Chevrolet 70 1969 Series Install guide

CHEVROLET
HEAVY DUTY TRUCK
SHOP MANUAL

1969
CHEVROLET
HEAVY DUTY TRUCK
(SERIES 70 and 80)
SHOP MANUAL
FOREWORD
This manual contains, in separate Service and Overhaul
sections, procedures for maintenance adjustments, minor
service operations, and replacement of components (Serv
ice) and for disassembly and assembly of major compo
nents (Overhaul) for Chevrolet Series 0 and 80 Heavy
Duty Trucks.
CHASSIS SERVICE SECTION
The Service Section of this manual includes procedures
for maintenance and adjustments, minor service opera
tions, and removal and installation of components.
The Index on this page enables the user to quickly locate
any desired section in the Service Section. At the beginning
of each individual 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 major subject within the section.
A summary of Special Tools will be found following
Section 9 of the Overhaul portion of this manual while
Specifications covering vehicle components are presented
at the end of each section.
This manual should be kept in a handy place for ready
reference. If properly used, it will enable the technician to
better serve the owners of Chevrolet vehicles.
All information, illustrations and specifications con
tained in this literature are based on the latest product
information available at the time of publication approval.
The right is reserved to make changes at any time without
notice.
• • •
CHEVROLET MOTOR DIVISION
General Motors Corporation
DETROIT, MICHIGAN
SERVICE SECTIO N IN D EX
0LUBRICATION
1CABS AND
BODY MOUNTINGS
2FRAME
3FRONT SUSPENSION
4REAR SUSPENSION
5BRAKES
6A GASOLINE ENGINES
6C SERIES 6V 53
DIESEL ENGINES
6D ENGINE MOUNTINGS
6K ENGINE COOLING SYSTEM
6M ENGINE FUEL SYSTEM
6T AIR COMPRESSOR
AND GOVERNOR
6Y ENGINE ELECTRICAL
7TRANSMISSIONS
AND CLUTCHES
8FUEL TANK & EXHAUST
9STEERING SYSTEM
10 WHEELS & TIRES
11 SHEET METAL
12 CHASSIS ELECTRICAL
AND INSTRUMENTS
13 RADIATOR AND
SURGE TANK
OVERHAUL SECTION
SPECIAL TOOLS
© 1969 Printe in U.S.A.
General Motors Corporation

INTRODUCTION
This manual contains on-the-vehicle maintenance, light repair information,
and unit replacement on all truck models listed on title page. Important infor
mation on the arrangement and use of this manual will be found on page v.
Operation of the vehicles from the standpoint of the driver is contained in a
separate Owner’s and Driver’s manual which is furnished with every new
Chevrolet Truck.
Every effort has been made to include timely and adequate information on
the various units and systems used on Chevrolet Trucks. The general mainte
nance and light repair procedures in the various manual sections are the result
of extensive service experience. This information should serve not only as a
reference for the experienced mechanical force, but also as a comprehensive
text for training purposes.
In some cases, considerable space is devoted to describing the operation
of a unit or system. The use of this space is justified by the presumption that in
order for a mechanic to maintain a unit or system in a serviceable condition, he
must first understand how the unit or system should function.
All information contained in this manual is based on the latest product
information available at the time of publication approval. Chevrolet Motor
Division reserves the right to make changes in design or add improvements at
any time without incurring any obligation to install same on vehicles previously
purchased.
TRUC MODEL DESIGNATION
i i i
CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

MODEL DATA
TRUC
SERIES
ENGINE CLUTCH FRONT AXLE REAR AXLE TRANSMISSION
STD. OPT. STD. OPT. STD. OPT. STD. OPT. STD. OPT.
HV-70 6V-53N —14" -F070 F090
F120
17221 18221,19201 5752C _
JV-70 6V-53N -14” 14"-2 F070 F090
FI 20
30DSC 34DSC, SLHD 385V 7041 Aux.
TV-70 6V-53M -14" -F070 F090
F110
17221 19101,17101
19202
5752C MT41C
HM-80 401M 478M 13" 13"-2
14"
14" 2
F070 F090
F120
17121 18121,17221,
18221,19201
541GL 541GD, 387V,
5752C
JM-80 401M 478M 13" 13" 2
14"
14"-2
F090 F120
F160
34DSC SLHD, SQHD 5652 401V, 7231A Aux.,
6041 Aux., 7041 Aux.,
325V
TM-80 401M 478M 13" 13"-2
14"
14"-2
F090 F110 17121 18121, 17221,
18221, 19201
541GL 541GD, 387V,
5652, 5752C
iv CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

