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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.
{CAUTION:
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 (if you have one). It was
developed for use on your vehicle.
{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.
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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, 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.
Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a speci ed 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 signi cantly 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 speci ed 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
The tools you will need are
under the passenger’s
seat. For crew cab models,
the jack and wheel
blocks are under the
driver’s side rear seat.For regular and extended cab vehicles the jack and
wheel blocks are located under the cover at the center
of the vehicle behind the front seats.
1. The vehicle will have
a cover if it is an
extended or
regular cab.
2. Move the seats forward and turn the wing nut on the
cover counterclockwise to remove it. For crew cab
models, reach under the rear seat to access the jack
and wheel blocks. To reinstall the jack and wheel
block assembly in the mounting bracket, insert the
tabs into the jack base by pushing the blocks up into
the assembly. The outer hole in the jack base aligns
with the tab on the bracket. When reinstalling, make
sure the jack is secure, but do not overtighten the
jack in the bracket. Crew Cab
Regular and
Extended Cab
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3. The wheel blocks and the wheel block retainer can
be removed by turning the wing
nut counterclockwise.
Put the wheel blocks at the front and rear of the tire
farthest away from the one being changed. That
would be the tire on the other side, at the opposite
end of the vehicle.
4. There is also a wing nut used to retain the storage
bag and tools located under the front passenger’s
seat. To remove it, turn the wing
nut counterclockwise.
You will use the jack handle extensions and the wheel
wrench to remove the underbody-mounted spare tire.
A. Jack Handle
Extensions
B. Bottle JackC. Extension Tool
D. Wheel Wrench
E. Wheel Blocks
1. Assemble the wheel wrench (D) and the jack
handle extensions (A) as shown.
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2. Insert the hoist end (chiseled end) of the extension
tool through the hole in the rear bumper and into
the funnel-shaped guide. The chiseled end of
the extension is used to lower the spare tire.
3. Turn the wheel wrench (D) 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. See “Secondary Latch System” later in
this section.4. When the tire has been
lowered, tilt the retainer
and slide it up the
cable so it can
be pulled up through
the wheel opening.
5. Put the spare tire near the at tire.
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