2008 GMC YUKON DENALI transmission

Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the transmission
uid level. The only reason for uid loss is a
transmission leak or overheating the transmission. If you
suspect a small leak, then use the following checking
procedures to check the uid level. However, if there is a
large leak, then it may be necessary to have the vehicle
towed to a dealer/retailer service department and have it
repaired before driving the vehicle further.
Notice:Use of the incorrect automatic transmission
uid may damage your vehicle, and the damages
may not be covered by your warranty. Always use
the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-12.
Change the uid and lter at the intervals listed in the
Maintenance Schedule. SeeScheduled Maintenance
on page 6-4. Be sure to use the transmission uid listed
inRecommended Fluids and Lubricants on page 6-12.
How to Check Automatic
Transmission Fluid
Notice:Too much or too little uid can damage
your transmission. Too much can mean that some
of the uid could come out and fall on hot engine
parts or exhaust system parts, starting a re.
Too little uid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission uid.
Before checking the uid level, prepare your vehicle as
follows:
1. Start the engine and park your vehicle on a level
surface. Keep the engine running.
2. Apply the parking brake and place the shift lever in
PARK (P).
3. With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, move the shift
lever back to PARK (P).
4. Allow the engine to idle (500 – 800 rpm) for at least
one minute. Slowly release the brake pedal.
5. Keep the engine running and press the Trip/Fuel
button or trip odometer reset stem until TRANS
TEMP (Transmission Temperature) displays on the
Driver Information Center (DIC).
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6. Using the TRANS TEMP reading, determine and
perform the appropriate check procedure. If the
TRANS TEMP reading is not within the required
temperature ranges, allow the vehicle to cool,
or operate the vehicle until the appropriate
transmission uid temperature is reached.
Cold Check Procedure
Use this procedure only as a reference to determine if
the transmission has enough uid to be operated safely
until a hot check procedure can be made. The hot check
procedure is the most accurate method to check the uid
level. Perform the hot check procedure at the rst
opportunity. Use this cold check procedure to check uid
level when the transmission temperature is between
80°F and 90°F (27°C and 32°C).
1. Locate the transmission dipstick at the rear of the
engine compartment, on the passenger side of the
vehicle.
The dipstick handle has
this graphic. SeeEngine
Compartment Overview on
page 5-12for more
information.
2. Flip the handle up, and then pull out the dipstick
and wipe it with a clean rag or paper towel.3. Install the dipstick by pushing it back in all the way,
wait three seconds, and then pull it back out again.
4. Check both sides of the dipstick, and read the
lower level. Repeat the check procedure to
verify the reading.
5. If the uid level is below the COLD check band,
add only enough uid as necessary to bring the
level into the COLD band. It does not take much
uid, generally less than one pint (0.5L). Do not
overll.
6. Perform a hot check at the rst opportunity after
the transmission reaches a normal operating
temperature between 160°F to 200°F
(71°C to 93°C).
7. If the uid level is in the acceptable range, push the
dipstick back in all the way, then ip the handle
down to lock the dipstick in place.
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Hot Check Procedure
Use this procedure to check the transmission uid level
when the transmission uid temperature is between
160°F and 200°F (71°C and 93°C).
The hot check is the most accurate method to check the
uid level. The hot check should be performed at the
rst opportunity in order to verify the cold check.
The uid level rises as uid temperature increases, so
it is important to ensure the transmission temperature is
within range.
1. Locate the transmission dipstick at the rear of the
engine compartment, on the passenger side of the
vehicle.
The dipstick handle has
this graphic. SeeEngine
Compartment Overview on
page 5-12for more
information.
2. Flip the handle up, and then pull out the dipstick
and wipe it with a clean rag or paper towel.
3. Install the dipstick by pushing it back in all the way,
wait three seconds, and then pull it back out again.4. Check both sides of the dipstick, and read the
lower level. Repeat the check procedure to
verify the reading.
5. Safe operating level is within the HOT cross hatch
band on the dipstick. If the uid level is not within
the HOT band, and the transmission temperature is
between 160°F and 200°F (71°C and 93°C), add
or drain uid as necessary to bring the level into the
HOT band. If the uid level is low, add only enough
uid to bring the level into the HOT band. It does not
take much uid, generally less than one pint (0.5L).
Do not overll.
6. If the uid level is in the acceptable range, push the
dipstick back in all the way, then ip the handle
down to lock the dipstick in place.
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Consistency of Readings
Always check the uid level at least twice using
the procedures described. Consistency
(repeatable readings) is important to maintaining proper
uid level. If uid is added, it may take 15 minutes or
longer to obtain an accurate reading because of residual
uid draining down the dipstick tube. If inconsistent
readings persist, check the transmission breather to be
sure it is clean and not clogged. If readings are still
inconsistent, contact your dealer/retailer.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how
to add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating
on page 5-26.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 30,000 miles (50 000 km) or
24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-23

