2012 GMC SIERRA 1500 Owners Manual

Black plate (71,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Vehicle Care 10-71
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.
All Passenger Car Tires Must
Conform to Federal Safety
Requirements In Addition To
These Grades.
Treadwear
The treadwear grade is a
comparative rating based on the
wear rate of the tire when tested
under controlled conditions on
a specified government test
course. For example, a tiregraded 150 would wear one and
a half (1½) 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 significantly 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
specified 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 specified
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.

Black plate (72,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-72 Vehicle Care
The grade C corresponds to a
level of performance which all
passenger car tires must meet
under the Federal Motor 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 inflated and not
overloaded. Excessive speed,
underinflation, or excessive
loading, either separately or in
combination, can cause heat
buildup and possible tire failure.Wheel Alignment and Tire
Balance
The tires and wheels were aligned
and balanced at the factory to
provide the longest tire life and best
overall performance. Adjustments to
wheel alignment and tire balancing
will not be necessary on a regular
basis. However, check the
alignment if there is unusual tire
wear or if the vehicle is pulling to
one side or the other. If the vehicle
vibrates when driving on a smooth
road, the tires and wheels might
need to be rebalanced. See your
dealer for proper diagnosis.
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.
Some aluminum wheels can be
repaired. See your dealer if any of
these conditions exist.
Your dealer will know the kind of
wheel that is needed.
Each new wheel should have the
same load-carrying capacity,
diameter, width, offset and be
mounted the same way as the
one it replaces.
Replace wheels, wheel bolts, wheel
nuts, or Tire Pressure Monitor
System (TPMS) sensors with new
GM original equipment parts.

Black plate (73,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Vehicle Care 10-73
{WARNING
Using the wrong replacement
wheels, wheel bolts, or wheel
nuts can be dangerous. It could
affect the braking and handling of
the vehicle. Tires can lose air,
and cause loss of control, causing
a crash. 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.
Whenever a wheel, wheel bolt,
or wheel nut is replaced on a dual
wheel setup, check the wheel
nut torque after 160, 1 600 and
10 000 km (100, 1,000 and 6,000 mi)
of driving. For proper torque,
see “Wheel Nut Torque” under
Capacities and Specifications on
page 12‑2.
See If a Tire Goes Flat on
page 10‑75 for more information. Used Replacement Wheels{WARNING
Replacing a wheel with a used
one is dangerous. How it has
been used or how far it has been
driven may be unknown. It could
fail suddenly and cause a crash.
When replacing wheels, use a
new GM original equipment
wheel.

Black plate (74,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-74 Vehicle Care
Tire Chains
{WARNING
If the vehicle has dual wheels
or P265/65R18, P275/55R20,
LT265/70R17, LT265/70R18,
LT265/60R20, P285/50R20,
P285/45R22 or 285/45R22 size
tires, do not use tire chains. They
can damage the vehicle because
there is 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 the vehicle and
you or others may be injured in a
crash.(Continued)
WARNING (Continued)
Use another type of traction
device only if its manufacturer
recommends it for use on the
vehicle and tire size combination
and road conditions. Follow that
manufacturer's instructions. To
help avoid damage to the vehicle,
drive slowly, readjust, or remove
the device if it is contacting the
vehicle, and do not spin the
vehicle's wheels.
If you do find traction devices that
will fit, install them on the rear
tires. Notice:
If the vehicle does not
have dual wheels and has a tire
size other than P265/65R18,
P275/55R20, LT265/70R17,
LT265/70R18, LT265/60R20,
P285/50R20, P285/45R22, or
285/45R22, use tire chains only
where legal and only when you
must. Use chains that are the
proper size for the tires. Install
them on the tires of the rear axle.
Do not use chains on the tires of
the front axle. Tighten them as
tightly as possible with the
ends securely fastened. Drive
slowly and follow the chain
manufacturer's instructions.
If you can hear the chains
contacting the vehicle, stop and
retighten them. If the contact
continues, slow down until it
stops. Driving too fast or
spinning the wheels with chains
on will damage the vehicle.

Black plate (75,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Vehicle Care 10-75
If a Tire Goes Flat
It is unusual for a tire to blowout
while driving, especially if the tires
are maintained properly. If air goes
out of a tire, it is much more likely to
leak out slowly. But if there ever is a
blowout, here are a few tips about
what to expect and what to do:
If a front tire fails, the flat tire
creates a drag that pulls the vehicle
toward that side. Take your foot off
the accelerator pedal and grip the
steering wheel firmly. Steer to
maintain lane position, and then
gently brake to a stop, well off the
road, if possible.
A rear blowout, particularly on a
curve, acts much like a skid and
may require the same correction as
used in a skid. Stop pressing the
accelerator pedal and steer to
straighten the vehicle. It may be
very bumpy and noisy. Gently
brake to a stop, well off the road,
if possible.{WARNING
Driving on a flat tire will cause
permanent damage to the tire.
Re-inflating a tire after it has
been driven on while severely
underinflated or flat may cause a
blowout and a serious crash.
Never attempt to re-inflate a tire
that has been driven on while
severely underinflated or flat.
Have your dealer or an authorized
tire service center repair or
replace the flat tire as soon as
possible.
{WARNING
Lifting a vehicle and getting
under it to do maintenance or
repairs is dangerous without the
appropriate safety equipment and
training. If a jack is provided with
the vehicle, it is designed only for
changing a flat tire. If it is used for
anything else, you or others could
be badly injured or killed if the
vehicle slips off the jack. If a jack
is provided with the vehicle, only
use it for changing a flat tire.
If a tire goes flat, avoid further
tire and wheel damage by
driving slowly to a level place,
well off the road, if possible.

Black plate (76,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-76 Vehicle Care
Turn on the hazard warning
flashers. SeeHazard Warning
Flashers on page 6‑5.
{WARNING
Changing a tire can be
dangerous. The vehicle can slip
off the jack and roll over or fall
causing injury or death. Find a
level place to change the tire. To
help prevent the vehicle from
moving:
1. Set the parking brake firmly.
2. Put an automatic transmission in P (Park) or
a manual transmission in
1 (First) or R (Reverse).
3. For four-wheel-drive vehicles, be sure the
transfer case is in a drive
gear– not in N (Neutral).
4. Turn off the engine and do not restart while the vehicle
is raised.
(Continued)
WARNING (Continued)
5. Do not allow passengers toremain in the vehicle.
6. Place wheel blocks on both sides of the tire at the
opposite corner of the tire
being changed.
When the vehicle has a flat tire (B),
use the following example as a
guide to assist in the placement of
the wheel blocks (A).
A. Wheel Block
B. Flat Tire The following information explains
how to use the jack and change
a tire.
Tire Changing
Removing the Spare Tire and
Tools
Crew Cab
A. Wing Nut Retaining Tool Kit
B. Tool Kit
C. Wheel Blocks
D. Jack

Black plate (77,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Vehicle Care 10-77
E. Jack Knob
F. Wing Nut Retaining WheelBlocks
Regular Cab
A. Wing Nut Retaining Tool Kit
B. Tool Kit
C. Wheel Blocks
D. Jack
E. Jack Knob
F. Wing Nut Retaining Wheel Blocks
Extended Cab
A. Wing Nut Retaining Tool Kit
B. Tool Kit
C. Wheel Blocks
D. Jack
E. Jack Knob
For regular cab models, the
equipment you will need is
behind the passenger seat. For extended and crew cab
models, the equipment is on the
shelf behind the passenger 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. Turn the wing nut counterclockwise to remove the
wheel blocks and the wheel
block retainer.
3. Turn the wing nut used to retain the storage bag and tools
counterclockwise to remove it.
Use the jack handle extensions and
the wheel wrench to remove the
underbody-mounted spare tire.

Black plate (78,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-78 Vehicle Care
A. Spare Tire (Valve StemPointed Down)
B. Hoist Assembly
C. Hoist Cable
D. Tire/Wheel Retainer
E. Hoist Shaft
F. Hoist End of Extension Tool
G. 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.
2. Assemble the wheel wrench (H)and the two jack handle
extensions (I), as shown.
3. Insert the hoist end (openend) (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. The ribbed square
end of the extension is used to
lower the spare tire.
4. 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.