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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 inflation 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 specific 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
Specification (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 specifications 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 a MS, for mud and snow.
SeeTire Sidewall Labeling on page 5-56for additional
information.
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Different Size Tires and Wheels
If you add wheels or tires that are a different size than
your original equipment wheels and tires, this could 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 anti-lock brakes, rollover airbags,
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
specific wheel and tire systems developed for your
vehicle, and have them properly installed by a GM
certified technician.
SeeBuying New Tires on page 5-73andAccessories
and Modifications on page 5-3for additional information.
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.
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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 (B), hoist extension (C), jack handle
extension (D), and the wheel wrench (E).
The spare tire is mounted in the rear underbody of the
vehicle.
You will use the hoist extension, the jack handle
extensions and the wheel wrench to remove the
underbody-mounted spare tire.To lower the spare tire from the vehicle:
A. Spare Tire
B. Tire/Wheel Retainer
C. Hoist Cable
D. Hoist AssemblyE. Hoist Shaft
F. Jack Handle and
Hoist Extensions
G. Wheel Wrench
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1. Assemble the wheel wrench (G) to one or two of
the jack handle extensions and the hoist extension.
Insert the hoist extension end through the hole
in the rear bumper.
2. Be sure the hoist extension end connects to the
hoist shaft (E). The chiseled end of the extension
is used to lower the spare tire.
3. Turn the wheel wrench counterclockwise to lower
the spare tire to the ground. Continue to turn the
wheel wrench until the spare tire can be pulled out
from under the vehicle.
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 5-91.4. 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
body supplier/installer.
The spare tire is a full-size tire, like the other tires
on the vehicle.
5. Put the spare tire near the flat tire.
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Removing the Flat Tire and
Installing the Spare Tire
If your vehicle has plastic wheel nut caps, loosen
them by turning the wheel wrench counterclockwise.
The wheel nut caps are designed to remain with
the center cap. Remove the center cap.
If the wheel has a smooth center piece, place the chisel
end of the wheel wrench in the slot on the wheel and
gently pry it out.
1. Do a safety check before proceeding. SeeChanging
a Flat Tire on page 5-80for more information.
2. Loosen all the wheel nuts with the wheel wrench.
Do not remove them yet.
3. Assemble the jack and tools:Front Flat:Assemble the jack (A) together with the
jack handle (B), 1 or 2 jack handle extensions (D)
and the wheel wrench (E).
Rear Flat:Assemble the jack (A) together with the
jack handle (B), 2 jack handle extensions (D),
and the wheel wrench (E).
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{CAUTION:
Getting under a vehicle when it is jacked up is
dangerous. If the vehicle slips off the jack you
could be badly injured or killed. Never get under a
vehicle when it is supported only by a jack.
{CAUTION:
Raising your vehicle with the jack improperly
positioned can damage the vehicle and even
make the vehicle fall. To help avoid personal injury
and vehicle damage, be sure to fit the jack lift
head into the proper location before raising the
vehicle.5. Raise the vehicle by turning the wheel wrench
clockwise. Raise the vehicle far enough off the
ground so there is enough room for the spare
tire to fit.
6. Remove all the
wheel nuts.
7. Take flat tire off of the mounting surface.
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{CAUTION:
Rust or dirt on a wheel, or on the parts to which
it is fastened, can make wheel nuts become loose
after time. The wheel could come off and cause an
accident. When changing a wheel, remove any rust
or dirt from places where the wheel attaches to the
vehicle. In an emergency, 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 5-80.8. Remove any rust or dirt
from the wheel bolts,
mounting surfaces
and spare wheel.
{CAUTION:
Never use oil or grease on bolts or nuts because
the nuts might come loose. The vehicle’s wheel
could fall off, causing a crash.
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