spare tire GMC SIERRA 2008 User Guide

When It Is Time for New Tires
Various factors, such as maintenance, temperatures,
driving speeds, vehicle loading, and road conditions,
inuence when you need new tires.
One way to tell when it is
time for new tires is to
check the treadwear
indicators, which appear
when your tires have only
1/16 inch (1.6 mm) or less
of tread remaining. Some
commercial truck tires may
not have treadwear
indicators.
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 ination 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 specic 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 Specication
(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 specications 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
5-84

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
specic wheel and tire systems developed for
your vehicle, and have them properly installed
by a GM certied technician.
SeeBuying New Tires on page 5-84andAccessories
and Modifications on page 5-4for 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.
5-86

When your vehicle has a at tire, use the following
example as a guide to assist you in the placement of
the wheel blocks.
The following information will tell you next how to use
the jack and change a tire.Removing the Spare Tire and Tools
A. Wing Nut Retaining
Tool Kit
B. Tool Kit
C. Wheel BlocksD. Jack
E. Wing Nut Retaining
Wheel Blocks
Crew Cab
5-93

For regular cab models, the equipment you will need is
behind the passenger’s seat. For extended and crew
cab models, the equipment is on the shelf behind the
passenger’s side second row seat.
1. Turn the knob on the jack counterclockwise to lower
the jack head to release the jack from its holder.
2. Remove the wheel blocks and the wheel block
retainer by turning the wing nut counterclockwise.
3. Remove the wing nut used to retain the storage
bag and tools by turning it counterclockwise.
You will use the jack handle extensions and the wheel
wrench to remove the underbody-mounted spare tire.
A. Spare Tire (Valve
Stem Pointed Down)
B. Hoist Assembly
C. Hoist Cable
D. Tire/Wheel Retainer
E. Hoist Shaft
F. Hoist End of
Extension ToolG. Hoist Shaft Access
Hole
H. Wheel Wrench
I. Jack Handle
Extensions
J. Spare Tire Lock
(If equipped)
1. Open the spare tire lock cover on the bumper and
use the ignition key to remove the spare tire lock (J).
To remove the spare tire lock, insert the ignition key
turn and pull straight out.
5-95

2. Assemble the wheel wrench (H) and the two jack
handle extensions (I) as shown.
3. Insert the hoist end
(open end) (F) of the
extension through the
hole (G) in the rear
bumper.
Do not use the chiseled
end of the wheel wrench.Be sure the hoist end of the extension (F) connects
to the hoist shaft (E). The ribbed square end of the
extension is used to lower the spare tire.
4. Turn the wheel wrench (H) 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 5-105.
5. Use the wheel wrench
hook which allows you
to pull the hoist cable
towards you to assist in
reaching the spare tire.
5-96

6. Tilt the tire toward the vehicle with some slack in
the cable to access the tire/wheel retainer.
Separate the retainer from the guide pin by sliding
the retainer up the pin while pressing down on
the latch.Once the retainer is separated from the guide pin,
tilt the retainer and pull it through the center of
the wheel along with the cable and guide latch.
7. Put the spare tire near the at tire.
5-97

Removing the Flat Tire and
Installing the Spare Tire
Use the following pictures and instructions to remove
the at tire and raise the vehicle.
The tools you will be using include the jack (A), the
wheel blocks (B), the jack handle (C), the jack handle
extensions (D), and the wheel wrench (E).
1. Do a safety check before proceeding. SeeChanging
a Flat Tire on page 5-92for more information.2. If your vehicle has
wheel nut caps, loosen
them by turning the
wheel wrench
counterclockwise.
If the vehicle has a center cap with wheel nut caps,
the wheel nut caps are designed to stay with the
center cap after they are loosened. Remove the
entire center cap.
5-98

If the at tire is on the rear, position the jack under
the rear axle between the spring anchor and the
shock absorber bracket.
If you have added a snow plow to the front of your
vehicle, lower the snow plow fully before raising
the vehicle.
Make sure that the jack head is positioned so that
the rear axle is resting securely between the
grooves that are on the jack head.
{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.
5. Turn the wheel wrench clockwise to raise the
vehicle. Raise the vehicle far enough off the ground
so there is enough room for the spare tire to t
under the wheel well. Rear Position – All Models
5-101

7. Remove any rust or dirt
from the wheel bolts,
mounting surfaces, and
spare wheel.
8. Install the spare tire.
{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.
9. Put the wheel nuts back on with the rounded end of
the nuts toward the wheel.
10. Tighten each wheel nut by hand. Then use the
wheel wrench to tighten the nuts until the wheel
is held against the hub.
11. Turn the wheel wrench counterclockwise to lower
the vehicle. Lower the jack completely.
5-103

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. For the secondary latch to work, the
spare must be installed with the valve stem pointing
down. SeeStoring a Flat or Spare Tire and Tools
on page 5-108.
{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.To release the spare tire from the secondary latch:
1. Check under the
vehicle to see if the
cable end is visible.
If the cable is not
visible proceed
to Step 6.
2. If it is 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 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 5 ofRemoving the Spare Tire and Tools
on page 5-93.
5-105