation of
unit and install bezel.
P A R K IN G LA M P BULB
Replacement (Figs. 8-3 and 8-4)
NOTE: For housing replacement follow procedure
for the right side bulb replacement below.
1.
Left Side - Raise hood.
Right Side - Remove lamp assembly retaining
screws and pull outward on assembly.
2. Twist wiring harness socket 90 counterclockwise
and remove harness and bulb from housing.
3. Replace bulb and check lam p operation.
4. Insert bulb into housing, press in on harness
socket and twist 90 clockwise. Check that socket is
securely attached.
5. Left Side- Lower hood.
Right Side - Install housing in opening and install
retaining screws.
1. Remove lens retaining screws and remove lens
I'rom the housing.
2. Replace bulb and check lamp operation.
3. Install lens and retaining scrws.
P A R K IN G LAM P H O U S IN G
C-K M odels
Replacement (Fig. 8-3)
1. Remove parking lamp lens screw's and remove
the lens.
2. Remove lamp housing retaining screws and pull
housing forward.
3. Disconnect parking lamp wiring harness from
housing by rotating bulb socket counterclockwise.
4. Connect wiring harness to new housing by
inserting bulb socket into housing and rotating clockwise.
5. Install bulb if removed during disassembly.
Install lens and retaining screws.
G M odels
Replacement (Fig. 8-4)
Right Side
1. Remove both he ad la m p bezels.
2. Remove both parking lam p lens.
3. Remove grille.
4. Remove battery and battery box.
5. D isconnect wiring harness at connector.
6. Remove housing stud nuts and remove housing
with pigtail.
REAR SIDE MARKER LAM P BULB
A N D /O R H O U S IN G
C-K 03 models with E62 and G Models
Replacement
Same as Right Front Side M arker L am p Bulb a n d /
or Housing Replacement - All Vehicles.
NOTE: Bulb on G Models without interior trim
may be removed from inside the vehicle.
C-K 14, 0 3 and 63 with E63, and 0 6
Models
Replacement
1.
2.
3.
Remove lens to housing four screws.
Replace bulb and check operation.
Position lens and install four attaching screws.
Platform and Stake Rack M odels (E 5 6)
Exploded view o f the different rear lighting
arrangem ents are shown in Figures 8-7 and 8-8. The
bulbs may be replaced by removing the lam p lens
attaching screws and lamp lens. The lamp housings may
LICENSE
LAM P
A SSEMBLY
D A R K G REEN
BRO W N,
M A RK E R L A M P
LIG H T G REEN
LIG HT G R E EN
BROW N
L IC E N S E /
L A M P W IRE
ASSEM BLY
FUEL T A N K
METER ASSEM BLY
BROWN
( L H SIDE O N L Y )
R IG H T SIDE
Fig. 8 5 Rear Lighting (G Models)
be replaced by removing housing attaching nuts or
screws, or by rem oving nuts and bolts from bracket.
LIG H T S W ITCH
C-K Models (Fig. 8 -1 1)
TA IL, S TO P AND B AC KUP LAM P BULBS
Replacement
C-K 14, 0 3 and 6 3 w /E 6 3 and 0 6 Models
1. Disconnect battery ground cable.
2. Reaching up behind instrument cluster, depress
shaft retaining button and remove switch knob and rod.
3. Remove instrum ent cluster bezel screws on left
end. Pull out on bezel and hold switch nut with a wrench.
4. Disconnect multiple wiring connectors at switch
terminals.
5. Remove switch by rotating while holding switch
nut.
6. To install, reverse Steps 1-5 above.
All G Models
G Models (Fig. 8-11)
Replacem ent
Replacement
1. Remove lens to housing attaching screws.
2. Remove bulbs from sockets.
3. Remove housing attaching screws (nuts on G
Models).
4. Rotate wiring harness sockets counterclockwise
and remove housing.
5. To install, reverse Steps 1-4 above.
1. Disconnect battery ground cable.
2. Reaching up behind instrum ent panel, depress
shaft retaining button and remove switch knob-shaft.
3. From front o f instrument panel remove switch
retaining nut.
4. Push switch from panel opening and remove
multiple electrical connector at switch terminals.
5. To install, reverse Steps 1-4, making sure
grounding ring is installed on switch.
D IR E C T IO N A L S IG N A L LAM PS
H E ADLA M P BEAM SELECTOR S W ITC H
D irectional signal lamps are an integral part of
parking and tail lam p assemblies. Refer to the applicable
lam p or bulb replacem ent procedures covered previously.
Replacement
Replacement
1.
2.
3.
Remove lens to housing attaching screws.
Replace bulb and check operation.
Position lens and install attaching screws.
TAIL, S TO P AND B AC KUP LAM P HO U S IN G
CLEARANCE, LICENSE PLATE AND
ID E N T IF IC A T IO N LAM PS
Refer to Figures 8-7 through 8-10 for clearance,
license plate and identification lamp installations.
1. Fold back u pper left corner of the floor mat and
remove two screws retaining switch to the floor pan.
2. D isconnect w iring c onnector from switch
terminals.
3. Connect wiring to replacement switch and check
operation.
4. Position switch to floor pan and install retaining
screws.
5. Replace floor mat.
LICENSE PLATE
LAMP WIRE —
|view|A
FRONT MARKER
LAMP HARNESS
CENTER MARKER
WIRE
v v la m ps
V IEW
FRONT WIRE
ASSEMBLY
TAIL & STOP ~
LAMP ASSEMBLY
REAR LICENSE ^
LAMP ASSEMBLY
SIDE MARKER
LAMP \
•TAIL & STOP
LAMP HARNESS
SIDE MARKER
LAMP
C209 (03) WITH OPTION E56
C310 (03) WITH OPTION E56
Fig. 8-7 -Rear Lighting (C-K Platform and Stake Rack M odels)
C 3 0 ( 0 3 ) W I T H O P T I O N E56
CK 1 0 - 2 0 A N D C 3 0 9 ( 0 3 ) W I T H O P T I O N E6 2
S TO P LA M P S W ITC H
See Section 5 (Brakes) o f this
adjustm ent and replacement procedures.
m an u a l
for
G MODELS
INSTRUMENTS, GAUGES AND CONTROLS
GENERAL DESCRIPTION
All instruments and gauges are installed in the
instrum ent cluster. Instruments and gauges can be
serviced in the vehicle (C-K Models); however, the entire
cluster must be removed from the vehicle for servicing
o f the instruments and gauges (G Models). Illuminating
an d indicator lamps may be replaced without removing
the cluster from the vehicle. Bulbs are installed in plastic
holders which lock into the cluster housing.
Regular m aintenance is not required on the
in stru m e n t cluster o r its com po nen ts o th e r than
m aintaining clean, tight electrical connections, replacing
defective parts and keeping the speedometer cable
properly lubricated.
DIAGNOSIS
OIL PRESSURE IN D IC A T O R
C o n d itio n
Light n o t lit, ignition
on a n d engine not ru nn in g.
L ight on, engine ru n n in g
above idle speed.
P o s s ib le C a u s e
C o r re c tio n
1. Bulb b u rn e d out.
1. R ep lace bulb.
2. O p e n in light circuit.
2. L o cate an d correct open.
3. Defective oil pressure
switch.
3. R eplace oil pressure switch.
1. G r o u n d e d wiring between
light a n d switch.
1. L ocate a n d repair ground.
2. Defective oil pressure
switch.
2. R eplace oil pressure switch.
3. L o w oil pressure.
3. L o cate cause o f low oil pressure
and correct.
C O O L A N T T E M P E R A T U R E IN D IC A T O R
C o n d itio n
“ H O T ” indicator;
light not lit w hen
c r a n k in g engine.
L ight on, engine
running.
P o s s ib le C a u s e
C o r re c tio n
1. Bulb b u rn e d out.
1. R ep lace bulb.
2. O p en in light circuit.
2. L ocate a n d co rrect open.
3. Defective ignition
switch.
3. R eplace ignition switch.
1. W irin g g ro u n d e d between
light a n d switch.
1. L ocate a n d correct
g ro u n d e d wiring.
2. Defective te m p e ra tu re
switch.
2. R eplace te m p e ra tu re switch.
3. Defective ignition switch.
3. R eplace ignition switch.
4. C o o la n t te m p e ra tu re
above 258 degrees F.
4. L o cate a n d correct cause
of high coolant te m perature.
H O R N S W IL L N O T O P E R A T E
C o rre c tio n
Cause
L o o se c o n n e c ti o n s in circu it.
D efectiv e h o r n sw itch.
D efective h o r n relay.
D efe c ts w ith in h o rn .
HORNS HAVE
C h e c k a n d tig h te n c o n n e c tio n s . Be sure to c h eck
g ro u n d strap s.
R eplace d e fe c tiv e parts.
R eplace relay .
R e p la c e h o rn .
POOR T O N E
C o rre c tio n
Cause
L o w available v o lta g e a t h o rn .
D e fec ts w ith in h o rn .
HORNS OPERATE
C h eck b a t t e r y a n d charging circuit.
A lth o u g h h o r n s h o u ld b lo w at a n y v oltag e above
7.0 volts, a w e a k o r p o o r to n e m a y o c c u r at
o p e r a tin g voltages b e lo w 1 1.0 volts. I f h o r n has
w e a k o r p o o r t o n e a t o p e r a tin g vo ltage o f 11.0
vo lts o r h ig h er, r e m o v e h o rn an d replace.
IN T E R M I T T E N T L Y
C o rre c tio n
Cause
L o ose o r i n t e r m i t t e n t c o n n e c tio n s in h o r n
relay o r h o r n circuit.
D efective h o r n sw itc h.
D efective relay.
D efe c ts w ith in h o rn .
C h eck a n d tig h te n c o n n e c tio n s .
R eplace sw itch.
R e p la ce relay.
R eplace h o r n .
H O R N S BLO W C O N S T A N T L Y
Cause
S tic k in g h o r n relay.
H o r n relay en ergized b y g r o u n d e d o r s h o r te d
wiring.
H o rn b u t t o n can b e g r o u n d e d b y sticking
closed.
C o rre c tio n
R eplace relay.
C heck a n d a d ju s t wiring.
A d ju st o r re p la c e d a m a g e d parts.
SPEEDOM ETER
Cause
N oisy s p e e d o m e t e r cable.
P o in te r a n d o d o m e t e r in o p e ra tiv e .
I n a c c u r a te reading.
K in ked cable.
D efective s p e e d o m e t e r h ead .
Casing c o n n e c t o r loose o n s p e e d o m e t e r case.
C o rre c tio n
1. L o o s e n o v e r-tig h te n e d casing n u ts a n d
snap-on a t s p e e d o m e t e r head.
2. R eplace h o u s in g a n d core.
R eplace b r o k e n cable.
1. C h e c k tire size.
2. C h eck for c o rr e c t s p e e d o m e te r d riven gear.
R eplace cable. R e r o u te casing so t h a t b e n d s have
no less t h a n 6 " radius.
R eplace o r have re p a ire d a t a u th o r iz e d service
s ta tio n .
T ig h te n c o n n e c to r .
GAS GAUGE
E R R A T IC F U E L G A U G E R E A D IN G S
A N D O F F C A L IB R A T IO N C O M P L A IN T S
(G a u g e flu c tu a tio n d u rin g a c c e le ra tio n an d d e c e le ra
tio n is n o rm a l.)'
NOTE:
M any fuel g au g e ta n k u n its an d dash units
are rep laced b ecau se o f p o o r diag n o sis o r lack of
j k n o w led g e o f th e v ariab les in th e system . F o r ex am p le,
som e o w n ers c o m p la in th a t w h en th e ir gauge read s
e m p ty th e ta n k c a n n o t be filled to the cap a c ity stated
j in th e o w n e r's m a n u a l.
Possible reaso n s:
C h e c k the fo llo w in g fo r loose c o n n e c tio n :
1.
D ash u n it m o u n tin g screw s.
2.
I.P . h arn ess to p rin te d c ircu it.
3.
I P. h arn ess to flat w ire.
1. E m p ty fuel reserve o f 1 to 3 gallons.
2.
G a s sta tio n a tte n d a n t did n ot tak e tim e to c o m
3.
C a r w as filled on a hill o r w ith a h eavy tru n k lo ad
pletely fill th e tank.
4.
F la t w ire to tru n k h arn ess.
c a u sin g the tan k v en t pipe to be b lo ck ed and th e re
5.
F e e d w ire to ta n k unit.
fo re p re v e n tin g th e tan k fro m being com p letely
6.
T a n k u n it g ro u n d to body.
filled.
C H A R G IN G S Y S T E M IN D IC A T O R
C o n d itio n
P o s s ib le C a u s e
C o r re c tio n
Light on, ignition off.
1. S h o rte d positive diode.
1. L ocate and replace
sh o rte d diode.
Light not on, ignition
on and engine not
running.
1. Bulb b u rn e d out.
1. R e p la c e bulb.
2. O p e n in light circuit.
2. L ocate and correct open.
3 . Open
3. R e p l a c e
L ight on, engine
ru n n in g above idle
speed.
in f i e l d .
ro to r.
1. N o gen e ra to r output.
1. C h e c k and correct cause
of no outp u t.
2. S h orted negative diode.
2. L o c a te and replace shorted
diode.
3. Loose o r broken
ge n e ra to r belt.
3. T ig h te n or replace and
tigh ten g e n e ra to r belt.
ON-VEHICLE SERVICE
COMPONENT PART
REPLACEMENT
N E U T R A L S T A R T S W ITC H
C-K Models (Fig. 8 -1 2)
Replacem ent and Adjustment
1. Disconnect battery ground cable.
2. Disconnect electrical harness at switch.
3. Remove switch m ounting screws and remove
switch.
4. Position shift lever in neutral gate notch.
5. Insert ,096"gauge pin to depth o f 3 /8 inch into
switch gauge hole, switch assembly is lixed in neutral
position with internal plastic shear pin.
6. Assemble the switch to column by inserting the
switch carrier tang in the shift tube slot and fasten in
position by assembling m ounting screws to retainers.
N OTE: If retainer strips out it must be replaced.
7. Remove .096" gauge pin.
8. Move shift lever out o f neutral gate notch to
park gate position to shear switch internal plastic pin.
9. Return shift lever to neutral gate notch.
10. Switch gauge hole will freely adm it .080"
gauge pin to a depth o f 3 /8 inch.
11. If pin will not freely enter gauge hole, switch
must be reset as below.
12. Connect battery ground cable and electrical
harness.
Reset Installation Procedure
1. Place shift lever in neutral gate notch.
2. Loosen attaching screws.
3. Rotate switch on column and insert .096" gauge
pin to depth o f 3 /8 inch.
4. Tighten attaching screws.
5. Repeat installation procedure Steps 7 through
12 above.
G-P Models
Replacement
1.
2.
(Fig.
8 -12)
Raise vehicle on a hoist.
Disconnect the switch harness from the switch.
.098 DIA
GAUGE PINs
SWITCH LEVER
TRANS LEVER
SWITCH LEVER
SWITCH
TRANS LEVERv
M O U N T IN G
BRACKET
L STEERING
COLUMN
M O U N T IN G
BRACKET
LO CK IN G PIN
C-K MODELS
V IE W A
SWITCH
G MODELS
LO CKING PIN
V IEW A
P MODELS
Fig. 8-12 -Neutral S tart Switch Replacement - Typical
3. Remove switch m ounting bolts and remove
switch.
4. Assemble new switch loosely to m ounting
bracket.
5. Align .093/.097" hole in Lever (B) with hole in
Switch Assembly. Insert Pin (A) to hold in N E U T R A L
position.
6. Set Transmission Lever (C) in N E U T R A L
position by the following method.
N O T E: O btain N E U T R A L by moving T ransm is
sion Lever counterclockwise to LI detent, then
clockwise three detents to the N E U T R A L detent
position.
7. Install Rod into Transm ission Lever and Switch
Lever. Secure with clips.
8. Tighten switch attaching screws.
9. Lower vehicle from hoist and carefully check
switch operation.
B AC KING LAM P S W ITC H
See " N e u tra l Start Switch" for automatic transm is
sion models.
6.
Check operation to make sure back-up lights
come on in reverse gear only.
Transmission M ounted Switch
Replacement
1.
2.
3.
4.
Raise vehicle on a hoist.
Disconnect switch wiring harness.
Remove switch from transmission.
To install a new switch, reverse Steps 1-3 above.
W IN D SH IE LD W A S H E R /W IP E R S W ITC H
C-K Models
Replacement
1. Disconnect battery ground cable.
2. Remove instrum ent panel bezel screws and
bezel.
3. Remove switch attaching screws.
4. Pull out on switch assembly and disconnect
electrical harness - remove switch.
5. To install, reverse Steps 1-4 above. Check switch
operation before reinstalling instrument panel bezel.
Colum n M ounted Sw itch (M anual
Transm ission)
G Models
Replacem ent
Replacement
1.
2.
3.
switch.
4.
position
5.
1.
2.
Disconnect battery ground cable.
Reach up behind left side o f instrum ent panel,
Disconnect battery ground cable.
Disconnect switch wiring harness.
Remove column m ounting screws and remove
and:
Assemble the switch to the column. Fasten in
by installing m o unting screws.
Install battery ground cable.
a. Remove plug connector from rear o f switch.
b. Remove (3) mounting screws securing bezel
and ground wires to switch.
3. Replace switch, installing ground wire and
connector. Check operation o f switch, first observing
washer solvent level.
IG N IT IO N S W ITC H
C-K M odels
See Section 3B - Steering,
replacement procedure.
for
ignition
switch
G M odels
Replacem ent (Fig. 8 -1 3 )
1. Disconnect battery ground cable.
2. Remove lock cylinder by positioning switch in
" A C C ” position and inserting stiff wire in small hole in
cylinder face. Push in on wire to depress plunger and
continue to turn key counterclockwise until lock cylinder
can be removed.
3. Remove metallic ignition switch nut.
4. Pull ignition switch out from behind instrument
panel an d remove "th e ft resistant" connector. Use a
screwdriver to unsnap locking tangs on con nettor from
their position on switch.
5. Snap connector into place on new ignition
switch.
6. Place switch into position I'rom behind instru
m ent panel, first adding grounding ring then install
ignition switch nut.
7. Install lock cylinder, key inserted.
8. Install battery ground cable.
IN S T R U M E N T CLUSTER
C-K Models
Replacem ent (Fig. 8 -1 4 )
1.
2.
Disconnect battery ground cable.
Remove head lam p switch control knob.
3. Remove radio control knobs.
4. Remove eight screws and remove instrum ent
bezel.
5. Reach up under instrum ent cluster and discon
nect speedometer by first depressing tang on rear of
speedometer head, then pulling cable free from head as
tang is depressed.
6. Disconnect oil pressure gauge line at fitting in
engine com partm ent.
7. Pull instrument cluster out just fa r enough to
disconnect line from oil pressure gauge.
8. Remove cluster to bench for further disassembly
(laminated printed circuit, speedometer head, gauges).
9. Install cluster in reverse order o f removal.
G Models
Replacement (Fig. 8 -1 5 )
1. Disconnect battery ground cable.
2. Reach up under instrument cluster and discon
nect speedometer cable by first depressing tang on rear
o f speedometer head, then pulling cable free from head
as tang is depressed.
3. Unplug instrum ent panel harness connector
from printed circuit.
4. Disconnect oil pressure line from gauge if so
equipped.
5. Remove two nuts attaching instrum ent cluster
studs to lower opening in instrument panel.
6. Pull top o f cluster away from instrum ent panel
and lift out bottom o f cluster.
7. Remove cluster to bench for further disassembly
(laminated printed circuit, speedometer head, gauges).
8. Install cluster in reverse order o f removal,
noting that clips at top o f cluster slip into instrum ent
panel opening after bottom of cluster is installed.