GENERAL INFORMATION
IMPORTANT-READ THIS PAGE
TRUC MODELS COVERED
This manual contains “ on-the-vehicle” main
tenance, light repair overhaul information on
Chevrolet Truck Models listed on page iv. Since
many truck models with various combinations of
equipment are covered in this manual, the reader
must necessarily refer to truck model applica
tions and methods of distinguishing design differ
ences in each manual section.
All standard equipment and the most com
monly used regular production options are
included in this manual. Many special equipment
and accessory items are available on these Chev
rolet Trucks, however, these items are too nu
merous to permit their coverage in this manual.
MANUAL ARRANGEMENT
This manual is divided into major sections in
the sequence shown on the margin of the title
page. A black tab bearing the major section num
ber is placed on the first page of each major
section which indexes with the tab on the title
page. Many of the major sections are divided into
sub-sections, each sub-section containing impor
tant and specific information on related units or
components. A section index is also included on
the first page of each major section, when the
major section is divided into sub-sections.
PAGE AND ILLUSTRATION
NUMBERS
The manual pages are numbered consecu
tively throughout the manual. Illustrations are
numbered consecutively within each section, or
within each sub-section when the major section is
so divided.
SPECIFICATIONS
Service data, fits, and tolerances are listed at
end of each section or sub-section under the head
ing "Specifications." In some cases reference
must also be made to these “Specifications” for
model application and methods of distinguishing
the various design and construction differences.
Manufacturers model or part numbers are
used in many instances in the “ Specifications”
tabulations. These numbers are provided primar
ily for unit identification or truck model applica
tion reference, and should be referred to when
ordering parts. All detail service part numbers
must be obtained from the applicable Parts Book.
SPECIAL TOOLS
Special tools and equipment are mentioned,
and in many instances illustrated, throughout the
text. These tools are specially designed to ac
complish certain operations efficiently and read
ily. Such tools are mentioned in the text by tool
vendor’s numbers.
SERVICE BULLETINS
Service bulletins are issued, when required,
supplementing or in some cases superseding in
formation in this manual. Information in these
bulletins should be noted in the text of the applic
able manual section and the bulletin filed for
ready reference.
ALPHABETICAL INDEX
Important subjects, with manual page number
references, are alphabetically listed in the index
in the back of this manual.
v
CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

VEHICLE MODEL IDENTIFICATION
AND WEIGHT RATING PLATE
The vehicle identification
and weight rating plate is loca
ted on the cab left door pillar of
all models.
Figure I —Vehicle Identification and GVW Plate
ENGINE SERIAL NUMBERS
The engine serial numbers on all engines are located on the
J'l^t block surface just forward of the right cylinder head.
Figure 2— Gasoline (Typical) Figure 3-6 -53 Diesel
SERVICE PARTS IDENTIFICATION
The "Service Parts Identification” label is located on inside of glove com
partment door of steel tilt and conventional cab models. This label lists all
special equipment installed on the vehicle. This information is imprinted on the
label at the factory and represents only the special equipment on the vehicle
when it was shipped from the factory. Always refer to this information when
ordering parts.
SERIAL SERVICE PARTS IDENTIFICATION
PAINT
NOTE* THE special equipment liste d below h as been in stalle d on
THIS VEHICLE. FOR PROPER IDENTIFICATION OF REPLACEMENT
PARTS BE SURE TO SPECIFY THE APPLICABLE OPTION NUMBERS.
OPTION
NO.
DESCRIPTION
OPTION
NO.
DESCRIPTION
Figure 4—Service Part Identification Plate
vi CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

