appearance, the system should be drained, flushed and
refilled with fresh coolant. Check the front of the A/C
condenser (if equipped) or radiator for any accumulation
of bugs, leaves, etc. If dirty, clean by gently spraying water
from a garden hose vertically down the face of the A/C
condenser (if equipped) or the back of the radiator core.
Check the engine cooling system hoses for brittle rubber,
cracking, tears, cuts and tightness of the connection at the
coolant recovery bottle and radiator. Inspect the entire
system for leaks.
DO NOT REMOVE THE COOLANT PRESSURE CAP
WHEN THE COOLING SYSTEM IS HOT.
Cooling System — Drain, Flush And Refill
NOTE:Some vehicles require special tools to add coolant
properly. Failure to fill these systems properly could lead to
severe internal engine damage. If any coolant is needed to
be added to the system please contact your local autho-
rized dealer.
If the engine coolant (antifreeze) is dirty or contains visible
sediment, have an authorized dealer clean and flush with
OAT coolant (antifreeze) (conforming to MS.90032).
Refer to the “Maintenance Plan” in this section for the
proper maintenance intervals.
Selection Of Coolant
Refer to “Fluids And Lubricants” in “Technical Specifica-
tions” for further information.
CAUTION!
• Mixing of engine coolant (antifreeze) other than
specified Organic Additive Technology (OAT) en-
gine coolant (antifreeze), may result in engine dam-
age and may decrease corrosion protection. Organic
Additive Technology (OAT) engine coolant is differ-
ent and should not be mixed with Hybrid Organic
Additive Technology (HOAT) engine coolant (anti-
freeze) or any “globally compatible” coolant (anti-
freeze). If a non-OAT engine coolant (antifreeze) is
introduced into the cooling system in an emergency,
the cooling system will need to be drained, flushed,
and refilled with fresh OAT coolant (conforming to
MS.90032), by an authorized dealer as soon as pos-
sible.
• Do not use water alone or alcohol-based engine
coolant (antifreeze) products. Do not use additional
rust inhibitors or antirust products, as they may not
(Continued)
8
SERVICING AND MAINTENANCE 547
the correct type thermostat. Other designs may result in
unsatisfactory engine coolant (antifreeze) performance,
poor gas mileage, and increased emissions.
Brake System
In order to assure brake system performance, all brake
system components should be inspected periodically. Refer
to the “Maintenance Plan” in this section for the proper
maintenance intervals.
WARNING!
Riding the brakes can lead to brake failure and possi-
bly a collision. Driving with your foot resting or riding
on the brake pedal can result in abnormally high brake
temperatures, excessive lining wear, and possible
brake damage. You would not have your full braking
capacity in an emergency.
Fluid Level Check — Brake Master Cylinder
The fluid level of the master cylinder should be checked
when performing under the hood service or immediately if
the brake system warning lamp indicates system failure.
The brake master cylinder has a translucent plastic reser-
voir. On the outboard side of the reservoir, there is a“MAX” mark and a “MIN” mark. The fluid level must be
kept within these two marks. Do not add fluid above the
MAX mark because leakage may occur at the cap.
With disc brakes the fluid level can be expected to fall as
the brake linings wear. However, an unexpected drop in
fluid level may be caused by a leak and a system check
should be conducted.
Refer to “Fluids And Lubricants” in “Technical Specifica-
tions” for further information.
WARNING!
•
Use only manufacturer’s recommended brake fluid.
Refer to “Fluids And Lubricants” in “Technical
Specifications” for further information. Using the
wrong type of brake fluid can severely damage your
brake system and/or impair its performance. The
proper type of brake fluid for your vehicle is also
identified on the original factory installed hydraulic
master cylinder reservoir.
• To avoid contamination from foreign matter or mois-
ture, use only new brake fluid or fluid that has been
(Continued)
552 SERVICING AND MAINTENANCE
NOTE:To prevent dirt and water from entering the
transmission after checking or replenishing fluid, make
sure that the dipstick cap is properly reseated. It is normal
for the dipstick cap to spring back slightly from its fully
seated position, as long as its seal remains engaged in the
dipstick tube.
Fluid And Filter Changes — Eight-Speed
Transmission
Under normal operating conditions, the fluid installed at
the factory will provide satisfactory lubrication for the life
of the vehicle.
Routine fluid and filter changes are not required. However,
change the fluid and filter if the fluid becomes contami-
nated (with water, etc.), or if the transmission is disas-
sembled for any reason.
Fluid And Filter Changes — Six Speed Transmission
Refer to the “Maintenance Plan” for the proper mainte-
nance intervals.
In addition, change the fluid and filters if the fluid becomes
contaminated (with water, etc.), or if the transmission is
disassembled for any reason.
Rear Axle And 4x4 Front Driving Axle Fluid Level
For normal service, periodic fluid level checks are not
required. When the vehicle is serviced for other reasons the
exterior surfaces of the axle assembly should be inspected.