IN D IC A T O R AND IL L U M IN A T IN G BULBS
All Models
Replacement (Figs. 8-14 and 8 -1 5 )
1. Reach up under instrument panel and turn bulb
holder counterclockwise to remove from cluster housing.
2. Pull bulb straight out to remove from holder.
3. Install replacem ent bulb in holder, press inward
to lock in place.
4. Insert holder into housing, with lugs on holder
entering notches in case, and turn clockwise to lock
holder against printed circuit.
LA M IN A TE D (P R IN T E D ) C IR C U IT
All Models
Replacement
1. Remove instrument cluster assembly as p re
viously described in this section.
2. Remove all instrument cluster lam p bulb
assemblies.
3. Remove laminated circuit retaining screws.
NOTE: These screws serve as a ground for the
BEZEL
(TYPICAL)
CLUSTER
IN S TR U M E N T
CLUSTER
IN S TR U M E N T
CLUSTER
G
SOCKET
VIEW A
PRINTED CIRCUIT
INSTRUMENT CLUSTER
A Hi BEAM IND.
B INSTR. CLUSTER
C OIL PRESSURE IND.
D ENGINE TEMP IND.
E BRAKE WARNING IND.
F GEN. TELL TALE
G FUEL GAGE CLIPPING
H AMP GAGE CLIPPING
J BRAKE WARN (EXC U35)
K CLOCK & U35
L TEMP GAGE CLIPPING
M BRAKE WARN & U35
N FUEL GAGE CLIPPING & 16
P TURN SIGNAL IND.
Fig. 8-15--lnstrum ent Cluster Assembly (G Models)
circuit and must be reinstalled to provide the
prop er ground.
4. G Models - Remove fuel, tem perature and
a m m eter term inal nuts retaining laminated circuit to
rear of cluster.
5. Lift lam inated circuit from cluster cover.
6. To install, reverse Steps 1-5 and check electrical
operation o f all affected components.
SPEEDO M ETER
N O T E: Servicing o f the speedometer assembly
should only be p erfo rm e d by trained technicians
having the pro per test equipment.
C-K Models
Replacem nt
1.
2.
3.
stem.
Disconnect battery ground cable.
Remove h eadlam p switch control knob.
Remove radio control knobs and clock adjuster
4. Remove instrument cluster bezel and steering
column cover.
5. Remove instrument cluster lens.
6. Remove transmission P R N D L indicator and
case front cover.
7. Remove speedometer to cluster screws and
speedometer assembly.
8. To install, reverse removal procedure. Check
speedometer operation.
G Models
Replacement
1. Remove instrument cluster as previously de
scribed in this section.
2. Remove four screws retaining cluster rear cover
containing speedometer.
3. Remove two hex head screws and ru bb er
grommets securing speedometer assembly to cluster
cover.
4. To install, reverse removal procedure and check
operation o f speedometer assembly.
C A U T IO N : Use care to prevent kinking the
speedom eter
installation.
cable
d uring
rem oval
and
TE M P E R A T U R E GAUGE
C-K Models
Replacement
SPEED O M ETER CABLE CORE
All Vehicles
Replacement
1. Disconnect battery ground cable.
2. Disconnect speedometer cable from speedom e
ter head by reaching up under instrum ent panel,
depressing spring clip and pulling cable from head.
3. Remove old core by pulling it out at end of
speedom eter cable casing.
N O T E : If old cable core is broken it will be
necessary to remove lower piece from transmission
end o f casing.
4. Lubricate entire length of cable core with
speedom eter cable lubricant.
5. To install, reverse Steps 1-3 above.
C A U T IO N : Use care to prevent kinking
speedometer cable core during installation.
1. Perform Steps 1-5 o f "Instrum ent Cluster Replacement".
2. Remove tem perature gauge attaching screws
and remove the gauge.
3. To install, reverse Steps 1 and 2 above and
check gauge operation.
NOTE: Be sure gauge studs engage clips holding
laminated circuit to back of cluster housing.
G Models
Replacement
1. Remove instrument cluster assembly as pre
viously described in this section.
2. Remove terminal nuts retaining laminated
circuit to gauge unit.
3. Remove attaching screws, cover and gauge
assembly from cluster housing.
4. Remove terminal attaching nuts and gauge unit
from cover plate.
5. To install, reverse removal procedure and check
opeation of gauge.
TE M P E R A TU R E SEN DING U N IT
FUEL G AUG E
Replacement
C-K M odels
Replacement
1. Perform Steps 1-5 of "Instrum ent Cluster Replacem ent".
2. Remove fuel gauge attaching screws and remove
the gauge.
3. To install, reverse Steps 1-2 above. Check gauge
operation.
G Models
Replacem ent
1. Remove instrum ent cluster assembly as p re
viously described.
2. Remove instrum ent cluster bulb holders, ground
screws, nuts an d washers retaining laminated circuit to
fuel gauge re a r cover.
3. Remove three screws retaining fuel gauge rear
cluster cover.
4. Lift gauge away from lam inated circuit and rear
cluster cover.
5. To install, reverse Steps 1-4 and check operation
o f fuel gauge.
N O T E : M ou nt insulator strip on fuel gauge studs
first, then resistor, then a nut on each stud, next the
lam inated circuit, then a plain washer on each o f
two studs holding lam inated circuit and finally a
nut on back o f the studs that have a washer and
lam inated circuit.
W A R N IN G : Do not remove cap with
engine hot, allow vehicle to
cool off first.
1. Relieve cooling system pressure by loosening
radiator cap to first stop. Tighten cap after pressure is
relieved.
2. Disconnect sending unit wiring harness.
3. Remove sending unit from the engine.
4. Install new sending unit and connect electrical
harness.
5. Check coolant level and unit operation.
NOTE: Coolant must have at least 0 F (-18 C )
freeze protection for sending unit to function
properly.
OIL PRESSURE GAUGE
C-K Models
Replacement
1. Perform Steps 1-5 of Instrument Cluster Replacement" procedure.
2. Reach up under the instrument panel and place
a cloth under the line to gauge connection. Remove line
to gauge nut.
3. Remove gauge to cluster attaching screws and
remove gauge.
2.
Remove se nding unit using
4.
To install, reverse Steps 1-3 above and check
Replace with new unit and check operation.
gauge operation.
G M odels
VO LTM ETER
Replacem ent
C-K Models
1. Remove instrument cluster as previously de
scribed in this section.
Replacement
N OTE: Oil pressure line connection may leak oil
when opened; w rap with cloth.
2. Remove bulb holders, grounding screws and lift
lam inated circuit aside as necessary.
3. Remove instrum ent cluster cover to separate oil
pressure gauge from cluster.
4. Remove pipe fitting and retaining nut from
gauge being replaced then remove gauge from cluster
DO N O T KINK PIPE.
5. To install replacement oil pressure gauge,
reverse Steps 1-4, then observe operation o f gauge.
Tool
J21757.
1. Perform Steps 1-5 of "Instrum ent Cluster Replacement" procedure.
2. Remove gauge to instrument panel screws and
remove meter.
3. To install, reverse Steps 1 and 2 above and
check meter operation.
NOTE: Be sure meter studs engage clips holding
printed circuit to back o f cluster housing.
G Models
Replacement
1. Remove instrument cluster assembly as pre
viously described in this section.
2. Remove terminal nuts retaining laminated
OIL PRESSURE S EN D IN G U N IT
circuit to meter.
3. Lay back lam inated circuit portio n after
All M odels
removing grounding screws and bulb holders.
4. Remove attaching screws, cover and meter from
Replacement
cluster housing.
5. Remove terminal attaching nuts and m eter from
1.
D isconnect w irin g harness c onnector from
cover plate.
sending unit terminal located in block above starter on
6. To install, reverse Steps 1-5 and check operation
L-6 engines, at left front o f distributor on V-8 (except
of meter.
454 V-8) or rear left side o f block (454 V-8) engines.
DIRECTIONAL SIGNAL SWITCH
The directional signal switch is a self-contained unit which incorporates
the hazard w arning switch and the lane changing signal.
The hazard w arning circuit is activated by a push-pull switch which is
loacated on the right side of the steering column, opposite the directional
signal lever. The switch knob must be pulled to cancel circuit.
The lane changing circuit is activated by holding the directional signal
lever in the first detent position; there is no lock in or cancelling device
in this position.
See Section 3B "Steering" for all servicing procedures.
W INDSHIELD WIPER AND WASHER
C-K-G MODELS
GENERAL DESCRIPTION
The wiper motor assembly consists o f com pound
externally to the gar shaft, operates the linkage which
w ound 12 volt D.C. motor, gear reduction mechanism
activates the blades.
an d parking switch enclosed in a common die cast
The wiper motor is equipped with an internal circuit
housing. T he arm ature has a w orm shaft which drives a
gear and shaft assembly. A crank arm which is attached
breaker
mounted
on
the
motor
brush
plate which
protects the motor from overheating.
A L IG N IN G PIN
PARK SWITCH
(CONTACTS OPENED
BY CAM)
Fig. 8-16--Washer M echanism M ounting on Wiper
Figure 8-16 shows the assembly o f the washer pum p
to the wiper motor.
ELECTRICAL C IR C U IT S
T he following facts should be kept in m ind
throughout the following explanation.
1. The wiper dash switch is a grounding type
switch, and therefore must be securely mounted.
2. W hen installed in a vehicle, the wiper motor is
connected to the chassis through a ground strap. This in
effect connects the wiper housing to the ground side of
the battery.
3. The ignition switch opens and closes the feed
wire circuit to the wiper. Therefore, it must be turned
O N to operate wipers.
The wiper motor operation is controlled by two
switches—a dash control switch and a parking switch
located in the w iper motor gear box.
The park in g switch contacts are normally closed and
are opened by a cam on the gear when the wiper blades
reach the park position. The park switch acts as a
holding switch to m aintain the motor circuits to ground
during that period o f operation between the time the
operato r turns the wiper off at the dash switch and the
blades reach the park position. Figure 8-17 shows the
park switch contact open.
" L o " Speed Operation
Fig. 8 1 7 - Gear in PARK Position—Contacts Open
2.
The series' field-armature circuit is completed via
wiper terminal No. 1 through the wiring harness to the
dash switch to ground.
" H I" Speed Operation
Turning the wiper dash switch to the " H I " or fast
speed position changes the shunt field coil circuit as
follows: (Refer to Figure 8-19).
With the dash switch in the HI speed position, the
shunt field coil current passes through a 20 ohm resistor
on the back o f the wiper terminal board to terminal No.
1 and then via the wiring harness to the dash switch to
ground. The arm atu re and series field circuit is also
completed via the wiring harness from wiper terminal
No. 1 to the dash switch to ground.
Turning the W iper "O F F "
Turning the w iper dash switch to the O F F position
opens the wiper circuits to ground at the dash switch. If,
however, the wiper blades are in any position other than
the normal park or off position, the wiper motor circuits
are completed to ground by the w iper motor park switch
as follows: (Refer to Figure 8-20).
1. The series field-armature circuit is completed to
ground via the park in g switch to the wiper housing to
chassis o f vehicle.
2. The shunt field coil circuit is completed to
ground via wiper terminal No. 3 through the wiring
harness to the dash wiring harness to wiper terminal No.
1, through the parking switch to ground.
W h e n the o perator turns the w iper dash switch to
the " L O ” speed position, the wiper motor circuits are
completed to ground at the dash switch as follows:
(R efer to Figure 8-18). C urrent flows from the battery
through the ignition switch to the center terminal of the
wiper term inal board. From the center terminal, current
then passes through the black with pink stripe lead to the
series field coils (Larger d iam eter wire) where it divides
and flows as follows:
1.
The shunt field coils to wiper terminal No. 3
through the wiring harness to the dash switch to ground.
IM P O R T A N T : Note that the shunt field
circuit during the parking operation bypasses
the resistor causing the w iper to operate in
LO Speed. Failure of the wiper to operate in
LO Speed during parking results in the wiper
failing to shut oft'.
With the wiper motor circuits completed to ground
via the parking switch, the w iper motor continues to
operate until the w iper gear cam opens the park switch
contact (Figure 8-17) stopping the wiper.
See Figure 8-21 for W iper O F F Circuit.
Pulse type wipers use the same wiper motor as
regular wipers but are controlled by an external mounted
control unit.
FUSE
WIPER TERMINAL
BOARD
^SERIES FIELD
SHUNT FIELD
(PARKING CIRCUIT)
LEGEND
POWER CIRCUIT TO SERIES FIELD
SERIES FIELD AND ARMATURE CIRCUIT
SHUNT FIELD CIRCUIT
Fig, 8 - 2 0 - P A R K I N G C i r c u i t
OFF
LO
HI
12 VOLTS
DASH X
SWITCH
BATTERY
BLACK WITH
PINK STRIPE
FUSE
.WIPER TERMINAL
BOARD
BLACK
( WI PER O F F )
SERIES FIELD;
SHUNT FIELD c
RESISTOR
20 OHMS
LEGEND
POWER CIRCUIT TO SERIES FIELD
SERIES FIELD AND ARMATURE CIRCUIT
SHUNT FIELD CIRCUIT
DIAGNOSIS
W IP E R - ON VEHICLE
Troubleshooting with wiper installed on the vehicle
consists of two basic steps: (A) Preliminary inspection
and (B) O perating wiper independent o f vehicle wiring
and dash switch.
Prelim inary Inspection Procedure
A.
items:
Preliminary Inspection - Check the following
1. Body w iring securely connected to wiper unit
and dash switch.
2. W iper ground connection to vehicle chassis.
3. D ash switch is mounted securely.
4. Fuse.
5. W ith ignition switch " O N " , there should be
12 volts at center terminal (No. 2) of wiper connector
body. Refer to Figure 8-22 for # 2 term inal location.
B.
To determ ine if wiper is cause o f trouble,
disconnect existing harness from wiper and connect
ju m p e r leads to wiper terminals as shown in Figure 8-22.
Try operating wiper in LO and HI speeds. Also check if
wiper will shut off properly (blades in park position).
If wiper operates correctly, trouble must be in
wiring harness or dash switch. Refer to TR O U B L E
CHART. If w iper fails to operate correctly, remove
wiper and check it per instructions in TRO U BLE
C H A R T - W IPER D ETACHED.
W IPER - OFF VEHICLE
Connect A m m eter (0-30 amps), Power Source and
Jum per wires to wiper as shown in Figure 8-22. Observe
current draw, determ ine type o f trouble that exists and
refer to the TR O U B L E C H A R T - W IPER DETA CH ED .
POW ER
SOURCE
C O N N E C T IO N S T O
W IP E R
GROUND
B L A C K ( P L A S T IC
COATED)
GEAR
IN P A R K P O S I T I O N - W I P E R
P A R K S W IT C H
OPENED
L o Speed — A s s h o w n
“ Hi”
Speed
-
D i s c o n n e c t Jumper
from Ter mi na l
Ho. 3.
Park
-
Reconnect
J u mp e r
to
No.
3 termi nal
and
d i s c o n n e c t Jumper from wi p e r housi ng.
NOTE:
To
r ec he c k park
position
of
gear ,
r ec on
n e c t l ump e r w i r e to Hs g. ( Gr d . ) m o m e n t a r i
ly.
Wi p er
gear
should
continue
to
rotate
u n t i l i t s t o p s in t h e p o s i t i o n s h own .
Fig. 8 22 Wiper M otor Diagnosis Diagram
O FF
CONTACTS
BY G E A R C A M
TROUBLE CHART
Wiper Performs Correctly in Step "B”
But O R IG IN A L TROUBLE Was
1 — Wiper inoperative
POSSIBLE CAUSE
—
No voltage supply at wiper (Blown
fuse or open in w ire that connects
to No. 2 w iper term inal.)
—
Defective Dash Switch
—
Wire from Wiper Terminal No. 1 to
dash switch open.
2 — Wiper w ould not shut o ff but had:
fa)
Both LO and HI speeds
(a)
Wire from wiper term inaM
to dash switch grounded.
(b)
LO speed only
(b)
Wire from w iper term inal No. 3
to dash switch grounded .
(c)
HI speed only
(c)
Wire from w iper term inal No. 3
to dash switch open.
3 — Wiper had " H I " speed o n ly
See item 2 (c) above
4 -
Wiper had " L O " speed only
See item 2 (b) above
5 -
In te rm itte n t Operation
Loose dash switch mounting.
Defective dash switch.
TRO UBLE C HA RT -
W IP E R D E T A C H E D
Check the items shown in the views opposite trouble description
Trouble Description
(1) Wiper Inoperative and
ITEM 1
Solder connections
ITEM 4
to Term inal Board
Splice Connections
ITEM 3
(a) A m m e te r Reading
Amp.
Check items:
— 0
1) Circuit breaker Contacts
Black
(plastic
Insulation)
Brush
pigtail to Field Coil leads
clean and closed
2) Solder Connections to
ITEM 6
Circuit breaker Terminals
Brushes slide freely in Holders
1, 2(a), 4 and 5
Brushes and Brush holders
are not damaged
ITEM 5
Field crossover
splice connections
are secure
(b) A m m e t e r
R e a d in g
—
2.0 —3.0 Amps
Check items:
1, 3, 4, 6
ITEM 2
Splice Joints
a) Black w ith Pink Stripe
to Series Field Coil
b) Solid Black to Shunt
Field Coil
(c) Am m eter Reading — 20 +
Amps
Check for co n d ition that
w ill stall wiper, such as
b ro k e n gear or locked
armature.
TRO UBLE C HA RT -
W IP E R D E T A C H E D (C O N T .)
Check Items shown in views opposite trouble description
Trouble Description
(1) S w itch C ontacts not opening
(2) Wiper w ill not shut o ff and
(2) Black Cotten Covered Lead
to No. 1 T e rm ina l grounded
(a) Wiper has both LO and HI
Speeds. Check
and (2).
Items (1)
(b ) Wiper has LO Speed Only.
Check Items (3) and (4).
(4 ) Grounded Field Coil See CHECKING THE
FIELD COIL',
(c) Wiper has HI Speed Only.
(Shunt field circ u it open)
Refer to trouble condition
(3 ) Black Plastic Covered Lead
"W iper Inoperative" and
check Items 1, 2 (b), 4 and
5.
(3) Wiper has " H I " Speed Only
to No. 3 T e rm in a l grounded
Refer
to
view
opposite trouble
condition
"W iper
In
operative" and check Items 1, 2 (b), 4 and 5.
(4) Wiper has " L O " Speed O nly
See Trouble Description 2 (b).
(5) Wiper Gear and/or crank arm
does not park correctly. Wiper
gear and/or crank arm stops
r o t a tin g im m ediately when
wiper m otor is shut o ff.
Check fo r bent, damaged or d irty park switch contacts. See
Item (1) in view opposite Trouble D escription No. 2 "W iper
w ill not shut " O f f" .
(6) Wiper Speed Excessive in Hi
Open resistor on back o f wiper term inal board.
Speed Mode
(Crank arm or gear rotation
exceeds 80 RPM)
TRO UBLE CHART Trouble Description
(7)
W IP E R D E T A C H E D (C O N T .)
Check items shown in view opposite trouble description.
In te rm itte n t Operation:
(a) Current Draw Normal
(3.5 — 5.0 amps.)
(b) C urrent Draw — 6 — 8
amps. (Wiper runs slow
and is noisy.)
(1)
Check for loose splice joints and/or solder joints.
Refer to view opposite trouble description (wiper Inop).
If items check out, a defective circu it breaker is indicated.
(1)
(2)
(3)
Check fo r shorted or grounded armature.
Check armature end play (.002" — .003" Normal)
Check gear shaft end play (.005" Max.)
C H E C K IN G T H E A R M A T U R E A N D F IE L D C O IL A S S E M B L Y
Field testing the armature and c o n tin u ity o f field coils
consists o f using a test light similar to that shown in Figure
A.
Disassemble M otor as required to gain access to the field
and armature assemblies.
