CHEVROLET EXPRESS 2007 Owners Manual

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.
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 a half (1.5) 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.
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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.
The grade C corresponds to a level of performance
which all passenger car tires must meet under the
Federal Motor Vehicle Safety Standard No. 109.
Grades B and A represent higher levels of
performance on the laboratory test wheel than the
minimum required by law. It should be noted that
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 on your vehicle were aligned and
balanced carefully at the factory to give you the longest
tire life and best overall performance. Adjustments to
wheel alignment and tire balancing will not be necessary
on a regular basis. However, if you notice unusual tire
wear or your vehicle pulling to one side or the other, the
alignment might need to be checked. If you notice your
vehicle vibrating when driving on a smooth road, the tires
and wheels might need to be rebalanced. See your
dealer/retailer 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 (except some aluminum
wheels, which can sometimes be repaired). See your
dealer/retailer if any of these conditions exist.
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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 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.
{WARNING:
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 Specications on page 6-116.
SeeChanging a Flat Tire on page 6-86for more
information.
Used Replacement Wheels
{WARNING:
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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Tire Chains
{WARNING:
If your vehicle has dual wheels or P245/70R17 or
LT245/75R16 size tires, do not use tire chains.
They can damage your 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 your 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 your
vehicle and tire size combination and road
conditions. Follow that manufacturer’s instructions.
WARNING: (Continued)
WARNING: (Continued)
To help avoid damage to your vehicle, drive
slowly, readjust, or remove the device if it is
contacting your 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 your vehicle does not have dual wheels
and has a tire size other than P245/70R17 or
LT245/75R16, use tire chains only where legal and
only when you must. Use chains that are the proper
size for your 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 your 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 your vehicle.
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If a Tire Goes Flat
It is unusual for a tire to blowout while you are driving,
especially if you maintain your vehicle’s tires properly.
If air goes out of a tire, it is much more likely to leak out
slowly. But if you should ever have 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 out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you would use
in a skid. In any rear blowout remove your foot from the
accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go. It may be
very bumpy and noisy, but you can still steer. Gently
brake to a stop, well off the road if 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, the next part shows how to use the
jacking equipment to change a flat tire safely.
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Changing a Flat Tire
If a tire goes flat, avoid further tire and wheel damage
by driving slowly to a level place. Turn on the hazard
warning flashers. SeeHazard Warning Flashers
on page 4-3.
{WARNING:
Changing a tire can be dangerous. The vehicle
can slip off the jack and roll over or fall on you or
other people. You and they could be badly injured
or even killed. Find a level place to change your
tire. To help prevent the vehicle from moving:
1. Set the parking brake firmly.
2. Put the shift lever in P (Park).
3. Turn off the engine and do not restart while
the vehicle is raised.
4. Do not allow passengers to remain in the
vehicle.
WARNING: (Continued)
WARNING: (Continued)
To be even more certain the vehicle will not move,
you should put blocks at the front and rear of the
tire farthest away from the one being changed.
That would be the tire, on the other side, at the
opposite end of the vehicle.
When the vehicle has a flat tire (B), use the following
example as a guide to assist you in the placement
of wheel blocks (A).
A. Wheel Block
B. Flat Tire
The following information explains how to use the jack
and change a tire.
6-86

Removing the Spare Tire and Tools
If you have a cargo van or a passenger van, the
equipment you will need is located in the passenger
side rear corner of the vehicle.
Remove the retaining wing bolt and lift it off of the
mounting bracket.
If you have a van with the 15-passenger seating
arrangement, the equipment you will need is secured
on the rear floor of the passenger side of the vehicle.To access the equipment, remove the retaining wing
bolt and lift it out of the mounting bracket.
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The tools you will be using include the jack (A),
jack handle (B), hoist extension (C), jack handle
extension (D), and the wheel wrench (E).
The spare tire is mounted in the rear underbody of the
vehicle.
You will use the hoist extension, the jack handle
extensions and the wheel wrench to remove the
underbody-mounted spare tire.To lower the spare tire from the vehicle:
A. Spare Tire
B. Tire/Wheel Retainer
C. Hoist Cable
D. Hoist AssemblyE. Hoist Shaft
F. Jack Handle and
Hoist Extensions
G. Wheel Wrench
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1. Assemble the wheel wrench (G) to one or two of
the jack handle extensions and the hoist extension.
Insert the hoist extension end through the hole
in the rear bumper.
2. Be sure the hoist extension end connects to the
hoist shaft (E). The chiseled end of the extension
is used to lower the spare tire.
3. 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.
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 6-97.4. When the tire has been lowered, pull the tire toward
you so you can reach the tire retainer and pull it up
through the wheel opening.
If you have a vehicle which was completed from
a cab and chassis, refer to the information
from body supplier/installer.
The spare tire is a full-size tire, like the other tires
on the vehicle.
5. Put the spare tire near the flat tire.
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Removing the Flat Tire and
Installing the Spare Tire
If your vehicle has plastic wheel nut caps, loosen
them by turning the wheel wrench counterclockwise.
The wheel nut caps are designed to remain with
the center cap. Remove the center cap.
If the wheel has a smooth center piece, place the chisel
end of the wheel wrench in the slot on the wheel and
gently pry it out.
1. Do a safety check before proceeding. SeeChanging
a Flat Tire on page 6-86for more information.
2. Loosen all the wheel nuts with the wheel wrench.
Do not remove them yet.3. Assemble the jack and tools:
Front Flat:Assemble the jack (A) together with the
jack handle (B), 1 or 2 jack handle extensions (D)
and the wheel wrench (E).
Rear Flat:Assemble the jack (A) together with the
jack handle (B), 2 jack handle extensions (D),
and the wheel wrench (E).
6-90