wheel GMC YUKON DENALI 2003 Service Manual

Q: Am I likely to stall when going downhill?
A: It’s much more likely to happen going uphill. But if it
happens going downhill, here’s what
to do.
Stop your vehicle by applying the regular brakes.
Apply the parking brake.
Shift to PARK (P) and, while still braking, restart the
Shift back to a low gear, release the parking brake,
If the engine won’t start, get out and get help.
engine.
and
drive straight down.
Driving Across an Incline
Sooner or later, an off-road trail will probably go across
the incline
of a hill. If this happens, you have to
decide whether
to try to drive across the incline. Here
are some things
to consider:
A hill that can be driven straight up or down may be
too steep to drive across. When you go straight up
or down a
hill, the length of the wheel base (the
distance from the front wheels
to the rear wheels)
reduces the likelihood the vehicle will tumble end
over end. But when you drive across an incline,
the much more narrow track width (the distance
between the left and right wheels) may not prevent
the vehicle from tilting and rolling over.
Also,
driving across an incline puts more weight on the
downhill wheels. This could cause a downhill
slide or a rollover.
Surface conditions can be a problem when you
drive across a hill.
Loose gravel, muddy spots,
or even wet grass can cause your tires
to slip
sideways, downhill.
If the vehicle slips sideways,
it can hit something that will trip
it (a rock, a rut, etc.)
and roll over.
Hidden obstacles can make the steepness of the
incline even worse. If you drive across a rock
with the uphill wheels, or
if the downhill wheels
drop into a rut or depression, your vehicle can tilt
even more.
For reasons like these, you need to decide carefully
whether to try to drive across an incline. Just because
the trail goes across the incline doesn’t mean you
have to drive it. The last vehicle to try it might have
rolled over.
4-24

Driving in Water
Heavy rain can mean flash flooding, and flood waters
demand extreme caution.
Find out how deep the water
is before you drive through
it. If it’s deep enough to cover your wheel hubs, axles
or exhaust pipe, don’t try
it - you probably won’t
get through. Also, water that deep can damage your
axle and other vehicle parts.
If the water isn’t too deep, drive slowly through it. At
faster speeds, water splashes on your ignition system
and your vehicle can stall. Stalling can also occur
if you
get your tailpipe under water. And, as long as your
tailpipe is under water, you’ll never be able to start your
engine. When you go through water, remember that
when your brakes get wet, it may take you longer
to stop.
I
- - - - -ng through rushing water can be
dangerous. Deep water can sweep your vehicle
downstream and you and your passengers
i could drown. If it’s only shallow water, it can
still wash away the ground from under your
tires, and you could lose traction and roll the
vehicle over. Don’t drive through rushing water.
I I
See Driving in Rain and on Wet Roads on page 4-29 for
more information on driving through water.
After Off-Road Driving
Remove any brush or debris that has collected on the
underbody, chassis or under the hood. These
accumulations can be a fire hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires and exhaust
system for damage.
Also, check the fuel lines and
cooling system for any leakage.
Your vehicle will require more frequent service due to
off-road use. Refer
to the Maintenance Schedule
for additional information.
4-27

Highway Hypnosis
Is there actually such a condition as “highway
hypnosis”? Or is it just plain falling asleep at the wheel?
Call it highway hypnosis, lack
of awareness, or
whatever.
There is something about an easy stretch of road with
the same scenery, along with the hum of the tires on the
road, the drone of the engine, and the rush of the
wind against the vehicle that can make you sleepy. Don’t
let
it happen to you! If it does, your vehicle can leave
the road in less than a second, and you could crash and
be injured.
What can you do about highway hypnosis? First, be
aware that
it can happen.
Then here are some tips:
Make sure your vehicle is well ventilated, with a
Keep your eyes moving. Scan the road ahead and
comfortably
cool interior.
to the sides. Check your mirrors and your
instruments frequently.
If you get sleepy, pull off the road into a rest,
service or parking area and take a nap, get some
exercise, or both. For safety, treat drowsiness
on the highway as an emergency.
Hill and Mountain Roads
Driving on steep hills or mountains is different from
driving in flat or rolling terrain.
If you drive regularly in steep country, or if you’re
planning to visit there, here are some tips that can make
your trips safer and more enjoyable. See Operating
Your All- Wheel-Drive Vehicle
Off Paved Roads on
page
4- 16 for information about driving off-road.
4-35