Jump Starting
If your vehicle’s battery (or batteries) has run down, you
may want to use another vehicle and some jumper
cables to start your vehicle. Be sure to use the following
steps to do it safely.
{CAUTION:
Batteries can hurt you. They can be dangerous
because:
They contain acid that can burn you.
They contain gas that can explode or
ignite.
They contain enough electricity to
burn you.
If you do not follow these steps exactly, some
or all of these things can hurt you.Notice:Ignoring these steps could result in costly
damage to your vehicle that would not be covered
by your warranty.
Trying to start your vehicle by pushing or pulling it
will not work, and it could damage your vehicle.
1. Check the other vehicle. It must have a 12-volt
battery with a negative ground system.
Notice:If the other vehicle’s system is not a 12-volt
system with a negative ground, both vehicles can
be damaged. Only use vehicles with 12-volt systems
with negative grounds to jump start your vehicle.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles are not touching
each other. If they are, it could cause a ground
connection you do not want. You would not be able
to start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake rmly on both vehicles involved
in the jump start procedure. Put the automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL before setting the parking brake. If
you have a four-wheel-drive vehicle, be sure the
transfer case is in a drive gear, not in NEUTRAL.
5-40

Tire Terminology and Denitions
Air Pressure:The amount of air inside the tire
pressing outward on each square inch of the tire.
Air pressure is expressed in pounds per square
inch (psi) or kilopascal (kPa).
Accessory Weight
:This means the combined
weight of optional accessories. Some examples of
optional accessories are, automatic transmission,
power steering, power brakes, power windows,
power seats, and air conditioning.
Aspect Ratio
:The relationship of a tire’s height
to its width.
Belt
:A rubber coated layer of cords that is
located between the plies and the tread. Cords
may be made from steel or other reinforcing
materials.
Bead
:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.
Bias Ply Tire
:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread.
Cold Tire Pressure
:The amount of air pressure
in a tire, measured in pounds per square inch (psi)
or kilopascals (kPa) before a tire has built up
heat from driving. SeeInflation - Tire Pressure
on page 5-60.Curb Weight
:The weight of a motor vehicle with
standard and optional equipment including the
maximum capacity of fuel, oil, and coolant, but
without passengers and cargo.
DOT Markings
:A code molded into the sidewall
of a tire signifying that the tire is in compliance
with the U.S. Department of Transportation (DOT)
motor vehicle safety standards. The DOT code
includes the Tire Identication Number (TIN), an
alphanumeric designator which can also identify the
tire manufacturer, production plant, brand, and date
of production.
GVWR
:Gross Vehicle Weight Rating.
SeeLoading Your Vehicle on page 4-34.
GAWR FRT
:Gross Axle Weight Rating for
the front axle. SeeLoading Your Vehicle
on page 4-34.
GAWR RR
:Gross Axle Weight Rating for the
rear axle. SeeLoading Your Vehicle on page 4-34.
Intended Outboard Sidewall
:The side of an
asymmetrical tire, that must always face outward
when mounted on a vehicle.
Kilopascal (kPa)
:The metric unit for air pressure.
Light Truck (LT-Metric) Tire
:A tire used on light
duty trucks and some multipurpose passenger
vehicles.
5-58

Fuses Usage
6 Trailer Brake Controller
7 Front Washer
8 Oxygen Sensors
9 Antilock Brakes System 2
10 Trailer Back-up Lamps
11 Driver Side Low-Beam Headlamp
12 Engine Control Module (Battery)
13Fuel Injectors, Ignition Coils
(Right Side)
14Transmission Control Module
(Battery)
15 Vehicle Back-up Lamps
16Passenger Side Low-Beam
Headlamp
17 Air Conditioning Compressor
18 Oxygen Sensors
19 Transmission Controls (Ignition)
20 Fuel Pump
21 Fuel System Control Module
22 Headlamp Washers
23 Rear Windshield Washer
24Fuel Injectors, Ignition Coils
(Left Side)
25 Trailer Park LampsFuses Usage
26 Driver Side Park Lamps
27 Passenger Side Park Lamps
28 Fog Lamps
29 Horn
30Passenger Side High-Beam
Headlamp
31 Daytime Running Lamps
32 Driver Side High-Beam Headlamps
33 Daytime Running Lamps 2
34 Sunroof
35Key Ignition System, Theft Deterrent
System
36 Windshield Wiper
37 SEO B2 Uptter Usage (Battery)
38 Electric Adjustable Pedals
39 Climate Controls (Battery)
40 Airbag System (Ignition)
41 Amplier
42 Audio System
43Miscellaneous (Ignition), Cruise
Control
44 Liftgate Release
45 Airbag System (Battery)
46 Instrument Panel Cluster
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Capacities and Specications
The following approximate capacities are given in English and metric conversions. SeeRecommended Fluids and
Lubricants on page 6-12for more information.
ApplicationCapacities
English Metric
Air Conditioning RefrigerantFor the air conditioning system refrigerant charge
amount, see the refrigerant caution label located
under the hood. See your dealer/retailer for more
information.
Cooling System 18.1 qt 17.1 L
Engine Oil with Filter 6.0 qt† 5.7 L†
Fuel Tank
Regular 26.0 gal 98.4 L
Extended 31.5 gal 119.2 L
Transmission Fluid (Pan Removal and Filter Replacement) 6.0 qt 5.7 L
Transfer Case Fluid 1.5 qt 1.4 L
Wheel Nut Torque 140 lbft 190Y
†Oil lter should be changed at every oil change.
After rell, the level must be rechecked. Add enough engine coolant so that the uid is within the proper
operating range.
Engine Specications
Engine VIN Code Transmission Spark Plug Gap
6.2L V8 8 Automatic 0.040 in (1.01 mm)
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