SECTION 0
LUBRICATION
INDEX
Subject Page No.
Lubrication Charts
Conventional Cab Models . . ..................... 2
Tilt Cab Models ......................................... 4
Tandem Bevel A x le s ................................. 6
Engine and Accessories ............................
Capacities
Crankcase ................................................. 8
Transmission ......................................... 8
Rear Axles .............................................. 8
Engine Oil - Symbol "E " ............................ 8
Engine Oil Recommendation ....................... 8
Viscosities ................................................... 9
Checking Engine Oil Level .......................... 9
Engine Oil Filter ......................................... 10
Air Cleaners
Carburetor Air Cleaner ......................... 11
Tractor Type Air Cleaner ....................... 11
Brake Power and Axle Cyl. Air Cleaner. . 11
Air Compressor Air Strainer .................. 11
Other Engine Oil U s e s ................................. 12
Crankcase Ventilation ................................. 13
Crankcase Breather ...................................... 14
Multi-Purpose Gear Lubricant - Symbol "MP" 14
Viscosities ................................................... 15
Subject Page No.
Rear Axle ...................................................... 15
Transmission................................................. 16
Universal Joints............................................ 16
Chassis Lubricant - Symbol " C " .................. 1
High Temperature Grease - Symbol ”S2” . . 1
Wheel Bearings .............................................. 1
Other High Temperature Grease Uses .... 1
Petroleum Jelly - Symbol "S3" .................. 1
Distributor Breaker Cam ............................ 1
Battery Terminals ......................................... 1
Waterproof Grease - Symbol "S4" ............. 18
Refrigerant Machine Oil - Symbol "S " . . . 18
Axle Shift Unit - Electric ............................ 18
Hydraulic Brake Fluid - Symbol "S12" . . . 18
Special Grease - Symbol "S1 "..................... 18
Type A Fluid - Symbol "S 1 9 " ....................... 18
Power Steering System ................................. 18
High Temperature Grease (Special)
- Symbol "S2 ” ............................................ 19
Clutch Release Bearing ................................. 19
High Temperature Grease (Special)
- Symbol "S28"............................................ 19
Stopmaster Brake U n it ................................. 19
Lubrication charts on following pages will lo
cate each lubrication point on the series shown
under each chart. Each point is numbered on the
charts, and each number is keyed to explanatory
text on same or opposite page.
Each item shown on charts requiring lubrica
tion is covered with a lubricant symbol. Explan
ations of symbols start on page following charts.
Explanations include type of lubricant recommend
ed, and detailed instructions regarding its applica
tion. The charts show recommended intervals when
various items should be lubricated. The intervals
are recommended for normal use; however, oper
ating conditions may require more frequent inter
vals. Recommended intervals should be followed
until operating experience indicates other periods.
No particular brand of lubricant is recom
mended as many reputable oil dealers can furnish
the right lubricants when advised of the correct
specifications or descriptions. The lubricant man
ufacturer must be responsible for the quality and
satisfactory performance of his product. His rep
utation is your best indication of quality.
MEANING OF LUBRICANT SYMBOLS
Symbol Explanation Page
"E " Engine Oil ........................................ 8
"MP" Multi-Purpose Gear Lubricant . . 15
"C " Chassis Lubricant........................... 1
"S-2" High Temperature G r e ase .............. 1
"S-3" Petroleum Jelly .............................. 1
"S-4" Waterproof Grease
....................... 18
"S- " Refrigeration Machine O i l .............. 18
"S-12" Hydraulic Brake F lu id .................... 18
"S-1 " Special G rease ................................. 18
"S-19” Type A F luid .................................... 18
"S-2 ” High Temperature Grease (Special) 19
"S-28" High Temperature Grease (Special) 19
CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

LUBRICATION 0-2
Figure 1 — Lubrication Chart— Conventional Cab Models
CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

LUBRICATION 0-3
LUBRICATION DATA
(CHART ON OPPOSITE PAGE)
Item
No. Item Remarks Symbol Miles t
1Spring Shackles & Brackets (1) .... 2 fittings each shackle
.............
C6,000
1 fitting each bracket ...............
C6,000
2Spring Slip Pads (1)
............................
. Apply each e n d .......................... C6,000
3Steering Knuckles
....................... ..
. 2 fittings each side ..................
C6,000
4Steering Tie Rod E n d s
.......................
1 fitting each end ..................... C6,000
5Steering Drag Link
............................
1 fitting each end .......................
C6,000
6Steering Idler Lever ( 1 )
....................
. 1 fitting .................................... C6,000
Power Steering Cylinder Ends (1) . . . . 2 fittings .
. ................................. C6,000
8Trans. Shift Relay Lever ( 1 )
............. 1 fitting .................................... C6,000
9Transmission Shift Rod U-Joints (1) . . 1 fitting each joint..................... C 6,000
10 Auxiliary Trans. Shift Tower (1) . . . . . 1 fitting .................................... C6,000
11 Prop. Shaft U-Joints............................ 1 fitting each joint
....................
C6,000
12 Prop. Shaft Slip Joint
.........................
. 1 fitting each joint ....................
C6,000
13 Steering Column U-Joints
..................
1 fitting each joint .......... ..
C6,000
14 Steering Column Slip Joint
...............
. 1 fitting ...................................... C6,000
15 Clutch Release Cross Shaft (1 )
..........
. 1 fitting each end ....................
C6,000
16 Clutch Release Bearing
....................
. Cup or fitting (sparingly) .... S2 6,000
1 Tru-Stop Brake (1)
............................
. 4 or 8 fittings ............................
C6,000
18 1 fitting
. ...................................
c6,000
19 Brake Camshaft - F. ( 2 )
....................
1 fitting ea. (apply sparingly) . c6,000
20 Clutch and Brake Master Cylinder . . . Fill - 1/2" below opening .... S12 6,000
21 Steering Gear Housing
.......................
. To level of filler plug ............... c6,000
22 Battery Terminals
............................
. Keep coated............................... S3 6,000
23 Electric Shift Unit (2-Spd.)
...............
. To level of filler plug .............
S 12,000
24 . To level of filler plug
.............
MP 6,000
24 Transmission (Clark) (Fuller)
..........
. To level of filler plug ...............
MP 6,000
Drain and refill .......................
MP 12,000
24 Transmission (Spicer) .......................
. To level of filler plug .............
MP 6,000
24 Transmission - Auxiliary (1 )
.............
. To level of filler plug ...............
M P 6,000
25 Rear Axle
...........................................
. To level of filler plug ...............
MP 6,000
Drain and refill .......................
24,000#
26 Front Wheel Bearings
.........................
. Hand pack or use lubricator . . S2 20,000*
2 Rear Wheel Bearings
.........................
. Hand pack or use lubricator . . S2 20,000*
28 Brake Cam Roller Pins - F. (2) .... • Apply ......................................... E20,000
29 Brake & Axle Cylinder Air Cleaner (1) . Clean and reinstall .
. ...............
6,000
30 Air-Hydraulic Cylinder ( 3 )
...............
. To level of plug.......................... 12,000
t When "C " Chassis Lubricant is specified, lubri #Or every 12,000 miles if truck is operated in
cate every 6,000 miles or 60 days, whichever exceptionally heavy work or at continuous high
occurs first. speeds.
* Or once a year, whichever occurs first. (1) Some Models.
(2) Air Brake only.
(3) Hydraulic Brakes only.
CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

