2003 GMC YUKON DENALI Owners Manual

Notice: Don’t let anyone tell you that underinflation
or overinflation is all right. It’s not. If your tires
don’t have enough air (underinflation), you can get
the following:
Too much flexing
Too much heat
0 Tire overloading
Bad wear
Bad handling
Bad fuel economy
If your tires have too much air (overinflation), you
can get the following:
Unusual wear
Bad handling
Rough ride
Needless damage from road hazards
When to Check
Check your tires once a month or more.
Also, check the tire pressure of the spare tire
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can’t tell
if your tires are properly inflated
simply by looking at them. Radial tires may look
properly inflated even when they’re underinflated.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and
moisture.
Tire Inspection and Rotation
Tires should be rotated every 7,500 miles (12,500 km).
Any time you notice unusual wear, rotate your tires
as soon as possible and check wheel alignment.
Also
check for damaged tires or wheels. See When It Is Time
for New Tires on page
5-58 and Wheel Replacement
on page
5-61 for more information.
Make sure the spare tire is stored securely. Push, pull,
and then try to rotate or turn the tire. If
it moves,
use the wheel wrench and jack handle extensions
to
tighten the cable. See Changing a Flat Tire on
page 5-63.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle.
The first rotation
is the most important. See “Part
A: Scheduled
Maintenance Services,” in Section
6, for scheduled
rotation intervals.
5-56

When rotating your tires, always use the correct rotation
pattern shown here.
Don’t include the spare tire in your tire rotation.
After the tires have been rotated, adjust the front and
rear inflation pressures as shown on the
Certificationnire label. Make certain that all wheel nuts
are properly tightened. See “Wheel Nut Torque”
under Capacities and Specifications on page
5-96.
Rust or dirt on a wheel, or on the parts to
which
it is fastened, can make wheel nuts
become loose after a time. The wheel could
come
off and cause an accident. When you
change a wheel, remove any rust or dirt from
places where the wheel attaches to the vehicle.
In an emergency, you can use a cloth or a
paper towel to do this; but be sure to use a
scraper or wire brush later,
if you need to, to
get all the rust or dirt
off. See “Changing a Flat
Tire”
in the Index.
5-57

When It Is Time for New Tires
One way to tell when it’s
time for new tires is
to
check the treadwear
indicators, which will
appear when your tires have only
1/16 inch
(1.6 mm) or less of tread
remaining. Some
commercial truck tires may
not have treadwear indicators.
You need a new tire
if any of the following statements
are true:
You can see the indicators at three or more places
around the tire.
You can see cord or fabric showing through the
. The tread or sidewall is cracked, cut or snagged
The tire has a bump, bulge or split.
The tire has a puncture, cut or other damage that
tire’s rubber.
deep
enough
to show cord or fabric.
can’t be repaired well because of the size or
location
of the damage.
Buying New Tires
To find out what kind and size of tires you need, look at
the CertificationlTire label.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specifications (TPC
Spec) number on each tire’s sidewall. When you get
new tires, get ones with that same TPC Spec number.
That way your vehicle will continue
to have tires
that are designed to give proper endurance, handling,
speed rating, traction, ride and other things during
normal service on your vehicle. If your tires have an
all-season tread design, the TPC number will be
followed by an
“MS” (for mud and snow).
If you ever replace your tires with those not having a
TPC Spec number, make sure they are the same size,
load range, speed rating and construction type (bias,
bias-belted or radial) as your original tires.
5-58

Mixing tires could cause you to iose control
while driving. If you mix tires of different sizes or types (radial and bias-belted tires), the
vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes may also cause damage to your vehicle.
Be sure to use the same size and type tires on
all wheels. If your vehicle has
17 inch road
tires (those originally installed
on your vehicle)
it is all right to drive with the 16 inch spare tire
that came with your vehicle. When new, your
vehicle included a spare tire and wheel
assembly with the same overall diameter as
your vehicle’s road tires and wheels. Because
this spare tire was developed for use on your
vehicle,
it will not affect vehicle handling or
cause damage to your vehicle.
if you use bias-ply tires on your vehicle, the
wheel rim flanges could develop cracks after many miles of driving.
A tire and/or wheel
could fail suddenly, causing a crash. Use only radial-ply tires with the wheels on your vehicle
Uniform Tire Quality Grading
Quality grades can be found where applicable on the
tire sidewall between tread shoulder and maximum
section width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration, which grades tires by
treadwear, traction and temperature performance.
(This applies only to vehicles sold in the United States.)
The grades are molded on the sidewalls of most
passenger car tires. The Uniform Tire Quality Grading
system does not apply to deep tread, winter-type
snow tires, space-saver or temporary use spare tires,
tires with nominal rim diameters of
10 to 12 inches
(25 to 30 cm), or to some limited-production tires.
5-59

