
How to Check Lubricant Front Axle
If the level is below the bottom of the filler plug hole,
you’ll need to add some lubricant. Add enough lubricant
to raise the level
to the bottom of the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind
of lubricant to use. See “Recommended Fluids and
Lubricants” in
the Index.
When to Check and Change Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant and when to change it. See
“Scheduled Maintenance Services”
in the Index.
How to Check Lubricant
If the level is below the bottom of the filler plug hole,
you’ll need
to add some lubricant.
6-28
-
ProCarManuals.com

NOTICE:
Using the wrong fluid can badly damage
brake system parts.
For example, just a few
drops of mineral-based oil, such
as engine
oil, in your brake system can damage brake
system parts
so badly that they’ll have to be
replaced. Don’t let someone put in the
wrong kind of fluid.
If you spill brake fluid on your vehicle’s
painted surfaces, the paint finish can be
damaged. Be careful not to spill brake fluid
on your vehicle. If you do, wash
it off
immediately. See “Appearance Care” in
the Index.
Brake Wear
If you have a C 3500 HD model, it has four-wheel disc
brakes without wear indicators.
If you ever hear a brake
rubbing noise, have the brake linings inspected.
If your pickup is not a
C 3500 HD model, it has front
disc brakes and rear drum brakes. Disc brake pads
(except
C 3500 HD models) have
built-in wear indicators that make a high-pitched
warning sound when the brake pads are worn and new
pads
are needed. The sound may come and go or be
heard all the time your vehicle is moving (except when
you are pushing on
the brake pedal firmly).
The brake wear warning sound means that soon
your brakes won’t work well. That could lead to
an accident. When you hear the brake wear
warning sound, have your vehicle serviced.
NOTICE:
Continuing to drive with worn-out brake pads
could result in costly brake repair.
ProCarManuals.com

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.
-
A CAUTION:
Poorly maintained and improperly used tires
are dangerous.
0 Overloading your tires can cause
overheating
as a result of too much friction.
You could have an air-out and a serious
accident. See “Loading Your Vehicle” in
the Index.
CAUTION: (Continued)
0 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.
cut, punctured or broken by a sudden
impact
-- such as when you hit a pothole.
Keep tires at the recommended pressure.
0 Worn, old tires can cause accidents. If your
tread
is badly worn, or if your tires have
been damaged, replace them.
0 Overinflated tires are more likely to be
6-50
ProCarManuals.com

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 “When It’s Time for New Tires” and
“Wheel Replacement” later
in this section for more
information. If your vehicle has dual rear wheels, also
see “Dual Tire Operation” later in this section. 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 “Scheduled
Maintenance Services” in the Index for scheduled
rotation intervals.
I FRT FRT
I
If your vehicle has single rear wheels, always use one of
the correct rotation patterns shown here when rotating
your tires.
If your vehicle has front tires with different load ranges
or tread designs (such as all season vs. odoff road)
than
the rear tires, don’t rotate your tires front to rear.
6-52
ProCarManuals.com

Dual Tire Operation Buying New Tires
To find
out what kind and size of tires you need, look
at the CertificationEire label. When the vehicle is new, or whenever a wheel, wheel bolt
or wheel
nut is replaced, check the wheel nut torque after
100,
1,OOO and 6,000 miles (160, 1 600 and 10 OOO km)
of driving. For proper torque, see “Wheel Nut Torque” in
the Index.
The outer tire on a dual wheel setup generally wears faster
than
the inner tire. Your tires will wear more evenly and
last longer if you rotate the tires periodically.
If you’re
going to be doing a lot of driving on high-crown roads,
you can reduce tire wear by adding 5 psi (35 kPa) to the
tire pressure in the outer tires.
Be sure to return to the
recommended pressures when no longer driving under
those conditions. See “Changing a Flat Tire”
in the
Index for more information.
If you operate your vehicle with a tire that is badly
underinflated, the
tire can overheat. An overheated
tire
can lose air suddenly or catch fire. You or others
could be injured. Be sure all tires (including the
spare,
if any) are properly inflated.
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
“MS”
(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.
ProCarManuals.com

L
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.
Uniform Tire Quality Grading
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 -- A, B, C
The traction grades, from highest to lowest, are A, B, and
C, and they 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 braking (straightahead) traction tests and does not
include cornering (turning) traction.
ProCarManuals.com

Tires
To clean your tires, use a stiff brush with a tire cleaner.
NOTICE: ~~ -
When applying a tire dressing always take care to
wipe
off any overspray or splash from all painted
surfaces on the body or wheels
of the vehicle.
Petroleum-based products may damage the
paint finish.
Sheet Metal Damage
If your vehicle is damaged and requires sheet metal
repair or replacement, make sure the body repair shop
applies anti-corrosion material
to the parts repaired or
replaced to restore corrosion protection.
Finish Damage
Any stone chips, fractures or deep scratches in the finish
should be repaired right away. Bare metal will corrode
quickly and may develop into a major repair expense.
Minor chips and scratches can be repaired with touch-up
materials available from your dealer or other service
outlets. Larger areas
of finish damage can be corrected
in your dealer’s body and paint shop.
6-66
ProCarManuals.com

Vehicle Identification Number (VIN)
111 111 111111 II
SAMPLE4UXVM072675 IS1 I
ENGINEA7 f 1 ASSEMBLY
CODE MODEL YEAR PLANT
This is the legal identifier for your vehicle. It appears on
a plate in the front corner of the instrument panel, on the
driver’s side. You can see
it if you look through the
windshield from outside your vehicle. The VIN also
appears on the Vehicle Certification
and Service Parts
labels and the certificates
of title and registration.
Engine Identification
The 8th character in your VIN is the engine code. This
code will help you identify your engine, specifications
and replacement parts.
Service Parts Identification Label
You’ll find this label on the inside of the glove box. It’s
very helpful
if you ever need to order parts. On this
label is:
your VIN,
the model designation,
0 paint information and
a list of all production options and
special equipment.
Be sure that this label is not removed from the vehicle.
6-69
ProCarManuals.com