25 WATT LAMP
________
115 V.
p
A
_________
______________
Test Probes
Typical Test Light
FIGURE A
Armature Checks:
Grounded—Touch test light probes to armature lamina and
com m utator. If armature is grounded, the lamp
w ill light.
Open
— A bar to bar check w ith the test light w ill
indicate an open armature (Fig. B). If lamp does
n o t lig h t b e tw e e n a n y tw o a d ja c e n t
c o m m u ta to r b a rs , an open armature is
indicated.
Shorted — Test armature on growler fo r shorted condition.
Field Coil Checks:
I M P O R T A N T : I n s u l a t e br u s h e s f r o m a r m a t u r e
com m utator. A th in piece of paper w ill be adequate.
FIGURE B
C H E C K IN G T H E A R M A T U R E A N D F IE L D A S S E M B L Y (C O N T .)
Open Check
Connect test light to fo llo w in g points.
Refer to Figure C .
C h eck ing for
Open S h u n t Field
Shunt Field:
Brush lead " A " and black w ire term inal
(No. 3) on wiper term inal board. If lamp
fails to light, check splice joints — Items
2, 4 and 5 in T rouble Chart opposite
w iper inoperative.
Series Field:
Brush lead " A ” and No. 2 term inal on
wiper term inal board Figure C . If lamp
fails to lig h t, check splice joints — Items
2, 4 and 5 in T rouble Chart opposite
w iper inoperative.
Ground Check
Connect 'test light to field lamina and
wiper term inal board, terminals 2 and 3.
(Be sure End Cap and Field Lamina are
not touching w iper gear casting.)
T o u c h in g Bru sh
B ra ide d Lead
.. A ..
Field Lam in a
figure
c
D I A G N O S I S - W AS H E R SYSTEM
C O N D IT IO N
1. W a s h e r inoperative
2. W a s h e r p u m p s
c o n tin u o u sly w hen
wipers are o pe ra ting
A PP A R E N T CAUSE
C O R R E C T IO N
A. In a d e q u a te q u a n tity
o f w a sh e r solution
A. A d d w asher
solution
B. H oses d a m a g e d or loose
B. C u t sh o rt length
to insure air
tight c o nn e ction
o r replace hose
C. Plugged screen at end
o f j a r cov er hose
C. C lean screen
D. Loose electrical
c o n n e c tio n to w a sh e r
p u m p o r w iper switch
D. C h e c k electrical
co n n e c tio n and
re p a ir if necessary
E. O p e n circuit in feed
w ire to p u m p solenoid
coil
E. L o c a te o pen circuit
an d rep air
F. W ip e r switch defective
F. R eplace wiper switch
G. P u m p solenoid coil
defective
G . R ep lac e solenoid
H. W a s h e r nozzles plugged
H. Clean w a sh er nozzles
I. R a tc h e t wheel to oth
missing
I. R eplace ra tc h e t wheel
J. R a tc h e t pawl spring
missing
J. R e plac e ra tc h e t pawl
spring
K. Defective p u m p valve
assem bly
K. R e pla c e p u m p valve
assembly
A. G r o u n d e d wire from
p u m p solenoid to
switch
A. L o c a te g ro u n d e d wire
an d repair
B. W ip e r Switch Defective
B. R eplace w iper switch
C. R a tc h e t wheel tooth
m issing
C. R ep lace ra tc h e t wheel
D. R a tc h e t wheel dog
bro k e n o r not c on ta c tin g
ra tc h e t wheel teeth
D. R eplace o r repair
ra tc h e t wheel dog
E. L o c k-ou t tang b ro k e n or
bent on piston a c tu a tin g
plate
E. R eplace piston
a c tu a tin g p late
ON-VEHICLE SERVICE
COMPONENT
PART
REPLACEMENT
W IP E R M O TO R
C-K Models
Replacement (F ig . 8 -2 3 )
1. M ake sure wiper motor is in Park position.
2. Open hood and disconnect ground cable from
battery.
3. Disconnect electrical harness at wiper motor and
hoses at washer pump.
4. Reach down through access hole in plenum and
loosen wiper drive rod attaching screws. Remove drive
rod from w iper motor crank arm.
5. Remove wiper motor to dash panel attaching
screws and remove the motor assembly.
6. To install, reverse Steps 1-5 above.
N O T E : Lubricate w iper motor crank arm pivot
prior to reinstallation.
G M odels
Replacement (F ig . 8 -2 4 )
1. M ake sure wiper motor is in Park position.
2. Open hood and disconnect battery ground cable.
3. Remove wiper arm s from wiper transmission
linkage.
4. Remove rem ain in g screws securing cowl panel
cover and lift off’.
5. Loosen nuts holding transmission linkage to
w iper motor crank arm and lift linkage off arm.
6. Disconnect power feed to wiper motor at
multiple connector.
7. Remove left dash defroster outlet from flex hose
and push hose aside for access to wiper motor screws.
8. Remove one screw securing left hand heater
duct to engine cover shroud and slip heater duct down
and out.
9. Protect carpet, then remove windshiled washer
hoses from washer pump.
10. Remove three screws securing wiper motor to
cowl and lift w iper motor out from under dash for
further disassembly on bench.
11. To install, reverse Steps 1-10 above.
NOTE: Install wiper in the PARK position. Lube
wiper motor crank arm pivot prior to installation.
UNIT REPAIR
W IP E R /W A S H E R DISASSEMBLY
Park Switch (Fig. 8 -2 5)
1.
2.
Remove washer pu m p (fig. 8-16).
Remove screw retaining park switch.
3.
4.
Remove spacer.
Unsolder lead.
Term inal Board (Fig. 8-25)
1.
2.
3.
Remove washer pump.
Remove spacer.
Unsolder leads.
Gear Assembly
1. Remove washer pump.
2. Remove park switch (See park switch removal).
U nsolder lead only if required.
3. Clam p crank arm in vise and loosen crank arm
retaining nut. Remove nut and crank arm (fig. 8-26).
4. Remove seal cap and using No. 22 External
Snap Ring Pliers, remove the " C " retaining ring (fig.
8-27). Next, remove washer, end play washers, and outer
spacer ( lig. 8-28).
5. Slide the gear assembly out of the housing and
remove the inner spacer washer (fig. 8-29).
6. To reassemble the gear box, reverse the
disassembly procedure.
Crank Arm Assembly
1. Operate wiper gear to park position (fig. 8-26).
2. Position crank arm on gear shift flats according
to postion shown in Figure 8-26.
3. Install crank arm retaining nut finger tight, then
Fig. 8 2 4
d a m p crank arm
securely.
in vise and tighten
W ip e r
retaining nut
M O TO R DISASSEMBLY
N OTE: Motor section may
independently o f the gear box.
be
disassembled
Brush P late and Circuit Breaker
Removal
1. Scribe a reference line along the side of the
casting and end cap to insure proper reassembly.
2. Remove two motor through bolts.
3. Feed exposed excess length o f motor leads
through the casting g rom m et and carefully back the case
and field assembly plus the arm ature away from the
casting (fig. 8-30).
N O TE: It may be necessary to remove the
arm ature end play adjusting screw and insert a rod
M o to r ( G
M o d e ls )
through the opening in order to apply pressure
against the end o f the armature.
4.
breaker
5.
plate to
Unsolder black cotton-covered lead from circuit
(fig. 8-31).
Straighten out the four tabs that secure brush
field coil retainers (fig. 8-31).
C A U TIO N : Be careful not to break any o f the
retainer tabs.
6. Install " U " shaped brush retainer clip over
brush holder that has brush lead attached to circuit
breaker (fig. 8-31).
7. Holding the opposite brush from that retained
in Step 6, carefully lift brush holder off mounting tabs
far enough to clear arm ature com m utator (fig. 8-32).
8. Allow the brush, held in Step 7, to move out of
its holder. Remove brush spring and lift brush holder off
arm ature shaft.
Arm ature
Case and Field Assembly
Removal
Removal
1. Follow Steps l thru 8 under brush plate and
circuit breaker removal.
2. Lift arm ature out of case and field assembly.
3. If arm a tu re is being replaced, remove thrust ball
from end o f defective arm ature shaft and install it in
new arm ature.
NOTE: Thrust ball may be easily removed with a
magnet.
1. Remove brush plate and armature.
2. The end case and field assembly is serviced as a
unit. To free the field and case assembly, cut the solid
black plastic insulation and black with pink stripe leads
in a location convenient for splicing-preferably near the
wiper terminal board. Refer to Figure 8-3 1 for splicing
location.
ARMATURE END
PLAY ADJUSTING
SCREW A N D LOCKNUT
PARK SWITCH
M O U N T IN G SCREW
SPACER
Fig. 8-27
F ig . 8 -2 5 - - Park S w i t c h
"C "
R in g
Rem oval
Rem oval
SPACER
FLAT WASHER
o
FLAT WASHER
CRANK ARM
\
SHIM (AS REQUIRED)
SNAP RING
SEAL
f m
CUT MOTOR LEADS IN THIS
GENERAL AREA FOR SPLICING
BRUSH PLATE ASSEMBLY
RETAINER TAB (4)
“ U " BRUSH
RETAINER CLIP
BLACK LEAD TO
CIRCUIT BREAKER
Fig. 8-29 - D riv e G e a r
Rem oval
CIRCUIT
BREAKER
SPLICE NOTES:
1-SOLID BLACK TO
SHUNT FIELD COIL
2-SERIES FIELD COIL
TO BLACK WITH PINK
STRIPE LEAD
Fig. 8-31--Circuit B r e a k e r
C A S T IN G
GROMMET
STAKE M A R K S C A S E T O FIELD
L A M IN A
(4
P LA C E S )
3.
Remove steel thrust plate and ru bb er disc from
case b earing as required.
M O T O R ASSEMBLY
1. If new field and case assembly is being installed,
splice the black and black with pink stripe leads o f the
new field with the corresponding leads o f the wiper
term inal board.
2. Install rubber thrust disc, steel thrust disc and
felt lubricting washer in case assembly bearing in order
indicated.
3. Lubricate end of arm atu re shaft that fits in case
bearing. Next, install thrust ball in end of shaft.
4. Assemble arm ature in case and field assembly
(fig. 8-33).
5. Position partially assembled brush plate (fig.
8-34) over arm a tu re shaft fa r enough to allow assembly
o f re m ain in g brush in its brush holder, then position
brush plate on mounting tabs in position shown in
Figure 8-31.
N O TE : Circuit breaker should be opposite field
cross over splice connections (Figure 8-32).
6. C e n te r b rush plate m o u n tin g holes over
m ounting tabs and bend tabs toward brush holders as
required to secure brush plate in position.
CAUTION: Be sure tabs are centered in brush
plate m ounting holes.
7. Remove brush retainer clips and resolder black
cotton covered lead to circuit b reaker (fig. 8-31).
8. If new case and field assembly is used, scribe a
line on it in the same location as the one scribed on the
old case. This will insure proper alignment of the new
BRUSH HOLDER
Fig. 8 -3 4 - - Bru sh
P l a t e A s s e m b ly
case with the scribed line made on the housing (Step 1
under Brush Plate Removal).
9. Position arm ature worm shaft inside housing
and. using scribed reference marks, line up as near as
possible the case and filed assembly with the housing.
10. M aintaining the arm ature in its assembled
position in the case, start the arm ature worm shaft
through the field and housing bearing until it starts to
mesh with the worm gear. At the same time, carefully
pull the excess black and black and pink stripe leads
through the housing grommet.
CAUTION: It m ay be necessary at this point to
rotate arm ature slightly before the armature
worm will engage with worm gear teeth.
11. Rotate the case as required to align the bolt
holes in the case with those in the housing.
12. Secure the case to the housing with the two tie
bolts.
13. Adjust arm ature end-play as described under
"W iper Adjustments".
W IPER A D JU S T M E N T S
Arm ature End-Play
Loosen adjusting screw locknut (Figure 8-27) and
tighten the adjusting screw until finger tight, tighten
locknut.
Gear Assembly End-Play
A dd end-play washers as required to obtain .005"
m inimum end-play (Figure 8-27).
W ASHER P U M P
The washer p u m p a n d / o r valve assembly may be
removed from the w iper assembly as a unit; therefore, it
is not necessary to remove the wiper assembly from the
vehicle if only the washer pum p a n d /o r valve assembly
requires service.
W hen the pu m p is removed from the wiper
Replacement
RELAY A R M A T U R E
A R M A T U R E LEG
ARMATURE
SPRING
P A W L SPRING
I
RAT CHET D O G
RATCHET P A W L
RATCHET WHEEL
1. Raise vehicle hood and disconnect ground cable
from battery.
2. G Models - Remove left heater duct attached to
engine shroud, for access.
3. Disconnect washer hoses and electrical connec
tions from assembly.
4. Remove three screws securing washer p u m p and
cover to w iper assembly. Remove pu m p from wiper gear
box.
5. To install, reverse Step 1-4 above.
Pump Valve
Replacement
T A N G O F SPRING
‘ ACTS A S T O O T H
O F RATCHET WHEEL
Fig . 8-35
W asher Pum p
A s s e m b ly
assembly, all working parts are readily accessible and
may easily be serviced as necessary (fig. 8-35). A crosssection o f the w asher pu m p valve assembly is shown in
Figure 8-36.
1.
G
Models -
Remove
the washer
pum p
as
outlined above.
C-K Models - Raise hood. Disconnect washer hoses
and electrical connections from assembly.
2. Remove the four screws that attach the valve
assembly to the pu m p housing.
CAUTION: D uring re-assembly be sure gasket
between housing and valve plate is properly
positioned in the housing and valve plate
grooves. Also be sure triple "O " ring is properly
installed between valve and pipe assembly.
3. To install, reverse removal procedure.
SPRING
PISTON
COMPRESSED
IN TA KE
VALVE
OPEN
DIRE CT IO N OF T R A V E L
FROM
WASHER
JAR
---------------- I / / 7
T
'
' ACTUATOR P LATE
EXHAUST
INTAKE STROKE
V ALV ES
CLOSED
PISTON
SPRING
E X P A ND E D
INT A KE
VALVE
CLOSED
DIR E CT IO N OF T R A V E L •
ACTUATOR PLATE
TO
NOZZLES
EXHAU ST
EXHAUST STROKE
VALVES
OPEN
Fig. 8 - 3 6 -Cross S e c t io n
of W in d s h ie ld
W asher
Pum p
V a lv e A s s e m b ly
WINDSHIELD WIPER AND WASHER
P MODELS
GENERAL DESCRIPTION
T he system consists o f a c o m p oun d w ound
rectangular-shaped motor attached to a gear box
containing a parking switch in addition to the gear train.
The gear train consists o f a motor arm ature helical
gearshaft which drives an interm ediate gear and pinion
assembly. The pinion gear o f the interm ediate gear and
pinion drives an output gear and shaft assembly.
T u rning the w iper switch to the LO speed position
completes the circuits from the wiper terminals 1 and 3
to ground. C u rren t then flows from the battery via wiper
terminal No. 2 through the series field and divides; (1)
part passes through the arm ature to ground via wiper
terminal No. 1 to the wiper switch and (2) the second
part passes through the shunt field to ground through
wiper terminal No. 3 to the wiper switch (fig. 8-37).
NOTE: The wiper switch must be securely
grounded to body metal.
Moving the wiper switch to the HI speed position
opens the shunt field circuit to ground at the switch.
However, the shunt field is connected to a 20 ohm
WIPER GEAR
TRAIN
WIPER
TERMINAL
BOARD
DASH
SWITCH
PARK
SWITCH
SERIES F
I b l\ I I I UN
SHUNT F - NAT . WIRE
SWITCH
Fig. 8-37--LO S p e e d
C ir c u it
Fig. 8-38--HI S p e e d
C ir c u it
resistor which is connected across wiper terminals 1 and
3. The shunt field current then flows via terminal No. 3
through the resistor to terminal No. 1 to the switch, to
groun d (fig. 8-38).
The parking circuit covers that portion o f wiper
operation when the w iper switch is turned "off" and the
w iper blades have not reached the park position.
W hen the w iper blades are not in the normal park
position, the parking switch contacts are still closed. The
w iper will continue to operate until the wiper output gear
is turned to a position where its cam opens the park
switch. R eferring to Figure 8-39, it can be seen that the
w iper motor circuits are completed to ground through
the parking switch.
N O TE : The w iper m otor
grounded to body metal.
must
be
securely
The shunt field circuit is completed from terminal
No. 3 via the switch to terminal No. 1 through the
parking switch to ground. The series field and arm ature
circuit is also completed from terminal No. 1 through the
parking switch to ground.
NOTE: The shunt field is connected direct to
ground, by-passing the resistor. This results in LO
speed operation during the parking operation.
W hen the output gear cam opens the park switch
contacts, the wiper is OFF.
DASH
SWITCH
BLACK
PARK
SWITCH
■I..I..I.......-
SERIES
IGNITION
SWITCH
SHUNT F
Fig. 8-39 - P A R K IN G
C ir c u it
DIAGNOSIS
W IPER - ON VEHICLE
1.
Inspect for the following items:
a. W iring harness is securely connected to wiper
and switch.
b. W iper motor is securely grounded to body.
c. W ip e r switch is securely m ounted and
grounded.
d. Check fuse.
2. If items in Step 1 check out. try operating wiper
in both "L O " and "H I" speeds, then turn wiper off
(blades should return to park position). If wiper fails to
operate correctly, proceed to Step 3.
3.
Disconnect wiring harness from wiper and try
operating wiper as shown in Figure 8-40.
a. If wiper operates correctly independently of
switch and vehicle wiring, refer to the DIAGNOSIS
C H A RT - WIPER O N VEHICLE.
b. If wiper still fails to operate correctly in Step
3, disconnect wiper linkage from motor crankarm and
try operating wiper again. If wiper opeates correctly
independently of linkage, check linkage for cause of
wiper malfunction.
c. If wiper fails to operate correctly indepen
dently o f linkage, remove wiper motor from vehicle and
refer to DIA G N O IS CH A RT-W IPER O F F VEHICLE.
D I A G N O S I S - WIPER O N VEHICLE
NOTE: Ignition sw itch m ust be "o n" for all electrical tests.
C O N D IT IO N
A P PA R E N T CAUSE
C O R R E C T IO N
A. Blown fuse
A. L ocate sh o rt circuit
a n d repair. R e p la c e fuse.
B. O p e n circuit in feed wire
(N o. 2 term in a l on w iper
m o to r)
B. L o ca te b ro k e n wire a n d
rep air
C. Loose m o u n tin g of w iper
switch
C. T ig h te n sw itch m o u n tin g
D . D efective w ip er switch
D. R e p la c e switch
E. O pen circuit in wire to
w ip e r sw itch (N o. 1 term inal
on w iper m o to r)
E. L o c a te b ro k e n wire
a n d repair
A. G r o u n d e d W ire (No. 1
te rm in a l on wiper m o to r) to
w ip e r sw itch
A. L o c a te sh ort circuit an d
re p a ir
A. D efective w iper switch
A. R e p la c e wiper switch
B. G r o u n d e d wire (N o. 3
term in a l on wiper m o to r) to
w ipe r sw itch
B. L o c a te a n d re p a ir sh o rt
c ircuit
A. D efective w iper switch
A. R e p la c e w iper switch
B. O p en circuit in wire (N o. 3
te rm in a l on wiper m o to r) to
w ip e r sw itch
B. L o c a te a n d re p a ir b ro k e n
w ire
3. W ip e r has " H i" speed only
A. O pen circuit in wire (N o. 3
te rm in a l on wiper m o to r) to
w iper sw itch
A. L o c a te b ro k e n wire
a n d re p a ir
4. W ip e r has "L o " speed only
A. G r o u n d e d wire (No. 3
term in a l on w iper m o to r) to
w iper sw itch
A. L o c ate sh ort circuit and
repair
B. D efective wiper switch
B. R eplace w iper switch
A. Loose w iper g r o u n d strap
c o n n e c tio n
A. T ighten stra p
c o n nectio n
1. W ip e r In o p e ra tiv e o r
in te rm itte n t
2. W ip e r will n o t sh u t off:
A. W ip e r has b o th " L o " and
"H i" speeds
B. W ip e r has "L o " speed only
C. W ip e r has " H i" speed only
5. Blades do not re tu r n to
full p a r k position
D I A G N O S I S - WIPER OFF VEHICLE
C O N D IT IO N
A PP A R E N T CAUSE
C O R R E C T IO N
A. Broken o r d a m a g e d g ear
train (only if inoperative)
A. Replace gears as required
B. P o o r solder con nection s at
term in a l board
B. R esolder wires at term inals
C. Loose splice jo in ts at b rush
plate
C. R e c r im p or solder splice
join ts
D. B rushes binding in bru sh
h o ld er
D. Clean h o ld e r o r replace
bru sh , sp ring o r bru sh
plate assembly.
