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Noise Control System................................. 332
Tampering with Noise Control System
Prohibited.............................................. 332
Bulb Replacement....................................... 334
Halogen Bulbs........................................... 334
Headlamps................................................ 334
Front Turn Signal, Sidemarker and
Parking Lamps....................................... 336
Center High-Mounted Stoplamp (CHMSL) ... 336
Taillamps................................................... 337
Replacement Bulbs................................... 338
Windshield Wiper Blade Replacement....... 338
Tires............................................................ 340
Tire Sidewall Labeling............................... 341
Tire Terminology and Definitions............... 345
Inflation - Tire Pressure............................. 348Dual Tire Operation................................... 350
Tire Inspection and Rotation...................... 351
When It Is Time for New Tires.................. 353
Buying New Tires...................................... 353
Different Size Tires and Wheels................ 355
Uniform Tire Quality Grading..................... 356
Wheel Alignment and Tire Balance............ 357
Wheel Replacement.................................. 357
Tire Chains............................................... 359
If a Tire Goes Flat.................................... 360
Changing a Flat Tire................................. 360
Removing the Spare Tire and Tools.......... 362
Removing the Flat Tire and Installing
the Spare Tire....................................... 365
Secondary Latch System........................... 371
Storing a Flat or Spare Tire and Tools...... 375
Spare Tire................................................. 376
Section 5 Service and Appearance Care
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Page 349 of 452

A Tire and Loading Information label is attached to
the vehicle’s center pillar (B-pillar), below the
driver’s door latch. This label shows your vehicle’s
original equipment tires and the correct inflation
pressures for your tires when they are cold.
The recommended cold tire inflation pressure,
shown on the label, is the minimum amount of air
pressure needed to support your vehicle’s
maximum load carrying capacity.
For additional information regarding how much
weight your vehicle can carry, and an example of
the tire and loading information label, see
Loading Your Vehicle on page 259. How you load
your vehicle affects vehicle handling and ride
comfort, never load your vehicle with more weight
than it was designed to carry.
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 cannot tell if your tires are
properly inflated simply by looking at them. Radial
tires may look properly inflated even when
they’re underinflated. Check the tire’s inflation
pressure when the tires are cold. Cold means your
vehicle has been sitting for at least three hours
or driven no more than 1 mile (1.6 km).
Remove the valve cap from the tire valve stem.
Press the tire gage firmly onto the valve to
get a pressure measurement. If the cold tire
inflation pressure matches the recommended
pressure on the tire and loading information label,
no further adjustment is necessary. If the
pressure is low, add air until you reach the
recommended amount.
If you overfill the tire, release air by pushing on
the metal stem in the center of the tire valve.
Recheck the tire pressure with the tire gage.
Be sure to put the valve caps back on the valve
stems. They help prevent leaks by keeping out dirt
and moisture.
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Dual Tire Operation
When the vehicle is new, or whenever a wheel,
wheel bolt or wheel nut is replaced, check the
wheel nut torque after 100, 1,000 and 6,000 miles
(160, 1 600 and 10 000 km) of driving. For proper
wheel nut tightening information, see “Removing
the Flat Tire and Installing the Spare Tire” later in
this section, underChanging a Flat Tire on
page 360. Also see “Wheel Nut Torque” under
Capacities and Speci cations on page 393.
The outer tire on a dual wheel setup generally
wears faster than the inner tire. Your tires will wear
more evenly and last longer if you rotate the
tires periodically. SeeTire Inspection and Rotation
on page 351. Also seeScheduled Maintenance
(Gasoline Engine) on page 399.{CAUTION:
If you operate your vehicle with a tire
that is badly underin ated, the tire can
overheat. An overheated tire can lose air
suddenly or catch re. You or others could
be injured. Be sure all tires (including the
spare) are properly in ated.
SeeTires on page 340andIn ation - Tire
Pressure on page 348for more information on
proper tire inflation.
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Tire Inspection and Rotation
Tires should be rotated every 5,000 to 8,000 miles
(8 000 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.
SeeWhen It Is Time for New Tires on page 353
andWheel Replacement on page 357for
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 ratchet/wheel wrench to tighten the
cable. SeeChanging a Flat Tire on page 360.
If your vehicle has dual rear wheels, also seeDual
Tire Operation on page 350.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The
first rotation is the most important. SeeScheduled
Maintenance (Gasoline Engine) on page 399.If your vehicle has single rear wheels, always use
the correct rotation patterns shown here when
rotating your vehicle’s tires. Do not include
the spare tire in the tire rotation, if the spare
tire/wheel assembly does not match your vehicle’s
road tires and wheels in size and type.
Single Rear Wheels
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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 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.
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Removing the Spare Tire and Tools
If you have a cargo van or a passenger van,
the equipment you will need is located in
the passenger side rear corner of the vehicle.
Remove the retaining
wing bolt and lift it off of
the mounting bracket.
If you have a van with the 15-passenger seating
arrangement, the equipment you will need is
secured on the rear floor of the passenger side
of the vehicle.To access the equipment, remove the retaining
wing bolt and lift it out of the mounting bracket.
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The tools you will be using include the jack (A),
jack handle extension (B), jack handle (C),
wheel wrench (D), and the ratchet (E).
The spare tire is stored underneath the rear of
your vehicle. You will use the wheel wrench (D)
and the ratchet (E) to lower the spare tire from
the vehicle.To lower the spare tire from the vehicle, do the
following:
1. Attach the wheel
wrench and ratchet,
with the DOWN side
facing you. The
wheel wrench has a
socket end and a flat
chisel end. Note that
there is an UP side
and a DOWN side on
the ratchet.
2. Put the flat chisel end of the wheel wrench on
an angle through the hole between the body
and the bumper. Be sure the flat end
connects into the hoist shaft.
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3. Turn the ratchet counterclockwise to lower the
spare tire to the ground. If the spare tire does
not lower to the ground, the secondary
latch is engaged causing the tire not to lower.
SeeSecondary Latch System on page 371.4. When the tire has been lowered, pull the tire
toward you so you can reach the tire retainer
and pull it up through the wheel opening.
If you have a vehicle which was completed from a
cab and chassis, refer to the information from
the body supplier/installer.
The spare tire is a full-size tire, like the other tires
on your vehicle.
364