height CHEVROLET SUBURBAN 2009 User Guide

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.
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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. SeeOff-Road Driving on
page 4-13, for additional information.
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
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(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 5-70andLoading the Vehicle on page 4-33.
(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
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(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 5-70andLoading the Vehicle on page 4-33.
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.(B) Tire Width
:The three-digit number indicates
the tire section width in millimeters from sidewall
to sidewall.
(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 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
:These characters
represent the load index and speed rating of the
tire. The load index represents the load carry
capacity a tire is certied to carry. The speed
rating is the maximum speed a tire is certied to
carry a load.
Passenger (P-Metric) Tire
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(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.
(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) Load Range
:Load Range.
(G) Service Description
:The service description
indicates the load index and speed rating of a
tire. If two numbers are given as in the example,
120/116, then this represents the load index
for single versus dual wheel usage (single/dual).
The speed rating is the maximum speed a
tire is certied to carry a load.
Light Truck (LT-Metric) Tire
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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.Cold Tire Pressure
:The amount of air pressure
in a tire, measured in pounds per square inch
(psi) or kilopascals (kPa) before a tire has built up
heat from driving. SeeInflation - Tire Pressure
on page 5-70.
Curb Weight
:The weight of a motor vehicle with
standard and optional equipment including the
maximum capacity of fuel, oil, and coolant,
but without passengers and cargo.
DOT Markings
:A code molded into the sidewall
of a tire signifying that the tire is in compliance
with the U.S. Department of Transportation (DOT)
motor vehicle safety standards. The DOT code
includes the Tire Identication Number (TIN),
an alphanumeric designator which can also identify
the tire manufacturer, production plant, brand,
and date of production.
GVWR
:Gross Vehicle Weight Rating. See
Loading the Vehicle on page 4-33.
GAWR FRT
:Gross Axle Weight Rating for the
front axle. SeeLoading the Vehicle on page 4-33.
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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 your 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 your 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.
SeeChanging a Flat Tire on page 5-86for more
information.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on the vehicle is dangerous.
You cannot know how it has been used or how far
it has been driven. It could fail suddenly and
cause a crash. If you have to replace a wheel, use
a new GM original equipment wheel.
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