
If the differential is at operating  temperature  (warm),  add enough  lubricant 
to  raise  the level  to the bottom 
of the  filler  plug hole. 
If  the  differential  is cold,  add enough  lubricant  to  raise  the level to 
1/2 inch 
( 12 mm) below  the  filler plug hole. 
What to Use 
Refer  to the  Maintenance  Schedule  to  determine  what kind of lubricant to 
use. See “Recommended  Fluids  and Lubricants” in the Index. 
Engine Coolant 
The  following  explains  your cooling  system and  how to add  coolant  when it 
is low. If you have a problem  with  engine  overheating,  see  “Engine 
Overheating” 
in the Index. 
The  proper  coolant  for  your  vehicle will: 
Give  freezing protection  down  to -34°F (-37°C). 
0 Give boiling  protection  up to 262°F  (128°C). 
Protect  against rust and corrosion. 
Help  keep  the proper  engine  temperature. 
Let the warning  gages work as they  should. 
What  to Use 
Use a mixture of one-half cleun water (preferably  distilled) and one-half 
antifreeze  that  meets “GM Specification  6038-M,” which won’t  damage 
aluminum parts. 
You can also use  a recycled  coolant  conforming to “GM 
Specification  6038-M.”  Use  GM Coolant  Supplement  (Sealer)  with a 
complete  coolant  flush and refill. If  you  use this  mixture.  you don’t  need to 
add  anything  else. 
A CAUTION: 
Adding  only plain water to your  cooling  system can be 
dangerous. Plain water,  or some  other  liquid  like  alcohol,  can 
boil  before  the  proper  coolant mix  will.  Your  vehicle’s  coolant 
warning  system 
is set for  the  proper  coolant mix. With plain 
water  or the  wrong  mix,  your engine  could get too hot  but 
you 
wouldn’t  get  the overheat warning.  Your engine  could catch fire 
and  you or others  could  be  burned. Use 
a 50/50 mix  of clean 
water  and 
a proper  antifreeze. 
6-35 
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Every 50,000 Miles (83 000 km) 
Automatic Transmission Service 
Every 60,000 Miles (100 000 km) 
Crankcase Depression Regulator  Valve (CDRV)  System Inspection 
Engine  Accessory  Drive Belt Inspection 
Exhaust  Gas Recirculation  (EGR) System Inspection 
(if equipped) 
Exhaust Pressure Regulator  Valve Inspection 
Maintenance  Schedule I - Gasoline  Engines  With 
Light 
Duty Emissions 
The services  shown in this  schedule up to 60,000 miles (1 00 000 km)  should 
be  performed  after 
60,000 miles (100 000 km) at the  same  intervals. 
Footnotes 
3 The  California  Air Resources  Board has determined that the  failure  to 
perform  this maintenance  item  will not nullify  the emission warranty  or 
limit  recall  liability prior  to the completion  of vehicle useful life.  We, 
however,  urge that all recommended  maintenance services  be performed at 
the indicated  intervals and the maintenance  be recorded. 
:$* Drive  axle  service: 
Locking Differential - Drain fluid and refill at  first  engine oil change. 
At  subsequent oil  changes, check fluid  level and add fluid 
as needed. If 
driving in dusty areas  or towing a trailer, drain fluid and  refill every 
15,000 miles (25 000 km). 
0 Standard  Differential - Check fluid  level and add fluid as needed  at 
every  oil change. 
If driving in dusty  areas  or towing  a trailer, drain 
fluid and refill every 15,000 miles (25 000 km). 
More  frequent  lubrication  may  be required  for heavy-duty  or off-road 
use. 
3500 HD  Models  with applications requiring  extreme overload/trailer 
towing  conditions  and high  speed (above 
45 mph or 72 kmh) 
conditions  for extended  periods of time must have the  drive  axle fluid 
changed  every 
3,000 miles (5 000 km) or 3 months, whichever  occurs 
first,  or must  use 
75W-140 synthetic fluid meeting GM specifications. 
See  “Recommended Fluids and Lubricants” 
in this  section. 
7-12 
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Maintenance  Schedule II - Gasoline Engines With 
Light  Duty  Emissions 
The  services  shown in this schedule up to 60.000 miles ( 100 000 km)  should 
be  performed  after 
60.000 miles ( 100 000 km) at the same  intervals. 