LUBRICATION 0-4
CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

LUBRICATION 0-5
LUBRICATION DATA
(CHART ON OPPOSITE PAGE)
Item
No. Item Remarks Symbol Miles t
1 Spring Shackles and Brackets .............
2 fittings each shackle ............. . . . C 6,000
1 fitting each bracket................ . .. c 6,000
2 Spring Slip Pads - Rear ....................
Apply each e n d ............... .. . .. c 6,000
3 Steering Knuckles . ..............................
. 2 fittings each side ..................
. .. c 6,000
4 Steering Tie Rod E n d s .......................
1 fitting each end .......... ... c 6,000
5 Steering Drag Links ............................
. 1 fitting each end..................... ..
. . . c 6,000
6 Steering Idler Lever ( 1 ) .................. ..
1 fitting..................... ..
. .. c 6,000
Power Steering Cylinder Ends (1) . . . . 2 fittings .
. .................... ............
. . . c 6,000
8 Cab Hinges ......................................... 1 fitting each s id e
............... .. . . . . c 6,000
qCab Hold-Down Latch
.......................
1 fitting .................. .. ............ ..
... c6,000
10 Brake Camshafts (1) (2) ..................... 1 fitting each
..............................
. . . c6,000
11 Clutch and Brake Pedals
....................
. 2 fittings ................................. ..
. . . c6,000
12 Tru-Stop Brake (1)............................... 4 or 8 fittings
. ......................... ..
. . . c6,000
13 Clutch Release Cross Shaft (1 )
..........
1 fitting each s id e .......... ..
... c 6,000
14 Clutch Release Bearing .......... ..
. Cup or fitting (sparingly) .... . . . S2 6,000
15 Prop. Shaft U-Joints .......... .. ............
1 fitting each joint..................... . .. c6,000
16 Prop. Shaft Slip Joints .......................
1 fitting each joint . ....................
. . . c6,000
1 Steering Column U-Joints .......... ..
1 fitting each joint..................... ... c6,000
18 Steering Column Slip Joint ............... 1 fitting.................................... ..
. .. c6,000
19 Speedometer Adapter.......................... 1 fitting ......................................
. . . c6,000
20 Transmission Shift L ev e rs
...............
. 2 fittings .......... ..
. . . c6,000
21 Transmission Shift Linkage (Clark) . 2 fittings . ...................................
. .. c6,000
22 Auxiliary Trans. Shift Tower (1) . . . 1 fitting . . ............... ..
. .. c6,000
23 Auxiliary Trans. Shift Levers (1) . . . . 2 fittings
............. .. ....................
. .. c6,000
24 Transmission Shift Rod U-Joints (1) . 1 fitting each joint
. ................. . .. c6,000
25 Hand Brake Bell Crank ( 1 ) ..................
1 fitting .................................... . . . c6,000
26 Steering Gear Housing ....................... To level of filler plug
.............
. . . SG 6,000
2 Clutch and Brake Master Cylinder . . Fill - 1/2" below opening . . . . . . . S12 6,000
?R Battery Terminals .......... .. ............... Keep coated .............
..
. . . S3 6,000
29 Electric Shift Unit (2-Spd.)
...............
. To level of filler plug ...... ... S 12,000
30 Brake Cam Roller Pins (2) ..................
• Apply . ............ ............................ . . . E20,000
31 Transmission (N.P.)
....................... .. . To level of filler plug
.............
. . . MP 6,000
31 Transmission (Clark)
. ......................
To level of filler plug ...... . . . MP 6,000
31 Transmission (Spicer) ....................... . To level of filler plug . ............
. . . M P 6,000
31 Transmission - Auxiliary (1 )
.............
To level of filler plug ...............
. . . M P 6,000
32 Rear Axle ............................................ To level of filler plug ...... ... MP 6,000
Drain and refill . . ......................
. . . MP 24,000#
33 Front Wheel Bearings
. ......................
Hand Pack or use lubricator . . . . . S2 20,000*
34 Rear Wheel Bearings.......................... Hand pack or use lubricator . . . . . S2 20,000*
35 Brake & Axle Cyl. Air Cleaner (1) . . . Clean and reinstall
..................
6,000
36 To level of plug
.......... .. ............ . . . S6 12,000
t When "C " Chassis Lubricant is specified, lubri #Or every 12,000 miles if truck is operated in
cate every 6,000 miles or 60 days, whichever exceptionally heavy work or at continuous high
occurs first. speeds.
* Or once a year, whichever occurs first. (1) Some Models.
(2) Air Brake only.
(3) Air-Hydraulic Brakes only.
CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

