Page 270 of 414

How to Add Automatic
Transmission Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission fluid to use. SeeRecommended
Fluids and Lubricants on page 6-13.
Using a funnel, add fluid down the transmission dipstick
tube 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 does not take much fluid, generally less
than one pint (0.5 L). Do not overfill.
Notice:Use of the incorrect automatic transmission
uid may damage your vehicle, and the damages
may not be covered by your warranty. Always
use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-13.
•After adding fluid, recheck the fluid level as
described under “How to Check Automatic
Transmission Fluid,” earlier in this section.
•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.
Engine Coolant
If your vehicle has the DURAMAX®Diesel engine, see
the DURAMAX®Diesel manual for more information.
The cooling system in your vehicle is filled with
DEX-COOL
®engine coolant. This coolant is designed
to remain in your vehicle for five years or 150,000 miles
(240 000 km), whichever occurs first, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating on
page 5-27.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
•Give freezing protection down to−34°F (−37°C).
•Give boiling protection up to 265°F (129°C).
•Protect against rust and corrosion.
•Help keep the proper engine temperature.
•Let the warning lights and gages work as they
should.
5-24
Page 283 of 414

Brakes
Brake Fluid
The brake master cylinder
reservoir is filled with
DOT-3 brake fluid. See
Engine Compartment
Overview on page 5-14for
the location of the
reservoir.
There are only two reasons why the brake fluid level in
the reservoir might go down. The first is that the
brake fluid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
the fluid level goes back up. The other reason is
that fluid is leaking out of the brake hydraulic system.
If it is, you should have the brake hydraulic system fixed,
since a leak means that sooner or later the brakes
will not work well.It is not a good idea to top off the brake fluid. Adding
brake fluid will not correct a leak. If fluid is added when
the linings are worn, there will be too much fluid
when new brake linings are installed. Add or remove
brake fluid, as necessary, only when work is done on the
brake hydraulic system.
{CAUTION:
If you have too much brake uid, it can spill on
the engine and/or fuel operated heater parts, if
equipped. If your vehicle has a diesel engine
and a fuel operated heater, see “Fuel Operated
Heater (FOH)” in the diesel engine supplement.
The uid will burn if the engine is hot enough.
You or others could be burned, and your
vehicle could be damaged. Add brake uid
only when work is done on the brake hydraulic
system. See “Checking Brake Fluid” in this
section.
Refer to the Maintenance Schedule to determine when
to check the brake fluid. SeeScheduled Maintenance
on page 6-4.
5-37
Page 292 of 414
All-Wheel Drive
Lubricant checks in this section also apply to these
vehicles. However, there are two additional systems that
need lubrication.
Transfer Case
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. SeeScheduled
Maintenance on page 6-4.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
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.
Use care not to overtighten the plug.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. SeeRecommended Fluids
and Lubricants on page 6-13.
5-46
Page 293 of 414
Rear Axle
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. SeeScheduled
Maintenance on page 6-4.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.If you have the 1500 Series, the proper level is
from 5/8 inch (15 mm) to 1 5/8 inch (40 mm) below
the bottom of the filler plug hole. The proper level for
the 2500 and 3500 Series is from 0 to 1/4 (6 mm) below
the bottom of the filler plug hole. Add only enough
fluid to reach the proper level.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. SeeRecommended Fluids
and Lubricants on page 6-13.
5-47
Page 294 of 414

Front Axle
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 on page 6-4.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
If the level is below the
bottom of the filler plug
hole, you may need to add
some lubricant.When the differential is cold, add enough lubricant to
raise the level to 3/8 inch (10 mm) below the filler
plug hole.
When the differential is at operating temperature
(warm), 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. SeeRecommended Fluids
and Lubricants on page 6-13.
Noise Control System
Tampering with Noise Control
System Prohibited
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.
5-48
Page 300 of 414
6. Remove the bulb socket by squeezing the tab on
the side of the socket while turning it
counterclockwise.
7. Turn the bulb counterclockwise to remove it.
8. Install a new bulb.
9. Reverse the steps to reinstall the taillamp assembly.
Replacement Bulbs
Exterior Lamp Bulb Number
Back-up, Rear Parking,
Stoplamp, and Turn Signal Lamp3157
Center High Mounted Stop
Lamp (CHMSL)912
Front Parking and Turn
Signal Lamp3157KX
Front Sidemarker Lamp 194
Headlamps
Composite High-Beam
Headlamp9005
Composite Low-Beam
Headlamp9006GS
Sealed Beam Headlamp H6054
For replacement bulbs not listed here, contact your
dealer/retailer.
Windshield Wiper Blade
Replacement
Windshield wiper blades should be inspected for wear
and cracking. SeeScheduled Maintenance on page 6-4
for more information on wiper blade inspection.
5-54
Page 311 of 414

How to Check
Use a good quality pocket-type gage to check tire
pressure. You cannot tell if your tires are
properly inflated simply by looking at them. Radial
tires may look properly inflated even when they
are underinflated. Check the tire’s inflation
pressure when the tires are cold. Cold means your
vehicle has been sitting for at least three hours
or driven no more than 1 mile (1.6 km).
Remove the valve cap from the tire valve stem.
Press the tire gage firmly onto the valve to
get a pressure measurement. If the cold tire
inflation pressure matches the recommended
pressure on the Tire and Loading Information
label, no further adjustment is necessary. If the
pressure is low, add air until you reach the
recommended amount.
If you overfill the tire, release air by pushing on
the metal stem in the center of the tire valve.
Recheck the tire pressure with the tire gage.
Be sure to put the valve caps back on the valve
stems. They help prevent leaks by keeping out dirt
and moisture.
Dual Tire Operation
When the vehicle is new, or whenever a wheel, wheel bolt
or wheel nut is replaced, check the wheel nut torque after
100, 1,000 and 6,000 miles (160, 1 600 and 10 000 km)
of driving. For proper wheel nut tightening information,
see “Removing the Flat Tire and Installing the Spare Tire”
later in this section, underChanging a Flat Tire on
page 5-82. Also see “Wheel Nut Torque” under
Capacities and Specifications on page 5-116.
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.
SeeTire Inspection and Rotation on page 5-71. Also
seeScheduled Maintenance on page 6-4.
{CAUTION:
If you operate your vehicle with a tire that is
badly underin ated, the tire can overheat. An
overheated tire can lose air suddenly or catch
re. You or others could be injured. Be sure all
tires (including the spare) are properly in ated.
SeeTires on page 5-56andInflation - Tire Pressure on
page 5-64for more information on proper tire inflation.
5-65
Page 317 of 414

Tire Inspection and Rotation
We recommend that you regularly inspect your
vehicle’s tires, including the spare tire, for signs of
wear or damage. SeeWhen It Is Time for New
Tires on page 5-73for more information.
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km). SeeScheduled Maintenance
on page 6-4.
The purpose of a regular tire rotation is to achieve
a uniform wear for all tires on the vehicle. This
will ensure that your vehicle continues to perform
most like it did when the tires were new.
Any time you notice unusual wear, rotate the tires
as soon as possible and check wheel alignment.
Also check for damaged tires or wheels. See
When It Is Time for New Tires on page 5-73and
Wheel Replacement on page 5-78.
If your vehicle has dual rear wheels, also seeDual
Tire Operation on page 5-65.If your vehicle has single rear wheels, always use
the correct rotation patterns shown here when
rotating your vehicle’s tires. Do not include
the spare tire in the tire rotation, if the spare
tire/wheel assembly does not match your vehicle’s
road tires and wheels in size and type.
Single Rear Wheels
5-71