tires CADILLAC DTS 2008 1.G Service Manual

You need new tires 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
cannot be repaired well because of the size or
location of the damage.
The rubber in tires degrades over time, even if they are
not being used. This is also true for the spare tire, if your
vehicle has one. Multiple conditions affect how fast this
aging takes place, including temperatures, loading
conditions, and ination pressure maintenance. With
proper care and maintenance tires will typically wear out
before they degrade due to age. If you are unsure about
the need to replace your tires as they get older, consult
the tire manufacturer for more information.
Buying New Tires
GM has developed and matched specic tires for
your vehicle. The original equipment tires installed
on your vehicle, when it was new, were designed
to meet General Motors Tire Performance Criteria
Specication (TPC Spec) system rating. If you need
replacement tires, GM strongly recommends that you
get tires with the same TPC Spec rating. This way,
your vehicle will continue to have tires that are designed
to give the same performance and vehicle safety,
during normal use, as the original tires.
GM’s exclusive TPC Spec system considers over a
dozen critical specications that impact the overall
performance of your vehicle, including brake system
performance, ride and handling, traction control, and
tire pressure monitoring performance. GM’s TPC Spec
number is molded onto the tire’s sidewall near the tire
size. If the tires have an all-season tread design, the TPC
Spec number will be followed by an MS for mud and
snow. SeeTire Sidewall Labeling on page 5-53for
additional information.
5-71

GM recommends replacing tires in sets of four. This is
because uniform tread depth on all tires will help keep
your vehicle performing most like it did when the tires
were new. Replacing less than a full set of tires can affect
the braking and handling performance of your vehicle.
SeeTire Inspection and Rotation on page 5-68for
information on proper tire rotation.
{CAUTION:
Mixing tires could cause you to lose control of
your vehicle while driving. If you mix tires of
different sizes, brands, or types (radial and
bias-belted tires), the vehicle may not handle
properly, and you could have a crash. Using
tires of different sizes, brands, or types may
also cause damage to your vehicle. Be sure to
use the correct size, brand, and type of tires
on all wheels.
CAUTION: (Continued)
CAUTION: (Continued)
Your vehicle may have a compact spare tire
and wheel assembly. If the vehicle has a
compact spare tire and wheel, they have the
same overall diameter as your vehicle’s
full-size tires and wheels. Because they were
designed and developed for use on your
vehicle, it is all right to drive your vehicle with
the compact spare installed properly. Compact
spare tires are designed for temporary use
only. SeeSpare Tire on page 5-89.
5-72

{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.
If you must replace your vehicle’s tires with those that
do not have a TPC Spec number, make sure they
are the same size, load range, speed rating, and
construction type (radial and bias-belted tires) as
your vehicle’s original tires.
Vehicles that have a tire pressure monitoring system
could give an inaccurate low-pressure warning if
non-TPC Spec rated tires are installed on your vehicle.
Non-TPC Spec rated tires may give a low-pressure
warning that is higher or lower than the proper warning
level you would get with TPC Spec rated tires.
SeeTire Pressure Monitor System on page 5-63.
Your vehicle’s original equipment tires are listed on
the Tire and Loading Information Label. SeeLoading
the Vehicle on page 4-20, for more information about the
Tire and Loading Information Label and its location on
your vehicle.
Different Size Tires and Wheels
If you add wheels or tires that are a different size than
your original equipment wheels and tires, this may affect
the way your vehicle performs, including its braking, ride
and handling characteristics, stability, and resistance
to rollover. Additionally, if your vehicle has electronic
systems such as, antilock brakes, traction control, and
electronic stability control, the performance of these
systems can be affected.
{CAUTION:
If you add different sized wheels, your
vehicle may not provide an acceptable
level of performance and safety if tires not
recommended for those wheels are selected.
You may increase the chance that you will crash
and suffer serious injury. Only use GM specic
wheel and tire systems developed for your
vehicle, and have them properly installed by
a GM certied technician.
SeeBuying New Tires on page 5-71andAccessories
and Modifications on page 5-3for additional information.
5-73

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 (NHTSA), 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 (UTQG)
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.
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 specied
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 signicantly 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 specied 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.
5-74

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 might need to be checked. If you notice your
vehicle vibrating when driving on a smooth road, the tires
and wheels might need to be rebalanced. See your
dealer/retailer 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. Some aluminum wheels can
sometimes be repaired. See your GM dealer/retailer if
any of these conditions exist.
Your GM dealer/retailer 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.
5-75