LUBRICATION 0-6
Item
No. Item Remarks Symbol Miles
1 Prop. Shaft U-Joint ............................... 1 fitting each joint .......................
C6,000
2 Prop. Shaft Slip Joint ............................ 1 fitting each joint ....................... C6,000
3 Rear Spring Pin and Bracket ....... 1 fitting each s id e
.......................
C6,000*
4 Rear Axles . ........................................... To level of filler plug ...............
MP 6,000
Drain and refill ............... .. . . . MP 24,000#
5 Brake Camshafts (1) ............................
1 fitting each ............................... C 6,000t
6 Brake Shoe Roller Pins (1) ........ Apply
.................................... E20,000
7 Wheel Bearings . . ............ .. . . . Hand pack or use lubricator . . . S2 20,000*
t Lubricate every 6,000 miles or 60 days,
whichever occurs first.
# Or every 12,000 miles if truck is operated in
exceptionally heavy work or at continuous high
speed.
★ Or once a year, whichever occurs first.
(1) Some Models.
Figure 3 —Lubrication Chart—Tandem Bevel (SLHD, SQHD, 30DSC, and 34DSC)
CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

LUBRICATION 0-7
0
©
O p -(2)
Item
No. Item Remarks
1 Engine ............................... .. ................. Keep to "FU LL” mark . . .
2 Engine Oil Filter.................................... See instructions ...............
3 Engine Air Cleaner . .............................. Clean and refill ........... .. .
4 Crankcase Breather (1) ....................... See instructions ............. ..
5 Air Compressor Air Strainer (1) .... Clean and install ...............
6 Governor Air Filter (2) ....................... Clean and install ...............
Distributor (2) ...................................... 1/2 turn of cam lubricator
Breaker pivot - 1 drop . . .
Rotor felt - 4 drops . . . ,
9 Starter ................................................... See instructions...........
10 Power Steering Reservoir (1) ............... To "OIL LE VE L" mark
11 Tachometer Adapter ( 1 ) ....................... 1 fitting..........................
(1) Some Models.
(2) Gas Engine Only.
# Replace lubricator at 24,000 mile intervals.
@ 2,000 miles on Diesel Engines.
Symbol
E
E
E
E
E
S19
C
Figure 4—Engine Lubrication Chart
Miles
Daily
12,000®
6,000
6,000
12,000#
6,000
6,000
6,000
6,000
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SHOP MANUAL