Driving on Snow or Ice
Most of the time, those places where your tires meet
the road probably have good traction.
However,
if there is snow or ice between your tires and
the road, you can have a very slippery situation.
You’ll have a
lot less traction or “grip” and will need to
be very careful.
27
3
What’s the worst time for this? “Wet ice.” Very cold
snow or ice can be slick and hard
to drive on. But wet
ice can be even more trouble because it may offer
4-38
the least traction of all. You can get wet ice when it’s
about freezing
(32°F; OOC) and freezing rain begins
to fall. Try to avoid driving on wet ice until salt and sand
crews can get there.
Whatever the condition
- smooth ice, packed, blowing
or loose snow
- drive with caution.
Accelerate gently. Try not to break the fragile traction.
If you accelerate
too fast, the drive wheels will spin and
polish the surface under the tires even more.
Your anti-lock brakes improve your vehicle’s stability
when you make a hard stop on a slippery road.
Even though you have an anti-lock braking system,
you’ll want to begin stopping sooner than you would on
dry pavement. See Braking on page
4-6.
Allow greater following distance on any
slippery road.
Watch for slippery spots. The road might be fine
until you hit a spot that’s covered with ice. On
an otherwise clear road, ice patches may appear in
shaded areas where the sun can’t reach: around
clumps of trees, behind buildings or under bridges.
Sometimes the surface of a curve or an overpass
may remain icy when the surrounding roads
are clear. If you see a patch of ice ahead of you,
brake before you are on it. Try not
to brake
while you’re actually on the ice, and avoid sudden
steering maneuvers.

Then, shut the engine off and close the window almost
all the way
to preserve the heat. Start the engine
again and repeat this only when you feel really
uncomfortable from the cold. But do it as little as
possible. Preserve the fuel as long
as you can. Po help
keep warm, you can get out of the vehicle and do
some fairly vigorous exercises every half hour or
so until
help comes.
If You Are Stuck: In Sand, Mud, Ice
or Snow
In order to free your vehicle when it is stuck, you will
need
to spin the wheels, but you don’t want to spin your
wheels
too fast. The method known as “rocking” can
help you get
out when you’re stuck, but you must
use caution.
you let yeerr tires spin at high speed, -..zy
can explode, and you or others could be
injured.
And, the transmission or other parts of
the vehicle can overheat. That could cause an
engine compartment fire or other damage.
When you’re stuck, spin the wheels as little as possible. Don’t spin the wheels above
35 mph
(55 km/h) as shown on the speedometer.
Nofice: Spinning your wheels can destroy parts of
your vehicle
as well as the tires. If you spin the
wheels too fast while shifting your transaxle back
and forth, you can destroy your transaxle. See
“Rocking Your Vehicle
To Get It Out.”
For information about using tire chains on your vehicle,
see
Tire Chains on page 5-62.
4-41

Rocking Your Vehicle To Get It Out
First, turn your steering wheel left and right. That will
clear the area around your front wheels. If your vehicle
has the Stabilitrak@System, turn the system off by
pressing the Stabilitrak@button
so that the STABILITY
SYS DISABLED message and the traction off light
are illuminated on the instrument panel cluster. Then
shift back and forth between REVERSE (R) and
a
forward gear, spinning the wheels as little as possible.
Release the accelerator pedal while you shift, and press
lightly on the accelerator pedal when the transmission
is in gear. By slowly spinning your wheels in the forward
and reverse directions, you will cause a rocking
motion that may free your vehicle.
If that doesn’t get
you out after a few tries, you may need to be towed out.
Or, you can use your recovery hooks
if your vehicle
has them. If you do need to be towed out, see Towing
Your Vehicle on page 4-44.
Using the Recovery Hoods
Your vehicle is equipped with recovery hooks. The
hooks are provided at the front
of your vehicle. You may
need to use them
if you’re stuck off-road and need to
be pulled to some place where you can continue driving.
4-42

Towing Loading Your Vehicle
Towing Your Vehicle
Consult your dealer or a professional towing service if
you need to have your disabled vehicle towed. See
Roadside Assistance Program on page
7-5.
If you want to tow your vehicle behind another vehicle
for recreational purposes (such as behind a motorhome),
see “Recreational Vehicle Towing” following.
Recreational Vehicle Towing
Recreational vehicle towing means towing your vehicle
behind another vehicle
- such as behind a motorhome.
The two most common types of recreational vehicle
towing are known as “dinghy towing” (towing your vehicle
with all four wheels on the ground) and “dolly towing”
(towing your vehicle with two wheels
on the ground and
two wheels
up on a device known as a “dolly”).
Your vehicle was not designed
to be towed with any of
its wheels on the ground.
If your vehicle must be
towed, see Towing Your Vehicle on page
4-44.
Notices Towing an all-wheel-drive vehicle with all
four wheels on the ground, or even with only two
of
its wheels on the ground, will damage drivetrain
components. Don’t tow an all-wheel-drive vehicle
if
any of its wheels will be on the ground.
II II
GAWR FRT GAWR RR
!E mNERS MANUAL FOR ADDITIONAL INFORMATION[-]
The Certificationmire label is found on the rear edge of
the driver’s door.
The label shows the size of your original tires and the
inflation pressures needed
to obtain the gross weight
capacity of your vehicle. This is called the GVWR (Gross
Vehicle Weight Rating). The GVWR includes the
weight of the vehicle, all occupants, fuel and cargo.
The Certificationmire label also tells you the maximum
weights for the front and rear axles, called Gross
Axle Weight Rating (GAWR). To find out the actual loads
on your front and rear axles, you need to go
to a
4-44