Footnotes 
-i- The  California  Air Resources  Board has determined that the Failure  to 
perform  this maintenance  item  will 
not nullify the emission  warranty or 
limit recall liability prior 
to the  completion of vehicle  useful  life. We, 
however.  urge  that  all  recommended  maintenance  services  be performed at 
the  indicated  intsrkrds 
and t!w rnlrinlcn;nnx be recor-ded. 
0 
0 
0 
0 
Locking Differential - Drain iluid mci wi.il! :ii !.iI-st cngine oii change. 
At subsequent  oil changes,  check  fluid level  and  add fluid as needed. If 
driving in dusty  areas  or  towing a trailer.  drain fluid and refill every 
15,000  miles 
(25 000 km). 
Standard  Differential - Check tluid  level  and  add fluid as needed  at 
every  engine 
oil change.  If--driving in dusty  areas  or towing  a trailer. 
drain  fluid  and  refill every 
15,000 miles (25 000 km). 
More  frequent  lubrication  may  be  required  for  heavy-duty  or  off\
-road  use. 
3500 HD Models with applications  requiring  extreme overload/trailer 
towing  conditions  and  high speed  (above 
45 mph or 72 km/h) 
conditions  for  extended  periods 
of time must have the drive axle fluid 
changed  every 
3,000 miles (5 000 km) or 3 months, whichever  occurs 
first,  or  must  use  7SW-140  synthetic tluid  meeting 
GM specifications. 
See  "Recommended  Fluids and  Lubricants" 
in this section. 
7,500 Miles (12 500 km) 
0 Change  engine oil and filter  (or  every 12 months. whichever  occurs 
first). 
A11 E1?7iLs.~io1I Corlti-ol Serl7ic-e. 
Lubricate  the front  suspension,  king  pin  bushings.  steering linkage, 
transmission  shift linkage, transfer  case  shift linkage. parking brake 
cable  guides. 
rear driveline  center splines, front axle propshaft  splines, 
brake  pedal  springs and clutch  pedal springs. 
Ball joints  and  king  pin 
bushings  should 
not be  lubricated  unless their temperature is 10" F 
(-12" C). or higher.  When  weather  is cold,  let  the  ball  joints and king 
pin  bushings  warm  up before lubrication  or they  could  be damaged. 
Perform  each of  the  listed lubrication  service items  at  this mileage 
interval  (or every 
12 months.  whichever  occurs  first). 
(ColltillltL'd) 
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I 
Maintenance  Schedule II - Gasoline  Engines  With 
Light  Duty  Emissions 
0 Replace spark plugs. At1 Emission  Control  Senlice. 
0 Inspect spark plug wires. Ai7 Emission Control  Service. ; 
0 Replace  air  cleaner filter. An E~~zission Control Sunice. 
- 
r! Inspect fuel tank, cap and lines for  damage or leaks. Inspect fuel  cap 
gasket  for  any  damage.  Replace parts 
as needed. An E~nission Control 
Service. ? 
DATE 
SERVICED BY: ACTUAL MILEAGE I 
< 
Maintenance  Schedule I - Gasoline  Engines  Heavy 
Duty  Emissions 
The  services  shown in this schedule  up to 60.000  miles ( 100 000 km)  should 
be  performed  after 
60.000 miles (100 000 km) at the same intervals. 
Footnotes 
*<: Drive  axle  service: 
a 
a 
0 
a 
Locking Differential - Drain  fluid and refill at first engine  oil change. 
At  subsequent  oil changes,  check fluid level  and  add fluid as needed. 
If 
driving in dusty  areas  or towing  a trailer, drain fluid and refill every 
15,000  miles 
(25 000  km). 
Standard Differential 
- Check fluid level  and add fluid as needed  at 
every  engine  oil change. 
If driving in dusty  areas or towing a trailer, 
drain fluid and refill every 
15,000 miles (25 00 km). 
More  frequent  lubrication  may  be required for  heavy-duty or off-road 
use. 
3500 HD Models with applications requiring extreme overload/trailer 
towing  conditions  and high  speed  (above 
45 mph or 72 km/h) 
conditions  for  extended periods  of time must  have the drive  axle fluid 
changed every 
3,000 miles (5 000 km)  or 3 months, whichever occurs 
first,  or must  use 
75W-140 synthetic fluid meeting GM specifications. 