LUBRICATION 0-8
CRAN CASE CAPACITIES
QTS. QTS.
ENGINE L/FILTER W/FILTER
M OD EL U.S. IMP. U.S. IMP.
401M, 4 8M. . . 8. . . 6-3/4 10-1/2. 8-3/4
6V-53N .............
14. . . 11-3/4 16. . . . 13-1/4
(1) Add 1 quart with oil cooler.
Crankcase capacities are for normal refill.
Add oil as indicated when oil filter is drained and
element changed. Capacities given may be ap
proximate - keep level as close as possible to
"F U L L ” mark without over-filling. Do not oper
ate with level below "ADD" mark.
TRANSMISSION CAPACITIES
PINTS
MAIN U.S. IMP.
CL325/32 .......... 14 11-3/4
CL385/38 . ............................ ........ 14 11-3/4
CL401 ............ 20 16-3/4
NP540/541. . . ...................... ........ 10 8-1/4
SP5652/5 52. ........ 13 10-3/4
MT41 (Automatic). . . . . . 18 15
AUXILIARY U.S. IMP,
SP5831. ...... 43-1/4
SP6041. ...... 86-3/4
SP 041. ...... , 11 9-1/4
REAR AXLE CAPACITIES
BEVEL PINTS
U.S. IMP.
E1 101 ...................
29 24-1/4
E1 121 ...................
29 24-1/4
E18121. ...... 29 24-1/4
E19101 . .................. 34 28-1/4
E19121 ............. ... , 34 28-1/4
TWO-SPEED
E1 221. ...... 29 24-1/4
E18221. ...... 29 24-1/4
34 28-1/4
E19221 . .................. 34 28-1/4
TANDEM-BEVEL PINTS
U.S. IMP.
E30DSC. . 30F.(2);2 R.
E34DSC. . 29F.(2);32H.
E34DSC. . 29F.(2);32R.
SLHD . . . 32-l/2F.(l);32R.
SQHD . . . 34F.(1);31R.
25F.(2);20-3/4
24-l/4F.(2);26-3/4R,
24-l/4F.(2);26~3/4R.
2 F.(l);26-3/4R.
28-l/4F.(l);25-3/4R.
(1) Add 2 pints at top of inter-axle differential
cover.
(2) Add 2 pints at forward hole in top of differen
tial carrier.
ENGINE OIL
(SYMBOL “E” ON CHARTS)
ENGINE OIL RECOMMENDATIONS
The oil industry markets various types of
engine oil under certain service designations and
specification numbers.
The selection of a reliable supplier, with
close attention to his oil and filter element change
recommendations can provide satisfactory lubri
cation and longer life for your engine.
DIESEL ENGINE
Use only high quality oils which are:
(1) MIL-L-2104B engine oils (see NOTE),
-or-
(2) Oils which pass the vehicle manufacturers
tests (including General Motors Standard
GM 6042M).
NOTE: Supplement 1 engine oils (based upon
now obsoleted MIL-L-2104A) have been super
seded by MIL- L-2104B engine oils, so these
Supplement 1 oils are therefore becoming
unavailable.
Where a history of satisfactory performance
with Supplement 1 oils has been established, how
ever, they can still be used.
The use of proper engine oils and oil change
intervals are your best assurance of continued
reliability and performance from your Chevrolet
engine.
IMPORTANT: Non-deter gent and other lower
quality engine oils are specifically not recom
mended in Diesel engines.
Diesel Engine Oil Change Periods
The intervals at which "crankcase oil should
be changed depend entirely upon the type and
quality of oil used, the severity of truck operation,
and the mechanical condition of the engine. Nor
mally oil changing is closely related to filter
element and air cleaner element changing. Drain
oil after a run or when oil is hot.
While it is extremely important that only first
quality "Heavy Duty" lubricating oils be used, it is
imperative that:
CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

LUBRICATION 0-9
1. Engine oil be drained initially after the
first 100 hours of operation. On highway vehicles
this corresponds to approximately 2,000 miles of
service. The drain interval may then be gradually
increased or decreased. Following the recom
mendations of the oil supplier (based on analysis
of the drained oil) until the most practical oil and
filter element change period for the particular
service has been established. For vehicles oper
ating exclusively in highway service, extended
intervals may be permissible, while vehicles
operating in "city-service" may require more
frequent oil changes.
2. Solvents should not be used as flushing
oils. Dilution of the fresh refill oil supply can
occur which may be detrimental.
GASOLINE ENGINE
Use only high quality oils which are:
(1) Intended for Service Designations "M S”
and "D M ” ^see NOTE).
-or-
(2) Products passing vehicle manufacturers
tests (including General Motors Standard
GM 6042M).
NOTE: Supplement 1 engine oils (based upon
now obsoleted MIL-L-2104A) have been super
seded by MIL-L-2104B engine oils. However,
Supplement 1 engine oils (MS-DM) with a history
of satisfactory performance are available, and
may be used.
The use of proper engine oils and oil change
intervals are your best assurance of continued
reliability and performance from your Chevrolet
engine.
IMPORTANT: Non-detergent and other lower
quality engine oils are specifically not recom
mended in gasoline engines.
Gasoline Engine Oil Change Periods:
It is recommended that the engine crankcase
oil be initially drained and refilled with new oil
after the first 2,000 miles of service. Thereafter,
the intervals at which crankcase oil should be
changed depend entirely upon the type and quality
of oil used, the severity of truck operation, and the
mechanical condition of the engine. 2,000 mile
change intervals are suggested, as these intervals
are compatible with the 6,000 mile chassis lubri
cation intervals. However, different intervals may
be necessary, depending upon operating and temp
erature conditions as explained following:
In highway freight haul with very little idling
and/or cold operation, while using MIL-L-2104A
or API Service ”DG" (NOTE 2) oils, drain crank
case every 2,000 miles or 60 days, whichever
comes first and change filter every 2,000 miles or
every 2 months, whichever occurs first (NOTE 1
following).
When operating in variable or intermittent low
temperature where use of "D G " oil has resulted in
some sludge and/or varnish formation, use "Sup
plement 1" (API Service "DM") (NOTE 3) and drain
crankcase every 2,000 miles or 60days, whichever
comes first, and change filter every 2,000 miles or
every 2 months, whichever occurs first (NOTE 1).
Series 3 (API Service "DS") engine oils should
hot be used in Chevrolet gasoline engine, except
upon recommendation of the oil supplier.
NOTE 1 - Use of independent laboratory oil
analysis reports or oil supplier recommendation
(based upon oil sample analysis) should be made to
determine if more or less frequent oil and filter
change periods are required, or possible.
NOTE 2 - Some oil suppliers may designate
as "MS-DG."
NOTE 3 - Some suppliers may designate as
"MS-DG-DM."
BREAK-IN OILS AND ADDITIVES
The use of proprietary blends of supplement
ary additives or concentrates such as engine oil
supplements, break-in oils, tune-up compounds,
friction reducing compounds, etc., is not recom
mended in lubricating oils of the Diesel engines in
Chevrolet Trucks. A lubricating oil additive is
available from Chevrolet dealers specifically for
gasoline engines.
VISCOSITIES
Atmospheric temperatures and severity of
service determine the viscosity grade of engine oil
to use. Viscosity numbers constitute a classifica
tion of lubricants in terms of viscosity or fluidity,
but with no reference to any other characteristics
or properties.
As a guide to the selection of the proper grade
or viscosity of oil to be used at various atmos
pheric temperatures, refer to respective gasoline
or Diesel engine "Viscosity Chart" (figs. 5 and 6).
If cold starting is a problem the use of lighter
oils will lessen such starting difficulties.
MULTI-VISCOSITY TYPE ENGINE OILS
Multi-Viscosity lubricating oils, as a group,
are not normally recommended. However, some
may be effectively used to facilitate starting when
prolonged exposure of the engine to temperatures
below freezing is unavoidable. Consult your sup
plier regarding the performance characteristics of
this type of oil and obtain his assurance of adequate
lubrication before subjecting the engine to heavy-
duty service.
CHEC ING ENGINE OIL LEVEL
Daily, or oftener if necessary, check oil level.
Make the check preferably after a day's run and
CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

