GMC SIERRA DENALI 2003 Owners Manual

Inflation - Tire Pressure
The CertificationKire label, which is on the rear edge of
the driver’s door, shows the correct inflation pressures
for your tires when they’re cold. “Cold” means your
vehicle has been sitting for at least three hours or driven
no more than
1 mile (1.6 km).
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
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
5-62
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 5-64 and Wheel Replacement
on page
5-67 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
5-69.

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;
After the tires have been rotated, adjust the front and
rear inflation pressures as shown on the
CertificationEire label. Make certain that all wheel nuts
are properly tightened. See “Wheel Nut Torque”
under
Capacities and Specificatiol on ge 5-104.
When rotating your tires, always use the correct rotation
pattern shown here.
Don’t include the spare tire in your tire rotation. 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 Flal
Tire”
in the Index.
5-63

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
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.
around
the tire.
tire’s rubber.
deep enough to show cord or fabric.
Buying New Tires
To find out what kind and size of tires you need, look at
the Certificationflire 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.
The tire has a puncture, cut or other damage that
can’t be repaired well because of the size or
location of the damage.
5-64

Mixing tires could cause you to lose 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 yo^ Jse bias-ply tires on y--. ,chicle, 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.
5-65

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, B, 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.
5-66

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. Usin,
__ __ wrong replacement wheels,
whc
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 5-69 for more
information.
5-67

Used Replacement Wheels
-
Putting a used wheel 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.
I I
Tire Chains
Don’t use lire chains. There’s not enough
clearance. Tire chains used on a vehicle
without the proper amount sf clearance can cause damage to the brakes, suspension or
other vehicle parts. The area damaged by the
CAUTION: (Continued) tire chains could cause
, -u to lose cc..-rol
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.
If a Tire Goes Flat
It’s unusual for a tire to “blow out” while you’re driving,
especially
if you maintain your tires properly. If air
goes out of a tire, it’s much more likely to leak out
slowly. 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.
5-68

A rear blowout, particularly on a curve, acts much like a Changing a Flat Tire
skid and may require the same correction you’d use
in a skid. In any rear blowout, remove your foot from the
If a tire goes flat, avoid further tire and wheel damage
accelerator pedal. Get the vehicle under control by by driving slowly
to a level place. Turn on your
steering
the way you want the vehicle to go. it may be hazard warning flashers.
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.
C..-nging 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.
5-69

L
Removing the Spare Tire and Tools
The following steps will tell you how to use the jack and
change a tire.
The equipment you’ll need is under the passenger’s
side second row seat. The spare tire is located
underneath the vehicle.
1. Pull up the second row seat with the loop at the
base
of the seat cushion to access the tools.
5-70

2. The wheel blocks and the wheel block retainer can
be removed by turning the wing nut
counterclockwise.
3. To release the bottle jack from its holder, turn the
knob on
the bottle jack eotintercloekwise to lower
the jack head slightly.
4. There is also a wing nut used to retain the storage
bag and tools. To remove it, turn the wing nut
counterclockwise.
You’ll use the jack handle and the wheel wrench to
remove the underbody-mounted spare tire.
A. Hoist Assembly
B. Wheel Wrench
C. Extensions
D. Hoist Shaft
E. Valve Stem, Pointed
Down
F. Spare Tire
G. Tire Retainer
H. Hoist Cable
I. Hoist Lock
(If Equipped)
J. Hoist Shaft Access
Hole
K. Hoist End
5-71