weigh station and weigh your vehicle. Your dealer can If
you put things inside your vehicle - like suitcases,
help you with this. Be sure to spread out your load
tools, packages, or anything else
- they go as fast as
equally on both sides of the centerline.
the vehicle goes.
If you have to stop or turn quickly,
Never exceed the GVWR for your vehicle, or the GAWR
for either the front or rear axle. or
if there
is a crash, they’ll keep going.
And,
if you do have a heavy load, you should
spread it out.
Do no. .Jad ,3ur vehic., any heavier than the
GVWR, or either the maximum front or rear
GAWR. If you do, parts on your vehicle can
break, and
it can change the way your vehicle
handles. These could cause you to lose
control and crash.
Also, overloading can
shorten the life
of your vehicle.
Your warranty does not cover parts or components that
fail because
of overloading.
The label will help you decide how much cargo and
installed equipment your truck can carry.
Using heavier suspension components to get added
durability might not change your weight ratings. Ask your
dealer to help you load your vehicle the right way. Things you put inside your vehicle can strike
and injure people
in a sudden stop or turn, or
in a crash.
Put things in the cargo area of your
vehicle. Try to spread the weight evenly.
0 Never stack heavier things, like suitcases,
inside the vehicle
so that some of them
are above the tops of the seats.
* Don’t leave an unsecured child restraint in
your vehicle.
When you carry something inside the
vehicle, secure
it whenever you can.
Don’t leave a seat folded down unless you
need to.
There’s also important loading information for off-road
driving
in this manual. See “Loading Your Vehicle
for Off-Road Driving” under Operating Your
All-Wheel-Drive Vehicle
Off Paved Roads on page 4-16.
4-45

Automatic Level Control
The automatic level control rear suspension comes as a
part of the AutorideTMsuspension. See AutorideTM on
page
4-46.
This type of level control is fully automatic and will
provide a better leveled riding position as well as better
handling under a variety of passenger and loading
conditions. An air compressor connected
to the rear
shocks will raise or lower the rear of the vehicle
to maintain proper vehicle height. The system is
activated when the ignition key
is turned to RUN and
will automatically adjust vehicle height thereafter.
The system may exhaust (lower vehicle height) for up
to
10 minutes after the ignition key has been turned to
OFF. You may hear the air compressor operating when
the height is being adjusted.
If a weight-distributing hitch is being used, it is
recommended
to allow the shocks to inflate, thereby
leveling the vehicle prior to adjusting the height.
AutorideTM
The AutorideTM feature provides superior vehicle ride
and handling under a variety
of passenger and loading
conditions.
The system is fully automatic and
uses a computer
controller
to continuously monitor vehicle speed, wheel
to body position, IifVdive and steering position of the
vehicle. The controller then sends signals to each shock
absorber
to independently adjust the damping level to
provide the optimum vehicle ride.
AutorideTM also interacts with the towlhaul mode that,
when activated, will provide additional control of
the shock absorbers. This additional control results in
better ride and handling characteristics when the vehicle
is loaded or towing a trailer. See "Tow/Haul Mode"
under Towing a Trailer on page
4-47 for more
information.
4-46

Backing Up
Hold the bottom of the steering wheel with one hand.
Then,
to move the trailer to the left, just move that hand
to the left. To move the trailer to the right, move your
hand
to the right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Notice: Making very sharp turns while trailering
could
cause the trailer to come in contact with the
vehicle. Your vehicle could
be damaged. Avoid
making very sharp turns while trailering.
When you’re turning with a trailer, make wider turns
than normal.
Do this so your trailer won’t strike
soft shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance.
Turn Signals When Towing a Trailer
The arrows on your instrument panel will flash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also flash, telling other drivers
you’re about
to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument panel will flash for turns even
if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
4-54
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gear before you start
down a long or steep downgrade.
If you don’t shift
down, you might have to use your brakes
so much that
they would get hot and no longer work well.
You can tow in
DRIVE (D). You may want to shift the
transmission
to THIRD (3) or, if necessary, a lower gear
selection
if the transmission shifts too often
(e.g., under heavy loads and/or hilly conditions).
You may also want
to activate the tow/haul mode if the
transmission shifts
too often. See “Tow/Haul Mode”
under Towing a Trailer
on page 4-47.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes.
If you turn your
engine
off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar
to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) for a
few minutes before turning the engine
off. If you do get
the overheat warning, see Engine Overheating
on
page 5-25.