width CHEVROLET SILVERADO 2009 2.G Owners Manual

Q:What is wrong with this?
A:The belt is twisted across the body.
{CAUTION:
You can be seriously injured by a twisted belt. In a
crash, you would not have the full width of the belt
to spread impact forces. If a belt is twisted, make
it straight so it can work properly, or ask your
dealer/retailer to x it.
1-29

Driving Across an Incline
An off-road trail will probably go across the incline of a
hill. To decide whether to try to drive across the
incline, consider the following:
{CAUTION:
Driving across an incline that is too steep will
make your vehicle roll over. You could be
seriously injured or killed. If you have any doubt
about the steepness of the incline, do not drive
across it. Find another route instead.
A hill that can be driven straight up or down
might be too steep to drive across. When going
straight up or down a hill, the length of the wheel
base — the distance from the front wheels to
the rear wheels — reduces the likelihood the vehicle
will tumble end over end. But when driving across
an incline, the narrower track width — the distance
between the left and right wheels — might not
prevent the vehicle from tilting and rolling over.
Driving across an incline puts more weight on the
downhill wheels which could cause a downhill
slide or a rollover.
Surface conditions can be a problem. Loose
gravel, muddy spots, or even wet grass can cause
the tires to slip sideways, downhill. If the vehicle
slips sideways, it can hit something that will trip
it —a rock, a rut, etc. — and roll over.
Hidden obstacles can make the steepness of the
incline even worse. If you drive across a rock with the
uphill wheels, or if the downhill wheels drop into a rut
or depression, the vehicle can tilt even more.
For these reasons, carefully consider whether to try to
drive across an incline. Just because the trail goes
across the incline does not mean you have to drive it.
The last vehicle to try it might have rolled over.
If you feel the vehicle starting to slide sideways, turn
downhill. This should help straighten out the vehicle and
prevent the side slipping. The best way to prevent
this is to “walk the course” rst, so you know what the
surface is like before driving it.
4-22

Two-Tiered Loading
Depending on the model of your pick-up, you can
create an upper load platform by positioning
two or four 2 inches (5 cm) by 6 inches (15 cm)
wooden planks across the width of the pickup box.
The planks must be inserted in the pickup box
depressions. The length of the planks must allow
for at least a 3/4 inch (2 cm) bearing surface
on each end of the plank.
When using this upper load platform, be sure the
load is securely tied down to prevent it from
shifting. The load’s center of gravity should be
positioned in a zone over the rear axle. The zone
is located in the area between the front of each
wheel well and the rear of each wheel well.
The center of gravity height must not extend above
the top of the pickup box areboard.
Any load that extends beyond the vehicle’s
taillamp area must be properly marked according
to local laws and regulations.
Remember not to exceed the Gross Axle Weight
Rating (GAWR) of the front or rear axle.Add-On Equipment
When you carry removable items, you may need
to put a limit on how many people you carry
inside your vehicle. Be sure to weigh your vehicle
before you buy and install the new equipment.
Notice
:Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
Remember not to exceed the Gross Axle Weight
Rating (GAWR) of the front or rear axle.
* Equipment Maximum Weight
Ladder Rack and
Cargo750 lbs (340 kg)
Cross Toolbox and
Cargo400 lbs (181 kg)
Side Boxes and Cargo 250 lbs per side
(113 kg per side)
* The combined weight for all rail-mounted
equipment should not exceed 1,000 lbs (454 kg).
4-38

4. At a wall measure from the ground upward (A) to
the recorded distance from Step 3 and mark it.
5. Draw or tape a horizontal line (B) on the wall or at
surface the width of the vehicle at the height of the
mark in Step 4.
Notice:Do not cover a headlamp to improve beam
cut-off when aiming. Covering a headlamp may
cause excessive heat build-up which may cause
damage to the headlamp.
6. Turn on the low-beam headlamps and place a
piece of cardboard or equivalent in front of the
headlamp not being adjusted. This allows only the
beam of light from the headlamp being adjusted
to be seen on the at surface.7. Locate the vertical headlamp aiming screws, which
are under the hood near each headlamp assembly.
The adjustment screw can be turned with a
E8 Torx
®socket.
8. Turn the vertical aiming screw until the headlamp
beam is aimed to the horizontal tape line. Turn it
clockwise or counterclockwise to raise or lower the
angle of the beam.
5-57

20-Inch Tires
If your vehicle has the optional 20-inch
P275/55R20 size tires, they are classied as
touring tires and are designed for on road use. The
low-prole, wide tread design is not recommended
for “off-road” driving or commercial uses such
as snow plowing. SeeOff-Road Driving on
page 4-12andAdding a Snow Plow or Similar
Equipment on page 4-39for additional information.
Notice:If the vehicle has low-prole tires,
they are more susceptible to damage from road
hazards or curb impact than standard prole
tires. Tire and/or wheel assembly damage
can occur when coming into contact with road
hazards like, potholes, or sharp edged
objects, or when sliding into a curb. The
vehicle warranty does not cover this type of
damage. Keep tires set to the correct ination
pressure and, when possible avoid contact
with curbs, potholes, and other road hazards.
Tire Sidewall Labeling
Useful information about a tire is molded into the
sidewall. The following illustrations are examples
of a typical P-Metric and a LT-Metric tire sidewall.
(A) Tire Size
:The tire size code is a combination
of letters and numbers used to dene a particular
tire’s width, height, aspect ratio, construction
type, and service description. See the “Tire Size”
illustration later in this section for more detail.
Passenger (P-Metric) Tire
5-66

