Black plate (12,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-12 Vehicle Care
Automatic Transmission
Fluid
When to Check and Change
Automatic Transmission Fluid
It is usually not necessary to
check the transmission fluid level.
The only reason for fluid loss is a
transmission leak or overheated
transmission. If a small leak is
suspected, then use the following
checking procedures to check the
fluid level. However, if there is a
large leak, then it may be necessary
to have the vehicle towed to a
dealer and have it repaired before
driving the vehicle further.
Notice:Use of the incorrect
automatic transmission fluid may
damage the vehicle, and the
damages may not be covered by
the vehicle warranty. Always use
the automatic transmission fluid
listed in Recommended Fluids
and Lubricants on page 11‑11. Change the fluid and filter at the
scheduled maintenance intervals
listed in
Maintenance Schedule on
page 11‑3. Be sure to use the
transmission fluid listed in
Recommended Fluids and
Lubricants on page 11‑11.
How to Check Automatic
Transmission Fluid
Notice: Too much or too
little fluid can damage the
transmission. Too much can
mean that some of the fluid could
come out and fall on hot engine
parts or exhaust system parts,
starting a fire. Too little fluid
could cause the transmission
to overheat. Be sure to get an
accurate reading if checking the
transmission fluid. Before checking the fluid level,
prepare the vehicle as follows:
1. Start the engine and park the
vehicle on a level surface. Keep
the engine running.
2. Apply the parking brake and place the shift lever in P (Park).
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 P (Park).
4. Allow the engine to idle (500 –800 rpm) for at least
1 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).
Black plate (13,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-13
6. Using the TRANS TEMPreading, 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 fluid temperature is
reached.
Cold Check Procedure
Use this procedure only as a
reference to determine if the
transmission has enough fluid to be
operated safely until a hot check
procedure can be made. The hot
check procedure is the most
accurate method to check the fluid
level. Perform the hot check
procedure at the first opportunity.
Use this cold check procedure to
check fluid level when the
transmission temperature is
between 27°C and 32°C
(80°F and 90°F).
1. Locate the transmission dipstick at the rear of the engine
compartment, on the passenger
side of the vehicle.
See Engine Compartment
Overview on page 10‑6 for more
information.
2. Flip the handle up, 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 fluid level is below theCOLD check band, add only
enough fluid as necessary to
bring the level into the COLD
band. It does not take much
fluid, generally less than 0.5 L
(1 pt). Do not overfill.
6. Perform a hot check at the first opportunity after the
transmission reaches a normal
operating temperature between
71°C to 93°C (160°F to 200°F).
7. If the fluid level is in the acceptable range, push the
dipstick back in all the way, then
flip the handle down to lock the
dipstick in place.
Black plate (14,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-14 Vehicle Care
Hot Check Procedure
Use this procedure to check the
transmission fluid level when the
transmission fluid temperature is
between 71°C and 93°C (160°F
and 200°F).
The hot check is the most accurate
method to check the fluid level. The
hot check should be performed at
the first opportunity in order to verify
the cold check. The fluid level rises
as fluid temperature increases,
so it is important to ensure the
transmission temperature is within
range.
1. Locate the transmission dipstickat the rear of the engine
compartment, on the passenger
side of the vehicle.
See Engine Compartment
Overview on page 10‑6 for more
information.
2. Flip the handle up, 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 theHOT cross hatch band on the
dipstick. If the fluid level is not
within the HOT band, and the
transmission temperature is
between 71°C and 93°C (160°F
and 200°F), add or drain fluid as
necessary to bring the level into
the HOT band. If the fluid level is
low, add only enough fluid to
bring the level into the HOT
band. It does not take much
fluid, generally less than 0.5 L
(1 pt). Do not overfill.
6. If the fluid level is in the acceptable range, push the
dipstick back in all the way, then
flip the handle down to lock the
dipstick in place.
Black plate (24,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-24 Vehicle Care
more fully engages, so an increase
in fan noise may be heard. This is
normal and should not be mistaken
as the transmission slipping or
making extra shifts. It is merely the
cooling system functioning properly.
The fan will slow down when
additional cooling is not required
and the clutch disengages.
This fan noise may also be heard
when starting the engine. It will go
away as the fan clutch partially
disengages.
If the vehicle has electric cooling
fans, the fans may be heard
spinning at low speed during most
everyday driving. The fans may turn
off if no cooling is required. Under
heavy vehicle loading, trailer
towing, high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly.The fans will change to low speed
when additional cooling is no longer
required.
Power Steering Fluid
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
See
Engine Compartment Overview
on page 10‑6 for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is
heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired.
How to Check Power Steering
Fluid
Notice:Extremely small amounts
of contamination can cause
steering system damage and
cause it to not work properly. Do
not allow contaminants to contact
the fluid side of the reservoir
cap/dipstick or from entering the
reservoir.
To check the power steering fluid:
1. Turn the key off and let the engine compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the fluid level on the dipstick.
