wheel CADILLAC STS 2005 1.G Repair Manual

{CAUTION:
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 needed, to get all
the rust or dirt off. SeeChanging a Flat Tire on
page 5-74.
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.
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
tire’s rubber.
The tread or sidewall is cracked, cut or snagged
deep enough to show cord or fabric.
The tire has a bump, bulge or split.
The tire has a puncture, cut or other damage that
can’t be repaired well because of the size or
location of the damage.
5-67

{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes
(other than those originally installed on your
vehicle) or types (radial and bias-belted tires),
the vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes (other than those originally installed on
your vehicle) may also cause damage to your
vehicle. Be sure to use the correct size and
type tires on all wheels. It is all right to drive
with your compact spare temporarily, it was
developed for use on your vehicle. See
Compact Spare Tire on page 5-84.
{CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim anges 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.
Vehicles equipped with performance tires P235/
50R17 95V (front axle) and P255/45R17 98V (rear axle)
are mounted on wheels with different rim widths. The
front axle tires are mounted on rims 7.5 inches (19.05 cm)
wide and the rear axle tires require wheels with a
minimum rim width of 8 inches (20.32 cm). The original
equipment wheels designed for P255/45R17 98V size
tires are etched with the words REAR ONLY. When
replacing P255/45R17 98V size tires have them mounted
on wheels with a minimum width of 8 inches (20.32 cm)
and marked REAR ONLY. SeeWheel Replacement on
page 5-71.
5-69

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 specied 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 inated and not
overloaded. Excessive speed, underination, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.
Wheel Alignment and Tire Balance
The tires and wheels on your vehicle were aligned and
balanced carefully at the factory to give you the longest
tire life and best overall performance. Adjustments to
wheel alignment and tire balancing will not be necessary
on a regular basis. However, if you notice unusual tire
wear or your vehicle pulling to one side or the other, the
alignment may need to be checked. If you notice your
vehicle vibrating when driving on a smooth road, your
tires and wheels may need to be rebalanced. See your
dealer for proper diagnosis.
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.
5-71

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.
{CAUTION:
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 or tire chain
clearance to the body and chassis.
SeeChanging a Flat Tire on page 5-74for more
information.
Used Replacement Wheels
{CAUTION:
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.
5-72

Tire Chains
{CAUTION:
If your vehicle has P255/45R17 98V,
P255/45R18 99W or 255/45ZR18 99Y size tires,
do not use tire chains, there is not enough
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.
CAUTION: (Continued)
CAUTION: (Continued)
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 is contacting your vehicle, and do
not spin your wheels.
If you do nd traction devices that will t,
install them on the rear tires only.
Notice:If your vehicle has P235/50R17 95S size
tires, use tire chains only where legal and only when
you must. Use only SAE Class “S” type chains
that are the proper size for your tires. Install them
on the rear tires and tighten them as tightly as
possible with the ends securely fastened. Drive
slowly and follow the chain manufacturer’s
instructions. If you can hear the chains contacting
your vehicle, stop and retighten them. If the contact
continues, slow down until it stops. Driving too
fast or spinning the wheels with chains on will
damage your vehicle.
5-73

If a Tire Goes Flat
It is 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 is 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 at tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel rmly.
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 would;
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.{CAUTION:
Lifting a vehicle and getting under it to do
maintenance or repairs is dangerous without
the appropriate safety equipment and training.
The jack provided with your vehicle is
designed only for changing a at tire. If it is
used for anything else, you or others could be
badly injured or killed if the vehicle slips off
the jack. Use the jack provided with your
vehicle only for changing a at tire.
If a tire goes at, the next part shows how to use your
jacking equipment to change a at tire safely.
Changing a Flat Tire
If a tire goes at, avoid further tire and wheel damage
by driving slowly to a level place. Turn on your vehicle’s
hazard warning ashers. SeeHazard Warning Flashers
on page 3-6for more information.
5-74

{CAUTION:
Changing a tire can be dangerous. The vehicle
can slip off the jack and roll over or fall on you
or other people. You and they could be badly
injured or even killed. Find a level place to
change your tire. To help prevent the vehicle
from moving:
1. Set the parking brake rmly.
2. Put the shift lever in PARK (P).
3. Turn off the engine and do not restart
while the vehicle is raised.
4. Do not allow passengers to remain in the
vehicle.
To be even more certain the vehicle will not
move, you should put 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, at the opposite end of the vehicle.When your vehicle has a at tire, use the following
example as a guide to assist you in the placement of
wheel blocks.
The following information will tell you next how to use
the jack and change a tire.
5-75

Removing the Spare Tire and Tools
The equipment you will need is in the trunk.
To gain access to the spare tire and jacking equipment,
do the following:
1. Open the trunk. SeeTrunk on page 2-14for more
information.
2. Remove the compact spare tire cover.
3. Turn the nut holding the jack counterclockwise and
remove it. Then remove the jack and wheel wrench.
4. Remove the compact spare tire. SeeCompact
Spare Tire on page 5-84for more information
about the compact spare tire.
5-76

The tools you will be using include the jack (A) and the
wheel wrench (B).
Removing the Flat Tire and
Installing the Spare Tire
If your vehicle has wheel covers, use the at end of the
wheel wrench to remove the covers. Turn the wheel
wrench clockwise to gently pry off the wheel cover.
Be careful not to scratch the aluminum wheel edge and
do not try to remove the wheel cover with your hands.
5-77

If your vehicle has wheel nut caps, turn the wheel
wrench counterclockwise to remove the caps.
Once the wheel cover and wheel nut caps have been
removed, use the following steps to remove the at tire
and install the spare tire.1. Place the wheel wrench (A) securely over the wheel
nut (B). Turn the wheel wrench counterclockwise to
loosen all the wheel nuts. Do not remove them yet.
5-78