wheel GMC ENVOY 2004 Manual PDF

Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a specied 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 signicantly 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 specied 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 specied 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 inated and not
overloaded. Excessive speed, underination, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.
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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.
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.
SeeChanging a Flat Tire on page 5-76for more
information.
5-71

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 a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
Tire Chains
{CAUTION:
Don’t use tire chains. There’s not enough
clearance. Tire chains used on a vehicle
without the proper amount of clearance can
cause damage to the brakes, suspension or
other vehicle parts. The area damaged by the
tire chains could cause you to lose control of
your vehicle and you or others may be injured
in a crash. 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 nd traction
devices that will t, install them on the
rear tires.
5-72

If a Tire Goes Flat
It’s unusual for a tire to “blowout” while you’re driving,
especially if you maintain your tires properly. If air goes
out of a tire, it’s much more likely to leak out slowly.
But if you should ever have a “blowout,” here are a few
tips about what to expect and what to do:
If a front tire fails, the at tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel rmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you’d use
in a skid. In any rear blowout, remove your foot from the
accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go. It may be
very bumpy and noisy, but you can still steer. Gently
brake to a stop, well off the road if possible.{CAUTION:
Lifting a vehicle and getting under it to do
maintenance or repairs is dangerous without
the appropriate safety equipment and training.
The jack provided with your vehicle is
designed only for changing a at tire. If it is
used for anything else, you or others could be
badly injured or killed if the vehicle slips off
the jack. Use the jack provided with your
vehicle only for changing a at tire.
If a tire goes at, the next part shows how to use your
jacking equipment to change a at tire safely.
5-75

Changing a Flat Tire
If a tire goes at, avoid further tire and wheel damage
by driving slowly to a level place. Turn on your
hazard warning ashers.
{CAUTION:
Changing a tire can cause an injury. The
vehicle can slip off the jack and roll over you
or other people. You and they could be badly
injured. Find a level place to change your tire.
To help prevent the vehicle from moving:
1. Set the parking brake rmly.
2. Put the shift lever in PARK (P).
3. If you have a four-wheel-drive vehicle, be
sure the transfer case is in a drive
gear – not in NEUTRAL.
4. Turn off the engine.
5. 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 of the vehicle, at the
opposite end.The following steps will tell you how to use the jack and
change a tire.
5-76

The tools you’ll be using include the wheel wrench (A),
wheel blocks (B), extension(s) (socket end) (C),
handle (jack end) (D), and jack (E).
The following instructions explain how to remove the
spare tire mounted underneath your vehicle.
Notice:If you remove or restow a tire from/to the
storage position under the vehicle when it is
supported by a jack, you could damage the tire
and/or your vehicle. Always remove or restow a tire
when the vehicle is on the ground.1. To remove the underbody-mounted spare, insert
the socket end of the extension on a 45° angle
downward into the hoist drive shaft hole. It is
exposed when the rear gate is open and is just
above the rear bumper. Be sure the socket end of
the extension connects to the hoist shaft.
5-78

2. Turn the wheel wrench counterclockwise to lower
the spare tire. Keep turning 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.
When the tire has been completely lowered, tilt the
retainer at the end of the cable and pull it through
the wheel opening. Pull the tire out from under
the vehicle.
Notice:If you drive away before the spare tire or
secondary latch system cable has been reinstalled,
you could damage your vehicle. Always reinstall
this cable before driving your vehicle.
3. Put the spare tire near the at tire.4. Position the chisel end of your wheel wrench in the
notch of the center cap and pry off the center cap.
See “Removing the Flat Tire and Installing the Spare
Tire” later in this section to continue changing the
at tire.
5-79

To release the spare tire from the secondary latch do
the following:
1. Check under the
vehicle to see if the
cable is visible.
2. If it is not visible, proceed to Step 6.
If visible, rst try to tighten the cable by turning the
wheel wrench clockwise until you hear two clicks
or feel it skip twice. You cannot overtighten
the cable.
3. Loosen the cable by turning the wheel wrench
counterclockwise three or four turns.
4. Repeat this procedure at least two times.
If the spare tire lowers to the ground, continue with
Step 2 of “Removing the Spare Tire and Tools”
earlier in this section.5. Turn the wrench counterclockwise until
approximately 6 inches (15 cm) of cable is exposed.
6. Attach the jack handle, extension and the wheel
wrench to the jack and place it under the vehicle
towards the front of the rear bumper. Position
the center lift point of the jack under the center of
the spare tire.
7. Turn the wrench clockwise to raise the jack until it
lifts the end tting.
8. Continue raising the jack until the spare tire stops
moving upward and is held rmly in place. The
secondary latch has released and the spare tire is
balancing on the jack.
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9. Lower the jack by turning the wheel wrench
counterclockwise. Keep lowering the jack until the
spare tire slides off the jack or is hanging by
the cable.
10. Disconnect the jack handle from the jack and
carefully remove the jack. Use one hand to push
against the spare while rmly pulling the jack out
from under the spare tire with the other hand.
If the spare tire is hanging from the cable, insert the
socket end of the extension connected to the wheel
wrench into the hoist shaft hole in the bumper on an
angle. Turn the wheel wrench counterclockwise to
lower the spare the rest of the way.11. Tilt the retainer at the end of the cable and pull it
through the wheel opening. Pull the tire out from
under the vehicle.
12. If the cable is hanging under the vehicle, turn the
wheel wrench in the hoist shaft hole in the bumper
clockwise to raise the cable back up.
Have the hoist assembly inspected as soon as you can.
You will not be able to store a spare or at tire using
the hoist assembly until it has been repaired or replaced.
5-82

Removing the Flat Tire and Installing
the Spare Tire1. Using the wheel wrench, loosen all the wheel nuts.
Don’t remove them yet.
2. Turn the jack adjusting knob clockwise by hand to
raise the jack lift head.
3. Place the handle, extension and wheel wrench onto
the jack.
5-83