E. O pen circuit in a r m a tu r e
E. R e p la c e a r m a tu r e
A. Defective p ark switch
A. R e plac e term in a l board
assem bly
B. G r o u n d e d red lead wire
B. R e p a ir sh o rt circuit in
red wire
A. G r o u n d e d sh u n t field coil
A. R e p la c e fram e an d field
assem bly
B. G r o u n d e d black wire
B. R e p a ir sho rt circuit in
black wire
A. O p en circuit in shu nt field
coil
A. R e p la c e fram e and field
assem bly
B. O pe n circuit in black wire
B. R e p a ir brok en wire o r p o o r
so ld e r conn ection
3. W ip e r sh u ts off - but
not in p a rk position
A. P a rk switch defective or
co n ta c ts dirty
A. R eplace term inal board
assem bly o r clean c ontacts
4. "H i" speed to o fast
A. R esistor defective
A. R e p la c e term inal b oard
assem bly
1. W ip er In o p e ra tiv e o r
In te r m itte n t
2. W ip e r will not shut-off:
A. W ip e r has n o rm a l "H i"
a n d "L o " speed
B. W ipe r has "L o " speed only
C. W ip er has "H i" speed only
LO SPEED - A S SHOW N
H I SPEED - D IS C O N N E C T JU M P E R W IR E FROM
TEST LIGH T PROBES FOR
T E R M IN A L NO. 3.
GROUND CHECK.
D IS C O N N E C T IT FROM G RD . S T R A P .
IF LA M P
LIG H T S , AR M ATU R E IS
OFF - LEAVE JU M P E R CONNECTED TO N O S . 1 & 3 BUT
W IP E R SHOULD
STOP W IT H GEAR SH AFT FLATS A S SH OW N.
CHECK FOR
TEST LIG H T PROBES,
POOR WELD
BAR TO BAR CHECK
JO IN T S
FOR OPENS - LA M P
SHOULD LIG H T BETWEEN
ADJACENT BARS
W IP E R
GROUND S T R A P
Fig. 8 40- Jumper Wire Connections
Fig. 8-41--Checking Armature
D I A G N O S I S - W A S H E R SYSTEM
C O N D IT IO N
A PPA R E N T CAUSE
C O R R E C T IO N
1. W a sh e rs inoperative
A. In a d e q u a te q u a n tity o f
w a sh e r solution
A. A d d w a sh e r solution
B. Hoses d a m a g e d o r loose
B. C u t s h o rt len gth off
en d o f hose to insure
air tight c o n n e c tio n
or replace hose
C. Plugged screen at end
o f ja r cover hose
C. C lean screen
D . Loose electrical
c o nn e c tion to w ash er
p u m p o r w iper switch
D. C h e c k electrical
c o n n e c tio n s an d
re p a ir if necessary
E. O p e n circuit in feed
wire to ra tc h e t relay
coil
E. L o c a te open circuit
a n d re p a ir
F. W ip e r sw itch defective
F. R e p la c e w iper switch
G . R a tc h e t relay coil
defective
G . R e p la c e ra tc h e t relay
H . W a s h e r nozzles plugged
H . C lean w a sh e r nozzles
I. R a tc h e t wheel to o th
missing
I. R ep lac e ra tc h e t wheel
J. R a tc h e t paw l spring
missing
J. R e p la c e r a tc h e t pawl
sprin g
K . D efective p u m p valve
assembly
K . R e p la c e p u m p valve
assem bly
A. G r o u n d e d wire from
r a tc h e t relay to sw itch
A. L o c a te g ro u n d e d wire
a n d re p a ir
B. W ip e r sw itch defective
B. R e p la c e w ip er switch
C. R a tc h e t wheel to oth
m issing
C. R e p la c e ra tc h e t wheel
D. R a tc h e t wheel dog
b ro k e n or not c o n ta c tin g
ra tc h e t wheel teeth
D . R e p la c e o f repair
r a tc h e t wheel dog
E. L oc k -o ut tang b ro k e n o r
b ent on piston a c tu a tin g
plate
E. R e p lac e piston
a c tu a tin g plate
2. W a s h e r p u m p s co n tin o u sly
w h en w ipers are o p e ratin g
ON-VEHICLE SERVICE
W IP E R M O T O R
....
W iper
r
motor
,
replacement
1
.
procedures
1
are
not
included here since installation is perform ed by the
individual body manufacturers; however, disassembly of
,,
J
the unit will be covered.
UNIT REPAIR
CAUTION: Failure to clamp crank arm may
result in stripping o f wiper gears.
4. Remove crank arm, seal cap, retaining ring, and
end-play washers.
W IP E R M O TO R
Disassembly (Fig. 8 -4 3)
Gear Box
1. Remove the two washer pump mounting screws
and lift p u m p off washer.
2. Remove washer pum p drive cam as required
(figs. 8-46 and 8-47). The cam is pressed on the shaft but
can be wedged off by using two screwdrivers between
cam and plate.
3. C lam p crank arm in a vise and remove crank
arm retaining nut.
NOTE: Seal cap should be cleaned and repacked
with a w aterp roof grease before reassembly.
5. Drill out gear box cover retaining rivets, remove
cover from gear train.
N OTE: Screws, nuts and lockwashers for reassem
bling cover to wiper are contained in the service
repair package.
6. Remove output gear and shaft assembly, then
slide intermediate gear and pinion assembly off shaft.
R E M O V E BR U SH S P R IN G F R O M SLO T
A N D P LA C E IT IN G R O O V E
AS SH O W N
Nuf
Crank Arm
Seal Cap
Retaining Cap
Washer
Gear Box Cover
7. Output
G ear and
Shaft Assembly
Intermediate Gear
9. Wave Washer
1 0 . Gear Box Housing
11. Brush Plate Assembly and
Mounting Brackets
12. Brushes
13. Wave Washers
14. Flat Washers
15.
16.
17.
18.
19.
Armature
Thrust Plug
Frame and Field
End Plate
Tie Bolts (Two Required)
7.
II' necessary, remove terminal board and park Motor
switch assembly as follows:
Reassemble motor using reverse o f disassembly
a. Unsolder motor leads from terminals. Code
procedure.
motor leads.
b. Drill out rivets securing terminal board and
NOTE: A rm ature end play is controlled by end
park switch ground strap to mounting plate.
play washers. See Figure 8-44 for proper assembly
o f end play washers. Lubricate arm ature shaft
N OTE: Screws, nuts and washers for attaching a
bushings with light machine oil.
replacem ent terminal board park switch assembly
are included with the replacement assembly.
Gear Box
M otor
1. Follow Steps 1 through 7b under gear box
disassembly.
2. Remove motor through bolts, tap motor frame
lightly, and remove motor from mounting plate.
3. Remove brush spring tension (fig. 8-43), slide
arm a tu re and end plate from motor frame. Pull end
plate from arm ature.
N O T E: Thrust plug located between arm ature
shaft and end plate.
4. Remove end play adjusting washers from
arm ature, noting a rra n g e m en t for proper reinstallation.
Inspection
Check and inspect all parts for wear; replace as
necessary. All parts can be replaced individually except
motor fram e and field, which is serviced as an assembly.
Service kits also provide screws, nuts and washers to
replace gear cover and terminal board rivets.
Assembly
Refer to Figure 8-43 for exploded view o f motor
and gear train.
1. Assemble gear box using reverse o f disassembly
procedure.
NOTE: Lubricate gear teeth with Delco Cam and
Ball Bearing lubricant (or equivalent). Be sure
cover is properly located over dowel pins and be
sure to reinstall ground strap.
2. Place wiper in park position and install crank
arm on output shaft, rotate crank so alignm ent marks
line up with those on cover (fig. 8-45).
3. Replace retaining nut, place crank arm in vise,
tighten retaining nut.
W IN D SH IE LD W ASHER
The positive displacement washer pum p used on the
two-speed non-depressed park wipers (tig. 8-46) use a
pum p mechanism consisting of a piston, piston spring
and valve a rra n g e m en t driven by a (4) lobe cam, and
follower assembly (fig. 8-48). The cam is attached to one
shaft o f the wiper motor output gear (fig. 8-47).
Program m ing is accomplished electrically and m echani
cally by a relay assembly and ratchet wheel arrangement.
PUMP M OUNTING SCREWS
F ig . 8-46
W asher
P u m p A t t a c h in g
Sc re w s
Replacement
1.
2.
3.
4.
Disconnect battery ground cable.
Remove two pu m p m ounting bolts.
Remove washer pu m p assembly.
To install reverse Steps 1-3 above.
C A U TIO N : Install washer multiplug harness
connector with battery lead on term inal with no
tang (Jig. 8-46). Incorrect installation o f
Fig. 8 4 8
W asher
Pum p
D r iv e C a m
and
A c tu a to r
connector will result in direct ground and
destroy wiper motor fuse.
Disassembly-Assembly
(Figures 8-4 9-8-5 2 )
1.
Remove washer pum p cover by squeezing.
2.
Solenoid assembly - ratchet dog.
a. Remove ratchet dog retaining screw. Hold
spring loaded solenoid plunger in position and carefully
lift solenoid assembly and ratchet dog off fram e of
pump.
b. Separate ratchet dog from solenoid mounting
plate as required.
SOLENOID COIL
4 LOBE CAM
(PRESS FIT
O N SHAFT)
VALVE
ASSEMBLY
\
\
S
i\
™
SOLENOID
PLUNGER
,
'/
RATCHET
PAWL
SPRING
C A M FOLLOWER
UPPER PIN
"E " RING
RATCHET
PAWL
RATCHET D O G
R ET A IN IN G
S C R EW
S O L E N O ID
ASSEMBLY
VA LV E ASSEMBLY
M O U N T IN G SCREW
GROOVES
BOTH SIDES
Fig. 8-51- R e le a s in g
Fig. 8 - 5 0 - - W a s h e r P u m p - E x p lo d e d
Ratchet pawl.
a. Disconnect ratchet pawl spring.
b. Remove ratchet pawl retaining ring and slide
ratchet pawl off cam follower shaft.
Ratchet wheel.
a. Follow Step 1 under solenoid - ratchet dog
disassembly.
b. Move ratchet wheel spring out of shaft groove
and slide ratchet wheel off its shaft.
5.
F ro m
Lockout
P o s itio n
V ie w
3.
4.
Pum p
b.
To separate pum p and pum p actuator plate
from frame, pull pu m p housing in direction o f the arrow
until grooves in housing clear the frame. Then remove
actuator plate from ratchet wheel and cam follower
shafts.
6. Valve assembly.
a.
Remove four screws that attach the valve
assembly to pum p housing.
Pum p and actuator plate assembly.
a.
Remove solenoid assembly - ratchet pawl and
ratchet wheel as outlined in their respective procedures.
C A U TIO N : D uring assembly, be sure gasket
between housing and valve plate is properly
positioned in housing and valve plate grooves.
Also be sure triple " 0 " ring is properly
installed between valve body and pipe assembly.
SPRING
PISTON
COMPRESSED
I NTA KE
VALVE
OPEN
FROM
WASHER
ACTUATOR P LATE
EXHAUST
INTAKE STROKE
V AL V ES
CLOSED
PISTON
SPRING
E X P A ND E D
I NT A K E
VALVE
CLOSED
ACTUATOR PLATE
TO
N O ZZ L ES
EXHAUST
EXHAUST STROKE
VALVES
OPEN
F ig. 8-52 -C ross S e c t io n
o f W in d s h i e l d
W asher
Pum p
V a lv e
CIRCUIT PROTECTION
GENERAL DESCRIPTION
All electrical circuits are protected against excessive
loads which might occur due to shorts or overloads in the
w iring system. Such protection is provided by either a
circuit breaker, fuse or fusible link. Each o f these
protective devices are explained below.
C IR C U IT BREAKER (Fig. 8-53)
A circuit breaker is a protective device designed to
open the circuit w hen a current load is in excess o f rated
breaker capacity. If there is a short or other type of
overload condition in the circuit, the excess current willl
open the circuit breaker and cause it to cycle if it
automatically resets, thus, indicating there is something
wrong in the system. The circuit breaker will continue to
cycle until the trouble is found and corrected. Excessive
cycling of the breaker will eventually dam age the
breaker contacts to the point that replacement o f the
breaker is necessary.
FUSE (Fig. 8-53)
A common method o f protection is to use a fuse in
the circuit. W henever there is an excessive current
through the circuit, the fusible element will melt and
open the circuit. The disadvantage o f using a fuse
F U SIB L E L IN K BEFORE SHORT C IR C U I T
CUT WIRE HERE
FU S IB L E LIN K AFTER SHORT C IR C U I T
F ig . 8 -5 4--Fusible L in k
Fig . 8 5 3
Fuse an d
C i r c u it B r e a k e r
instead o f a circuit breaker is the fuse in a one-time
protection and replacem ent is required.
FUSIBLE LIN K (FIG . 8 -5 4)
In addition to circuit breakers and fuses, the wiring
harness incorporates fusible links to protect the wiring.
Links are used rather than a fuse in wiring circuits that
are not normally fused, such as the ignition circuit.
w iring fusible links are color coded red in the
charging and load circuits to m atch color coding o f the
circuit they protect. Each link is four gauge sizes smaller
than the cable it is designed to protect and are marked
on the insulation with wire gauge size because the heavy
insulation makes the link ap p e a r a heavier gauge than it
actually is.
E ngine co m p artm ent wiring harnesses incorporate
several fusible links. The same size wire with special
hypalon insulation must be used when replacing a
fusible link.
The links are:
1. A molded splice at the starter solenoid “ Bat”
terminal, 14 gauge red wire. Servicing requires splicing
in a new link.
2. A 16 gauge red fusible link is located at junction
block to protect all unfused wiring of 12 gauge or larger.
The link is molded into the bulkhead connector.
3. The generator w arn in g light and field circuitry
(16 gauge wire) is protected by a fusible link (20 gauge
red wire) used in the “ battery feed to voltage regulator
# 3 term inal” . The link is installed as a molded splice in
the circuit at the junction block. Service by splicing in a
new 20 gauge wire.
DIA G N O SIS
Failures in a circuit are usually caused by short or
open circuits. Open circuits are usually caused by breaks
in the wiring, faulty connections or mechanical failure in
a component such as a switch or curcuit breaker. Short
circuits are usually caused by wires from different
components of the circuit contacting one anothe or by a
wire or component grounding to the metal o f the body
due to a screw driven through the wires, insulation cut
through by a sharp metal edge, etc.
The following inform ation m ay aid in locating and
correcting a fuilure in the body wiring electrical system.
1. If a major portion o f the electrical circuit
becomes inoperative simultaneously, the failure may be
due to im proper connections between the front and rear
harness, or between the front harness and the chassis
wiring connector on top o f fuse block.
2. If only one of the circuits is inoperative, the
failure is due to and open circuit or short in the affected
circuit. Short circuits usually result in blown fuses or in
the case o f power equipm ent circuits, in the circuit
breaker opening the circuit. If the fuse is not blown and
the circuit affected is a lamp circuit, check the bulb
before proceeding with any checking procedures.
3. The dome lam p and courtesy lamp circuits are
designed so that the switches are in the " g ro u n d " side o f
the circuit. If a condition is encountered where the lamps
rem ain " o n " even though the ja m b or courtesy lamp
switches are not actuated, the failure is probably due to
defective switches, or to the wire leading to the switches
being grounded to the metal body.
ON-VEHICLE SERVICE
CONNECTOR
FUSIBLE LINK
\
^
/ T “X
t
j
THOROUGHLY TAPE ALL J u j H
EXPOSED WIRES
CONNECTOR CR1MPEI d
AND SOLDERED
Fig. 8 - 5 5 - F u s ib le L in k
( |
R e p la c e m e n t
CO M PO NENT PART
REPLACEMENT
Fusible Link Replacem ent (Fig. 8 -5 5 )
A new fusible link can be installed, after the short
circuit is located and repaired, as follows:
1. Disconnect battery ground cable.
2. Disconnect fusible link from junction block or
starter solenoid.
3. Cut harness directly behind connector to remove
d am ag ed fusible link (fig. 8-54).
4. Strip harness wire approximately 1/2".
5. Position clip around new fusible link and
harness wire, crim p so that all wires are securely
fastened.
6. Solder connection using rosin core solder. Use
sufficient heat to o btain a good solder joint.
7. T ape all exposed wires with plastic electrical
tape to prevent corrosion and shorting.
8. Connect fusible link to junction block or starter
solenoid.
9. Connect battery ground cable.
H E A D LA M P S W A R N IN G BUZZER
R eplacem ent (Fig. 8 -5 6 )
1. D isco nn ect electrical
(Lamps) socket o f fuse panel.
2. D iscon nect electrical
(Ignition) socket o f fuse panel.
c onnector
from
LPS
connector
from
IG N
F ig . 8 5 6 - H e a ld a m p
W a r n in g
Buzzer
3. Disconnect electrical connector to isntrument
panel harness.
4. Remove strap securing buzzer to instrument
panel harness.
5. Install replacement h eadlam p w arning buzzer in
reverse wequence o f removal.
SEAT BELT W A R N IN G SYSTEM
All C-K type light duty trucks have a non-sequential
timer controlled seat belt w arning system. This system
has an instrum ent panel w arning light that will
illuminate every time the ignition switch is turned on,
w hether or not the d riv e r’s seat belt is buckled, but will
automatically go off after 4-8 seconds. The buzzer is also
controlled by the 4-8 second timer, but will operate only
if the driver has not buckled-up prior to turning on the
ignition. If no attempt is m ade to buckle-up after turning
on the ignition, the buzzer will also shut-off autom ati
cally after 4-8 seconds.
A trouble shooting diagnostic chart and wiring
schematic are shown in Figures 8-57 and 8-58.
SEA T BELT REMINDER L IG H T /B U Z Z E R DIA G N O SIS
W H E N D IA G N O S IN G A W A R N IN G S Y S T E M F A IL U R E A N D T H E
S Y S T E M A U T O M A T IC A L L Y S H U T S O F F BE C A U S E OF T H E 4 - 8
S E C O N D T IM E R , A M IN IM U M O F 3 M IN U T E S M U S T BE A L L O W E D
B E T W E E N T H E D IA G N O S T IC STEPS T O A L L O W T H E T IM E R T O
R E S E T IK F Y IN O F F P O S IT IO N D U R IN G T H IS P E R IO D ).
R E M IN D E R L IG H T N E V E R ON
BU ZZER N O R M A L
1
C H E C K C O N N E C T IO N O F L A M P
L IG H T A N D B U Z Z E R ON C O N T IN O U S L Y - B U T .