Black plate (32,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-32 Vehicle Care
.For the 2500 series, the proper
level is from 0 mm to 13 mm
(0 in to 1/2 in) below the bottom
of the fill plug hole, located at
the front of the axle. Add only
enough fluid to reach the proper
level.
Starter Switch Check
{WARNING
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. 2. Firmly apply both the parking
brake and the regular brake.
See Parking Brake on
page 9‑45.
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 P (Park) or N (Neutral).
If the vehicle starts in any other
position, contact your dealer for
service.
Automatic Transmission
Shift Lock Control
Function Check
{WARNING
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. See Parking Brake on
page 9‑45.
Be ready to apply the regular
brake immediately if the vehicle
begins to move.
Black plate (4,1)GMC Yukon/Yukon XL Owner Manual - 2012
11-4 Service and Maintenance
.Visually inspect windshield wiper
blades for wear, cracking,
or contamination. SeeExterior
Care on page 10‑98. Replace
worn or damaged wiper blades.
See Wiper Blade Replacement
on page 10‑33.
.Check tire inflation pressures.
See Tire Pressure on
page 10‑56.
.Inspect tire wear. See Tire
Inspection on page 10‑62.
.Visually check for fluid leaks.
.Inspect engine air cleaner filter.
See Engine Air Cleaner/Filter on
page 10‑15.
.Inspect brake system.
.Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of
wear. See Exterior Care on
page 10‑98.
.Check restraint system
components. See Safety System
Check on page 3‑29.
.Visually inspect fuel system for
damage or leaks.
.Visually inspect exhaust system
and nearby heat shields for
loose or damaged parts.
.Lubricate body components. See
Exterior Care on page 10‑98.
.Check starter switch. See Starter
Switch Check on page 10‑32.
.Check automatic transmission
shift lock control function. See
Automatic Transmission Shift
Lock Control Function Check on
page 10‑32.
.Check ignition transmission lock.
See Ignition Transmission Lock
Check on page 10‑33.
.Check parking brake and
automatic transmission park
mechanism. See Park Brake and
P (Park) Mechanism Check on
page 10‑33.
.Check accelerator pedal for
damage, high effort, or binding.
Replace if needed.
.Visually inspect gas strut for
signs of wear, cracks, or other
damage. Check the hold open
ability of the strut. See your
dealer if service is required.
.Inspect sunroof track and seal,
if equipped. See Sunroof on
page 2‑22.
.Check hybrid low pressure
coolant level, if equipped.
Black plate (11,1)GMC Yukon/Yukon XL Owner Manual - 2012
Service and Maintenance 11-11
Recommended Fluids, Lubricants, and Parts
Recommended Fluids and Lubricants
Fluids and lubricants identified below by name, part number, or specification can be obtained from your dealer.Usage Fluid/Lubricant
Engine Oil Use only engine oil licensed to the dexos1 specfication, or equivalent, of
the proper SAE viscosity grade. ACDelco dexos1 Synthetic Blend is
recommended. See
Engine Oil on page 10‑8.
Engine Coolant 50/50 mixture of clean, drinkable water and use only DEX-COOL Coolant.
See
Engine Coolant on page 10‑17.
Hydraulic Brake System DOT 3 Hydraulic Brake Fluid (GM Part No. 12377967, in
Canada 89021320).
Windshield Washer Optikleen
®Washer Solvent.
Power Steering System GM Power Steering Fluid (GM Part No. 89021184, in Canada 89021186).
Automatic Transmission DEXRON
®-VI Automatic Transmission Fluid.
Key Lock Cylinders Multi-Purpose Lubricant, Superlube (GM Part No. 12346241, in
Canada 10953474).
Chassis Lubrication Chassis Lubricant (GM Part No. 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. 89021671, in
Canada 89021672).
Black plate (12,1)GMC Yukon/Yukon XL Owner Manual - 2012
11-12 Service and Maintenance
UsageFluid/Lubricant
Front Axle (2500 Series Vehicles with Four-Wheel Drive) SAE 75W-90 Synthetic Axle Lubricant (GM Part No. 89021677, in
Canada 89021678).
Rear Axle SAE 75W-90 Synthetic Axle Lubricant (GM Part No. 89021677, in
Canada 89021678).
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. 12345879, in
Canada 10953511).
Hood Hinges Multi-Purpose Lubricant, Superlube (GM Part No. 12346241, in
Canada 10953474).
Outer Tailgate Handle Pivot Points Multi-Purpose Lubricant, Superlube (GM Part No. 12346241, in
Canada 10953474).
Weatherstrip Conditioning Weatherstrip Lubricant (GM Part No. 3634770, in Canada 10953518) or
Dielectric Silicone Grease (GM Part No. 12345579, in Canada 992887).
Weatherstrip Squeaks Synthetic Grease with Teflon, Superlube (GM Part No. 12371287, in
Canada 10953437).