2008 GMC YUKON XL automatic transmission

(c)Visually inspect hoses and have them replaced if they
are cracked, swollen, or deteriorated. Inspect all pipes,
fittings, and clamps; replace with genuine parts as
needed. To help ensure proper operation, a pressure test
of the cooling system and pressure cap and cleaning the
outside of the radiator and air conditioning condenser is
recommended at least once a year.
(d)Inspect wiper blades for wear, cracking, or
contamination. Clean the windshield and wiper blades, if
contaminated. Replace wiper blades that are worn or
damaged. See Windshield Wiper Blade Replacement on
page 5-62andWindshield, Backglass, and Wiper
Blades on page 5-113 for more information.
(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 1-92.
(f)Lubricate all key lock cylinders, hood latch assembly,
secondary latch, pivots, spring anchor, release pawl,
rear compartment hinges, outer liftgate handle pivot
points, rear door detent link, roller mechanism, liftgate
handle pivot points, latch bolt, fuel door hinge, cargo
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.
(h)Change automatic transmission fluid and filter 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 5-28
for what to use. Inspect hoses. Clean radiator,
condenser, pressure cap, and filler 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 works properly, if equipped.
Replace as needed.
6-8

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 2-43.
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.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.
6-11

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 dealer/retailer if service is required.
Hood and Liftgate Support Gas Strut
Service
Visually inspect gas strut for signs of wear, corrosion,
cracks, loss of lubricant, or other damage. Check
the hold open ability of gas strut. If necessary, replace
with genuine parts from your dealer/retailer.
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.
Tire Sealant and Compressor Kit
Check the sealant expiration date printed on the
instruction label of the Tire Sealant and Compressor Kit
(if equipped) at least once a year. See your
dealer/retailer for a replacement canister.
6-12

Recommended Fluids and
Lubricants
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 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.
Usage Fluid/Lubricant
Windshield
WasherOptikleen
®Washer Solvent.
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).
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
Vehicles with
Four-Wheel
Drive)SAE 80W-90 Axle Lubricant
(GM Part No. U.S. 89021671, in
Canada 89021672).
Front Axle
(2500 Series
Vehicles with
Four-Wheel
Drive)SAE 75W-90
Synthetic Axle Lubricant
(GM Part No. U.S. 89021677,
in Canada 89021678) meeting
GM Specication 9986115.
6-13

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 Auto.
Trans.)Spline Lubricant, Special Lubricant
(GM Part No. U.S. 12345879, in
Canada 10953511) or lubricant
meeting requirements of
GM 9985830.
Hood HingesMulti-Purpose Lubricant, Superlube
(GM Part No. U.S. 12346241, in
Canada 10953474).
Usage Fluid/Lubricant
Outer Tailgate
Handle Pivot
PointsMulti-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).
6-14

Audio System (cont.)
Rear Seat Audio (RSA)...............................3-125
Setting the Clock.........................................3-82
Theft-Deterrent Feature...............................3-127
XM™ Satellite Radio Antenna System...........3-130
Audio System(s).............................................3-84
Rear Side Window Antenna.........................3-130
Automatic Headlamp System............................3-18
Automatic Transmission
Fluid..................................................5-22, 5-24
Operation...................................................2-31
Autoride
®.......................................................4-49
Auxiliary Roof Mounted Lamp Switch.................3-19
B
Battery..........................................................5-45
Electric Power Management..........................3-21
Run-Down Protection...................................3-22
Bench Seat, Split (60/40).................................1-12
Brake
Emergencies................................................ 4-6
Brakes..........................................................5-41
System Warning Light..................................3-44
Braking........................................................... 4-4
Braking in Emergencies..................................... 4-6
Break-In, New Vehicle.....................................2-26
Bucket Seats, Rear.........................................1-18Bulb Replacement...........................................5-59
Halogen Bulbs............................................5-59
Headlamp Aiming........................................5-56
License Plate Lamps....................................5-61
Replacement Bulbs......................................5-61
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps........................................5-60
Buying New Tires...........................................5-80
C
Calibration.............................................2-49, 2-52
California Fuel.................................................. 5-6
California Perchlorate Materials Requirements....... 5-4
California Proposition 65 Warning....................... 5-4
Canadian Owners................................................ ii
Capacities and Specications..........................5-124
Carbon Monoxide...........2-13, 2-15, 2-47, 4-30, 4-49
Care of
Safety Belts..............................................5-110
Cargo Cover..................................................2-73
CD, MP3 ............................................3-103, 3-108
Center Console Storage Area...........................2-71
Center Seat...................................................1-11
Chains, Tire...................................................5-86
Charging System Light....................................3-43
Check
Engine Light...............................................3-48
Checking Things Under the Hood......................5-12
2

Tires (cont.)
Removing the Spare Tire and Tools...............5-90
Secondary Latch System............................5-100
Spare Tire................................................5-107
Storing a Flat or Spare Tire and Tools..........5-103
Tire Sidewall Labeling..................................5-65
Tire Terminology and Denitions....................5-69
Uniform Tire Quality Grading.........................5-83
Wheel Alignment and Tire Balance.................5-84
Wheel Replacement.....................................5-85
When It Is Time for New Tires......................5-80
Tow/Haul Mode...............................................2-37
Tow/Haul Mode Light.......................................3-53
Towing
Recreational Vehicle.....................................4-45
Towing a Trailer..........................................4-49
Your Vehicle...............................................4-45
Traction
StabiliTrak
®System....................................... 4-6
Trailer
Recommendations.......................................4-63
Transmission
Fluid, Automatic..................................5-22, 5-24
Transmission Operation, Automatic....................2-31
Trip Odometer................................................3-39
Turn and Lane-Change Signals.......................... 3-8
Turn Signal/Multifunction Lever........................... 3-7
U
Ultrasonic Rear Parking Assist (URPA)...............2-58
Uniform Tire Quality Grading............................5-83
Universal Home Remote System.......................2-64
Operation...................................................2-64
Using this Manual............................................... iii
V
Vehicle
Control........................................................ 4-3
Damage Warnings........................................... iv
Loading......................................................4-35
Symbols......................................................... iv
Vehicle Customization, DIC..............................3-72
Vehicle Data Recording and Privacy..................7-16
Vehicle Identication
Number (VIN)............................................5-116
Service Parts Identication Label..................5-116
Vehicle, Remote Start....................................... 2-8
Ventilation Adjustment......................................3-33
Visors...........................................................2-21
Voltmeter Gage..............................................3-44
13