B U C K L IN G B E L T W IL L T U R N O F F B U Z Z E R
____
1
T tS T L IG H T O F F
....... ....i
1
M E N T P A N E L JU M P ER
j
1
C O N N E C T S H O R T T E S TE R B E TW EE N
T H E P IN K A N D B L A C K W IR ES A T
1
I
□
R E P A IR B L A C K W IR E
A N D TO BO DY G R O U N D
T IM E R C O N N E C T O R
T E S T L IG H T ON
R E P L A C E T IM E R
R E P A IR B L A C K W IR E
R E M IN D E R L IG H T /B U Z Z E R N E V E R ON
1
R E M IN D E R L IG H T N O R M A L
B U Z Z E R N E V E R ON
C H E C K FUSE
D IS C O N N E C T H A R N E S S TO D R IV E R 'S
B U C K L E SW IT C H A T J U N C T IO N W IT H
2. C H E C K IN S T R U M E N T P A N E L JU M P ER
GROUND
T E S T L IG H T O F F
3
IN S T R U M E N T P A N E L JU M P ER
T E S T L IG H T ON
C O N N E C T S H O R T T E S T E R T O T IM E R
AND
F E E D C IR C U IT (P IN K ) A T T IM E R
C O N N E C TO R A N D TO B O D Y G R O U N D
R E P A IR P IN K W IR E
T F S T L IG H T O F F
- BODY
T U R N IG N IT IO N K E Y O FF
W A IT T H R E E (31 M IN U T E S
C O N N E C T S H O R T T E S T E R TO
T IM E R O U IP U T C IR C U IT (A T
BR O W N A N D Y E L L O W W IR E S I
A N D TO BO DY G R OUND
Diagnosis
CHASSIS
Fig. 8-57 -Seat Belt Reminder System
3. C O N N E C T S H O R T T E S T E R TO
L A M P C IR C U IT ( Y E L L O W ) A T
J U N C T IO N OF Y E L L O W A N D
B L A C K W IR E S (P O IN T A )
T U R N K E Y ON
B U Z Z E R IN O P E R A T IV E
T E S T L IG H T O F F
]
ELECTRICAL
R E P A IR Y E L L O W W IR E
T E S T L IG H T ON
2. C H E C K L A M P B U L B
.........
[
1
C H E C K B U Z Z E R BY A P P L Y IN G
12 V O L T PO W ER S O U R C E T O
W IT H S H O R T T E S TE R
C H E C K C O N T IN U IT Y
BETW EEN G R O U N D
R E P L A C E T IM E R
BU ZZER O PERATES
T E S T L IG H T ON
T E R M IN A L S A N D R E P L A C E
IF D E F E C T IV E
T E R M IN A L A N D
BODY G ROUND
RECO NNECT BO DY HARNESS AT
IN S T R U M E N T P A N E L JU M P E R
A N D D IS C O N N E C T L E A D A T
T H E D R IV E R S B U C K L E
2. C O N N E C T S H O R T T E S T E R T O
H A R N E S S A T B U Z Z E R (B R O W N
A N D W H IT E W IR E S ) A N D B O D Y
GROUND
BU ZZE R O PERATES
TES T L IG H T O F F
R E P L A C E B U C K L E SW ITC H
R E P A IR G R O U N D
C O N N E C T IO N
B U Z Z E R IN O P E R A T IV E
T E S T L IG H T ON
T E S T L IG H T O F F
1
T ES T L IG H T ON
C H E C K L IG H T A N D
BUZZER
2. C H E C K F O R B R E A K IN
LA M P A N D B U ZZER
C IR C U IT S A N D R E P A IR
R E P A IR B R O W N W IR E
R E P A IR S H O R T IN
BO DY HARNESS
R E P A IR ( B L A C K ) G R O U N D
W IR E C O N N E C T IO N T O BO D Y
8 -5 9
Fig. 8-58--Seat Belt Reminder System Schematic
SPECIFICATIONS
FUSES — CIRCUIT BREAKERS
The w ir in g c irc u its a re p ro te c te d fro m s h o rt c irc u its b y a c o m b i
n a tio n o f fu se s, c ir c u it b re a k e rs , a n d fu s ib le th e rm a l lin k s in th e
w ir in g its e lf. This g r e a tly re d u ce s th e h a z a rd o f e le c tr ic a lly
c a u s e d f ir e s in th e v e h ic le s .
T he h e a d la m p c irc u its a r e p ro te c te d b y a c ir c u it b r e a k e r in th e
lig h t s w itc h . A n e le c tr ic a l o v e rlo a d on th e b r e a k e r w ill cause
th e la m p s to g o on a n d o f f , o r in some cases to re m a in o ff.
Id le S to p S o le n o id , C ru is e C o n tro l'!',
D ire c tio n a l S ig n a l L a m p, Tim e D e la y
R e la y , Em ission C o n tro l S o le n o id ,
T ra n sm issio n D o w n s h ift ( M 4 0 ) .............................
10 A m p
In -lin e fuses a re lo c a te d in th e a u x ilia r y h e a te r c irc u its (C -K -P
m o d e ls) a n d u n d e rh o o d la m p , f r o n t a n d r e a r A /C c irc u its (C-K
m o d e ls)
“ W h e n in c o rp o r a te d b y b o d y b u ild e r
In a d d it io n to a fu s e , th e w in d s h ie ld w ip e r m o to r is a ls o p r o
te c te d b y a c ir c u it b re a k e r . If th e m o to r o v e rh e a ts , d u e to
o v e r lo a d in g ca u s e d b y h e a v y sn o w , e tc ., th e w ip e rs w ill re m a in
s to p p e d u n til th e m o to r co o ls.
Do n o t use fuses o f h ig h e r a m p e r a g e th a n th o s e re c o m m e n d e d a b o v e
The f o llo w in g w ir in g harnesse s a re p ro te c te d b y a " f u s ib le li n k " w h ic h is a
s p e c ia l w ire in c o rp o ra te d in th e c ir c u it h e a d la m p h i-b e a m in d ic a t o r , h o rn , a ir
c o n d it io n in g
h ig h b lo w e r ,
ig n it io n c irc u its (C -K -P m o d e ls ) s ta rte r s o le n o id
( p u ll- in a n d h o ld ) c ir c u it (C -K m o d e ls ). S h o u ld a n e le c tr ic a l o v e rlo a d o c c u r, this
Fuses lo c a te d in th e J u n c tio n B lo c k b e n e a th th e d a sh on th e
d riv e rs s id e a re :
w ire w i ll f a i l a n d p re v e n t d a m a g e to th e m a jo r ha rn e ss.
G TRUCK
C -K TRUCK
H e a te r, F ro n t A /C , G e n e r a to r W a r n in g
L a m p .................................................................................
Id le S to p S o le n o id , A u x . B a tte ry , R a d io ,
T im e D e la y R e la y , Em ission C o n tro l S o le n o id ,
T ra n sm issio n D o w n s h ift ( M 4 0 ) .............................
C ig a r e tte L ig h te r, C lo c k , D om e L a m p,
C a rg o L a m p .................................................................
Fuel G a u g e , B ra k e W a r n in g L a m p ,
T e m p e ra tu re W a r n in g L a m p, O il
Pressure W a r n in g Lam p .......................................
C o u rte s y L am p, R oof M a r k e r L am p,
License P la te L a m p, P a rk in g Lam p,
S id e M a r k e r L a m p , T a il L a m p,
C le a ra n c e Lam p .......................................................
D ir e c tio n a l S ig n a l In d ic a to r L a m p, S to p L am p,
T ra ffic H a z a r d ............................................................
In s tru m e n t C lu s te r L a m p, H e a te r D ia l Lam p,
R a d io D ia l L am p, C ru is e C o n tro l Lam p,
W in d s h ie ld W ip e r S w itch L a m p .......................
W in d s h ie ld W ip e r / W a s h e r .......................................
C ru is e C o n tro l, R e a r W in d o w A u x ., Fuel T a n k,
T a c h o m e te r, B a c k -u p L a m p , D ir e c tio n a l
S ig n a l In d ic a to r L a m p , D ir e c tio n a l
S ig n a l L a m p , H e a d la m p B u z z e r ..........................
20 A m p
15 A m p
20 A m p
4 Am p
20 A m p
15 A m p
4 Amp
25 A m p
H e a te r, A J C ......................................................................
Id le S to p S o le n o id , C ru is e C o n tro l,
D ire c tio n a l S ig n a l L a m p, D ire c tio n a l
S ig n a l In d ic a to r L a m p , T ransm ission
D o w n s h ift ( M - 4 0 ) .......................................................
C ig a r e tte L ig h te r, Dom e L a m p , S p o t Lam p . . .
Fuel G a u g e , B ra k e W a r n in g L am p,
T e m p e ra tu re W a r n in g L a m p , G e n e ra to r
W a r n in g L am p, O il Pressure W a r n in g Lam p
S to p L a m p, T ra ffic H a z a r d .......................................
A u x ilia r y B a tte ry , B a c k in g L a m p, R a d io
D ia l Lam p, R a d io ....................................................
In s tru m e n t C lu s te r L a m p, H e a te r D ia l Lam p,
T ransm ission C o n tro l Lam p w ith T ilt W h e e l,
C ru is e C o n tro l L a m p, W /S W ip e r
Sw itch L a m p, H e a d la m p B u z z e r .......................
License L a m p , P a rk in g L a m p , S id e
M a r k e r L a m p , T a il L a m p .......................................
W in d s h ie ld W i p e r .........................................................
25 A m p
10 A m p
15 A m p
3 Am p
15 A m p
15 A m p
3 Am p
15 A m p
25 A m p
An in - lin e fu s e is lo c a te d in th e A m m e te r a n d th e a u x ilia r y
h e a te r c irc u its .
Do n o t use fuses o f h ig h e r a m p e r a g e r a tin g th a n th o se re c o m m e n d e d a b o v e
The f o llo w in g w ir in g harnesse s a r e p ro te c te d b y a " f u s ib le lin k " w h ic h is a
s p e c ia l w ire in c o rp o ra te d in th e c ir c u it, ig n it io n , h o rn a n d h e a d la m p h i-b e a m
15 A m p
in d ic a t o r c irc u its , a ir c o n d it io n in g h ig h b lo w e r . S h o u ld a n e le c tr ic a l o v e rlo a d
o c c u r, th is w ir e w i ll f a i l a n d p re v e n t d a m a g e to th e m a jo r harness.
P TRUCK
H e a te r ” , A ir C o n d i t i o n i n g t .....................................
In s tru m e n t C lu s te r L a m p , W in d s h ie ld
W ip e r S w itch L a m p ..................................................
D ir e c tio n a l S ig n a l In d ic a to r L a m p , S to p L am p,
T r a ffic H a z a r d ............................................................
Fuel G a u g e , B ra k e W a r n in g Lam p . . .
License P la te L a m p, P a rk in g L am p,
S id e M a r k e r L a m p , T a il L a m p,
C le a ra n c e L a m p , Id e n tific a tio n Lam p
W in d s h ie ld W a s h e r / W ip e r ........................
C ig a r e tte L ig h t e r f , C lo c k t, C o u rte s y !,
Dom e L a m p t ...............................................
A u x ilia r y B a t t e r y f, B a c k -u p Lam p,
R a d io .................................................................
25 A m p
3 Am p
15 A m p
3 Am p
15 A m p
25 A m p
15 A m p
15 A m p
CIRCUIT BREAKERS
DEVICE OR
CIRCUIT
PROTECTED
M ODELS
AMPERES
L O C A T IO N
C -K -P -G
15
L ig h t
switch
T a ilg a te w in d o w
m o to r
C -K
30
Dash
( fo rw a rd s id e )
R ear A /C
(C 6 9 o v e rh e a d )
G
35
Dash
( fo rw a rd sid e )
H e a d la m p a n d
p a rk in g la m p
c irc u it
LAMP BULB DATA
C-K-P TRUCK
LAMP BULB DATA
G TRUCK
Q U A N T IT Y
TRADE#
POW ER
Cab
1
1 004
15 CP
U t i l i t y & S u b u rb a n
1
2 1 1 -2
12 CP
O il Pressure in d ic a t o r la m p 1
1
168
G e n e r a to r in d ic a t o r la m p 1
1
In s tru m e n t c lu s te r la m p s 2
5
USED IN
USED IN
Q U A N T IT Y
TRADE#
POW ER
D om e la m p s
2
2 1 1 -2
12 CP
O il p re ssu re in d ic a to r la m p
1
168
3 CP
G e n e r a to r in d ic a to r la m p
1
168
3 CP
3 CP
In s tru m e n t c lu s te r la m p s
3
168
3 CP
168
3 CP
H e a d la m p b e a m in d ic a to r
168
3 CP
1
168
3 CP
D om e Lamps:
H e a d la m p b e a m in d ic a to r
la m p
P a rk , d ir e c t io n a l s ig n a l
la m p
1
168
3 CP
Lam p a s s e m b ly — t a il &
2
1 157
1
67
2
1157
3 -3 2 CP
H e a d Lamps
2
6014
5 0 -6 0 W
T e m p e ra tu re in d ic a t o r la m p
1
168
s to p la m p
License L a m p 4
3 -3 2 CP
4 CP
D ir e c tio n a l s ig n a l
( fr o n t p a rk la m p s )6
3 CP
D ir e c tio n a l s ig n a l in d ic a to r
la m p
la m p s
2
1157
3 -3 2 CP
T a il, sto p la m p s
2
1157
3 -3 2 CP
License la m p
1
67
H e a d la m p s 1
2
6014
T e m p e ra tu re in d ic a to r la m p
1
168
3 CP
3 CP
4 CP
5 0 -6 0 W
D ir e c tio n a l s ig n a l in d ic a to r
la m p
2
168
M a r k e r la m p s
4
168
3 CP
B ra k e w a r n in g in d ic a to r la m p
1
168
3 CP
32 CP
2
168
3 CP
B a c k -u p la m p
2
1156
C le a ra n c e a n d m a rk e r la m p s
4
168
3 CP
R a d io d ia l la m p
1
1893
2 CP
R oof m a rk e r la m p s 5
5
194
2 CP
H e a te r o r A /C c o n tro l
1
194
2 CP
T ra n sm issio n c o n tro l w / t ilt
B ra k e w a r n in g in d ic a to r
1
168
3 CP
T ra n sm issio n c o n tro l (a u to )
1
1 445
0 .7 CP
B a c k in g la m p (exc.
m o to r ho m e )
2
1 156
3 2 CP
B a c k in g la m p (m o to r h om e)
2
1 295
5 0 CP
H e a te r o r A /C
1
161
1 CP
C o rn e r m a rk e r la m p s
( p la tfo r m )
C a r g o la m p (C -K c a b )
R a d io d ia l la m p — A M
7
67
4 CP
1
1 142
21 CP
1
1 816
3 CP
216
1 CP
C ru is e c o n tro l la m p
1
53
1 CP
C o u rte s y la m p
1
1003
15 CP
W in d s h ie ld w ip e r sw itch
1
161
1 CP
C lo c k
1
168
3 CP
10
1895
2 CP
1
93
15 CP
R e a r id e n t if ic a t io n 7
U n d e rh o o d la m p
S e a t b e lt w a r n in g
1
168
3 CP
C a rg o /d o m e la m p
2
2 1 1 -2
12 CP
Four w h e e l d riv e in d ic a to r
1
168
3 CP
1 O n C A , K A 1 0 -3 5 in s tru m e n t clu ste rs o n ly .
2 3 la m p s used on in s tru m e n t c lu s te r on P m o d e ls o r C -K w /o
gauges.
3 D o u b le f ila m e n t s e a le d
beam 60W
h ig h b e a m , 5 0 W lo w
beam .
4 2 la m p s used w ith ste p b u m p e r a n d P m o d e ls.
5 4 r e q u ir e d on P m o d e ls .
6 1 1 5 7 N A , 2 .2 -2 4 CP on C -K m o d e ls.
7 W id e s id e P ic k u p .
1
1 445
0 .7 CP
1
53
1 CP
W /S w ip e r sw itch la m p
1
161
1 CP
1 D o u b le f ila m e n t s e a le d b e a m 6 0 W
beam .
1
— A M /F M
w heel
C ru ise c o n tro l
h ig h b e a m , 5 0 W
lo w
SECTION 9
ACCESSORIES
C O N TE N TS
Cruise M a ste r....................................................................... 9 - 1
G e n e ra l D e s c rip tio n ........................................................ 9 - 1
D ia g n o sis............................................................................. 9-3
Electrical S y s te m ............................................................ 9-3
Servo and Vacuum S y s te m ........................................ 9-3
On-Vehicle Service............................................................... 9-7
M aintenance and A d ju stm en ts................................. 9-7
R e g u la to r......................................................................... 9-7
Servo U n i t ...................................................................... 9-7
Brake Release Switches............................................. 9-7
Column M ounted E ngagem ent Switch................ 9-7
C o m p onent Part R ep la c e m e n t.................................. 9-7
R e g u la to r......................................................................... 9-7
S e r v o ................................................................................. 9-8
Colum n M ounted Engagem ent Sw itch................ 9-8
Specifications...................................................................... 9-10
R a d io ....................................................................................... 9-10
G eneral D e sc rip tio n ........................................................
D iagnosis.............................................................................
Radio D e a d ......................................................................
Radio Cuts on and off................................................
Radio Stations Mix T ogether...................................
Radio N o is y .....................................................................
Distorted T o n e ................................................................
Testing W indshield A n t e n n a .....................................
On-Vehicle Service..............................................................
Maintenance and A d ju stm en ts.................................
Radio Installation Precautions................................
Trim m ing R a d i o ..........................................................
Com ponent Part R e p lac e m e n t..................................
R a d io ................................................................................
S p e a k e r ............................................................................
A n te n n a ...........................................................................
Special T o o ls ......................................................................
9-10
9-10
9-10
9-10
9-10
9-10
9-11
9-11
9-11
9-11
9-11
9-11
9-12
9-12
9-12
9-13
9-15
CRUISE MASTER
GENERAL DESCRIPTION
T he Cruise M aster is a speed control system which
employs engine manifold vacuum to power the throttle
servo unit. The servo moves the throttle, when speed
adjustm ent is necessary, by receiving a varying am ount
o f controlled vacuum from the regulator unit. The
speedom eter cable (from the transmission) drives the
regulator, and a cable (from the regulator) drives the
instrum ent panel speedometer. The engagem ent of the
regulator unit is controlled by an engagem ent switch
located at the end o f the turn signal lever. Two brake
release switches are prov id ed: an electric switch
disengages the regulator unit and a vacuum valve
decreases the vacuum in the servo unit to quickly return
the throttle to idle position.
T he purpose of the Cruise M aster system is to allow
the driver to m ain tain a constant highway speed without
the necessity o f continually applying foot pressure to the
accelerator pedal. Speed changes are easily made and
override features allow the vehicle to be stopped, slowed
or accelerated as desired.
Engaging th e Cruise System
T he driver accelerates to the desired cruise speed
and partially depresses and releases the cruise control
engagem ent switch button located at the end of the
directional signal lever. The cruise system takes over
speed control, and within engine limitation, m aintains
this speed regardless o f changes in terrain.
The Engagem ent
functions:
Switch
button
perform s
these
1. Above 30 mph, when partially depressed and
released, it engages the cruise system.
2. W hen depressed
disengages the system.
fully
and
held
there,
it
3. W hen released slowly from the fully depressed
position, it will engage the system at the existing speed
and cruise at that speed (above 30 mph).
NOTE: See Fig. 9-1C "E ngage Switch O peration".
Speed Changes
Override-The accelerator pedal may be depressed at
any time to override the cruise system. Release o f the
accelerator pedal will return the vehicle to the previous
cruise speed.
To Cruise At A Higher Speed-Depress the accelera
tor pedal to reach the new desired speed. Then, fully
depress and slowly release the cruise control engagem ent
switch button. The system re-engages at the higher speed
when the button is slowly released.
To Cruise At A Lower Speed-Disengage the system
by depressing the engagem ent switch button fully and
holding it there until the vehicle has decelerated to the
new desired speed; then release the button slowly. The
TH E
C R U ISE
CO NTRO L
ENGAGE
SWITCH
A S S E M B L IE S ,
BOTH
TU R N
S IG N A L
&
IN S T R U M E N T
PANEL
M O U N T E D
TYPES,
INCORPORATE
THREE
POSITION
SWITCHES.
