Page 553 of 594

At Least Once a Year
Starter Switch Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular
brake. SeeParking Brake on page 2-49.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. Try to start the engine in each gear. The vehicle
should start only in PARK (P) or NEUTRAL (N). If
the vehicle starts in any other position, contact your
GM Goodwrench
®dealer for service.
Automatic Transmission Shift Lock
Control System Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle. It should be parked on a level
surface.
2. Firmly apply the parking brake. SeeParking Brake
on page 2-49.
Be ready to apply the regular brake immediately if
the vehicle begins to move.
3. With the engine off, turn the ignition to RUN, but do
not start the engine. Without applying the regular
brake, try to move the shift lever out of PARK (P)
with normal effort. If the shift lever moves out
of PARK (P), contact your GM Goodwrench
®dealer
for service.
6-13
Page 554 of 594

Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition to LOCK in each shift lever position.
The ignition should turn to LOCK only when the
shift lever is in PARK (P).
The key should come out only in LOCK.
Contact your GM Goodwrench
®dealer if service is
required.
Parking Brake and Automatic
Transmission Park (P) Mechanism Check
{CAUTION:
When you are doing this check, your vehicle
could begin to move. You or others could be
injured and property could be damaged. Make
sure there is room in front of your vehicle in
case it begins to roll. Be ready to apply the
regular brake at once should the vehicle begin
to move.Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular brake, set the
parking brake.
To check the parking brake’s holding ability:
With the engine running and transmission in
NEUTRAL (N), slowly remove foot pressure from
the regular brake pedal. Do this until the vehicle is
held by the parking brake only.
To check the PARK (P) mechanism’s holding
ability: With the engine running, shift to PARK (P).
Then release the parking brake followed by the
regular brake.
Contact your GM Goodwrench
®dealer if service is
required.
Underbody Flushing Service
At least every spring, use plain water to ush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
6-14
Page 555 of 594

Recommended Fluids and
Lubricants (Gasoline Engine)
This maintenance section applies to vehicles with a
gasoline engine. If your vehicle has a diesel engine, see
the maintenance schedule section in the DURAMAX
®
Diesel Engine Supplement.
Fluids and lubricants identi ed below by name, part
number, or speci cation may be obtained from
your dealer.
Usage Fluid/Lubricant
Engine OilEngine oil which meets
GM Standard GM6094M and
displays the American Petroleum
Institute Certi ed for Gasoline
Engines starburst symbol.
GM Goodwrench
®oil meets all
the requirements for your vehicle.
To determine the proper viscosity
for your vehicle’s engine, see
Engine Oil (Gasoline Engine)
on page 5-20.
Engine Coolant50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
coolant. SeeEngine Coolant
on page 5-35.
Usage Fluid/Lubricant
Hydraulic Brake
SystemDelco
®Supreme 11 Brake Fluid or
equivalent DOT-3 brake uid.
Windshield
WasherGM Optikleen
®Washer Solvent.
Hydraulic
Clutch System
(5–Speed
Trans.)Hydraulic Clutch Fluid
(GM Part No. U.S. 12345347, in
Canada 10953517) or equivalent
DOT-3 brake uid.
Hydraulic
Clutch System
(6–Speed
Trans.)Hydraulic Clutch Fluid. Use only
GM Part No. U.S. 88958860, in
Canada 88901244, Super DOT-4
brake uid.
Power Steering
SystemGM Power Steering Fluid
(GM Part No. U.S. 89021184, in
Canada 89021186).
Manual
Transmission
(5–Speed with
Low Gear,
RPO MW3)GM Goodwrench
®Synthetic
Manual Transmission Fluid
(GM Part No. U.S. 12346190, in
Canada 10953477) or equivalent
SAE 75W-85 GL-4 gear oil.
6-15
Page 556 of 594

Usage Fluid/Lubricant
Manual
Transmission
(5–Speed
without
Low Gear,
RPO MG5)Synchromesh Transmission Fluid
(GM Part No. U.S. 12345349, in
Canada 10953465).
Manual
Transmission
(6–Speed)Synthetic Transmission Fluid
approved to Allison Transmission
®
speci cation TES-295
(GM Part No. U.S. 12378515, in
Canada 88900701).
Automatic
TransmissionDEXRON
®-VI Automatic
Transmission Fluid.
Key Lock
CylindersMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Floor Shift
LinkageLubriplate Lubricant Aerosol
(GM Part No. U.S. 12346293, in
Canada 992723) or lubricant
meeting requirements of NLGI #2
Category LB or GC-LB.
Usage Fluid/Lubricant
Chassis
LubricationChassis Lubricant
(GM Part No. U.S. 12377985, in
Canada 88901242) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Front Axle
(1500 Series)SAE 80W-90 Axle Lubricant
(GM Part No. U.S. 1052271, in
Canada 10950849).
Front Axle
(1500 HD,
2500, 2500 HD,
and 3500
Series)SAE 75W-90 Synthetic
Axle Lubricant
(GM Part No. U.S. 12378261,
in Canada 10953455) meeting
GM Speci cation 9986115.
Rear AxleSAE 75W-90 Synthetic
Axle Lubricant
(GM Part No. U.S. 12378261,
in Canada 10953455) meeting
GM Speci cation 9986115.
Manual
Transfer CaseDEXRON
®-III Automatic
Transmission Fluid. Look for
“Approved for the H-Speci cation”
on the label.
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Page 557 of 594

Usage Fluid/Lubricant
Automatic
Transfer CaseAUTO-TRAK II Fluid
(GM Part No. U.S. 12378508, in
Canada 10953626).
Front Axle
Propshaft
Spline or
One-Piece
Propshaft
Spline
(Two-Wheel
Drive with
Auto. Trans.)Spline Lubricant, Special Lubricant
(GM Part No. U.S. 12345879,
in Canada 10953511) or
lubricant meeting requirements of
GM 9985830.
Rear Driveline
Center SplineChassis Lubricant
(GM Part No. U.S. 12377985, in
Canada 88901242) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Hood HingesMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).Usage Fluid/Lubricant
Body Door
Hinge Pins,
Tailgate Hinge
and Linkage,
Folding Seats,
and Fuel Door
HingeMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Tailgate Handle
Pivot Points,
Hinges, Latch
Bolt, and
LinkageMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Weatherstrip
ConditioningDielectric Silicone Grease
(GM Part No. U.S. 12345579,
in Canada 992887).
Weatherstrip
SqueaksSynthetic Grease with
Te on, Superlube
(GM Part No. U.S. 12371287,
in Canada 10953437).
6-17
Page 558 of 594