1999 GMC SUBURBAN Owner's Manual

6-42
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 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
-- 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.

6-43 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.
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.

6-44
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.
See ªChanging a Flat Tireº in the Index for
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 an
accident. If you have to replace a wheel, use a new
GM original equipment wheel.
Tire Chains
NOTICE:
If your vehicle has P265/75R16, LT265/75R16,
P265/70R16 or P265/70R17 size tires, don't use
tire chains. They can damage your vehicle
because there's not enough clearance.
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.
NOTICE: (Continued)

6-45
NOTICE: (Continued)
If you have a tire size other than P265/75R16,
LT265/75R16, P265/70R16 or P265/70R17, use
tire chains only where legal and only when you
must. Use chains that are the proper size for your
tires. Install them on the tires of the rear axle.
Don't use chains on the tires of the front axle.
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.
Appearance Care
Remember, cleaning products can be hazardous. Some
are toxic. Others can burst into flame if you strike a
match or get them on a hot part of the vehicle. Some are
dangerous if you breathe their fumes in a closed space.
When you use anything from a container to clean your
vehicle, be sure to follow the manufacturer's warnings
and instructions. And always open your doors or
windows when you're cleaning the inside.
Never use these to clean your vehicle:

Gasoline

Benzene

Naphtha

Carbon Tetrachloride

Acetone

Paint Thinner

Turpentine

Lacquer Thinner

Nail Polish Remover
They can all be hazardous
-- some more than
others
-- and they can all damage your vehicle, too.

6-46
Don't use any of these unless this manual says you can.
In many uses, these will damage your vehicle:

Alcohol

Laundry Soap

Bleach

Reducing Agents
Cleaning the Inside of Your Vehicle
Use a vacuum cleaner often to get rid of dust and loose
dirt. Wipe vinyl, leather, plastic and painted surfaces
with a clean, damp cloth.
Cleaning of Fabric/Carpet
Your dealer has two cleaners, Multi-Purpose Interior
Cleaner and Capture Non
-Solvent Dry Spot and
Soil Remover for cleaning fabric and carpet. They will
clean normal spots and stains very well. You can get
GM
-approved cleaning products from your dealer.
(See ªAppearance Care and Materialsº in the Index.)
Here are some cleaning tips:

Always read the instructions on the cleaner label.

Clean up stains as soon as you can
-- before they set.
Carefully scrape off any excess stain.

Use a clean cloth or sponge, and change to a
clean area often. A soft brush may be used if
stains are stubborn.

If a ring forms on fabric after spot cleaning,
clean the entire area immediately or it will set.
Using Multi-Purpose Interior Cleaner
on Fabric
1. Vacuum and brush the area to remove any loose dirt.
2. Always clean a whole trim panel or section.
Mask surrounding trim along stitch or welt lines.
3. Mix powdered cleaner following the directions on
the container label to form thick suds.
4. Use suds only and apply with a clean sponge.
Don't saturate the material and don't rub it roughly.
5. As soon as you've cleaned the section, use a sponge
to remove the suds.
6. Wipe cleaned area with a clean, damp towel or cloth.
7. Wipe with a clean cloth and let dry.

6-47 Special Fabric Cleaning Problems
Stains caused by such things as catsup, coffee (black),
egg, fruit, fruit juice, milk, soft drinks, vomit, urine and
blood can be removed as follows:
1. Carefully scrape off excess stain, then sponge the
soiled area with cool water.
2. If a stain remains, follow the multi
-purpose interior
cleaner instructions described earlier.
3. If an odor lingers after cleaning vomit or urine,
treat the area with a water/baking soda solution:
1 teaspoon (5 ml) of baking soda to 1 cup (250 ml)
of lukewarm water.
4. Let dry.
Stains caused by candy, ice cream, mayonnaise, chili
sauce and unknown stains can be removed as follows:
1. Carefully scrape off excess stain.
2. First, clean with cool water and allow to
dry completely.
3. If a stain remains, follow instructions for
Multi
-Purpose Interior Cleaner.
Cleaning Vinyl
Use warm water and a clean cloth.