THESE POSITIONS ARE:
( A)
THE “ R E LEA SE D ” OR N O R M A L POSITION
( B)
TH E " E N G A G E ” POSITION
( C)
TH E “ T R IM -D O W N ” POSITION.
P A R T IA L L Y DEPRESSING T H E E N G A G E SWITCH
W IL L A C T I V A T E T H E S Y S T E M A N D IT W IL L
REMAIN
ACTIVITED
WHEN
THE SWITCH
IS
R E L E A S E D
D E A C T IV A T
APPLIED OR
DEPRESSED
“TRIM -DOW N
.
T H E
C R U IS E
SYSTEM
IS
E D
W HEN
THE
BRAKES
ARE
W H E N T H E E N G A G E S W I T C H IS
F U L L Y
A N D
HELD
IN
THE
” POSITION.
TH E “ T R I M -D O W N ”
SW ITCH
POSITION
IS
N O R M A L L Y
USED
TO
DECREASE
THE
C R U I S I N G S P E E D . W H I L E T H E S W I T C H IS H E L D
IN T H E “ T R I M - D O W N ” PO S ITIO N T H E C R U IS E
S Y S T E M IS “ O F F ” A N D T H E C A R S P E E D W I L L
G R A D U A L L Y DECREASE. WHEN TH E DESIRED
C R U I S I N G S P E E D IS R E A C H E D , T H E S W I T C H IS
SLOW LY RELEASED AN D T H E CRUISE SYSTEM
W IL L
R E -E N G A G E.
IF
THE
SW ITCH
IS
R E L E A S E D
FR O M
TH E
“ T R IM -D O W N ”
P O S I T I O N V E R Y R A P I D L Y , I T IS Q U I T E L I K E L Y
THAT
TH E SYSTEM W IL L N O T RE-ENGAGE.
THIS
IS N O R M A L
AND
IS A V O I D E D
BY A
SLOWER,
MORE
DELIBERATE
RELEASE
OF
THE
SW ITCH
FROM
THE
“ TR IM -D O W N ”
POSITION.
NOTE:
A
SPEEDSWITCH
BUILT
INTO
THE
R E G U L A T O R
A S S E M B L Y
P R E V E N T S
E N G A G IN G
TH E
CRUISE
SYSTEM
BELOW
A P PR O X . 3 0 MPH.
Fig. 9-lC-Cruise Master Engagement Switches
system re-engages at the lower speed when the button is
slowly released.
E N G A G E
H O L D
Cruise M aster Units
O U T P U T
5. The Cruise Brake Release Valve, which is
mounted on the brake pedal bracket, disengages the
system pneum atically when the brake pedal is depressed.
6. The Cable and Casing Assemblies drive the
regulator and speedometer.
TO
S P E E D O M E T E R
1. The E ngagem ent Switch, which is located at the
end o f the directional signal lever, is used to control the
system a n d for up w ard and dow nw ard speed
adjustments.
2. The Regulator (fig. 9-2C) is m ounted in the
speedom eter cable line. It is a com bination speed sensing
device and control unit. W h en engaged, it senses vehicle
speed and positions the Servo Unit to m aintain the
selected speed.
3. The Servo Unit is mounted on the left front
in n e r fender and is connected by a cable to the throttle
linkage. It opens or closes the throttle as dictated by the
Regulator.
4. The Cruise Brake Release Switch, which is
mounted on the brake pedal bracket, disengages the
system electrically when the brake pedal is depressed.
T E R M I N A L
T E R M I N A L
J
T O
TEE-
IN PU T
F R O M
T R A N S M I S S I O N
L O C K N U T
ORIFICE
C O N N E C T O R
F R O M
T UBE
E N G I N E
V A C U U M
''
AIR
FILTER
&
H O U S I N G
S O L E N O I D
C O V E R
pig 9.2c . Regulator Unit
&
A S S E M B L Y
ACCESSORIES
DIAGNOSIS
ELECTRICAL SYSTEM TR O U B LES H O O TIN G
1.
2.
Check fuse and connector.
Check electric brake switch as follows:
a. U nplug connector at switch.
b. C on nect o h m m e te r across cruise m aster
contacts on brake switch. The ohm m eter must indicate
no continuity when the pedal is depressed and continuity
w hen pedal is released. The cruise release brake switch
(electric) is adjusted as is the stand ard stop light brake
switch.
c. Replace electric brake switch if needed.
3. Check clutch release switch (m anual transm is
sion only) same as electric release switch above.
E ngagem ent Sw itch Test
Check eng agem en t switch and connecting wiring as
follows: Unplug engagem ent switch connector (brown,
blue, black) at electrical wiring harness connector then
p erform the following tests (fig. 9-3C).
T e s t # 1—Connect oh m m e te r between terminal # 1
(brown wire) and te r m i n a l # 2 (blue wire). Continuity
shall be m aintained until switch is depressed all the way
T e s t # 2 —Connect o hm m e ter between te r m i n a l # 1
(brow n wire) a n d t e r m i n a l # 3 (black wire). N o
continuity shall be shown; however, w hen the button is
partially depressed, continuity shall be indicated. W hen
the button is pressed all the way down, no continuity
shall be shown.
T e s t # 3 —Connect oh m m eter between t e r m in a l # 2
(blue wire) and te r m i n a l # 3 (black wire). Button
released, no continuity; however, when the button is
depressed partially and fully, continuity shall be shown.
Harness Test (Fig. 9-3C)
1. Disconnect engage switch wire harness connec
tor from the m ain harness connector (red, brown/white,
and white wires).
2. Connect ohm m e te r between point C (brow n/
white stripe wire in m ain wire harness) and ground.
Make sure the Regulator is well grounded to the chassis.
The oh m m e te r should read between 42 and 49 ohms. If a
resistance either above or below the value indicated is
shown, then disconnect the connector from the Regulator
and measure the resistance of the brow n/w hite stripe
wire from point C to D. It should measure 40 ohms ± 2
ohms.
3. If a resistance either above or below the value
indicated is shown, the m ain wiring harness should be
replaced.
NOTE: W hen disconnecting or reconnecting the
main wiring harness connector from the Regulator,
care should be exercised so as not to d am age the
blade connectors or the wiring harness. The
disconnect may be facilitated by prying carefully
on the plastic connector with a small screwdriver.
4. M easuring the solenoid coil circuit resistance
between point E (Hold Term inal) and ground, the ideal
resistance should be between 5 and 6 ohms. A reading o f
less than 4 ohms indicates shorting in the coil circuit. A
reading of more than 7 ohms indicates excessive
resistance in the coil circuit. Either extremity indicates
replacement o f the Regulator assembly. The m ain
harness wiring from point F to G (white wire) should
also be checked for continuity.
SERVO A N D V A C U U M SYSTEM TEST
To determ ine the condition o f the d iaphragm ,
remove hose from the Servo U nit and apply 14 inches of
vacuum to the tube opening and hold in for one minute.
The vacuum shall not leak down more than 5 inches o f
vacuum in one minute. If leakage is detected, replace the
Servo. To utilize engine as a vacuum source, proceed as
follows:
1. Disconnect Servo cable at carburetor and
vacuum hose from the Servo, then connect engine
vacuum directly to the Servo fitting.
2. Note position o f Servo diaphragm .
3. Start e n g in e - th e diaph rag m should pull in.
4. Clamp off engine vacuum supply line and check
for leakage.
The cruise release brake valve (vacuum) and
connecting hoses can likewise be checked using a vacuum
pump.
9-4
BRO W N
E N G A G E M E N T S W IT C H
(S H O W N IN " H IS T ”
P O S IT IO N )
C R U ISE R ELEA SE V A L V E
BLA C K
BRO W N
- C R U IS E
BR A K E
TO B R A K E
LICHT
CIRCUIT
BRAKE
B LACK
R ELEA SE &
LIG H T S W IT C H
C O N N E C T O R AT ST E E R IN G C O L U M N
B R O W N - W H IT E
R E S IS T A N C E W IR E
40 n
PE DAL
Fig. 9-3C-Electro-Pneumatic
REST P O S IT IO N
TRUCK
SPEED R E G U L A T O R
IG N IT IO N
SW IT C H
FU SE
DIRECTIO N OF R O T A T IO N ,
CLUTCH S P R IN G '
B O W D E N C A B L E TO
C A R B U R E T O R L IN K A G E
I
SERVICE
W IT H SPEED IN C R EA S E
HO LD
CLUTCH
E N G A G E P O S IT IO N
MANUAL
Schematic
V A R IA B L E O R IF IC E
(A IR C O N T R O L V A LV E )
FIX EO O R IFIC E
LO CK IN
CAM
L O W SPEED
I SW ITC H
'( N A ) B ELO W
1 35M PH )
VACUUM
SHUT OFF V A L V E
SERVO
POWER U N IT
TRIM D O W N
S O L E N O ID COIL
(C O R E S H O W N IN
D E - E N ER G IZ ED P O S IT IO N )
JQ
TO M A N IF O L D
VACUUM
V O LT S DC
E L E C T R O -P N E U M A T IC S C H E M A T IC D IA G R A M , C R UISE MASTER SYSTEM
L
LIGHT
E N G A G E M E N T SW IT C H P O S IT IO N S
P O S IT IO N
CRUISE MASTER TROUBLESHOOTING
CHECK I
FOR SYSTEMS W ITH E R R A TIC CRUISE PERFORMANCE
CHECK II
FOR IN O P E R A TIV E SYSTEMS M A K E A L L TESTS WITH TRANSM ISSION SELECTOR
IN " P A R K " & P AR K IN G BRAKE ON EXCEPT WHERE IN D IC A T E D OTHERWISE.
RECONNECT A N Y DISCONNECTED HOSES A N D /O R E LE C T R IC A L CONNECTORS
IN PROPER M AN NER A T THE COMPLETION OF TEST.
CHECK I
1.
CHECK SERVO C ABLE AD JU S TM EN T • MUST H AVE M IN IM U M A M O U N T OF LOST MOTION
SEE SERVICE AD JU S TM EN T PROCEDURE
2.
CHECK FOR PINCHED, K IN K E D , PLUGGED, OR DAM AG ED V AC U U M HOSES. ALSO CHECK
VAC U UM FITTIN G S .
3.
CHECK SPEEDOMETER C ABLE RO U TING . IT MUST N O T BE K IN K E D OR H AVE TOO SHARP
A T U R N IN G R AD IU S (NOT LESS TH A N 6 " R AD IU S). CHECK D R IV E CABLE FOR DISTORTED
OR BENT TIPS. FERRULES MUST BE SNUG.
4.
CHECK FOR A BIN D IN G TH R O T T LE
5.
CHECK AD JU S TM EN T OF BRAKE RELEASE SWITCH & V AC U U M RELEASE V A L V E . (SEE
SERVICE & ADJUSTM ENTS)
6.
CHECK FOR PROPER OPERATING PROCEDURE OF THE ENGAGE SW ITCH.
7.
IF STEPS 1 THRO UG H 6 DO NOT SOLVE THE PROBLEM PROCEED W ITH CHECK H.
%
LIN K A G E C O N D ITIO N .
SPECIAL NOTE P E R T A IN IN G TO ENG AG EM ENT-CRUISING SPEED ZER O ING .
IF THE CAR CRUISES BELOW ENG AG EM ENT
SPEED,
SCREW THE O R IFIC E
TUBE
OU TW AR D . IF THE CAR CRUISES ABO VE THE ENG AG EM ENT SPEED, SCREW THE O R IFICE
TUBE IN W ARD . EACH 1/4 TURN W IL L CHANGE THE CAR SPEED A P P R O X IM A T E LY ONE MPH.
ENG AG EM ENT AC C U R AC Y TESTING TO BE DONE A T 60 MPH. SNUG UP LOCK N UT AFTER
EACH ADJU STM EN T.
C A U T IO N :
DO NOT REMOVE O R IFIC E TUBE FROM CASTING.
CHECK
n
O N -V E H IC L E SERVICE
M A IN T E N A N C E AN D
ADJUSTMENTS
T he com ponents of the Cruise-Master System are
designed to be replaced should they become inoperative.
The Regulator is cali- brated in such a m a n n e r during
m a nu facturin g that overhaul operations are impractical.
However, one adjustm ent m ay be m ade to the Regulator
to correct speed drop or increase at the time o f
engagem ent.
R E G ULATO R (FIG . 9-6C )
O ne regulator adjustm ent is possible - Engagement
Cruising Speed Zeroing (to remove any difference
between engagem ent and cruising speed). N o regulator
adjustm ent should be made, however, until the Servo
Cable adjustm ent has been checked and vacuum hoses
are checked for leaks, kinks, or other restrictions.
If the vehicle cruises at a speed a few mph above or
below the en gagem en t speed, this error can be corrected
with a simple adjustm ent o f the orifice tube in the
regulator (fig. 9-2C).
CAUTION: Never remove orifice tube from
casting. It cannot be reinstalled once it has
been removed.
1. To check cruise speed error, engage CruiseM aster at 55 mph.
2. If vehicle cruises below engagem ent speed,
screw orifice tube outw ard
3. If vehicle cruises above engagem ent speed.
screw orifice tube inward
NO TE: Each 1/4 turn o f the orifice tube will
change cruise speed approximately one mph. Snugup lock nut after each adjustment.
If a Regulator is found to be defective and not
simply out-of-adjustment, it must be replaced. D uring
replacement, check the hoses which connect to the
Regulator and replace any which are cracked or
deteriorated.
SERVO U N IT (FIG . 9-7C )
Before adjusting the Servo Cable, make sure the
carburetor is set at its lowest idle throttle position by
manually setting the fast idle cam at its lowest step with
the ignition switch " O F F " . Adjust the cable so there is as
little lost motion at the Servo as possible (Fig. 9-7C).
If the Servo Unit is found to be defective,
replacement is required. N ote the condition o f the hoses
and replace any which are cracked or deteriorated.
BRAKE RELEASE SW ITC H ES (Fig. 9-8C )
Electric
The Cruise M aster brake release switch electrical
contacts must be switched open when the brake pedal is
depressed .38" to .64", measured at the brake pedal.
An inoperative switch must be replaced. Switch
replacement procedure is similar to standard brake lamp
switch replacement.
Vacuum
The vacuum valve plunger must clear the pedal arm
w hen the arm is moved 5/16 inch, measured at the
switch (fig. 9-9C).
An inoperative (sticking, plugged, or leaking)
vacuum valve must be replaced. V acuum valve
replacement is sim ilar to brake lam p switch replacement.
Be certain that the hose to the valve is connected firmly
and is not cracked or deteriorated.
C O LU M N M O U N T E D EN G A G EM EN T
SW ITCH
T he e n g a g e m e n t switch is serviced
replacement o f the turn signal lever assembly.
only
by
COM PO NENT PART
REPLACEMENT
REGULATOR
Replacement
1. Disconnect battery ground cable.
2. Disconnect speedometer cables at regulator.
3. Disconnect vacuum and wiring harness at
regulator body.
4. Remove regulator to bracket screws and remove
regulator.
5. To install, reverse Steps 1-4 above.
"
CRUISE CONTROL
V A C U U M HOSE
CO NTRO L CABLE ADJUSTMENT
W ith Cable installed to Cable Bracket and Carburetor,
CABLE
SERVO BOOT
install C able to Servo Bracket. Using second ball on
Servo Chain, install Servo Chain on Cable.
W ith throttle com pletely closed ( ignition off and fast idle
Cam o ff) adjust C able Jam Nuts until Servo Chain is
almost tight ( some slack).Tighten Jam Nuts to specified
torque, then rem ove plastic retainer ( not shown) ( used to
retain boot in depressed position) and pull rubber boot
( part of Servo) over w asher ( part of Cable).
ACCELERATOR
CABLE SUPPORT
SERVO
CABLE
V IE W
CARB
LEVER
Snap Fastener Tab
over end of stud in
direction of arrow .
A
SERVO
CABLE
L F 4/L F8/L S 9
Fig. 9-7C-Servo Composite (C-K Trucks)
SERVO
wiring harness on column.
Replacement
4. Remove turn signal lever (see Section 3B o f this
Manual).
5. Connect a 15" piece o f piano wire to cruise
master wiring harness plug for installation before easing
turn signal lever assembly up and out of the column.
1. Disconnect battery ground cable.
2. Disconnect vacuum line at servo can.
3. Remove servo cover. Disconnect ball chain from
cable retainer.
4. Remove servo to bracket screw(s) and remove
servo.
5. To install, reverse Steps 1-4 above.
6. Adjust the servo cable as outlined in Figure
9-7C.
C O L U M N M O U N T E D E N G A G EM EN T
S W ITC H
Removal
1. Disconnect the battery ground cable.
2. Disconnect cruise master engagem ent switch
w iring harness plug on steering column.
3. Remove plastic protector from cruise master
Installation
1. Attach new engagement switch harness plug to
pian o wire routed through column.
2. Pull connector and wire gently down column to
prevent scraping wire insulation.
3. Install turn signal lever (see Section 3B o f this
Manual).
4. Slide plastic wiring protector over harness and
up column.
5. Connect cruise m aster w irin g h arness on
column.
6. Connect battery ground cable.
Fig. 9-8C-Release Switches, Valve and Brackets
B R A K E P E D A L IN
N O R M A L P O S IT IO N
BRAKE
W HEN
PEDAL
P O S IT IO N
VACUUM
VALVE
38 TO
.6 4
OPENS
IN S T A L L A T IO N
VACUUM
O F S E L F - A D J U S T IN G
RELEASE
VALVE
1.
In s ta ll m o u n tin g c lip in to b ra c k e t.
2.
D e p ress b ra k e pedal & pu sh v a lv e in to clip
u n til s h o u ld e r o n v a lv e asm b o tto m s o u t
a g a in s t c lip .
3.
A d ju s t v a lv e b y b rin g in g p ed al to n o rm a l
p o s itio n so t h a t v a lv e is o p e n w h e n pedal
is de p ressed to d im e n s io n sh o w n .
SPECIFICATIONS
CRUISE-MASTER
Solenoid R esistance................................................................................................................................................................. 5 ohms ± 1/4 ohm
Solenoid Wire R esistan ce...................................................................................................................................................................... 40 ohms
Maximum allowable Vacuum Leakage rate for Servo u n i t .................................................................. 5 inches of Vacuum Per Minute
Not Greater than 1 inch of Vacuum per 10 seconds
Operational Test S peed .............................................................................................................................................................................. 5 5 MPH
RADIO
GENERAL DESCRIPTION
A M and A M / F M radios only are available on light
duty trucks.
R ear speakers are available for certain series o f C-K
and G Trucks.
C-K model trucks incorporate a windshield antenna.
The antenna lead snaps onto the center o f the
windshield, inside the vehicle. G model antennas are
mounted externally on the right front fender.
DIAGNOSIS
T he radio trouble diagnosis guide is intended as an
aid in locating m inor faults which can be corrected
w ithout a specialized knowledge o f radio and without
special radio test equipm ent. If the suggestions given
here do not affect a correction, further testing should be
done only by a trained radio technician having proper
test equipm ent.
R A D IO DEAD
T urn on radio.
No Thum p Heard
Check fuse.
Fuse blown-Check receiver and speaker connectors.
Connectors loose or defective-Correct as required.
Connectors okay-Check speaker by substituting a
known good speaker.
Radio does not play even with a known good
substitute speaker-Defective receiver. Remove for
servicing.
Radio
plays
with
substitute
speaker-Replace
speaker.
Thum p Heard
Check a n te n n a connection at back o f radio and at
base o f windshield or antenna.
Connections defective-Substitute a known good
lead-in cable.
Radio plays-Defective cable.
Radio still won't play, even with a known good
lead-in cable-Substitute and
trim a known good
radio.
Good radio plays-Defective radio.
Good radio still won’t play-Defective
antenna.
