2002 CHEVROLET C3500 HD maintenance schedule

4-30
Towing a Trailer
CAUTION:
If you don't use the correct equipment and drive
properly, you can lose control when you pull a
trailer. For example, if the trailer is too heavy,
the brakes may not work well
-- or even at all.
You and your passengers could be seriously
injured. Pull a trailer only if you have followed
all the steps in this section. Ask your dealer for
advice and information about towing a trailer
with your vehicle.
NOTICE:
Pulling a trailer improperly can damage your
vehicle and result in costly repairs not covered
by your warranty.
NOTICE: (Continued)
NOTICE: (Continued)
To pull a trailer correctly, follow the advice in
this part, and see your dealer for important
information about towing a trailer with your
vehicle. Additional rear axle maintenance is
required for a vehicle used to tow a trailer.
See ªScheduled Maintenance Servicesº in
the Index.
To identify what the vehicle trailering capacity is for
your vehicle, you should read the information in
ªWeight of the Trailerº that appears later in this section.
Trailering is different than just driving your vehicle by
itself. Trailering means changes in handling, durability
and fuel economy. Successful, safe trailering takes
correct equipment, and it has to be used properly.
That's the reason for this part. In it are many
time
-tested, important trailering tips and safety rules.
Many of these are important for your safety and that
of your passengers. So please read this section carefully
before you pull a trailer.

4-37 When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:

start your engine,

shift into a gear, and

release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for
more on this. Things that are especially important
in trailer operation are automatic transmission fluid
(don't overfill), engine oil, axle lubricant, belts, cooling
system and brake system. Each of these is covered in
this manual, and the Index will help you find them
quickly. If you're trailering, it's a good idea to review
these sections before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
Power Winches
If you wish to use a power winch on your vehicle,
only use it when your vehicle is stationary or anchored.
NOTICE:
Using a power winch with the transmission in gear
may damage the transmission. When operating
a power winch, always leave the transmission
in NEUTRAL (N).
Use the regular brakes, set the parking brake, or block
the wheels to keep your vehicle from rolling.

6-10
Noise Control System
The following information relates to compliance with
federal noise emission standards for vehicles with a Gross
Vehicle Weight Rating (GVWR) of more than 10,000 lbs.
(4 536 kg). The Maintenance Schedule provides
information on maintaining the noise control system
to minimize degradation of the noise emission control
system during the life of your vehicle. The noise control
system warranty is given in your warranty booklet.
These standards apply only to vehicles sold in the
United States.
Tampering With Noise Control
System Prohibited
Federal law prohibits the following acts or the
causing thereof:
1. The removal or rendering inoperative by any person,
other than for purposes of maintenance, repair or
replacement, of any device or element of design
incorporated into any new vehicle for the purpose
of noise control, prior to its sale or delivery to
the ultimate purchaser or while it is in use; or
2. The use of the vehicle after such device or element
of design has been removed or rendered inoperative
by any person.Among those acts presumed to constitute tampering are
the acts listed below.
Insulation:

Removal of the noise shields or any
underhood insulation.
Engine:

Removal or rendering engine speed governor
(if equipped) inoperative so as to allow engine
speed to exceed manufacturer specifications.
Fan and Drive:

Removal of fan clutch (if equipped) or rendering
clutch inoperative.

Removal of the fan shroud (if equipped).
Air Intake:

Removal of the air cleaner silencer.

Modification of the air cleaner.
Exhaust:

Removal of the muffler and/or resonator.

Removal of the exhaust pipes and exhaust pipe clamps.

6-14 Engine Oil Additives
Don't add anything to your oil. The recommended oils
with the starburst symbol are all you will need for good
performance and engine protection.
When to Change Engine Oil
If any one of these is true for you, use the short trip/city
maintenance schedule:

Most trips are less than 5 miles (8 km). This is
particularly important when outside temperatures are
below freezing.

Most trips include extensive idling (such as frequent
driving in stop
-and-go traffic).

You frequently tow a trailer.