Rub with a clean, damp cloth to remove dirt.
You may have to do it more than once.

Things like tar, asphalt and shoe polish will stain if
you don't get them off quickly. Use a clean cloth
and a vinyl/leather cleaner. See your dealer for
this product.
Cleaning Leather
Use a soft cloth with lukewarm water and a mild soap
or saddle soap and wipe dry with a soft cloth. Then,
let the leather dry naturally. Do not use heat to dry.

For stubborn stains, use a leather cleaner. See your
dealer for this product.

Never use oils, varnishes, solvent
-based or abrasive
cleaners, furniture polish or shoe polish on leather.

Soiled or stained leather should be cleaned
immediately. If dirt is allowed to work into the
finish, it can harm the leather.

6-48 Cleaning the Top of the Instrument Panel
Use only mild soap and water to clean the top surfaces
of the instrument panel. Sprays containing silicones or
waxes may cause annoying reflections in the windshield
and even make it difficult to see through the windshield
under certain conditions.
Cleaning Interior Plastic Components
Use only a mild soap and water solution on a soft
cloth or sponge. Commercial cleaners may affect the
surface finish.
Care of Safety Belts
Keep belts clean and dry.
CAUTION:
Do not bleach or dye safety belts. If you do,
it may severely weaken them. In a crash,
they might not be able to provide adequate
protection. Clean safety belts only with mild
soap and lukewarm water.
Cleaning Glass Surfaces
Glass should be cleaned often. GM Glass Cleaner
or a liquid household glass cleaner will remove normal
tobacco smoke and dust films on interior glass.
(See ªAppearance Care and Materialsº in the Index.)
Don't use abrasive cleaners on glass, because they may
cause scratches. Avoid placing decals on the inside rear
window, since they may have to be scraped off later.
If abrasive cleaners are used on the inside of the rear
window, an electric defogger element may be damaged.
Any temporary license should not be attached across
the defogger grid.
Cleaning the Outside of the
Windshield, Backglass and
Wiper Blades
If the windshield is not clear after using the windshield
washer, or if the wiper blade chatters when running,
wax, sap or other material may be on the blade
or windshield.
Clean the outside of the windshield with GM Windshield
Cleaner, Bon Ami

Powder (non-scratching glass cleaning
powder), GM Part No. 1050011. The windshield is clean if
beads do not form when you rinse it with water.

6-49
Grime from the windshield will stick to the wiper
blades and affect their performance. Clean the blade by
wiping vigorously with a cloth soaked in full
-strength
windshield washer solvent. Then rinse the blade
with water.
Check the wiper blades and clean them as necessary;
replace blades that look worn.
Weatherstrips
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth at least every six
months. During very cold, damp weather more frequent
application may be required. (See ªRecommended
Fluids and Lubricantsº in the Index.)
Cleaning the Outside of Your Vehicle
The paint finish on your vehicle provides beauty,
depth of color, gloss retention and durability.
Washing Your Vehicle
The best way to preserve your vehicle's finish is to
keep it clean by washing it often with lukewarm or
cold water.Don't wash your vehicle in the direct rays of the sun.
Use a car washing soap. Don't use strong soaps or
chemical detergents. Be sure to rinse the vehicle well,
removing all soap residue completely. You can get
GM
-approved cleaning products from your dealer.
(See ªAppearance Care and Materialsº in the Index.)
Don't use cleaning agents that are petroleum based,
or that contain acid or abrasives. All cleaning agents
should be flushed promptly and not allowed to dry on
the surface, or they could stain. Dry the finish with a
soft, clean chamois or an all
-cotton towel to avoid
surface scratches and water spotting.
High pressure car washes may cause water to enter
your vehicle.
Cleaning Exterior Lamps/Lenses
Use lukewarm or cold water, a soft cloth and a car
washing soap to clean exterior lamps and lenses.
Follow instructions under ªWashing Your Vehicle.º
Finish Care
Occasional waxing or mild polishing of your vehicle by
hand may be necessary to remove residue from the paint
finish. You can get GM
-approved cleaning products
from your dealer. (See ªAppearance Care and Materialsº
in the Index.)