C hange windshield or antenna.
RAD IO C UTS ON AND OFF
Check for defective or loose receiver or antenna
connectors at rear o f radio or base o f windshield or
antenna.
Defective or loose connectors-Repair as necessary.
Connectors okay-Substitute a known good lead-in
cable.
Radio plays okay-Defective cable.
Radio still cuts out with a known good lead-in
cable-Check speaker by substituting a known good
speaker.
Radio plays okay-Replace speaker.
Radio still plays intermittently, even with a known
good speaker-Defective receiver.
R A D IO S T A T IO N S M IX TO G ETHER
T rim radio as described earlier in this section.
However, if two or more signals are picked up at the
same time, there is no known way to separate them.
RAD IO NO ISY
Static-Start engine, rev up engine several times, and
listen for speaker static.
are equipped with windshield antennas. To positively
identify antenna failure and eliminate the possibility of
unnecessary windshield replacement, W indshield A n
tenna Tester J-23520 should be used to determine
continuity of the thin a n ten na wire.
W hen a n tenn a failure is suspected, the following
checks should be made before replacing the windshield.
1. Check Tester J-23520 for operation on any
vehicle radio a n ten na that is operating normally to test
for a weak or dead battery.
2. Check all a ntenna connectings to insure that
an ten na is electrically coupled to the radio.
3. Turn ignition switch to accessory position, turn
radio " O N " , select AM band if receiver is A M / F M and
tune radio to an ofF station position.
4. Flold tester to a ntenna beginning at the upper
corner o f antenna:
T O O L J -2 3 5 2 0
Fig. 9-lR--Testing Windshield Antenna (Typical)
Static Heard-Trim radio - check for spark plug wire
breakdown, loose or im properly seated wire, or loose
or missing engine ground strap.
Check suppressors on voltage regulator, alternator,
and resistor on timing control solenoid.
Static Still Present-Defective receiver.
W EAK R A D IO SIG N A L
Test w in dshie ld a n te n n a as
"A n te n n a Testing" in this section.
described
under
D IS TO R TE D TO N E
T urn on radio, adjust for high volume and
m axim um bass. Check speaker by substituting a good
speaker.
No Distortion-Replace speaker.
Distortion-Defective receiver-remove for servicing.
TE S T IN G W IN D S H IE LD A N T E N N A (FIG.
9-1R )
All C-K model trucks with factory installed radios
CAUTION: The plastic Shield must be on tester
at all times to avoid scratching windshield.
a. If a shrill sound is emitted through the
speaker when both an ten na wires are tested, antenna is
operational.
b. If no sound is emitted through one or both
a n tenn a wires, move tester along the wire toward center
o f windshield and down toward radio.
c. If a shrill sound is picked up, find exact
location where the noise begins, this is the area o f the
defect. Replace windshield.
d. If no noise is heard over entire length o f
antenna, unplug a n tenna lead at radio and touch tester
to a n tenna socket in radio.
e. If radio now makes a shrill sound, check
connectors and a n te n n a lead for possible defect before
replacing windshield.
f. If no noise is emitted, radio, speaker, or fuse
is defective.
N OTE: M ake sure that a n tenn a tester is turned off
a fter completing an ten na test.
ON-VEHICLE SERVICE
M A IN T E N A N C E A N D
ADJUSTMENTS
R A D IO IN S TA LLA TIO N P R E C A U TIO N S
Listed below are common causes o f inoperative
radio receivers or poor reception on the AM scale upon
reinstallation after repair.
• R adio speakers not connected—this could cause
the o utput transister to burn out in the receiver.
• A n te n n a lead not plugged into the receiver or
windshield.
• A n te n n a trim m er not peaked.
T R IM M IN G R A D IO
If diagnosis indicates the radio receiver must be
trimmed, perform the following procedure:
1.
G Models-Set a ntenna mast at m axim um height.
2. Remove tuner control knob and bezel (right
h and knob).
3. Place ignition key in the " A C C " position.
4.
Turn volume control to maximum volume.
5. Tune radio to a weak station (near 1400 KC) on
the AM scale.
6. Adjust a ntenna trim m er screw ( ± 2 ° screw
rotation) until m axim um volume is received (fig. 9-2R).
7.
Turn radio volume off.
8.
Replace tuner control bezel and knob.
9.
Turn ignition to "lock".
through engine access area. Lower radio f a r enough to
disconnect electrical connectors and a n tenn a lead.
Remove radio.
9. Reverse Steps 1-8 for installation o f radio.
FR O N T SPEAKER
C-K Models
Replacement (Fig. 9-5R)
1.
2.
screws.
3.
remove
4.
5.
harness
6.
C O M PO N EN T PART
REPLACEMENT
Disconnect battery ground cable.
Remove instrum ent cluster bezel upper four
Remove instrument panel pad screws and
pad.
Remove speaker to dash panel screws.
Lift up on speaker, disconnect speaker wiring
and then remove speaker.
To install, reverse Steps 1-5 above.
G Models
Replacement (Fig. 9-4R)
R A D IO RECEIVER
C-K Models
Replacement (Fig. 9-3R)
1. Disconnect battery ground cable.
2. Pull off radio control knobs and remove knob
bezels. Remove nuts and washers from control shafts
using a deep well socket.
3. AM Radio-Remove the radio support bracket
stud nut and lockwasher.
A M /F M Radio-Remove radio support bracket to
instrum ent panel screws.
4. Lift up on the re a r edge of radio. Then push
radio forward until control shafts clear instrum ent panel.
Lower control far enough to disconnect electrical
harness.
5. Disconnect power feed, speaker and antenna
lead wires and remove radio.
6. To install, reverse Steps 1-5 above.
G M odels
Replacement (Fig. 9-4R)
1. Disconnect battery ground cable.
2. Remove engine cover.
3. Remove air cleaner on carburetor.
4. Remove stud in c arburetor throat for m ounting
air cleaner.
5. Cover carburetor throat with clean plastic to
prevent dirt or radio attachm ents from falling into
carburetor.
6. Remove knobs, washers and nuts from control
shafts on front o f radio.
7. Remove bracket to radio receiver screw.
8. Now guide radio forward and then down
1. Follow radio removal Steps 1 through 8.
2. Remove left heater duct (attached to engine
cover extension by one screw).
3. Remove speaker to mounting bracket screw and
lower speaker out engine cover opening.
4. Reverse
Steps
1-3
above
fo r
speaker
replacement.
REAR SPEAKER
C-K Models
Replacement (Fig. 9-6R)
1. Remove four screws securing speaker grille to
trim panel and remove grille.
2. Disconnect electrical connector from speaker.
3. Remove two screws securing speaker to trim
panel and remove speaker.
NOTE: On 109 and 209 (06) models, there is a
gasket between speaker and trim panel.
4. Install replacement speaker in reverse order o f
removal.
G Models
Replacement (Figs. 9-7R and 9-8R)
1. Remove the four most forward lower screws
securing right rear trim panel. Pull trim panel outward
slightly for access to speaker.
2. Disconnect electrical connector from speaker.
3. Remove four nuts securing speaker to grille
studs and remove speaker.
Fig. 9-3R--Radio Receiver (C-K Models)
4.
removal.
Install replacement speaker in reverse order of rod and mast assembly.
2.
To install, insert rod and mast assembly into
cable assembly and tighten mast nut. Prevent cable
ANTENNA
assembly from turning by using a second wrench.
C-K M odels (Fig. 9-9R )
Cable Assembly Replacement
Antenna Replacement
1.
Disconnect battery ground cable.
R e fe r to Section 2 o f this m anual "W indshield
R eplacem ent" procedure.
2.
Remove antenna assembly as described above.
3.
Remove cable body nut and then remove seal,
Cable Replacement
1.
2.
3.
4.
remove
bezel, gasket and ring ground.
4.
Disconnect battery ground cable.
U n sn a p a ntenna cable from windshield.
Remove bracket to dash panel screws.
Disconnect cable at rear o f radio receiver and
cable assembly.
G M odels (Fig. 9 -1 0R )
P e rfo rm
Steps
2-8
of
" R a d io
Receiver
Removal".
5.
Disconnect cable at rear o f receiver.
6.
Insert new cable through the dash panel (from
the forward side).
7.
Reverse Steps 1-5 above to complete installation.
Antenna Replacement
1.
Unscrew mast nut. Prevent the cable assembly
from turning by using two separate wrenches. Remove
N OTE:
Be
sure
cable
positioned in dash panel.
grom m et
is
properly
SPECIAL TOOLS
J— 2 3 5 2 0
GM
TABLE OF FREQUENTLY USED UNITS (u s.i
GM
SI (SYSTEME INTERNATIONAL d ’UNITES)
M u ltip ly
to get e qu iv al en t
to get equivalent
number of:
by
Multiply
by
LENGTH
Inch
ACCELERATION
2 5 .4
Foot
Yard
0 .3 0 4 8
0.914 4
M ile
1.609
m illim e tre s (mm)
metres (m)
metres
kilometres (km)
Foot2
Y a rd 2
0 .8 3 6 1
Quart
Gallon
Yard3
16 387.
16.387
0 .0 1 6
0 .9 4 6
3 .7 8 5
0 .7 6 4
Inch/sec2
0 .0 2 5 4
0.1 1 2 98
1.355 8
Horsepower
Ton
3.38
6.895
Pounds/sq. in.
mm3
cm 3
Ounce
Pound
k ilo p a s c a ls (kPa)
k ilo p a s c a ls
ENERGY OR WORK
BTU
Foot-pound
Kilowatt-hour
litres (1)
l itres
l i t r es
1 055.
1.355 8
3 600 000
or 3 .6x106
metres3 (m3)
joules (J)
joules
joules (J = W s )
LIGHT
0 .4 5 3 6
9 0 7 .1 8
0 .9 0 7
kilogram s (kg)
kilogram
tonne (t)
Footcandle
9.8 0 7
0.278 0
4.448
10.764
Miles/gal
Gal/mile
newtons (N)
newtons
newtons
0 .4 2 5 1
2 .3 5 2 7
Miles/hour
1.609 3
Degree Fahrenheit (°F-32) ~ 1.8 = degree C e lsiu s (°C)
32
40
0
~r
40
:c
F
98.6
I 40
80
212
120
j
160
20
40
200
—>*—
l T* ¥ • ■— L- ^ -
r-l------U - * ------ i -----1—
20
kilom etres/litre (km/l)
litres/kilom etre (l/km)
VELOCITY
TEM PERATURE
f
lumens/metre2 (lm/m2)
FUEL PERFORM ANCE
FORCE
Kilogram (force)
k ilo w a tts (kW)
PRESSURE OR STRESS
MASS
Pound
Ton
newton-metres (N m)
newton-metres
0.7 4 6
Inchesof mercury
4
4
4
6
metre/sec2 (m/s2)
metre/sec2
POWER
VOLUME
Inch3
0 .3 0 4 8
Pound-inch
Pound-foot
m illim e tr e s 2 (mm2)
ce ntim etre s2 (cm2)
metres2 (m2)
metres2
6 4 5 .2
6 .4 5
0 .0 9 2 9
Foot/sec2
TORQUE
AREA
Inch2
n u m b e r of:
60
80
100
°c
kilometres/hr. (km/h)
HOW T O USE C O N V E R S IO N C H A R T S
Left Column is units of 10, (0, 10, 20, 30 etc.);
Top Row is in units of one (0, 1, 2, 3, etc).
EXAMPLE: Feet to Inches Conversion Chart
feet
10
20
30
40
50
0
1
2
3
4
5
6
7
8
9
inches
inches
inches
inches
inches
inches
inches
inches
inches
inches
12
132
252
372
492
612
24
120
240
360
480
600
36
156
276
396
516
636
48
168
288
408
528
648
60
180
300
420
540
660
72
192
312
432
552
67?
84
204
324
444
564
684
96
216
336
456
576
696
108
228
348
468
588
708
10
20
30
40
50
ft
144
264
384
504
624
feet
1 2 f e e t e q u a l s 1 4 4 i n c h e s . R e a d a c r o s s f r o m 1 0 a n d d o w n f r o m 2.
6 fe e t equ a ls 7 2 inch e s. R e a d d o w n f r o m 6.
FE E T TO M E TR E S
ft
10
20
30
40
50
60
70
80
90
100
0
1
2
3
4
5
6
7
8
9
m
m
m
m
m
m
m
m
m
m
3.048
6.096
9.144
12.192
15.240
18.288
21.336
24.384
27.432
30.480
0.305
3.353
6.401
9.449
12.497
15.545
18.593
21.641
24.689
27.737
30.785
0.610
3.658
6.706
9.754
12.802
15.850
18.898
21.946
24.994
28.042
31.090
0.914
3.962
7.010
10.058
13.106
16.154
19.202
22.250
25 298
28.346
31.394
1.219
4.267
7.315
10.363
13.411
16.459
19.507
22.555
25.603
28.651
31.699
1.524
4.572
7.620
10.668
13.716
16.764
19.812
22.860
25.908
28.956
32.004
1.829
4.877
7.925
10.973
14.021
17.069
20.117
23.165
26.213
29.261
32.309
2.134
5.182
8.230
11.278
14.326
17.374
20.422
23.470
26.518
29.566
32.614
2.438
5.486
8.534
11.582
14.630
17.678
20.726
23.774
26.822
29.870
32.918
2.743
5.791
8.839
11.887
14.935
17,983
21.031
24.079
27.127
30.175
33.223
10
20
30
40
50
60
70
80
90
100
M ETRES TO FEET
m
10
20
30
40
50
60
70
80
90
100
0
1
2
3
4
5
6
7
8
9
ft
ft
ft
ft
ft
ft
ft
ft
ft
ft
32.8084
65.6168
98.4252
131.2336
164.0420
196.8504
229.6588
262.4672
295.2756
328.0840
3.2808
36.0892
68.8976
101.7060
134.5144
167.3228
200. f 312
232.9396
265.7480
298.5564
331.3648
6.5617
39.3701
72.1785
104.9869
137.7953
170.6037
203.4121
236.2205
269.0289
301.8373
334.6457
9.8425
42.6509
75.4593
108.2677
141.0761
173.8845
206.6929
239.5013
272.3097
305.1181
337.9265
13.1234
16.4042
19.6850
52.4934
45.9318
49.2126
78.7402
82.0210
85.3018
1 11.5486 114.8294 118.1102
144.3570 147.6378 150.9186
1 77.1654 180.4462 183.7270
209.9738 213.2546 216.5354
242 7822 246.0630 249.3438
275.5906 278.8714 282.1522
308.3990 311.6798 314.9606
341.2074 344.4882 347.7690
22.9659
26.2467
29.5276
55.7743
59.0551
62.3360
88.5827
95.1444
91.8635
121.3911 124.6719 127.9528
154.1995 157.4803 160.7612
187.0079 190.2887 193.5696
219.8163 223.0971 226.3780
252.6247 255.9055 259.1864
285.4331 288.7139 291.9948
318.2415 321.5223 324.8032
351.0499 354.3307 357.6116
m
10
20
30
40
50
60
70
80
90
100
mile
10
20
30
40
50
60
70
80
90
100
0
1
2
3
4
5
6
7
8
9
km
km
km
km
km
km
km
km
km
km
16.093
32.187
48.280
64.374
80.467
96.561
1 12.65
128.75
144.84
160.93
1.609
17.703
33.796
49.890
65.983
82.077
98.170
114.26
130.36
146.45
162.54
3.219
19.312
35.406
51.499
67.593
83.686
99.779
115.87
131.97
148.06
164.15
4.828
20.921
37.015
53.108
69.202
85.295
101.39
117.48
133.58
149.67
165.76
6.437
22.531
38.624
54.718
70.811
86.905
103.00
119.09
135.19
151.28
167.37
8.047
24.140
40.234
56.327
72.421
88.514
104.61
120.70
136.79
152.89
168.98
9.656
25.750
41.843
57.936
74.030
90.123
106.22
122.31
138.40
154.50
170.59
11.265
27.359
43.452
59.546
75.639
91.733
107.83
123.92
140 01
156.11
172.20
12.875
28.968
45.062
61.155
77.249
93.342
109.44
125.53
141.62
157.72
173.81
14.484
30.578
46.671
62.764
78.858
94.951
111.04
127.14
143.23
159.33
175.42
mile
10
20
30
40
50
60
70
80
90
100
K IL O M E T R E S TO M IL E S
km
10
20
30
40
50
60
70
80
90
100
0
1
2
3
4
5
6
7
8
9
mil
mil
mil
mil
mil
mil
mil
mil
mil
mil
6.214
12.427
18.641
24.855
31.069
37.282
43.497
49.711
55.924
62.138
0.621
6.835
13.049
19.263
25.477
31.690
37.904
44.118
50.332
56.545
62.759
1.243
7.457
13.670
19.884
26.098
32.311
38.525
44.739
50.953
57.166
63.380
1.864
8.078
14.292
20.506
26.720
32.933
39.147
45.361
51.575
57.788
64.002
2.486
8.699
14.913
21.127
27.341
33.554
39.768
45.982
52.196
58.409
64.623
3.107
9.321
15.534
21.748
27.962
34.175
40.389
46.603
52.817
59.030
65.244
3.728
9.942
16.156
22.370
28.584
34.797
41.011
47.225
53.439
59.652
65.866
4.350
10.562
16.776
22.990
29.204
35.417
41.631
47.845
54.059
60.272
66.486
4.971
11.185
17.399
23.613
29.827
36.040
42.254
48.468
54.682
60.895
67.109
5.592
11.805
18.019
24.233
30.447
36.660
42.874
49.088
55.302
61.515
67.729
km
10
20
30
40
50
60
70
80
90
100
G A L L O N S (U.S.) TO L IT R E S
U.S.
gal
0
1
2
3
4
5
6
7
8
9
L
L
L
L
L
L
L
L
L
L
7.5709
45.4251
83.2794
121.1337
158.9879
196.8422
234.6965
272.5507
310.4050
348.2593
386.1135
11.3563
49.2105
87.0648
124.9191
162.7734
200.6276
238.4819
276.3362
314.1904
352.0447
389.8990
18.9271
56.7814
94.6357
132.4899
170.3442
208.1985
246.0527
283.9070
321.7613
359.6156
397.4698
22.7126
60.5668
98.4211
136.2754
174.1296
211.9839
249.8382
287.6924
325.5467
363.4010
401.2553
-
10
20
30
40
50
60
70
80
90
100
37.8543
75.7085
113.5528
151.4171
189.2713
227.1256
264.9799
302.8342
340.6884
378.5427
3.7854
41.6397
79.4940
117.3482
155.2025
193.0568
230.9110
268.7653
306.6196
344.4738
382.3281
15.1417
52.9960
90.8502
128.7045
166.5588
204.4131
242.2673
280.1216
317.9759
355.8301
393.6844
26.4980
64.3523
102.2065
140.0608
177.9151
215.7693
253.6236
291.4779
329.3321
367.1864
405.0407
30.2834
68.1377
105.9920
143.8462
181.7005
219.5548
257.4090
295.2633
333.1176
370.9718
408.8261
34.0638
71.9231
109.7774
147.6316
185.4859
223.3402
261.1945
299.0487
336.9030
374.7573
412.6115
U.S.
gal
10
20
30
40
50
60
70
80
90
100 I
L IT R E S T O G A L L O N S (U.S.)
