2008 GMC YUKON DENALI 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 5-53 and Windshield, Backglass, and Wiper
Blades on page 5-103for 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,
door hinges, liftgate hinge, liftgate linkage, liftgate 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)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.
(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 5-23
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)If you drive regularly under dusty conditions, inspect
the filter at each engine oil change.
(l)Visually inspect belt for fraying, excessive cracks, or
obvious damage. Replace belt if necessary.
(m)Check vent hose at transfer case for kinks and
proper installation.
6-8

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 2-35.
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 2-35.
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.
6-10

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 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.
6-11

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, see
Engine Oil on page 5-13.
Engine Coolant50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
Coolant. SeeEngine Coolant on
page 5-23.
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 and Rear
AxleSAE 75W-90 Synthetic
Axle Lubricant
(GM Part No. U.S. 89021677,
in Canada 89021678) meeting
GM Specication 9986115.
6-12

Usage Fluid/Lubricant
Transfer CaseDEXRON
®-VI Automatic
Transmission Fluid.
Front Axle
Propshaft
SplineSpline 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).
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).
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).
6-13

Audio System (cont.)
Theft-Deterrent Feature...............................3-116
XM™ Satellite Radio Antenna System...........3-119
Audio System(s).............................................3-76
Rear Side Window Antenna.........................3-119
Automatic Headlamp System............................3-18
Automatic Transmission
Fluid..........................................................5-20
Operation...................................................2-30
Autoride
®.......................................................4-41
B
Battery..........................................................5-39
Electric Power Management..........................3-20
Run-Down Protection...................................3-21
Bench Seat, Split (60/40)................................... 1-9
Brake
Emergencies................................................ 4-5
Brakes..........................................................5-36
System Warning Light..................................3-39
Braking........................................................... 4-3
Braking in Emergencies..................................... 4-5
Break-In, New Vehicle.....................................2-25
Bucket Seats, Rear.........................................1-16
Bulb Replacement...........................................5-50
Halogen Bulbs............................................5-50
Headlamp Aiming........................................5-48
License Plate Lamps....................................5-52Bulb Replacement (cont.)
Replacement Bulbs......................................5-52
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps........................................5-51
Buying New Tires...........................................5-70
C
Calibration.....................................................2-40
California Fuel.................................................. 5-5
California Perchlorate Materials Requirements....... 5-4
California Proposition 65 Warning....................... 5-3
Canadian Owners................................................ ii
Capacities and Specications..........................5-114
Carbon Monoxide...........2-13, 2-15, 2-38, 4-29, 4-42
Care of
Safety Belts..............................................5-101
Cargo Cover..................................................2-61
CD, MP3 ...............................................3-94, 3-99
Center Console Storage Area...........................2-59
Chains, Tire...................................................5-76
Charging System Light....................................3-37
Check
Engine Light...............................................3-42
Checking Things Under the Hood......................5-10
Chemical Paint Spotting.................................5-105
Child Restraints
Child Restraint Systems...............................1-56
Infants and Young Children...........................1-52
2

Tires (cont.)
Ination - Tire Pressure................................5-60
Inspection and Rotation................................5-67
Installing the Spare Tire................................5-85
Pressure Monitor Operation...........................5-64
Pressure Monitor System..............................5-62
Removing the Flat Tire.................................5-85
Removing the Spare Tire and Tools...............5-79
Secondary Latch System..............................5-90
Spare Tire..................................................5-98
Storing a Flat or Spare Tire and Tools............5-94
Tire Sidewall Labeling..................................5-56
Tire Terminology and Denitions....................5-58
Uniform Tire Quality Grading.........................5-72
Wheel Alignment and Tire Balance.................5-74
Wheel Replacement.....................................5-74
When It Is Time for New Tires......................5-69
Tow/Haul Mode...............................................2-34
Tow/Haul Mode Light.......................................3-47
Towing
Recreational Vehicle.....................................4-40
Towing a Trailer..........................................4-42
Your Vehicle...............................................4-40
Traction
Locking Differential........................................ 4-5
StabiliTrak
®System....................................... 4-6Trailer
Recommendations.......................................4-55
Transmission
Fluid, Automatic...........................................5-20
Transmission Operation, Automatic....................2-30
Trip Odometer................................................3-33
Turn and Lane-Change Signals.......................... 3-8
Turn Signal/Multifunction Lever........................... 3-8
U
Ultrasonic Rear Parking Assist (URPA)...............2-44
Uniform Tire Quality Grading............................5-72
Universal Home Remote System.......................2-50
Operation...................................................2-51
Using this Manual............................................... iii
V
Vehicle
Control........................................................ 4-3
Damage Warnings........................................... iv
Loading......................................................4-34
Symbols......................................................... iv
Vehicle Customization, DIC..............................3-64
13