If you need to replace any of your wheels, wheel bolts,
wheel nuts, or Tire Pressure Monitor System (TPMS)
sensors, replace them only with new GM original
equipment parts. This way, you will be sure to have
the right wheel, wheel bolts, wheel nuts, and TPMS
sensors 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.
If your vehicle is a professional model, the wheels have
a unique offset and bolt hole diameter. Each of the
wheels on the professional vehicle have eight wheels
nuts. The wheels on the non-professional vehicle
have ve wheel nuts. SeeChanging a Flat Tire
on page 5-79for more information.
5-76

Used Replacement Wheels
{CAUTION:
Putting a used wheel on the vehicle is
dangerous. You cannot know how it has been
used or how far it has been driven. It could fail
suddenly and cause a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
Tire Chains
{CAUTION:
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
the 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 the
vehicle and tire size combination and road
conditions. Follow that manufacturer’s
instructions. To help avoid damage to the
vehicle, drive slowly, readjust or remove the
device if it is contacting the vehicle, and do
not spin the vehicle’s wheels. If you do nd
traction devices that will t, install them on
the front tires.
5-77

If a Tire Goes Flat
It is unusual for a tire to blowout while you are driving,
especially if you maintain your vehicle’s 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 creates 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 the
jacking equipment to change a at tire safely.
5-78

Spare Tire
Compact Spare Tire
Your vehicle may have a compact spare tire. Although
the compact spare tire was fully inated when the vehicle
was new, it can lose air after a time. Check the ination
pressure regularly. It should be 60 psi (420 kPa).
After installing the compact spare on the vehicle, stop as
soon as possible and make sure the spare tire is correctly
inated. The compact spare is made to perform well at
speeds up to 65 mph (105 km/h) for distances up to
3,000 miles (5 000 km), so you can nish your trip
and have the full-size tire repaired or replaced at your
convenience. Of course, it is best to replace the spare
with a full-size tire as soon as possible. The spare tire
will last longer and be in good shape in case it is needed
again.
Notice:When the compact spare is installed,
do not take your vehicle through an automatic car
wash with guide rails. The compact spare can
get caught on the rails. That can damage the tire
and wheel, and maybe other parts of your vehicle.
Do not use the compact spare on other vehicles.
And do not mix the compact spare tire or wheel with
other wheels or tires. They will not t. Keep the
spare tire and its wheel together.Notice:Tire chains will not t your compact
spare. Using them can damage your vehicle and can
damage the chains too. Do not use tire chains on
your compact spare.Spare Tire
Your vehicle may have a spare tire, which, when new,
was fully inated. A spare tire may lose air over time, so
check its ination pressure regularly. SeeInflation - Tire
Pressure on page 5-60andLoading the Vehicle on
page 4-20for information regarding proper tire ination
and loading your vehicle. For instructions on how to
remove, install or store a spare tire, seeRemoving the
Flat Tire and Installing the Spare Tire on page 5-81.
After installing the spare tire on your vehicle, you should
stop as soon as possible and make sure the spare is
correctly inated. Have the damaged or at road tire
repaired or replaced as soon as you can and installed
back onto your vehicle. This way, a spare tire will be
available in case you need it again.
Your vehicle may have a different size spare tire
than the road tire originally installed on your vehicle.
This spare tire was developed for use on your vehicle,
so it is all right to drive on it.
If your vehicle has a spare tire that does not match your
vehicle’s original road tires and wheels in size and
type, do not include the spare in the tire rotation.
5-89

Tires
To clean the tires, use a stiff brush with tire cleaner.
Notice:Using petroleum-based tire dressing
products on your vehicle may damage the paint
nish and/or tires. When applying a tire dressing,
always wipe off any overspray from all painted
surfaces on your vehicle.
Sheet Metal Damage
If the vehicle is damaged and requires sheet metal
repair or replacement, make sure the body repair
shop applies anti-corrosion material to parts repaired
or replaced to restore corrosion protection.
Original manufacturer replacement parts will provide
the corrosion protection while maintaining the vehicle
warranty.
Finish Damage
Any stone chips, fractures or deep scratches in the
nish should be repaired right away. Bare metal
will corrode quickly and may develop into major
repair expense.
Minor chips and scratches can be repaired with touch-up
materials available from your dealer/retailer. Larger
areas of nish damage can be corrected in your
dealer’s/retailer’s body and paint shop.
Underbody Maintenance
Chemicals used for ice and snow removal and dust
control can collect on the underbody. If these are not
removed, corrosion and rust can develop on the
underbody parts such as fuel lines, frame, oor pan,
and exhaust system even though they have corrosion
protection.
At least every spring, ush these materials from the
underbody with plain water. Clean any areas where mud
and debris can collect. Dirt packed in close areas of the
frame should be loosened before being ushed. Your
dealer/retailer or an underbody car washing system can
do this for you.
5-97