Page 345 of 419
6-42 Taillamps
A. Turn Signal Lamp
B. Back
-up Lamp
C. Stoplamp
1. Use a Phillips screwdriver
to remove the two screws
from the lamp assembly.2. Remove the lamp assembly.
3. Press the release tab and turn the bulb socket
counterclockwise to remove it from the
taillamp housing.
4. Pull the old bulb straight
out from the socket.
5. Press a new bulb into the socket, insert the socket
into the taillamp housing and turn the socket
clockwise into the taillamp housing until it clicks.
6. Reinstall the rear lamp assembly and tighten
the screws.
Page 346 of 419
6-43 Windshield Wiper Blade Replacement
Windshield wiper blades should be inspected at least
twice a year for wear and cracking. See ªWiper Blade
Checkº in the Index for more information.Replacement blades come in different types and are
removed in different ways. For proper type and length,
see ªNormal Maintenance Replacement Partsº in the
Index. Here's how to remove the Shepherd's Hook type.
To replace the windshield wiper blade assembly:
1. Lift the wiper arm and turn the blade until it is facing
away from the windshield.
2. Push the release lever and slide the wiper assembly
toward the driver's side of the vehicle.
3. Install a new blade by reversing Steps 1 and 2.
Page 347 of 419

6-44
Tires
Your new vehicle comes with high-quality tires made by
a leading tire manufacturer. If you ever have questions
about your tire warranty and where to obtain service,
see your GM Warranty booklet for details.
CAUTION:
Poorly maintained and improperly used tires
are dangerous.
Overloading your tires can cause
overheating as a result of too much friction.
You could have an air
-out and a serious
accident. See ªLoading Your Vehicleº in
the Index.
CAUTION: (Continued)
CAUTION: (Continued)
Underinflated tires pose the same danger
as overloaded tires. The resulting accident
could cause serious injury. Check all tires
frequently to maintain the recommended
pressure. Tire pressure should be checked
when your tires are cold.
Overinflated tires are more likely to be
cut, punctured or broken by a sudden
impact
-- such as when you hit a pothole.
Keep tires at the recommended pressure.
Worn, old tires can cause accidents.
If your tread is badly worn, or if your
tires have been damaged, replace them.
Page 348 of 419

6-45 Inflation -- Tire Pressure
The Certification/Tire label, which is on the rear edge of
the driver's door, shows the correct inflation pressures
for your tires when they're cold. ªColdº means your
vehicle has been sitting for at least three hours or driven
no more than 1 mile (1.6 km).
If you have an 8600 GVW truck (2500 series) with
LT245/75R16E tires, you can improve your ride
comfort by reducing tire inflation pressure, but only
when carrying reduced loads. If you have a maximum
of 8 passengers, and 200 lbs. (90 kg) of load, you can
set the front tires at 40 psi (280 kPa), and the rear
tires at 50 psi (350 kPa). When using the reduced tire
inflation pressure settings, don't exceed the following
loading conditions: GVWR ± 7900 lbs. (3583 kg),
GAWR FRONT ± 3730 lbs. (1692 kg), GAWR
REAR ± 4410 lbs. (2000 kg). When carrying loads
greater than 8 passengers and 200 lbs. (90 kg) and/or
when pulling a trailer, you must inflate your tires to the
pressure shown on the Certification/Tire label.NOTICE:
Don't let anyone tell you that underinflation or
overinflation is all right. It's not. If your tires
don't have enough air (underinflation), you can
get the following:
Too much flexing
Too much heat
Tire overloading
Bad wear
Bad handling
Bad fuel economy.
If your tires have too much air (overinflation),
you can get the following:
Unusual wear
Bad handling
Rough ride
Needless damage from road hazards.
Page 349 of 419

6-46
When to Check
Check your tires once a month or more.
Also, check the tire pressure of the spare tire.
How to Check
Use a good quality pocket
-type gage to check tire
pressure. You can't tell if your tires are properly inflated
simply by looking at them. Radial tires may look
properly inflated even when they're underinflated.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and moisture.
Tire Inspection and Rotation
Tires should be rotated every 6,000 to 8,000 miles
(10 000 to 13 000 km). Any time you notice unusual
wear, rotate your tires as soon as possible and check
wheel alignment. Also check for damaged tires or
wheels. See ªWhen It's Time for New Tiresº and
ªWheel Replacementº later in this section for more
information. Make sure the spare tire is stored securely.
Push, pull, and then try to rotate or turn the tire.
If it moves, use the ratchet/wheel wrench to tighten
the cable. See ªStoring a Flat or Spare Tire and Toolsº
in the Index.The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The first
rotation is the most important. See ªScheduled
Maintenance Servicesº in the Index for scheduled
rotation intervals.
When rotating your tires, always use one of the correct
rotation patterns shown here.
After the tires have been rotated, adjust the front and
rear inflation pressures as shown on the Certification/Tire
label. Make certain that all wheel nuts are properly
tightened. See ªWheel Nut Torqueº in the Index.
Page 350 of 419

6-47
CAUTION:
Rust or dirt on a wheel, or on the parts to which
it is fastened, can make wheel nuts become loose
after a time. The wheel could come off and cause
an accident. When you change a wheel, remove
any rust or dirt from places where the wheel
attaches to the vehicle. In an emergency,
you can use a cloth or a paper towel to do this;
but be sure to use a scraper or wire brush later,
if you need to, to get all the rust or dirt off.
See ªChanging a Flat Tireº in the Index.
When It's Time for New Tires
One way to tell when it's
time for new tires is to
check the treadwear
indicators, which will
appear when your tires have
only 1/16 inch (1.6 mm) or
less of tread remaining.
You need a new tire if any of the following statements
are true:
You can see the indicators at three or more places
around the tire.
You can see cord or fabric showing through the
tire's rubber.
The tread or sidewall is cracked, cut or snagged deep
enough to show cord or fabric.
The tire has a bump, bulge or split.
The tire has a puncture, cut or other damage that
can't be repaired well because of the size or location
of the damage.
Page 351 of 419

6-48 Buying New Tires
To find out what kind and size of tires you need,
look at the Certification/Tire label.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specification (TPC Spec)
number on each tire's sidewall. When you get new tires,
get ones with that same TPC Spec number. That way
your vehicle will continue to have tires that are designed
to give proper endurance, handling, speed rating,
traction, ride and other things during normal service
on your vehicle. If your tires have an all
-season tread
design, the TPC number will be followed by an
ªMSº (for mud and snow).
If you ever replace your tires with those not having a
TPC Spec number, make sure they are the same size,
load range, speed rating and construction type
(bias, bias
-belted or radial) as your original tires.
CAUTION:
Mixing tires could cause you to lose control while
driving. If you mix tires of different sizes or types
(radial and bias
-belted tires), the vehicle may
not handle properly, and you could have a crash.
Using tires of different sizes may also cause
damage to your vehicle. Be sure to use the same
size and type tires on all wheels.
CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim flanges could develop cracks after
many miles of driving. A tire and/or wheel could
fail suddenly, causing a crash. Use only radial
-ply
tires with the wheels on your vehicle.
Page 352 of 419

6-49 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, 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
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 1/2) 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.