See  “Recommended  Fluids and Lubricants” 
in this section. 
7-34 
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Maintenance  Schedule I - Gasoline  Engines  Heavy 
Duty Emissions 
(Continued) 
L! If your  engine  has a thermostatically controlled cooling fan, inspect all 
hoses and ducts  for proper  hook-up  (or every 12 months, whichever 
occurs  first). 
Be sure the valve  works  properly. This is a Noise 
Emission  Control  Service.  Applicable  only  to vehicles  sold  in  the 
United  States. 
DATE  SERVICED BY: ACTUAL  MILEAGE 1 I 
Maintenance  Schedule II - Gasoline  Engines  With 
Heavy  Duty  Emissions 
The  services shown in this schedule  up  to 60.000 miles ( 100 000 kn1) should 
be  performed  after 
60.000 miles ( IO0 000 km) at the same intervals. 
Footnotes 
.I, .!. -~*-~- Drive axle service: 
0 Locking  Differential - Drain fluid and  refill  at  first engine oil change. 
At  subsequent 
oil changes. check fluid and  add  fluid as needed. If 
driving in dusty  areas or towing  a trailer, drain fluid  and  refill every 
15,000 miles (25 000 km). 
0 Standard Differential - Check fluid  level  and  add  fluid as needed at 
every  engine oil change. If driving in dusty areas or towing a trailer, 
drain fluid  and  refill every  15,000  miles 
(25 000 km). 
0 More frequent  lubrication  may be required for heavy-duty or off-road 
use. 
0 3500 HD Models  with  applications requiring extreme overload/trailer 
towing conditions  and  high speed  (above  45 
mph or 72 km/h) 
conditions for extended  periods of time  must  have the drive axle fluid 
changed  every 3.000  miles 
(5 000 km) or 3 months, whichever occurs 
first,  or  rnust  use  75W-140  synthetic tluid  meeting 
GM specifications. 
See  "Recommended  Fluids  and  Lubricants" 
in this section. 
7-52 
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Maintenance  Schedule I - Diesel  Engines 
The  services shown in this schedule up to 60,000  miles (100 000 km) should 
be  performed  after 
60,000 miles  (100 000 km) at  the  same intervals. 
Footnotes 
* When  the vehicle  is operated in extreme  dust and dirt conditions 
(off-road),  the air cleaner  filter may  need  to be checked as often 
as every 
300 miles  (483 km) and replaced as necessary. 
** Drive  axle service: 
0 
0 
0 
0 
Locking  Differential - Drain fluid  and refill  at first  engine  oil change. 
At subsequent oil  changes, check fluid and add fluid 
as needed. If 
driving 
in dusty areas  or towing  a trailer, drain fluid and refill every 
15,000  miles (25 
000 km). 
Standard  Differential 
- Check fluid level and add fluid as needed  at 
every  engine  oil change.  If driving 
in dusty areas  or towing a trailer, 
drain fluid  and refill every  15,000 miles 
(25 000 km). 
More  frequent lubrication  may  be required  for heavy-duty  or off-road 
use. 
3500 HD Models with applications  requiring extreme overload/trailer 
towing  conditions  and  high speed (above 
45 mph or 72 km/h) 
conditions  for extended periods of time must have the drive axle fluid 
changed  every 
3,000 miles (5 000 km) or 3 months, whichever  occurs 
first,  or must  use  75W-140  synthetic fluid meeting 
GM specifications. 
See  “Recommended Fluids  and  Lubricants’’ 
in this section. 
2,500 Miles (4 000 km) 
0 Change  engine oil and filter (or every 3 months, whichever  occurs 
first). 
An Emission Control Service. 
0 Lubricate  the front  suspension,  king pin bushings,  steering linkage, 
transmission  shift linkage, transfer  case 
shift linkage, parking brake 
cable  guides, rear driveline  center  splines, front axle propshaft  splines, 
brake pedal  springs and clutch pedal springs.  Ball joints  and king  pin 
bushings  should not  be lubricated  unless their temperature 
is 10” F 
(-12” C), or higher.  When weather  is cold,  let  the  ball joints  and king 
pin  bushings  warm up before lubrication  or they  could  be damaged. 