While the tires available on General Motors passenger
cars and light trucks may vary with respect
to these
grades, they must also conform
to federal safety
requirements and additional General Motors Tire
Performance Criteria (TPC) standards.
Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a specified government test course.
For example, a tire graded
150 would wear one and
a half
(1.5) times as well on the government course as
a tire graded
100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart significantly from the norm
due
to variations in driving habits, service practices and
differences
in road characteristics and climate.
Traction - AA, A, 6, C
The traction grades, from highest to lowest, are AA, A,
B, and C. Those grades represent the tire’s ability
to stop on wet pavement as measured under controlled
conditions on specified government test surfaces of
asphalt and concrete.
A tire marked C may have poor
traction performance. Warning: The traction grade assigned
to this tire is based
on straight-ahead braking
traction tests, and does not include acceleration,
cornering, hydroplaning, or peak traction characteristics.
Temperature - A, B, C
The temperature grades are A (the highest), B, and C,
representing the tire’s resistance
to the generation
of heat and its ability
to dissipate heat when tested
under controlled conditions on a specified indoor
laboratory test wheel. Sustained high temperature can
cause the material
of the tire to degenerate and
reduce tire life, and excessive temperature can lead
to
sudden tire failure. The grade C corresponds to a
level of performance which all passenger car tires must
meet under the Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher levels of
performance on the laboratory test wheel than the
minimum required
by law.
Warning: The temperature grade for this tire is
established for a tire that is properly inflated and not
overloaded. Excessive speed, underinflation, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.
5-60

Wheel Alignment and Tire Balance
The wheels on your vehicle were aligned and balanced
carefully at the factory
to give you the longest tire life
and best overall performance.
Scheduled wheel alignment and wheel balancing are
not needed. However,
if you notice unusual tire wear or
your vehicle pulling one way or the other, the alignment
may need
to be reset. If you notice your vehicle
vibrating when driving on a smooth road, your wheels
may need
to be rebalanced.
Wheel Replacement
Replace any wheel that is bent, cracked, or badly rusted
or corroded.
If wheel nuts keep coming loose, the
wheel, wheel bolts and wheel nuts should be replaced.
If the wheel leaks air, replace it (except some
aluminum wheels, which can sometimes be repaired).
See your dealer
if any of these conditions exist.
Your dealer will know the kind of wheel you need.
Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted
the same way as the one it replaces.
If you need to replace any of your wheels, wheel bolts
or wheel nuts, replace them only with new
GM
original equipment parts. This way, you will be sure to
have the right wheel, wheel bolts and wheel nuts
for your vehicle. Using the wrong replacement wheels, wheel
bolts or wheel nuts on your vehicle can be
dangerous. It could affect the braking and handling
of your vehicle, make your tires lose
air and make you lose control. You could have
a collision in which you or others could be
injured. Always use the correct wheel, wheel
bolts and wheel nuts for replacement.
Notice: The wrong wheel can also cause problems
with bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper height,
vehicle ground clearance and
tire clearance to the
body and chassis.
See
Changing a Flat Tire on page 5-63 for more
information.
5-6 1

Used Replacement Wheels Tire Chains
-
Putting a used wheel on your vehicle is
dangerous. You can’t know how
it’s been used
or how far
it’s been driven. It could fail
suddenly and cause a crash. If you have to replace
a wheel, use a new GM original
equipment wheel. Don’t use
ti., ch; ... s. There’s
not ,..ough
clearance. Tire chains used
on a vehicle without
the proper amount of clearance can cause
damage to the brakes, suspension or other
vehicle parts. The area damaged by the tire
chains could cause you to lose control of your
vehicle and you or others may be injured
in a
crash. Use another type of traction device only
if its manufacturer recommends
it for use on
your vehicle and tire size combination and road conditions. Follow that manufacturer’s instructions. To help avoid damage to your
vehicle, drive slowly, readjust or remove
the
device if it’s contacting your vehicle, and don’t
spin your wheels.
If you do find traction devices
that will
fit, install them on the rear tires.
5-62

If a Tire Goes Flat
It’s unusual for a tire to “blowout” while you’re driving,
especially
if you maintain your tires properly. If air goes
out
of a tire, it’s much more likely to ieak out siowiy.
But if you should ever have a “blowout”, here are a few
tips about what
to expect and what to do:
If a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side. Take your foot
off the
accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake
to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you’d use
in a skid.
In any rear blowout, remove your foot from the
accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle
to go. It may be
very bumpy and noisy, but you can still steer. Gently
brake to a stop
- well off the road if possible.
If a tire goes flat, the next part shows how to use your
jacking equipment to change a flat tire safely.
Changing a Flat Tire
If a tire goes flat, avoid further tire and wheel damage
by driving slowly to a level place. Turn on your
hazard warning
fi hers.
Changing a tire can cause an injury. The
vehicle can slip
off the jack and roll over you
or other people. You and they could be badly injured. Find a level place to change your tire.
To help prevent the vehicle from moving:
1. Set the parking brake firmly.
2. Put the shift lever in PARK (P).
3. Turn off the engine.
4. Put the wheel blocks at the front and rear
of the tire farthest away from the one
being changed. That would be the tire on
the other side
of the vehicle, at the
opposite end.
5-63