If gear oil leakage is suspected inspect the fluid level. Refer
to “Fluids And Lubricants” in “Technical Specifications”
for further information. This inspection should be made
with the vehicle in a level position.
For 1500 Model axles, the fluid level should be even with
the bottom of the fill hole (within 1/4 in (6.4 mm) of edge
of hole) for the FDU215 HD front axle and C235FE rear
axle.
For all 2500/3500 Model axles, the fluid level should be 1/4
in ± 1/4 in (6.4 mm ± 6.4 mm) below the fill hole on the 9.25
in front and 3/4 in ± 1/4 in (19 mm ± 6.4 mm) on 10.5 in
rear axles. The 11.5 in rear axle level should be 1/4 in ± 1/4
in (6.4 mm ± 6.4 mm) below the fill hole.
Lubricant Selection
Refer to “Fluids And Lubricants” in “Technical Specifica-
tion” for further information.
556 SERVICING AND MAINTENANCE
NOTE:The presence of water in the gear lubricant will
result in corrosion and possible failure of differential
components. Operation of the vehicle in water, as may be
encountered in some off-highway types of service, will
require draining and refilling the axle to avoid damage.
Limited-Slip Differentials
1500 Model rear axles equipped with a Limited Slip
Differential require that 5 oz. (148 ml) Mopar Limited Slip
Additive be added to the gear lubricant. Refer to “Fluids
And Lubricants” in “Technical Specification” for further
information. The Mopar Limited Slip Additive should be
added to the gear lubricant whenever a fluid change is
made to an axle equipped with a Limited Slip Differential.
2500/3500 Model axles DO NOT REQUIREany limited
slip oil additive (friction modifiers).
NOTE: When refilling an axle with a Limited Slip Differ-
ential, (which requires a Limited Slip Additive), the Lim-
ited Slip Additive should be added before the gear lubri-
cant is added to insure proper additive fill.
Drain And Refill
Refer to the “Maintenance Plan” for the proper mainte-
nance intervals.
Transfer Case
Selection Of Lubricant
Use only the manufacturer’s recommended fluid. Refer to
“Fluids And Lubricants” in “Technical Specifications” for
further information.
Fluid Level Check
This fluid level can be checked by removing the filler plug.
The fluid level should be to the bottom edge of the filler
plug hole with the vehicle in a level position.
Drain And Refill
Refer to the “Maintenance Plan” for the proper mainte-
nance intervals.8
SERVICING AND MAINTENANCE 557
WARNING!
Using tires of different size and type (M+S, Snow)
between front and rear axles can cause unpredictable
handling. You could lose control and have a collision.
CAUTION!
To avoid damage to your vehicle or tires, observe the
following precautions:
•Because of restricted traction device clearance be-
tween tires and other suspension components, it is
important that only traction devices in good condi-
tion are used. Broken devices can cause serious
damage. Stop the vehicle immediately if noise occurs
that could indicate device breakage. Remove the
damaged parts of the device before further use.
• Install device as tightly as possible and then re-
tighten after driving about ½ mile (0.8 km).
• Do not exceed 30 mph (48 km/h).
• Drive cautiously and avoid severe turns and large
bumps, especially with a loaded vehicle.
• Do not drive for a prolonged period on dry pave-
ment.
(Continued)
CAUTION! (Continued)
•Observe the traction device manufacturer ’s instruc-
tions on the method of installation, operating speed,
and conditions for use. Always use the suggested
operating speed of the device manufacturer ’s if it is
less than 30 mph (48 km/h).
• Do not use traction devices on a compact spare tire.
Tire Rotation Recommendations
Tires on the front and rear axles of vehicles operate at
different loads and perform different steering, driving, and
braking functions. For these reasons, they wear at unequal
rates.
These effects can be reduced by timely rotation of tires. The
benefits of rotation are especially worthwhile with aggres-
sive tread designs such as those on all season type tires.
Rotation will increase tread life, help to maintain mud,
snow and wet traction levels and contribute to a smooth,
quiet ride.
Refer to the “Maintenance Plan” for the proper mainte-
nance intervals. More frequent rotation is permissible if
desired. The reasons for any rapid or unusual wear should
be corrected prior to rotation being performed.
580 SERVICING AND MAINTENANCE
CAUTION!(Continued)
the truck. For example, if the spare is used to replace
an outer rear tire it will have to be remounted on the
rim so that the wheel is dished inward. That way the
tread design of asymmetrical tires and the white
writing of the OWL tires will maintain proper posi-
tion.
DEPARTMENT OF TRANSPORTATION UNIFORM
TIRE QUALITY GRADES
The following tire grading categories were established
by the National Highway Traffic Safety Administration.
The specific grade rating assigned by the tire’s manu-
facturer in each category is shown on the sidewall of the
tires on your vehicle.
All passenger vehicle tires must conform to Federal
safety requirements in addition to these grades.
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 one-half
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 charac-
teristics and climate.
Traction Grades
The Traction grades, from highest to lowest, are AA, A, B,
and C. These 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.
Temperature Grades
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. 8
SERVICING AND MAINTENANCE 583