Perform each  of the  listed lubrication service items  at this mileage 
interval  (or every  12 months, whichever  occurs  first). 
DATE SERVICED BY: ACTUAL MILEAGE I 
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I Maintenance  Schedule I - Diesel Engines I 
0 Check the exhaust pressure  regulator  valve for proper operation; 
correct  any binding.  Inspect  hoses  for  cracks,  chafing or decay.  Replace 
parts  as needed. 
Arl Emission Control Service. 
0 Check  readfront  axle  fluid level and add fluid as needed.  Check 
constant  velocity joints and axle seals  for leaking. 
:c‘c 
DATE  SERVICED BY: ACTUAL  MILEAGE 
The services shown in this schedule  up to 60,000 miles ( 100 000 km) should 
be  performed  after  60,000  miles 
( 100 000 km) at  the  same intervals. 
Footnotes 
‘:’* Drive  axle  service: 
0 
0 
0 
0 
Locking Differential - Drain fluid and  refill  at  first engine oil change. 
At  subsequent 
oil changes,  check fluid level  and  add  fluid as needed. If 
driving 
in dusty  areas 01- towing a trailer,  drain fluid and  refill  every 
15,000  miles 
(25 000 km). 
Standard Differential 
- Check fluid  level and add  fluid as needed  at 
every  engine  oil change. 
If driving in dusty  areas or towing a  trailer. 
drain fluid  and  refill every 
15.000 miles (25 000 km). 
More frequent  lubrication  may  be  required  for heavy-duty  or off-road 
use. 
3500 HD  Models  with applications requiring extreme overload/trailer 
towing conditions  and high  speed  (above 
45 mph or 72 km/h) 
conditions  for  extended periods  of time  must  have the drive axle fluid 
changed  every 
3,000 miles (5 000 km)  or 3 months, whichever  occurs 
first,  or  must  use 
75W-140 synthetic fluid  meeting GM specifications. 
See  “Recommended  Fluids and Lubricants” 
in this section. 
7-80 
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USAGE 
Power  Steering  System Manual Transmission  (5-Speed 
with Low Gear,  RPO MT8) 
Manual Transmission  (5-Speed 
without  Low Gear, RPO  MG5) 
Automatic Transmission  Key  Lock  Cylinders 
FLUIDLUBRICANT 
GM  Power  Steering Fluid (GM Part 
No. 10500 I7 or  equivalent). 
Castrol  Syntorq' 
LT or equivalent 
(GM  Part No.  12346191 
- 1 gal.) 
(GM  Part 
No. I23461  90 - 1 qt.). 
Synchromesh  Transmission Fluid 
(GM  Part 
No. 12345349 or  equiva- 
lent). 
DEXR0N'-I11  Automauc 
Transmission  Fluid. 
Lubricate 
with Multi-Purpose Lu- 
bricant  (GM Part No. I2345  120) or 
synthetic SAE SW-30  engine  oil. 
Automatic  Transmission  Shift 
Linkage 
Clutch  Fork  Ball Stud  (5-Speed 
with  Low  Gear) 
Floor  Shift  Linkage 
Chassis  Lubrication 
Front Wheel  Bearings 
Differential,  Standard,  Front and 
Rear Axle 
Differential, Locking 
Transfer  Case  Engine 
oil. 
Chassis  lubricant  (GM Part 
No. 
12346003 or equivalent)  or lubri- 
cant meeting requirements  of  NLGI 
Grade  2, Category  LB or GC-LB. 
Engine 
oil. 
Chassis  lubricant  (GM Part No. 
I2346003  or  equivalent)  or  lubri- 
cant meeting  requirements  of NLGI 
Grade 
2, Category  LB or GC-LB. 
Wheel bearing lubricant  meeting 
requirements 
of NLGI  Grade 2, 
Category  GC  or GC-LB  (GM Part 
No. I2346003  or  equivalent). 
Axle Lubricant  (GM Part No. 
105227 
1 ) or SAE 8OW-90  GL-5 
Gear  Lubricant. 
Axle Lubricant  (GM Part 
No. 
105227 1) or  SAE  80W-90  GL-5 
Gear  Lubricant. 
DEXR0N"-111  Automatic 
Transmission  Fluid. 
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