spare GMC ENVOY 2008 User Guide

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 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.
5-77

Removing the Spare Tire and Tools
The jacking equipment needed to remove the spare tire
is stored under the rear seat. To release the jack from
its holder, turn the knob on the jack counterclockwise to
lower the jack head. SeeRear Seat Operation on
page 1-11for more information.The tools you will be using include the wheel wrench (A),
wheel blocks (B), extension(s) (socket end) (C),
handle (jack end) (D), and jack (E).
To remove the underbody-mounted spare from your
vehicle:
Notice:If you remove or restow a tire from/to the
storage position under the vehicle while 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.
5-84

A. Wheel Wrench
B. Hoist Shaft
C. Extension
D. Retainer
E. Spare or Flat Tire
(Valve Stem
Pointed Up)
1. Open the liftgate. SeeLiftgate/Liftglass on
page 2-12for more information.
2. Attach the wheel wrench (A) to the extension (C).3. Insert the socket end
of the extension (C) on
a 45 degree 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 (C) connects to the hoist shaft.
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4. 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. SeeSecondary Latch System on page 5-92
for more information.5. Tilt the retainer at the end of the cable when the
tire has been completely lowered, and pull it
through the wheel opening.
6. 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.
7. Put the spare tire near the at tire.
5-86

Removing the Flat Tire and
Installing the Spare Tire
1. Do a safety check before proceeding. SeeChanging
a Flat Tire on page 5-82for more information.
2. Use the at end of the wheel wrench to carefully
pry off the center cap.
3. Using the wheel
wrench, loosen all the
wheel nuts by turning
the nuts one turn
counterclockwise.
Do not remove
them yet.
4. Turn the jack adjusting knob clockwise by hand to
raise the jack lift head.
5. Place the handle, extension, and wheel wrench
onto the jack.A. Front Frame/Rear Axle
B. Jack
C. HandleD. Extension(s)
E. Wheel Wrench
6. Place the jack in the appropriate position nearest
the at tire.
Front PositionRear Position
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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 t the
jack lift head into the proper location before
raising the vehicle.7. Raise the vehicle by turning the jack handle
clockwise. Raise the vehicle far enough off the
ground so there is enough room for the spare
tire to t.
5-88

8. Remove all the wheel
nuts and the at tire.
{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 you change a
wheel, remove any rust or dirt from places
CAUTION: (Continued)
CAUTION: (Continued)
where the wheel attaches to the vehicle. In an
emergency, you can 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 5-82.
9. Remove any rust or dirt
from the wheel bolts,
mounting surfaces
and spare wheel.
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10. Place the spare tire on the wheel-mounting surface.
{CAUTION:
Never use oil or grease on studs or nuts.
Because the nuts might come loose. The
vehicle’s wheel could fall off, causing a crash.
11. Put the nuts on by hand. Make sure the cone
shaped end is toward the wheel.
12. Tighten each nut by hand until the wheel is held
against the hub. If a nut cannot be turned by hand,
use the wheel wrench and see your dealer as soon
as possible.13. Lower the vehicle by turning the jack handle
counterclockwise. Lower the jack completely.
5-90

Secondary Latch System
Your vehicle has an underbody-mounted tire hoist
assembly equipped with a secondary latch system. It is
designed to stop the spare tire from suddenly falling off
your vehicle if the cable holding the spare tire is
damaged. For the secondary latch to work, the tire must
be stored with the valve stem pointing up. SeeStoring a
Flat or Spare Tire and Tools on page 5-96for instructions
on storing the spare or at tire correctly.
{CAUTION:
Before beginning this procedure read all the
instructions. Failure to read and follow the
instructions could damage the hoist assembly
and you and others could get hurt. Read and
follow the instructions listed next.
{CAUTION:
Someone standing too close during the
procedure could be injured by the jack.
If the spare tire does not slide off the jack
completely, make sure no one is behind you or
on either side of you as you pull the jack out
from the under spare.
To release the spare tire from the secondary latch:
1. Check under the
vehicle to see if the
cable is visible. If it is
not visible, proceed
to Step 6.
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2. 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 ofRemoving the Spare Tire and Tools on
page 5-84.
5. Turn the wrench counterclockwise until
approximately 6 inches (15 cm) of cable is exposed.
6. Attach the jack handle, extension(s) 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.
5-93