1997 CADILLAC DEVILLE tires

Downloaded from www.Manualslib.com manuals search engine 5. Reinstall the headlamp housing socket back into the
headlamp assembly.
Headlamp Aiming
Your vehicle has the 55 x 135 mini-quad headlamp
system. These headlamps have horizontal and vertical
aim indicators. The aim has been pre-set at the factory
and should need
no further adjustment.
If your vehicle is damaged in an accident and the
headlamp aim seems to be affected, see your
Cadillac dealer. Headlamps
on damaged vehicles
may require recalibration of the horizontal aim by
your Cadillac dealer.
To check the aim, the vehicle should be properly
prepared as follows:
The vehicle must have all four tires on a perfectly
level surface.
The vehicle should not have any snow, ice or mud
attached to it.
0 There should not be any cargo or loading of the
vehicle, except it should have a full tank of gas and
one person or
160 lbs. (75 kg) on the driver’s seat.
0 Tires should be properly inflated.
The horizontal indicator should read “0.”
6-33

Downloaded from www.Manualslib.com manuals search engine Tires
Your new Cadillac comes with high-quality tires made
by a leading tire manufacturer.
If you ever have
questions about your tire warranty and where
to obtain
service, see your Cadillac Warranty booklet
for details.
U
Poorly maintained and improperly used tires
are dangerous.
0 Overloading your tires can cause
, overheating as a result of too much friction.
You could have an air-out and a serious
accident. See “Loading Your Vehicle” in
the Index.
0 Underinflated tires pose the same danger as
overloaded tires. The resulting accident
could cause serious injury. Check all tires
frequently to maintain the recommended pressure. Tire pressure should be checked
when your tires are cold.
CAUTION: (Continued)
0 Overinflated tires are more likely to be
cut, punctured or broken by a sudden
impact
-- such as when you hit a pothole.
Keep tires
at the recommended pressure.
0 Worn, old tires can cause accidents. If your
tread
is badly worn, or if your tires have
been damaged, replace them.
See “Inflation
-- Tire Pressure’’ in this section
speed driving.
’ for inflation pressure adjustment for higher
6-40

Downloaded from www.Manualslib.com manuals search engine Inflation -- Tire Pressure
“he Tire-Loading Information label, which is located 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).
If you’ll be driving at speeds higher than 100 mph
(160
km/h) where it is legal, raise the cold inflation
pressure
of each tire to 35 psi (240 Pa). When you end
this very high-speed driving, reduce the cold inflation
pressures to those listed on the.Tire-Loading
Information label.
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.
6-41

Downloaded from www.Manualslib.com manuals search engine When to Check
Check your tires once a month or more.
Don’t forget your compact spare tire. It should be at
60 psi (420 Pa).
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 6,000 to 8,000 miles
(10 000 to 13 000 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’s Time for New Tires” and
“Wheel Replacement’’ later in this section for
more information. 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 “Scheduled
Maintenance Services” in the Maintenance Schedule
booklet for scheduled rotation intervals.
When rotating your tires, always use the correct
rotation pattern shown here.
Don’t include the compact spare tire in your
tire rotation.
6-42

Downloaded from www.Manualslib.com manuals search engine After the tires have been rotated, adjust the front
and rear inflation pressures as shown on the
Tire-Loading Information label. Make certain
that all wheel nuts are properly tightened. See
“Wheel Nut Torque”
in the Index.
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.) When It’s 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:
0 You can see the indicators at three or more places
0 You can see cord or fabric showing through the
around the tire.
tire’s rubber.
0 The tread or sidewall is cracked, cut or snagged deep
enough to show cord or fabric.
0 The tire has a bump, bulge or split.
0 The tire has a puncture, cut or other damage that
can’t be repaired well because
of the size or location
of the damage.
6-43

Downloaded from www.Manualslib.com manuals search engine Buying New Tires
To find out what kind and size of tires you need, look at
the Tire-Loading Information label.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specification (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.
I
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.
It’s all right to drive with your compact spare,
though.
It was developed for use on your vehicle.
6-44

Downloaded from www.Manualslib.com manuals search engine ___ form Tire Quality Grading Treadwear
me 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.
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. 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 1/2) 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 -- A, B, C
The traction grades, from highest to lowest, are A, B and
C, and they 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.
6-45
Warning: The traction grade assigned to this tire is based '
on braking (straightahead) traction tests and does not
include cornering (turning) traction.

Downloaded from www.Manualslib.com manuals search engine 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 A and B 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.
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
Cadillac 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.
6-46