Page 557 of 600

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 starting this check, be sure there is enough
room around the vehicle. It should be parked on a
level surface.
2. Firmly apply the parking brake. SeeParking Brake
on page 2-50.
Be ready to apply the regular brake immediately if
the vehicle begins to move.3. With the engine off, turn the ignition to ON/RUN,
but do not start the engine. Without applying the
regular brake, try to move the shift lever out
of P (Park) with normal effort. If the shift lever
moves out of P (Park), contact your dealer/retailer
for service.Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition to LOCK/OFF in each shift lever position.
The ignition should turn to LOCK/OFF only
when the shift lever is in P (Park).
The ignition key should come out only in
LOCK/OFF.
Contact your dealer/retailer if service is required.
6-13
Page 558 of 600

Parking Brake and Automatic
Transmission P (Park) Mechanism
Check
{CAUTION:
When you are doing this check, the vehicle could
begin to move. You or others could be injured and
property could be damaged. Make sure there is
room in front of the 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 the transmission in
N (Neutral), slowly remove foot pressure from the
regular brake pedal. Do this until the vehicle is held
by the parking brake only.
To check the P (Park) mechanism’s holding ability:
With the engine running, shift to P (Park). Then
release the parking brake followed by the regular
brake.
Contact your dealer/retailer 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 559 of 600

Recommended Fluids and
Lubricants
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 manual.
Fluids and lubricants identi ed below by name, part
number, or speci cation can be obtained from your
dealer/retailer.
Usage Fluid/Lubricant
Engine OilEngine oil which meets GM
Standard GM6094M and displays
the American Petroleum Institute
Certi ed for Gasoline Engines
starburst symbol. To determine the
proper viscosity for your vehicle’s
engine, seeEngine Oil on
page 5-15.
Engine Coolant50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
coolant. SeeEngine Coolant on
page 5-29.
Hydraulic Brake
SystemDelco
®Supreme 11 Brake Fluid or
equivalent DOT-3 brake uid.
Windshield
WasherOptikleen
®Washer Solvent.
Usage Fluid/Lubricant
Power Steering
SystemGM Power Steering Fluid
(GM Part No. U.S. 89021184,
in Canada 89021186).
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.
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) -
Four-Wheel
DriveSAE 80W-90 Axle Lubricant
(GM Part No. U.S. 89021671,
in Canada 89021672).
Front Axle
(1500 HD,
1500 AWD,
2500,
2500 HD, and
3500 Series)SAE 75W-90
Synthetic Axle Lubricant
(GM Part No. U.S. 89021677,
in Canada 89021678) meeting
GM Speci cation 9986115.
6-15
Page 560 of 600