The vehicle is used for delivery service, police, taxi
or other commercial application.
Driving under these conditions causes engine oil to
break down sooner. If any one of these is true for your
vehicle, then you need to change your oil and filter
every 3,000 miles (5 000 km) or 3 months
-- whichever
occurs first.If none of them is true, use the long trip/highway
maintenance schedule. Change the oil and filter every
7,500 miles (12 500 km) or 12 months
-- whichever
occurs first. Driving a vehicle with a fully warmed
engine under highway conditions will cause engine oil
to break down slower.
What to Do with Used Oil
Used engine oil contains certain elements that may be
unhealthy for your skin and could even cause cancer.
Don't let used oil stay on your skin for very long.
Clean your skin and nails with soap and water, or a good
hand cleaner. Wash or properly throw away clothing or
rags containing used engine oil. See the manufacturer's
warnings about the use and disposal of oil products.
Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil from
the filter before disposal. Never dispose of oil by putting
it in the trash, pouring it on the ground, into sewers, or
into streams or bodies of water. Instead, recycle it by
taking it to a place that collects used oil. If you have a
problem properly disposing of your used oil, ask your
dealer, a service station or a local recycling center
for help.

6-17
Refer to the Maintenance Schedule to determine when to
replace the engine air cleaner/filter. See ªOwner Checks
and Servicesº in the Index.
CAUTION:
Operating the engine with the air cleaner/filter
off can cause you or others to be burned. The air
cleaner not only cleans the air, it stops flame if
the engine backfires. If it isn't there, and the
engine backfires, you could be burned. Don't
drive with it off, and be careful working on the
engine with the air cleaner/filter off.
NOTICE:
If the air cleaner/filter is off, a backfire can
cause a damaging engine fire. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/filter in place when
you're driving.
Automatic Transmission Fluid
If your vehicle has a diesel engine, see ªAutomatic
Transmission Fluidº in the Diesel Supplement.
When to Check and Change
A good time to check your automatic transmission
fluid level is when the engine oil is changed.
Change both the fluid and filter every
50,000 miles (83 000 km).
See ªScheduled Maintenance Servicesº in the Index.
How to Check
Because this operation can be a little difficult,
you may choose to have this done at the dealership
service department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false reading
on the dipstick.

6-20 How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission fluid to use. See ªRecommended
Fluids and Lubricantsº in the Index.
Add fluid only after checking the transmission fluid
while it is hot. (A cold check is used only as a
reference.) If the fluid level is low, add only enough of
the proper fluid to bring the level up to the HOT area'
for a hot check. It doesn't take much fluid, generally
less than one pint (0.5 L). Don't overfill.
NOTICE:
We recommend you use only fluid labeled
DEXRON-III, because fluid with that label is
made especially for your automatic transmission.
Damage caused by fluid other than DEXRON
-III
is not covered by your new vehicle warranty.

After adding fluid, recheck the fluid level as
described under ªHow to Check.º

When the correct fluid level is obtained, push the
dipstick back in all the way; then flip the handle
down to lock the dipstick in place.
Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine
oil is changed. However, the fluid in your manual
transmission doesn't require changing.
How to Check
Because this operation can be a little difficult, you
may choose to have this done at your GM dealership
service department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false reading.
NOTICE:
Too much or too little fluid can damage your
transmission. Too much can mean that some of
the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire.
Too little fluid could cause the transmission to
overheat. Be sure to get an accurate reading if
you check your transmission fluid.

6-21
Check the fluid level only when your engine is off, the
vehicle is parked on a level place and the transmission
is cool enough for you to rest your fingers on the
transmission case.
Then, follow these steps:1. Remove the filler plug.
2. Check that the lubricant level is up to the bottom of
the filler plug hole.
3. If the fluid level is good, install the plug and be sure
it is fully seated. If the fluid level is low, add more
fluid as described in the next steps.
How to Add Fluid
Here's how to add fluid. Refer to the Maintenance
Schedule to determine what kind of fluid to use.
See ªRecommended Fluids and Lubricantsº in
the Index.
1. Remove the filler plug.
2. Add fluid at the filler plug hole. Add only enough
fluid to bring the fluid level up to the bottom of the
filler plug hole.
3. Install the filler plug. Be sure the plug is fully seated.

6-22
Hydraulic Clutch
The hydraulic clutch linkage in your vehicle is
self
-adjusting. The clutch master cylinder reservoir
is filled with hydraulic clutch fluid.
It is not necessary to regularly check clutch fluid unless
you suspect there is a leak in the system. Adding fluid
won't correct a leak.
A fluid loss in this system could indicate a problem.
Have the system inspected and repaired.
When to Check and What to Use
Refer to the Maintenance
Schedule to determine how
often you should check the
fluid level in your clutch
master cylinder reservoir
and for the proper fluid.
See ªOwner Checks
and Servicesº and
ªRecommended Fluids and
Lubricantsº in the Index.
How to Check and Add Fluid
The proper fluid should be added if the level does not
reach the bottom of the diaphragm when it's in place in
the reservoir. See the instructions on the reservoir cap.
See ªEngine Compartment Overviewº in the Index
for information on location.