LUBRICATION 0-10
after engine has been stopped for a few minutes.
Remove dipstick, wipe clean with cloth, reinsert
and remove again. The upper mark on dipstick is
"F U L L ," the lower "ADD." Keep level as close as
possible to "FU LL" mark without overfilling. Do
not operate with level below "A DD” mark.
On gasoline engines the dipstick is on right
side and engine can be filled at right filler on
valve rocker cover after removing filler cap
(fig. ).
On tilt cab models, accessibility is through
door behind passenger seat. On other models, dip
stick and oil filler are accessible when hood is
raised.
ENGINE OIL FILTER
Oil filter element changing periods are closely
related to crankcase oil changing periods, the qual
ity of oil used, or the severity of the trucks service.
It is recommended that element be changed initially
at first oil change and thereafter at intervals indi
cated under "Engine Oil Recommendations" for
respective engine.
Location of oil filter is at right rear of crank
case on 6V-53 Diesel models and at left rear on
gasoline models (fig. 8).
ELEM ENT TYPE
1. Remove plug in filter shell to drain oil
from filter.
2. Back out center stud and withdraw shell and
stud as an assembly.
3. Withdraw element from adapter or base
and discard.
4. Clean old oil from filter adapter and shell.
5. If filter element spring, retainer or washer
require replacing, remove retainer ring from stud
and withdraw parts. After assembling new parts,
install ring in groove of center stud.
6. Replace old filter housing gasket.
. Position new filter element carefully on
center stud within the housing and place housing,
element and stud in place on base or adapter.
8. Torque center stud 40 to 50 ft. lbs., being
careful not to damage gaskets. Install drain plug.
DISPOSABLE TYPE
1. Turn filter from mounting on engine, then
discard assembly.
2. Thoroughly clean mounting at gasket area.
VISCOSITY CHART
r cold weather, **iec» viscosity bated on lowest anticipated temperature,
r hoi weather, select viscosity bcised on highest temperature expected during
» day.
Figure 5— Gasoline Engine Oil iscosity Chart Figure 6— Diesel Engine Oil iscosity Chart
CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

Figure 7— 0// Filler and Dipstick (Gasoline j
Fill Shell with engine oil, apply lubricant to
filter gasket, then thread filter onto stud until
gasket touches mounting. Torque PF- to 10 to
15 foot-pounds torque and PF-29 to 25 foot-pounds
torque with special wrench (J-22 5).
Whenever new element is installed, the engine
should be run and the filter inspected for signs of
an oil leak. The engine should then oe stopped, and
the on level brought up to the "F ULL" mark on the
oil level dipstick.
AIR CLEANERS
Air cleaners must be serviced at least every
12,000 miles. Under adverse conditions or exten
sive operation on dusty or sandy roads, unit should
be cleaned every day or at least every 200 miles.
Air cleaners on vehicles operating in dust storm
GASOLINE ENGINE DIESEL ENGINE t-2361
areas should be cleaned immediately after such
storms.
LUBRICATION 0-11
WARNING
USE EXTR EM E CAUTION TO BE
SURE THAT ALL VOLATILE CLEANING
FLUID (GASOLINE, EROSENE, ETC.)
IS REMOVED FROM AIR CLEANER AT
TIME OF CLEANING. UNCONTROLLED
FUEL ENTERING THE COMBUSTION
CHAMBER IN THIS M ANNERCANCAUSE
THE ENGINE TO "RUN-AW AY" AND
POSSIBLY DESTROY ITSELF AND CAUSE
INJURY TO PERSONNEL.
r X A / l k l / - ' C X I i n ~ ]
Figure 8—Engine Oil Filters Figure 9—Air Cleaner (Dry TypeI
CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

