warning GMC SIERRA DENALI 2018 Owners Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 405
Tire Rotation Tires should be rotated every
12 000 km (7,500 mi). See
Maintenance Schedule 0 448 .
Tires are rotated to achieve a
uniform wear for all tires. The
first rotation is the most
important.
Anytime unusual wear is
noticed, rotate the tires as soon
as possible, check for proper tire
inflation pressure, and check for
damaged tires or wheels. If the
unusual wear continues after the
rotation, check the wheel
alignment. See When It Is Time
for New Tires 0 407 and Wheel
Replacement 0 412 . Use this rotation pattern when
rotating the tires if the vehicle
has single rear wheels. Dual Tire Rotation
When the vehicle is new,
or whenever a wheel, wheel
bolt, or wheel nut is replaced or
serviced, 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 and wheel nut tightening
information, see “ Removing the
Flat Tire and Installing the Spare
Tire ” under Tire Changing 0 415 and “ Wheel Nut Torque ” under
Capacities and Specifications
0 461 .
The outer tire on a dual wheel
setup generally wears faster
than the inner tire. Tires last
longer and wear more evenly if
they are rotated. See Tire
Inspection 0 404 and Tire
Rotation 0 405 . Also see
Maintenance Schedule 0 448 .
{ WarningIf the vehicle is operated with a
tire that is underinflated, the tire
can overheat. An overheated tire
can lose air suddenly or catch
fire. You or others could be
injured. Properly inflate all tires,
including the spare.
See Tire Pressure 0 397 , for
information on proper tire
inflation.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
406 Vehicle Care
Use this rotation pattern when
rotating the tires if the vehicle
has dual rear wheels (except
polished forged aluminum
wheels).
Vehicles with polished forged
aluminum dual wheels have
three unique wheels; a front, a
rear outer and a rear inner.
These wheels cannot be rotated
to another position, however,
they can be rotated from left to
right to the same position. Use this rotation pattern when
rotating the tires if the vehicle
has polished forged aluminum
dual rear wheels. The spare
wheel can be used in any
position in the event of a flat tire,
and can be rotated with the rear
inner wheels. After the flat tire is
repaired, if the spare is not on
one of the inner rear positions, it
must be replaced by the correct
wheel in the front or rear outer
positions. When installing dual wheels,
check that the vent holes in the
inner and outer wheels on each
side are lined up.
Adjust the front and rear tires to
the recommended inflation
pressure on the Tire and
Loading Information label after
the tires have been rotated.
See Tire Pressure 0 397 and
Vehicle Load Limits 0 248 .
Check that all wheel nuts are
properly tightened. See “ Wheel
Nut Torque ” under Capacities
and Specifications 0 461 .
{ Warning
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
changing a wheel, remove any
rust or dirt from places where the
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 407Warning (Continued)wheel attaches to the vehicle. In
an emergency, a cloth or a paper
towel can be used; however, use
a scraper or wire brush later to
remove all rust or dirt.
Lightly coat the inner diameter of
the wheel hub opening with
wheel bearing grease after a
wheel change or tire rotation to
prevent corrosion or rust
build-up. Do not get grease on
the flat wheel mounting surface
or on the wheel nuts or bolts.
Reset the Tire Pressure Monitor
System (TPMS), if the vehicle
has one. See Tire Pressure
Monitor Operation 0 400 .
Check that the spare tire, if the
vehicle has one, is stored
properly. Push, pull, and then try
to rotate or turn the tire. If it
moves, tighten the cable. See “ Storing a Flat or Spare Tire and
Tools ” under Tire Changing
0 415 .
When It Is Time for New
Tires Factors, such as maintenance,
temperatures, driving speeds,
vehicle loading, and road conditions
affect the wear rate of the tires. Treadwear indicators are one way to
tell when it is time for new tires.
Treadwear indicators appear when
the tires have only 1.6 mm (1/16 in)
or less of tread remaining. Some
commercial truck tires may not have
treadwear indicators. See Tire
Inspection 0 404 and Tire Rotation
0 405 for additional information.
The rubber in tires ages over time.
This also applies to the spare tire,
if the vehicle has one, even if it is
never used. Multiple factors
including temperatures, loading
conditions, and inflation pressure
maintenance affect how fast aging
takes place. GM recommends that
tires, including the spare if
equipped, be replaced after six
years, regardless of tread wear. The
tire manufacture date is the last four
digits of the DOT Tire Identification
Number (TIN) which is molded into
one side of the tire sidewall. The
first two digits represent the week
(01-52) and the last two digits, the
year. For example, the third week of
the year 2010 would have a
four-digit DOT date of 0310.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
408 Vehicle Care Vehicle Storage Tires age when stored normally
mounted on a parked vehicle. Park
a vehicle that will be stored for at
least a month in a cool, dry, clean
area away from direct sunlight to
slow aging. This area should be free
of grease, gasoline, or other
substances that can deteriorate
rubber.
Parking for an extended period can
cause flat spots on the tires that
may result in vibrations while
driving. When storing a vehicle for
at least a month, remove the tires or
raise the vehicle to reduce the
weight from the tires.
Buying New Tires GM has developed and matched
specific tires for the vehicle. The
original equipment tires installed
were designed to meet General
Motors Tire Performance Criteria
Specification (TPC Spec)
system rating. When
replacement tires are needed, GM strongly recommends
buying tires with the same TPC
Spec rating.
GM's exclusive TPC Spec
system considers over a dozen
critical specifications that impact
the overall performance of the
vehicle, including brake system
performance, ride and handling,
traction control, and tire
pressure monitoring
performance. GM's TPC Spec
number is molded onto the tire's
sidewall near the tire size. If the
tires have an all-season tread
design, the TPC Spec number
will be followed by MS for mud
and snow. See Tire Sidewall
Labeling 0 391 for additional
information.
GM recommends replacing worn
tires in complete sets of four (six
for dual rear wheels). Uniform
tread depth on all tires will help
to maintain the performance of
the vehicle. Braking and handling performance may be
adversely affected if all the tires
are not replaced at the same
time. If proper rotation and
maintenance have been done,
all four tires (six for dual rear
wheels) should wear out at
about the same time. See Tire
Rotation 0 405 for information
on proper tire rotation. However,
if it is necessary to replace only
one axle set of worn tires, place
the new tires on the rear axle
(two for single rear wheels, four
for dual rear wheels).
{ Warning
Tires could explode during
improper service. Attempting
to mount or dismount a tire
could cause injury or death.
Only your dealer or authorized
tire service center should
mount or dismount the tires.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 409
{ Warning
Mixing tires of different sizes,
brands, or types may cause
loss of control of the vehicle,
resulting in a crash or other
vehicle damage. Use the
correct size, brand, and type
of tires on all wheels.
This vehicle may have a
different size spare than the
road tires originally installed
on the vehicle. When new, the
vehicle included a spare tire
and wheel assembly with a
similar overall diameter as the
road tires and wheels, so it is
all right to drive on it. The
spare tire was developed for
use on this vehicle and will not
affect vehicle handling. { Warning
Using bias-ply tires on the
vehicle may cause the wheel
rim flanges to develop cracks
after many miles of driving.
A tire and/or wheel could fail
suddenly and cause a crash.
Use only radial-ply tires with
the wheels on the vehicle.
Winter tires with the same speed
rating as the original equipment
tires may not be available for H,
V, W, Y and ZR speed rated
tires. Never exceed the winter
tires ’ maximum speed capability
when using winter tires with a
lower speed rating.
If the vehicle tires must be
replaced with a tire that does not
have a TPC Spec number, make
sure they are the same size,
load range, speed rating, and
construction (radial) as the
original tires. Vehicles that have a tire
pressure monitoring system
could give an inaccurate
low-pressure warning if non-TPC
Spec rated tires are installed.
See Tire Pressure Monitor
System 0 399 .
The Tire and Loading
Information label indicates the
original equipment tires on the
vehicle. See Vehicle Load Limits
0 248 for the label location and
more information about the Tire
and Loading Information label.
Different Size Tires and
Wheels If wheels or tires are installed that
are a different size than the original
equipment wheels and tires, vehicle
performance, including its braking,
ride and handling characteristics,
stability, and resistance to rollover
may be affected. If the vehicle has
electronic systems such as antilock
brakes, rollover airbags, traction
control, electronic stability control,

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
410 Vehicle Care or All-Wheel Drive, the performance
of these systems can also be
affected.
{ WarningIf different sized wheels are used,
there may not be an acceptable
level of performance and safety if
tires not recommended for those
wheels are selected. This
increases the chance of a crash
and serious injury. Only use GM
specific wheel and tire systems
developed for the vehicle, and
have them properly installed by a
GM certified technician.
See Buying New Tires 0 408 and
Accessories and Modifications
0 343 .
Uniform Tire Quality
Grading 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 tires,
compact 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. 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
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 tire
graded 150 would wear one and
one-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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 411norm due to variations in driving
habits, service practices and
differences in road
characteristics and climate.
Traction
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
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. 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
are not necessary on a regular
basis. Consider an alignment check
if there is unusual tire wear or the
vehicle is significantly pulling to one
side or the other. Some slight pull to
the left or right, depending on the
crown of the road and/or other road
surface variations such as troughs
or ruts, is normal. If the vehicle is
vibrating when driving on a smooth
road, the tires and wheels may need
to be rebalanced. See your dealer
for proper diagnosis.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
412 Vehicle Care
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. { WarningUsing 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.
CautionThe 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
0 461 .
See If a Tire Goes Flat 0 413 for
more information.
Used Replacement Wheels
{ WarningReplacing 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 413
Tire Chains
{ WarningIf the vehicle has dual wheels or
265/65R18, P265/65R18,
P275/55R20, LT265/70R17,
LT265/70R18, LT265/60R20,
LT275/65R18, P285/50R20,
285/45R22, or P285/45R22 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.
Use another type of traction
device only if its manufacturer
recommends it for use on the
vehicle and tire size combination
(Continued) Warning (Continued) 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.
CautionIf the vehicle does not have dual
wheels and has a tire size other
than 265/65R18, P265/65R18,
P275/55R20, LT265/70R17,
LT265/70R18, LT265/60R20,
LT275/65R18, P285/50R20,
285/45R22, or P285/45R22, use
tire chains only where legal and
only when you must. Use chains
that are the proper size for the
(Continued) Caution (Continued) 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.
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:

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
414 Vehicle Care 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
(Continued) Warning (Continued) 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.
{ WarningLifting 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. Turn on the hazard
warning flashers. See Hazard
Warning Flashers 0 180 .
{ WarningChanging 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).
(Continued)