(A) Tire Size:The tire size code is a combination
of letters and numbers used to dene a particular
tire’s width, height, aspect ratio, construction
type, and service description. See the “Tire Size”
illustration later in this section for more detail.(B) TPC Spec (Tire Performance Criteria
Specication)
:Original equipment tires designed
to GM’s specic tire performance criteria have
a TPC specication code molded onto the sidewall.
GM’s TPC specications meet or exceed all
federal safety guidelines.
(C) Dual Tire Maximum Load
:Maximum load
that can be carried and the maximum pressure
needed to support that load when used in a dual
conguration. For information on recommended
tire pressure seeInflation - Tire Pressure on
page 5-73andLoading the Vehicle on page 4-32.
(D) DOT (Department of Transportation)
:The Department of Transportation (DOT) code
indicates that the tire is in compliance with the
U.S. Department of Transportation Motor Vehicle
Safety Standards.
(E) Tire Identication Number (TIN)
:The letters
and numbers following DOT code are the Tire
Identication Number (TIN). The TIN shows
the manufacturer and plant code, tire size, and
date the tire was manufactured. The TIN is molded
onto both sides of the tire, although only one
side may have the date of manufacture.
Light Truck (LT-Metric) Tire
5-68

(F) Tire Ply Material:The type of cord and
number of plies in the sidewall and under the
tread.
(G) Single Tire Maximum Load
:Maximum load
that can be carried and the maximum pressure
needed to support that load when used as a
single. For information on recommended
tire pressure seeInflation - Tire Pressure on
page 5-73andLoading the Vehicle on page 4-32.
Tire Size
The following examples show the different parts of
a tire size.(A) Passenger (P-Metric) Tire
:The United States
version of a metric tire sizing system. The letter P
as the rst character in the tire size means a
passenger vehicle tire engineered to standards
set by the U.S. Tire and Rim Association.
(A) Light Truck (LT-Metric) Tire
:The
United States version of a metric tire sizing
system. The letters LT as the rst two characters
in the tire size means a light truck tire engineered
to standards set by the U.S. Tire and Rim
Association.
(B) Tire Width
:The three-digit number indicates
the tire section width in millimeters from sidewall
to sidewall.Passenger (P-Metric) Tire
Light Truck (LT-Metric) Tire
5-69

(C) Aspect Ratio:A two-digit number that
indicates the tire height-to-width measurements.
For example, if the tire size aspect ratio is 75, as
shown in item C of the light truck (LT-Metric) tire
illustration, it would mean that the tire’s sidewall is
75 percent as high as it is wide.
(D) Construction Code
:A letter code is used to
indicate the type of ply construction in the tire. The
letter R means radial ply construction; the letter D
means diagonal or bias ply construction; and the
letter B means belted-bias ply construction.
(E) Rim Diameter
:Diameter of the wheel in
inches.
(F) Service Description
:The service description
indicates the load range and speed rating of a
tire. The load index represents the load carry
capacity a tire is certied to carry. The load index
can range from 1 to 279. The speed rating is
the maximum speed a tire is certied to carry a
load. Speed ratings range from A to Z.
Tire Terminology and Denitions
Air Pressure:The amount of air inside the
tire pressing outward on each square inch of the
tire. Air pressure is expressed in pounds per
square inch (psi) or kilopascal (kPa).
Accessory Weight
:This means the combined
weight of optional accessories. Some examples of
optional accessories are, automatic transmission,
power steering, power brakes, power windows,
power seats, and air conditioning.
Aspect Ratio
:The relationship of a tire’s height
to its width.
Belt
:A rubber coated layer of cords that is
located between the plies and the tread. Cords
may be made from steel or other reinforcing
materials.
Bead
:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.
Bias Ply Tire
:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread.
5-70

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

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/retailer if any of these conditions exist.
Your dealer/retailer 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 the wheels, wheel bolts,
wheel nuts or Tire Pressure Monitor System (TPMS)
sensors, replace them only with new GM original
equipment parts. This way, you will be sure to have the
right wheel, wheel bolts, wheel nuts, and TPMS sensors
for the 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.
Whenever a wheel, wheel bolt or wheel nut is replaced
on a dual wheel setup, check the wheel nut torque after
100, 1,000 and 6,000 miles (160, 1 600 and 10 000 km)
of driving. For proper torque, see “Wheel Nut Torque”
underCapacities and Specifications on page 5-130.
SeeChanging a Flat Tire on page 5-93for more
information.
5-89