2008 GMC YUKON Owner's Manual

The vehicle should:
Be placed so the headlamps are 25 ft. (7.6 m) from
a light colored wall.
Have all four tires on a level surface which is level
all the way to the wall.
Be placed so it is perpendicular to the wall.
Not have any snow, ice, or mud on it.
Be fully assembled and all other work stopped while
headlamp aiming is being performed.
Normally loaded with a full tank of fuel and one
person or 160 lbs (75 kg) sitting on the driver seat.
Have the tires properly inated.
Have the spare tire is in its proper location in the
vehicle.
Headlamp aiming is done with the vehicle’s low-beam
headlamps. The high-beam headlamps will be correctly
aimed if the low-beam headlamps are aimed properly.To adjust the vertical aim:
1. Open the hood. SeeHood Release on page 5-13
for more information.
2. Locate the aim dot on the lens of the low-beam
headlamp.
3. Record the distance from the ground to the aim dot
on the low-beam headlamp.
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4. At a wall, measure from the ground upward (A) to
the recorded distance from Step 3 and mark it.
5. Draw or tape a horizontal line (B) on the wall the
width of the vehicle at the height of the mark in
Step 4.
Notice:Do not cover a headlamp to improve beam
cut-off when aiming. Covering a headlamp may
cause excessive heat build-up which may cause
damage to the headlamp.
6. Turn on the low-beam headlamps and place a
piece of cardboard or equivalent in front of the
headlamp not being adjusted. This allows only the
beam of light from the headlamp being adjusted
to be seen on the at surface.7. Locate the vertical headlamp aiming screws, which
are under the hood near each headlamp assembly.
The adjustment screw can be turned with a E8
Torx
®socket.
8. Turn the vertical aiming screw until the headlamp
beam is aimed to the horizontal tape line. Turn it
clockwise or counterclockwise to raise or lower the
angle of the beam.
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9. Make sure that the light from the headlamp is
positioned at the bottom edge of the horizontal tape
line. The lamp on the left (A) shows the correct
headlamp aim. The lamp on the right (B) shows the
incorrect headlamp aim.
10. Repeat Steps 7 through 9 for the opposite
headlamp.
Bulb Replacement
For the proper type of replacement bulbs, see
Replacement Bulbs on page 5-61.
For any bulb changing procedure not listed in this
section, contact your dealer/retailer.
Halogen Bulbs
{CAUTION:
Halogen bulbs have pressurized gas inside and
can burst if you drop or scratch the bulb. You or
others could be injured. Be sure to read and
follow the instructions on the bulb package.
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Taillamps, Turn Signal, Stoplamps
and Back-up Lamps
A. Taillamp/
Turn Signal Lamp
B. Back-up Lamp
C. Stoplamp/Taillamp
If your vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
To replace one of these bulbs:
1. Open the liftgate. SeePower Liftgate on page 2-15
for more information.2. Remove the two
screws from the
taillamp assembly.
3. Pull the taillamp assembly rearward until you
disengage the inner pins on the taillamp assembly
from the vehicle.
4. Press the release tab, if bulb socket has one, and
turn the bulb socket counterclockwise to remove it
from the taillamp assembly.
5. Pull the old bulb straight out from the bulb socket.
6. Press a new bulb into the bulb socket and insert
it into the taillamp assembly. Turn the bulb socket
clockwise into the taillamp assembly until it clicks.
7. Reinstall the taillamp assembly. When reinstalling,
make sure to line up the pins on the taillamp
assembly with the vehicle. If you do not do this, you
will not be able correctly install the taillamp
assembly.
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License Plate Lamp
1. Remove the two screws holding each of the license
plate lamps to the molding that is part of the
liftgate.
2. Twist and pull the license plate lamp forward
through the molding opening.3. Turn the bulb socket counterclockwise and pull the
bulb straight out of the socket.
4. Install the new bulb.
5. Reverse Steps 1 through 3 to reinstall the license
plate lamp.
Replacement Bulbs
Exterior Lamp Bulb Number
Back-up Lamp 7441
License Plate Lamp 168
Rear Turn Signal Lamp, Taillamp,
and Stoplamp3057KX
For replacement bulbs not listed here, contact your
dealer/retailer.
If your vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
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Windshield Wiper Blade
Replacement
Windshield wiper blades should be inspected for wear
or cracking. SeeScheduled Maintenance on page 6-4.
Replacement blades come in different types and
are removed in different ways. To replace the wiper
blade assembly:
1. Pull the windshield wiper arm connector away from
the windshield.
2. Squeeze the grooved areas on each side of the
blade, and turn the blade assembly away from
the arm connector.3. Install the new blade onto the arm connector and
make sure the grooved areas are fully set in the
locked position.
For the proper type and size, seeMaintenance
Replacement Parts on page 6-15.
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Backglass Wiper Blade Replacement
1. Lift the wiper blade assembly up and out of the park
rest position.
2. Pull the wiper blade assembly away from the
backglass. The backglass wiper blade will not
lock in a vertical position, so care should be used
when pulling it away from the vehicle.3. Turn the wiper blade assembly, and pull it off of the
wiper arm. Hold the wiper arm in position and push
the blade away from the wiper arm.
4. Replace the wiper blade.
5. Return the wiper blade assembly to the park rest
position.
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Tires
Your new vehicle comes with high-quality tires
made by a leading tire manufacturer. If you ever
have questions about your tire warranty and where
to obtain service, see your vehicle Warranty
booklet for details.
{CAUTION:
Poorly maintained and improperly used
tires are dangerous.
Overloading your vehicle’s tires can
cause overheating as a result of too
much exing. You could have an
air-out and a serious accident. See
Loading Your Vehicle on page 4-35.
Underinated tires pose the same
danger as overloaded tires. The
resulting accident could cause serious
injury. Check all tires frequently to
maintain the recommended pressure.
Tire pressure should be checked when
your vehicle’s tires are cold. See
Inflation - Tire Pressure on page 5-72.
CAUTION: (Continued)
CAUTION: (Continued)

Overinated tires are more likely to be
cut, punctured, or broken by a sudden
impact — such as when you hit a
pothole. Keep tires at the
recommended pressure.
Worn, old tires can cause accidents. If
the tire’s tread is badly worn, or if
your vehicle’s tires have been
damaged, replace them.
20-Inch Tires
If your vehicle has the optional 20-inch
P275/55R20 size tires, they are classied as
touring tires and are designed for on road use. The
low-prole, wide tread design is not recommended
for off-road driving. SeeOff-Road Driving on
page 4-13, for additional information.
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