L
10
20
30
40
50
60
70
80
90
100
0
1
2
3
4
5
6
7
8
9
gal
gal
gal
gal
gal
gal
gal
gal
gal
gal
2.6417
5.2834
7.9251
10.5668
13.2086
15.8503
18.4920
21.1337
23.7754
26.4171
0.2642
2.9059
5.5476
8.1893
10.8310
13.4727
16.1144
18.7561
21.3979
24.0396
26.6813
0.5283
3.1701
5.8118
8.4535
11.0952
13.7369
16.3786
19.0203
21.6620
24.3037
26.9454
1.5850
4.2267
6.8684
9.5102
12.1519
14.7936
17.4353
20.0770
22.7187
25.3604
28.0021
1.8492
4.4909
7.1326
9.7743
12.4160
15.0577
17.6995
20.3412
22.9829
25.6246
28.2663
2.1134
4.7551®
7.3968
10.0385
12.6802
15.3219
17.9636
20.6053
23.2470
25.8888
28.5305
2.3775
5.0192
7.6610
10.3027
12.9444
15.5861
18.2278
20.8695
23.5112
26.1529
28.7946
1.0567
0.7925
1.3209
3.6984
3.4342
3.9626
6.6043
6.0759
6.3401
8.9818
9.2460
8.7176
1 1.8877
11.3594
1 1.6235
14.0011 ''T O 6 5 2 ' 14.5294
17.1711
16.9069
16.6428
19.5487
19.2845
19.8128
22.1904
22.4545
21.9262
24.8321
25.0962
24.5679
27.2096
27.4738
27.7380
L
..
10
20
30
40
50
60
70
80
90
100
G A L L O N S (IM P .) T O L IT R E S
IMP
gal
10
20
30
40
50
60
70
30
90
100
0
1
2
3
4
5
6
7
8
9
L
L
L
L
L
L
L
L
L
L
4.5460
9.0919
54.6515
45.4596
50.0056
95.4652 100.0111
90.9192
136.3788 ‘ 140.9248 145.4707
181.8384 186.3844 190.9303
227.2980 231.8440 236.3899
272.7576 277.3036 281.8495
318.2172 322.7632 327.3091
363.6768 368.2223 372.7687
409.1364 413.6824 418.2283
454.5960 459.1420 463.6879
13.6379
59.0975
104.5571
150.0167
195.4763
240.9359
286.3955
331.8551
377.3147
422.7743
468.2339
18.1838
22.7298
27.2758
68.1894
72.2354
109.1030 113.6490 118.1950
154.5626 159.1086 163.6546
200.0222 204.5682 209.1142
245.4818 250.0278 254.5738
290.9414 295.4874 300.0334
336.4010 340.9470 345.4930
381.6606 386.4066 390.9526
427.3202 431.8662 436.4122
472.7798 477.3258 481.8718
63.6434
31.8217
36.3677
77.2813
81.8275
122.7409 127.2869
168.0005 172.7465
213.6601 218.2061
259.1197 263.6657
304.5793 309.1253
350.0389 354.5849
395.4985 400.0445
440.9581 445.9041
486.4177 490.9637
40.9136
86.3732
131.8328
177.2924
222.7520
268.2116
313.6712
359.1308
404.5904
450.0500
495.5096
IMP
gal
10
20
30
40
50
60
70
80
90
1O0
L IT R E S T O G A L L O N S (IM P .)
L
^ 10
20
30
40
50
60
70
80
90
100
0
1
2
3
4
5
6
7
8
9
gal
gal
gal
gal
gal
gal
gal
gal
gal
gal
2.1998
4.3995
6.5593
8.7990
10.9988
13.1986
15.3983
17.5981
19.7978
21.9976
0.2200
2.4197
4.6195
6.8193
9.0190
11.2188
13.4185
15.6183
I 7 . 8 l8 l
20.6178
22.2176
1.3199
3.5196
5.7194
7.9191
10.9189
12.3187
14.5184
16.7182
18.9179
21.1177
23.3175
1.5398
3.7396
5.93§4
8.1391
10.5389
12.5386
14.7384
16.9382
19.1379
21.3377
23.5374
1.7598
3.9596
6.1593
8.3591
10.5588
12.7586
14.9584
17.1581
19.3579
21.5576
23.7574
1.9798
4.1795
6.3763
8.5791
10.7788
12,9786
15.1783
17.3781
19.5779
21.7776
23.9774
0.8799
0.6599
0.4400
2.3597
3.079?
2.6397
5.0594
5.2794
4.8395
7.2592
7.4792
7.0392
9.4590
9.6789
9.2390
11,8787
11.6587
11.4388
13.8585
14.0785
13.6366
16.0682 " I ' O W
15.8383
l¥ .S 3 S < rh l i t g o " 18.4780
20.6777
20.4578
20.2378
22.6575
22.8775
22.4376
1.0999
3.2996
5.4994
7.6992
9.8989
12.0987
14.2984
16.4982
18:6980"
20.8977
23.0975
L
..
10
26
36
40
60
60
70
80
90
160
■
lb
10
20
30
40
50
60
70
80
90
100
0
.1
2
3
4
5
6
7
8
9
kg
kg
kg
kg
kg
kg
kg
kg
kg
kg
4.536
9.072
13.608
18.144
22.680
27.216
31.751
36.287
40.823
45.359
0.454
4.990
9.525
14.061
18.597
23.133
27.669
32.205
36.741
41.277
45.813
0.907
5.443
9.979
14.515
19.051
23.587
28.123
32.659
37.195
41.730
46.266
1.361
5.8S7
10.433
14.969
19.504
24.040
28.576
33.112
37.648
42.184
46.720
1.814
6.350
10.886
15.422
19.958
24.494
29.030
33.566
38.102
42.638
47.174
2.722
7.257
11.793
16.329
20.865
25.401
29.937
34.473
39.009
43.545
48.081
3.175
7.711
12.247
16.783
21.319
25.855
30.391
34 927
39.463
43.998
48.534
3.629
8.165
12.701
17.237
21.772
26.308
30.844
35.380
39.916
44.453
48.988
4 082
8618
13.154
17.690
22.226
26.762
31.298
35.834
40.370
44.906
49.442
2.268
6.804
11.340
15.876
20.412
24.948
29.484
r 34.019
38.555
43.092
47.627
lb
10
20
30
40
50
60
70
80
90
100
K IL O G R A M S TO PO UN D S
kg
10
20
30
40
50
60
70
80
90
100
0
1
2
3
4
5
6
7
8
9
lb
lb
lb
lb
lb
lb
lb
lb
lb
lb
6.614
28.660
50.706
72.752
94.799
116.84
138.89
160.94
182.98
205.03
227.08
8.818
30.865
52.911
74.957
97.003
119.05
141.10
163.14
185.19
207.23
229.28
11.023
33.069
55.116
77.162
99.208
121.25
143.30
165.35
187.39
209.44
231.49
13.228
35.274
57.320
79.366
101.41
123.46
145.51
167.55
189.60
211.64
233.69
15.432
37.479
59.525
81.571
103.62
125.66
147.71
169.76
191.80
213.85
235.89
17.637
39.683
61.729
83.776
105.82
127.87
149.91
171.96
194.01
216.05
238.10
19.842
41.888
63.934
85.980
108.03
130.07
152.12
174.17
196.21
218.26
240.30
22.046
44.092
66.139
88.185
110.23
132.28
154.32
176.37
198.42
220.46
2.205
4.409
24.251
26.455
46.297
48.502
68.343
70.548
92.594
90.389
112.44 "“ 114.64
134.48
136.69
156.53
158.73
178.57
180.78
200.62
202.83
222.67
224.87
kg
10
20
30
40
50
60
70
80
90
100
POUNDS PER SQ U A R E IN C H ES TO K ILO PA SCA LS
Ib /in ^
0
1
2
3
4
5
6
7
8
9
kPa
kPa
kPa
kPa
kPa
kPa
kPa
kPa
kPa
kPa
6.8948
75.8423
144.7899
213.7375
282,6850
351.6326
420.5802
489.5278
558.4753
627.4229
696.3705
13.7895
82.7371
151.6847
220.6322
289.5798
358.5274
427.4749
496.4225
565.3701
634.3177
703.2653
20.6843
89.6318
158.5794
227.5270
296.4746
365.4221
434.3697
503.3173
572.2648
641.2124
710.1601
27.5790
96.5266
165.4742
234.4217
303.3693
372.3169
441.2645
510.2120
579.1596
648.1072
717.0549
34.4738
103.4214
172.3689
241.3165
310.2641
379.21 16
448.1592
517.1068
586.0544
655.0019
723.9497
41.3685
110.3161
179.2637
248.21 13
317.1588
386.1064
455.0540
524.0015
592.9491
661 §967
730.8445
48.2663
117.2109
186.1584
255.1060
324.0536
393.0012
461.9487
530.8963
599.8439
668.7$ 14
737.7393
55.1581
124.1056
193.0532
262.0008
330.9483
399.8959
468.8435
537.791 1
606.7386
675.6S62
744.6341
62.0528
131.0004
199.9480
268.8955
337.8431
406.7907
475.7382
544.68 58
613.6334
682.5810
751.5289
0 .0 0 0 0
10
20
30
40
50
60
70
80
90
100
68.9476
137.8951
206.8427
275.7903
344.7379
412.6854
482.6330
551.5806
620.5281
689.4757
Ib /in ^
10
20
30
40
50
60
70
SO
90
100
K IL O P A S C A L S T O POUNDS PER SQUARE INCHES
kPa
10
20
30
40
50
60
70
80
90
100
kPa
0
1
2
3
4
5
6
7
8
9
lb/in^
lb /in ^
lb /in ^
lb /in ^
lb /in ^
lb /in ^
Ib /in ^
lb /in ^
Ib/in^
lb /in ^
1.4504
2.9007
4.3511
5.8015
7.2518
8.7022
10.1526
11.6030
13.0533
14.5037
.1450
1.5954
3.0458
4.4961
5.9465
7.3969
8.8473
10.2976
11.7480
13.1984
14.6487
.2901
1.7404
,3.1908
4.6412
6.0916
7.5419
8.9923
10.4427
11.8930
13.3434
14.7938
.4351
1.8855
3.3359
4.7862
6.2366
7.6870
9.1373
10.5877
12.0381
13.4884
14.9388
.5801
2.0305
3.4809
4.9313
6.3816
7.8320
9.1824
10.7327
12.1831
13.6335
15.0838
.7252
2.1556
3.6259
5.0763
6.5267
7.9770
9.4274
10.8778
12.3281
13.7785
15.2289
.8702
2.3206
3.7710
5.2213
6.6717
8.1221
9.5724
11.0228
12.4732
13.9236
15.3739
1.0153
2.4656
3.9160
5.3664
6.8167
8.2671
9.7175
11.1678
12.6182
14.0686
15.5190
1.1603
2.6107
4.0610
5.5114
6.9618
8.4121
9.8625
11.3129
12.7633
14.2136
15.6640
1.3053
2.7557
4.2061
5.6564
7.1068
8.5572
10.0076
11.4579
12.9083
14.3587
15.8090
10
20
30
40
50
60
70
80
90
100
ft lb
POUND FEET TO NEWTON-METRES
f t lb
10
20
30
40
50
60
70
80
90
100
0
1
2
3
4
5
6
7
8
9
N m
Nm
Nm
N m
Nm
Nm
Nm
Nm
N m
N Tin
13.5582
27.1164
40.6745
54.2327
67.7909
81.3491
94.9073
108.4654
122.0236
135.5818
1.3558
14.9140
28.4722
42.0304
55.5885
69.1467
82.7049
96.2631
109.8213
123.3794
136.9376
2.7116
16.2698
29.8280
43.3862
56.9444
70.5025
84.0607
97.6189
111.1771
124.7353
138.2934
4.0675
17.6256
31.1838
44.7420
58.3002
71.8584
85.4165
98.9747
112.5329
126.0911
139.6493
5.4233
18.9815
32.5396
46.0978
59.6560
73.2142
86.7724
100.3305
113.8887
127.4469
141.0051
6.7791
20.3373
33.8954
47.4536
61.0118
74.5700
88.1282
101.6863
1 15.2445
128.8027
142.3609
8.1349
21.6931
35.2513
48.8094
62.3676
75.9258
89.4840
103.0422
116.6003
130.1585
143.7167
9.4907
23.0489
36.6071
50.1653
63.7234
77.2816
90.3898
104.3980
117.9562
131.5143
145.0725
10.8465
24.4047
37.9629
51.5211
65.0793
78.6374
92.1956
105.7538
119.3120
132.8702
146.4283
12.2024
25.7605
39.3187
52.8769
66.4351
79.9933
93.5514
107.1096
120.6678
134.2260
147.7842
10
20
30
40
50
60
70
80
90
100
NEWTON METRES TO POUND FEET
N m
0
1
2
3
4
5
6
7
8
9
f t lb
ft-lb
ft-lb
ft-lb
ft-lb
ft-lb
ft-lb
ft-lb
ft-lb
ft-lb
2.9502
10.3258
17.7015
25.0771
32.4527
39.8283
47,2040
54.5796
61.9552
69.3308
76.7064
3.6878
11.0634
18.4390
25.8147
33.1903
40.5659
47.9415
55.3171
62.6928
70.0684
77.4440
4.4254
11.8010
19.1766
26.5522
33.9279
41.3035
48.6791
56.0547
63.4303
70.8060
78.1816
5.1692
12.5385
19.9142
27.2898
34.6654
42.0410
49.4167
56.7923
64.1679
71.5435
78.9191
,5.9005
13.2761
20.6517
28.0274
35.4030
42.7786
50.1542
57.5298
64.9055
72.2811
79.6567
6.6331
14.0136
21.3893
28.7649
36.1405
43.5162
50.8918
58.2674
65.6430
73.0186
80.3943
10
7.3756
20
14.7512
So
22.1269
40
29.5025
50
36.8781
60 r 44.2537
70
51.6293
80
59.0050
90
66.3806
100
73.7562
.7376
8.1132
15.4888
22.8644
30.2400
37.6157
44.9913
52.3669
59.7425
67.1181
74.4938
1.4751
2.2127
8.8507
9.5883
16.2264
16.9639
23.6020
24.3395
30.9776
31.7152
38.3532
39.0908
45.7288
46.4664
53.1045
53.8420
60.4801 h 61.21 76
67.8557
68.5933
75.2313
75.9689
Nm
10
20
30
40
50
60
70
80
90
100
D E C IM A L A N D M E T R IC E Q U IV A L E N T S
Fractions
Decimal
M etric
In.
MM.
Fractions
Decimal
Metri<
In.
MM.
1 /6 4
.
.0 1 5 6 2 5
. . .
.3 9 6 8 8
3 3 /6 4
.5 1 5 6 2 5
1 /3 2
.
.0 3 1 2 5
. . .
.7 9 3 7 5
1 7 /3 2
.5 3 1 2 5
3 /6 4 9. . . . .
.0 4 6 8 7 5
. . .
1 .1 9 0 6 2
3 5 /6 4
.5 4 6 8 7 5
1 /1 6
.
.0 6 2 5
1 .5 8 7 5 0
9 /1 6
5 /6 4
.
.0 7 8 1 2 5
. . .
1 .9 8 4 3 7
3 7 /6 4
.5 7 8 1 2 5
3 /3 2
.
.0 9 3 7 5
. . .
2 .3 8 1 2 5
1 9 /3 2
.5 9 3 7 5
7 /6 4
.
.1 0 9 3 7 5
. . .
2 .7 7 8 1 2
3 9 /6 4
.6 0 9 3 7 5
1 /8
.
.1 2 5
9 /6 4
.
.1 4 0 6 2 5
. . .
3 .5 7 1 8 7
4 1 /6 4
.6 4 0 6 2 5
5 /3 2
.
.1 5 6 2 5
. . .
3 .9 6 8 7 5
2 1 /3 2
.6 5 6 2 5
1 1 /6 4
.
.1 7 1 8 7 5
. . .
4 .3 6 5 6 2
4 3 /6 4
.6 7 1 8 7 5
3 /1 6
.
.1 8 7 5
4 .7 6 2 5 0
1 1 /1 6
.6 87 5
1 3 /6 4
.
.2 0 3 1 2 5
. . .
5 .1 5 9 3 7
4 5 /6 4
.7 0 3 1 2 5
7 /3 2
.
.2 1 8 7 5
. . .
5 .5 5 6 2 5
2 3 /3 2
.7 1 8 7 5
1 5 /6 4
.
.2 3 4 3 7 5
. . .
5 .9 5 3 1 2
4 7 /6 4
.7 3 4 3 7 5
1 /4
.
.250
............
6 .3 5 0 0 0
3 /4
1 7 /6 4
.
.2 6 5 6 2 5
. . .
6 .7 4 6 8 7
4 9 /6 4
.7 6 5 6 2 5
9 /3 2
____ .
.2 8 1 2 5
. . .
7 .1 4 3 7 5
2 5 /3 2
.7 8 1 2 5
1 9 /6 4
.
.2 9 6 8 7 5
. . .
7 .5 4 0 6 2
5 1 /6 4
.7 9 6 8 7 5
5 /1 6
.
.3 1 2 5
7 .9 3 7 5 0
1 3 /1 6
.8 1 2 5
2 1 /6 4
.
.3 2 8 1 2 5
. . .
8 .3 3 4 3 7
5 3 /6 4
.8 2 8 1 2 5
1 1 /3 2
.
.3 4 3 7 5
. . .
8 .7 3 1 2 5
2 7 /3 2
.8 4 3 7 5
2 3 /6 4
.
.3 5 9 3 7 5
. . .
9 .1 2 8 1 2
5 5 /6 4
.8 5 9 3 7 5
3 /8
.
.3 75
............
9 .5 2 5 0 0
7 /8
2 5 /6 4
.
.3 9 0 6 2 5
. . .
9 .9 2 1 8 7
5 7 /6 4
.8 9 0 6 2 5
1 3 /3 2
.
.4 0 6 2 5
. . .
1 0 .3 1 8 7 5
2 9 /3 2
.9 0 6 2 5
2 7 /6 4
.
.4 2 1 8 7 5
. . .
1 0 .7 1 5 6 2
5 9 /6 4
.9 2 1 8 7 5
7 /1 6
.
.4 3 7 5
1 1 .1 1 2 5 0
1 5 /1 6
.9 3 7 5
2 9 /6 4
.
.4 5 3 1 2 5
. . .
1 1 .5 0 9 3 7
6 1 /6 4
.9 5 3 1 2 5
1 5 /3 2
.
.4 6 8 7 5
. . .
1 1 .9 0 6 2 5
3 1 /3 2
.9 6 8 7 5
3 1 /6 4
.
.4 8 4 3 7 5
. . .
1 2 .3 0 3 1 2
6 3 /6 4
.9 8 4 3 7 5
1 /2
.
.5 0 0
............
1 2 .7 0 0 0 0
1
....
............
....
....
....
3 .1 7 5 0
.5 6 2 5
5 /8
.6 25
. . .
1 3 .4 9 3 7 5
. .
1 3 .8 9 0 6 2
. . .
1 4 .2 8 7 5 0
. .
1 4 .6 8 4 3 7
. . .
1 5 .0 8 1 2 5
. .
1 5 .4 7 8 1 2
1 5 .8 7 5 0 0
. .
1 6 .2 7 1 8 7
. . .
1 6 .6 6 8 7 5
. .
1 7 .0 6 5 6 2
. . .
1 7 .4 6 2 5 0
. .
1 7 .8 5 9 3 7
. . .
1 8 .2 5 6 2 5
. .
1 8 .6 5 3 1 2
....
.8 75
1 .0 0
1 3 .0 9 6 8 7
....
.750
____
. .
1 9 .0 5 0 0 0
. .
1 9 .4 4 6 8 7
. . .
1 9 .8 4 3 7 5
. .
2 0 .2 4 0 6 2
. . .
2 0 .6 3 7 5 0
. .
2 1 .0 3 4 3 7
. . .
2 1 .4 3 1 2 5
. .
2 1 .8 2 8 1 2
....
2 2 .2 2 5 0 0
. .
2 2 .6 2 1 8 7
. . .
2 3 .0 1 8 7 5
. .
2 3 .4 1 5 6 2
. . .
2 3 .8 1 2 5 0
. .
2 4 .2 0 9 3 7
. . .
2 4 .6 0 6 2 5
. .
2 5 .0 0 3 1 2
............
2 5 .4 0 0 0 0
-
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