2008 GMC SIERRA automatic transmission

Engine Specications
Engine VIN Code Transmission Spark Plug Gap
4.3L V6 X Automatic 0.060 in (1.52 mm)
4.8L V8 C Automatic 0.040 in (1.01 mm)
5.3L V8 Flexible Fuel with
Active Fuel Management™
(Iron Block)0 Automatic 0.040 in (1.01 mm)
5.3L V8 Flexible Fuel with
Active Fuel Management™
(Aluminum Block)3 Automatic 0.040 in (1.01 mm)
5.3L V8 with Active Fuel
Management™
(Aluminum Block)M Automatic 0.040 in (1.01 mm)
5.3L V8 with Active Fuel
Management™ (Iron Block)J Automatic 0.040 in (1.01 mm)
6.0L V8 (Iron Block) K Automatic 0.040 in (1.01 mm)
6.0L V8 with Active Fuel
Management™
(Aluminum Block)Y Automatic 0.040 in (1.01 mm)
5-132

Additional Required Services
(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 manual.The following services should be performed at the
rst maintenance service (IorII) after the indicated
miles (kilometers) shown for each item.
Additional Required Services
Service and Miles (Kilometers)25,000
(40 000)50,000
(80 000)75,000
(120 000)100,000
(160 000)125,000
(200 000)150,000
(240 000)
Inspect fuel system for damage
or leaks.• •••••
Inspect exhaust system for loose
or damaged components.• •••••
Vehicles without a lter restriction
indicator: Replace engine air cleaner
lter. SeeEngine Air Cleaner/Filter
(Gasoline Engines) on page 5-19.•••
Change automatic transmission
uid and lter (severe service).
See footnote (h).•••
Change automatic transmission
uid and lter (normal service).•
6-7

(e)Make sure the safety belt reminder light and safety
belt assemblies are working properly. Look for any
other loose or damaged safety belt system parts. If you
see anything that might keep a safety belt system
from doing its job, have it repaired. Have any torn or
frayed safety belts replaced. Also see Checking
the Restraint Systems on page 1-87.
(f)Lubricate all key lock cylinders, body door hinges,
hood latch assembly, secondary latch, pivots, spring
anchor, release pawl, tailgate hinges, tailgate linkage,
tailgate handle pivot points, latch bolt, fuel door
hinge, locks, and folding seat hardware. More frequent
lubrication may be required when exposed to a
corrosive environment. Applying silicone grease on
weatherstrips with a clean cloth will make them
last longer, seal better, and not stick or squeak.
(g)Check vent hose at transfer case for kinks and
proper installation. Check to be sure vent hose
is unobstructed, clear, and free of debris.(h)Change automatic transmission fluid and filter if the
vehicle Gross Vehicle Weight Rating (GVWR) is
over 8600 lbs or if the vehicle is mainly driven under
one or more of these conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
(i)Drain, flush, and refill cooling system. This service can
be complex; you should have your dealer/retailer perform
this service. See Engine Coolant on page 5-28for what to
use. Inspect hoses. Clean radiator, condenser, pressure
cap, and ller neck. Pressure test the cooling system and
pressure cap.
(j)A fluid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the fluid level checked. Add fluid if needed.
(k)Inspect system. Check all fuel and vapor lines and
hoses for proper hook-up, routing, and condition. Check
that the purge valve, if the vehicle has one, works
properly. Replace as needed.
6-10

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 dealer/retailer 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 ON/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 dealer/retailer
for service.
6-13

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 PARK (P).
The ignition key should come out only in
LOCK/OFF.
Contact your dealer/retailer 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 the 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 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

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 identied below by name, part
number, or specication can be obtained from your
dealer/retailer.
Usage Fluid/Lubricant
Engine OilEngine oil which meets GM
Standard GM6094M and displays
the American Petroleum Institute
Certied for Gasoline Engines
starburst symbol. To determine the
proper viscosity for your vehicle’s
engine, seeEngine Oil (Gasoline
Engine) on page 5-15.
Engine Coolant50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
coolant. SeeEngine Coolant on
page 5-28.
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 Specication 9986115.
6-15

Usage Fluid/Lubricant
Rear AxleSAE 75W-90 Synthetic Axle
Lubricant (GM Part No. U.S.
89021677, in Canada 89021678)
meeting GM Specication 9986115.
Transfer Case
(Four-Wheel
Drive)DEXRON
®-VI Automatic
Transmission Fluid.
Front Axle
Propshaft
Spline or
One-Piece
Propshaft
Spline
(Two-Wheel
Drive with
4-Speed 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
ConditioningWeatherstrip Lubricant (GM Part No.
U.S. 3634770, in Canada 10953518)
or Dielectric Silicone Grease (GM
Part No. U.S. 12345579, in Canada
992887).
Weatherstrip
SqueaksSynthetic Grease with Teon,
Superlube (GM Part No. U.S.
12371287, in Canada 10953437).
6-16

Audio System (cont.)
Navigation/Radio System, see Navigation
Manual.................................................3-112
Radio Reception........................................3-125
Rear Seat Audio (RSA)...............................3-122
Setting the Clock.........................................3-81
Theft-Deterrent Feature...............................3-123
XM™ Satellite Radio Antenna System...........3-126
Audio System(s).............................................3-84
Automatic Headlamp System............................3-19
Automatic Transmission
Fluid..................................................5-22, 5-25
Operation...................................................2-28
Auxiliary Roof Mounted Lamp Switch.................3-20
B
Battery..........................................................5-45
Electric Power Management..........................3-22
Run-Down Protection...................................3-23
Brake
Emergencies................................................ 4-5
Brakes..........................................................5-42
System Warning Light..................................3-44
Braking........................................................... 4-3
Braking in Emergencies..................................... 4-5
Break-In, New Vehicle.....................................2-22
Bulb Replacement...........................................5-59Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp............................................5-61
Halogen Bulbs............................................5-59
Headlamp Aiming........................................5-56
Headlamps.................................................5-60
License Plate Lamps....................................5-64
Pickup Box Identication and Fender
Marker Lamps.........................................5-62
Replacement Bulbs......................................5-65
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps........................................5-62
Buying New Tires...........................................5-84
C
Calibration.............................................2-55, 2-57
California Fuel.................................................. 5-7
California Perchlorate Materials Requirements....... 5-5
California Proposition 65 Warning....................... 5-4
Canadian Owners................................................ ii
Capacities and Specications..........................5-130
Carbon Monoxide...................2-14, 2-53, 4-31, 4-55
Care of
Safety Belts..............................................5-115
Cargo Lamp...................................................3-22
Cargo Management System.............................2-78
CD, MP3 ............................................3-102, 3-106
Center Console Storage Area...........................2-76
2