LUBRICATION 0-12
GASOLINE ENGINES (Figs. 9 and 10)
A paper element type air cleaner (dry or
paper wetted) is used on gasoline engine. Inspect
element assembly for damage and replace when
damaged or excessively dirty.
1. Remove wing nut from stud at top of air
cleaner, then lift cover and element from base.
2. The following procedure is to check and
service paper type element.
a. To determine if an air filter element re
quires cleaning or replacement, use air filter
viewer, A.C. Part Number 6484631 which has a
special lens for this purpose.
b. Position the viewer as shown in figure 4
----- ■ WING NUT
Figure 10—Air Cleaner (Welted Element Type)
and turn on viewer light. A dirt-clogged element
prevents the light from being visible from outside.
c. The paper wetted type air cleaner has been
impregnated with oil and cannot be cleaned. When
dirt-clogged or when light as described above is
not visible, the element must be replaced.
d. Some dry elements are washable; refer to
decal (fig. 5) for instructions. Clean element by
shaking out accumulated dirt, or clean by washing
with water and detergent ONLY. Rinse until water
runs clean. Shake off excess water and dry. DO
NOT OIL ELEM ENT.
IMPORTANT: DO NOT USE AIR PRESSURE
TO CLEAN OR DRY ELEMENT.
NOTE: Install a new element after five clean
ings.
e. If the dry type element is cleaned, recheck
after cleaning or washing as described above, and
every 3,000 miles thereafter. Under normal driv
ing conditions element should be checked every
6,000 miles.
3. Re-assemble and install in reverse order
of removal and disassembly procedures.
TRACTOR TYPE AIR CLEANER
1. Loosen two clamps or thumb screws at
taching reservoir to cleaner body, then pull reser
voir downward.
2. Drain oil from reservoir, and clean in
cleaning fluid to remove all accumulated deposits.
3. Pull element downward and out of cleaner
body. On some cleaners element is held in body
with two wing nuts.
4. Slush element up and down in bath of clean
ing fluid until all oil and dirt deposits are removed.
Permit element to dry thoroughly before installing,
but do not use compressed air.
5. Reinstall element in cleaner body being
sure element is pushed up as far as possible.
6. Fill reservoir up to "OIL LE V EL" mark,
using same grade oil as used in engine. Fill inside
of baffle to same level. Reinstall cover (if used)
over baffle at center of reservoir.
. Reinstall reservoir to cleaner body and
secure with two latches or wing nuts.
BRAKE POWER AND AXLE
CYLINDER AIR CLEANER
The brake power and 2-speed axle shift air
cleaner used on models with vacuum-hydraulic
brakes or 2-speed axle is dry type.
1. Remove element assembly from tube.
2. Wash element thoroughly in cleaning sol
vent to remove all accumulated dirt, then dry thor
oughly.
3. Reinstall dry, do not oil element.
CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL

LUBRICATION 0-13
Hair
Figure 11 — Air Compressor Air Strainers
AIR COMPRESSOR AIR STRAINER (Fig. 11)
The air compressor air strainer should be
inspected and replaced or cleaned at recommended
intervals.
On cleanable type, remove snap ring retaining
cover to shell, then remove cover. Remove hair
element, discs, and center tube from shell. Wash
all parts in cleaning solvent until clean, then dry.
Dip element in light engine oil and permit surplus
oil to drain. Install center tube, element, and discs.
Install cover and secure with snap ring.
Paper element type air compressor cleaner is
used on some models and should be replaced when
element shows visible evidence of damage or a dirt
clogged condition or is oil saturated.
Cellulose type element is cleanable in cleaning
solution and compressed air to remove accumu
lated dirt.
Foam-type element is cleanable in cleaning
solution by immersing and squeezing until clean.
Apply oil sparingly.
OTHER ENGINE OIL USES
DISTRIBUTOR
Breaker Pivot. Remove distributor cap and
apply one drop of S.A.E, 10 engine oil to breaker
arm pivot. Do not apply excessive lubricant.
»• m\
' ■ flfSlF j
Figure 12— Crankcase Breather (Gasoline) Figure 13— rankcase Ventilation System IV6-S3 Engine}
CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL