Page 436 of 536

Also check belt routing to make sure there is no interfer-
ence between the belts and other engine components.
Spark Plugs
Spark plugs must fire properly to assure engine perfor-
mance and emission control. New plugs should be in-
stalled at the specified mileage. The entire set should be
replaced if there is any malfunction due to a faulty spark
plug, malfunctioning spark plugs can damage the cata-
lytic converter. For proper type of replacement spark
plugs, refer to the “Vehicle Emission Control Informa-
tion” label in the engine compartment.
Engine Air Cleaner Filter
Under normal driving conditions, replace the air filter at
the intervals shown on Schedule “A”. If, however, you
drive the vehicle frequently under dusty or severe con-
ditions, the filter element should be inspected periodi-
cally and replaced if necessary at the intervals shown on
Schedule “B”.
WARNING!
The air induction system (air cleaner, hoses, etc) can
provide a measure of protection in the case of engine
backfire. Do not remove the air induction system (air
cleaner, hoses, etc) unless such removal is necessary
for repair or maintenance. Make sure that no one is
near the engine compartment before starting the
vehicle with the air induction system (air cleaner,
hoses, etc) removed. Failure to do so can result in
serious personal injury.
Engine Fuel Filter
A plugged fuel filter can cause stalling, limit the speed at
which a vehicle can be driven or cause hard starting.
Should an excessive amount of dirt accumulate in the
fuel tank, frequent filter replacement may be necessary.
436 MAINTAINING YOUR VEHICLE
Page 437 of 536
Catalytic Converter
The catalytic converter requires the use of unleaded fuel
only. Leaded gasoline will destroy the effectiveness of the
catalyst as an emission control device.
Under normal operating conditions, the catalytic con-
verter will not require maintenance. However, it is im-
portant to keep the engine properly tuned to assure
proper catalyst operation and prevent possible catalyst
damage.CAUTION!
Damage to the catalytic converter can result if your
vehicle is not kept in proper operating condition. In
the event of engine malfunction, particularly involv-
ing engine misfire or other apparent loss of perfor-
mance, have your vehicle serviced promptly. Contin-
ued operation of your vehicle with a severe
malfunction could cause the converter to overheat,
resulting in possible damage to the converter and the
vehicle.
NOTE: Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
MAINTAINING YOUR VEHICLE 437
7
Page 439 of 536

Emission-Related Components
Positive Crankcase (PCV) Valve
Proper operation of the crankcase ventilation system
requires that the PCV valve be free of sticking or plug-
ging from deposits. Deposits can accumulate in the PCV
valve and passages with increasing mileage. Have the
PCV valve, hoses, and passages checked for proper
operation at the intervals specified. If the valve is
plugged or sticking, replace with a new valve— do not
attempt to clean the old PCV valve! Check the ventila-
tion hoses for indications of damage, weepage or plug-
ging with deposits. Replace if necessary.
Maintenance Free Battery
The top of the maintenance free battery is permanently
sealed. You will never have to add water, nor is periodic
maintenance required.
WARNING!
Battery fluid is a corrosive acid solution and can
burn or even blind you. Don’t allow battery fluid to
contact your eyes, skin or clothing. Don’t lean over a
battery when attaching clamps. If acid splashes in
eyes or on skin, flush the area immediately with
large amounts of water.
Battery gas is flammable and explosive. Keep flame
or sparks away from the battery. Don’t use a booster
battery or any other booster source with an output
greater than 12 volts. Don’t allow cable clamps to
touch each other.
Battery posts, terminals and related accessories con-
tain lead and lead compounds. Wash hands after
handling.
MAINTAINING YOUR VEHICLE 439
7
Page 440 of 536

CAUTION!
It is essential when replacing the cables on the
battery that the positive cable is attached to the
positive post and the negative cable is attached to the
negative post. Battery posts are marked (+) positive
and negative (-) and identified on the battery case.
Also, if a “fast charger” is used while battery is in
vehicle, disconnect both vehicle battery cables be-
fore connecting the charger to battery. Do not use a
“fast charger” to provide starting voltage.
Air Conditioner Maintenance
For best possible performance, your air conditioner
should be checked and serviced by an Authorized Dealer
at the start of each warm season. This service should
include cleaning of the condenser fins and a performance
test. Drive belt tension should also be checked at this
time. NOTE:
Refer to Section 3 of the Warranty Information
book for further warranty information.
WARNING!
•Use only refrigerants and compressor lubricants
approved by the manufacturer for your air condi-
tioning system. Some unapproved refrigerants are
flammable and can explode, injuring you. Other
unapproved refrigerants or lubricants can cause
the system to fail, requiring costly repairs.
•The air conditioning system contains refrigerant
under high pressure. To avoid risk of personal
injury or damage to the system, adding refrigerant
or any repair requiring lines to be disconnected
should be done by an experienced repairman.
440 MAINTAINING YOUR VEHICLE
Page 442 of 536

The ball joints originally supplied with the vehicle are
permanently lubricated at the factory and do not require
service. However, if the seals on the ball joints are
damaged, the joints should be replaced. Serviceable
replacement ball joints are available.
Front suspension ball joints should be replaced only by a
qualified service technician using tools specially de-
signed for this purpose. Damage to the joints and/or
suspension components may result if improper replace-
ment procedures are used.
If seals are damaged the ball joints should be replaced to
prevent leakage or contamination of the grease.
Steering Linkage — Inspection
Whenever the vehicle is hoisted, all steering linkage
joints should be inspected for evidence of damage. If
seals are damaged, parts should be replaced to prevent leakage or contamination of the grease. Lubricate the
steering linkage regularly according to the “Maintenance
Schedule” in this manual.
Half-shaft Constant Velocity Joints
All four- wheel- drive 1500 models are equipped with
four constant velocity joints. Periodic lubrication of these
joints is not required. However, the joint boots should be
inspected for external leakage or damage periodically. If
external leakage or damage is evident, the joint boot and
grease should be replaced immediately. Continued op-
eration could result in failure of the joint due to water
and dirt contamination of the grease. This would require
complete replacement of the joint assembly. Refer to the
Service Manual for the detailed replacement procedure.
442 MAINTAINING YOUR VEHICLE
Page 443 of 536

Front Prop Shaft Lubrication — 2500/3500 (4X4)
Models
Lubricate the front driveshaft grease fitting at each oil
change listed in the appropriate Maintenance Schedule
for your vehicle (Schedule “A” and “B”). Use Mopar
type MS-6560 (lithium based grease), or equivalent.
Body Lubrication
Locks and all body pivot points, including such items as
seat tracks, doors, tailgate and hood hinges, should be
lubricated periodically to assure quiet, easy operation
and to protect against rust and wear. Prior to the appli-
cation of any lubricant, the parts concerned should be
wiped clean to remove dust and grit; after lubricating
excess oil and grease should be removed. Particular
attention should also be given to hood latching compo-
nents to insure proper function. When performing other
underhood services, the hood latch, release mechanism
and safety catch should be cleaned and lubricated.
The external lock cylinders should be lubricated twice a
year, preferably in the fall and spring. Apply a small
amount of a high quality lubricant such as Mopar Lock
Cylinder Lubricant directly into the lock cylinder.
Front Driveshaft Grease Fitting
MAINTAINING YOUR VEHICLE 443
7
Page 446 of 536

CRACKING DUE TO WEATHERING DOES NOT AD-
VERSELY AFFECT PERFORMANCE. If, however, exces-
sively deep localized cracks are present, or any part of the
exhaust system abnormally contacts the underbody hard-
ware, the isolator and/or hanger should be replaced.
Cooling System
Cooling System Maintenance
At the intervals shown in the Maintenance Schedules
Section of the manual, the system should be drained,
flushed and filled.
Inspection
Check engine coolant (antifreeze) protection every 12
months (before the onset of freezing weather, where
applicable). If coolant is dirty or rusty in appearance, the
system should be drained, flushed and refilled with fresh
coolant as specified. Inspect the entire cooling system for leaks. Check the face
of the radiator for any accumulation of bugs, leaves, or
other foreign matter. If dirty, clean the radiator core with
a garden hose. With the engine OFF, gently spray water
from the back of the radiator core.
For 3.7L, 4.7L, and 5.7L engines, check the coolant bottle
hoses for condition and tightness of the connections at
both the coolant bottle and radiator.
Coolant Level ( 3.7L, 4.7L, 5.7L Engines)
The coolant reserve system provides a quick visual
method of determining that the coolant level is adequate.
With the engine idling, and warmed to the normal
operating temperature, the level of the coolant in the
coolant bottle should be between the fluid level marks.
Check the coolant level whenever the hood is raised.
446 MAINTAINING YOUR VEHICLE
Page 447 of 536

The radiator normally remains completely full, so there is
no longer a need to remove the coolant pressure cap
except for checking coolant freeze point or replacement
with new antifreeze coolant.
WARNING!
Never add coolant to the radiator when the engine is
overheated. Do not loosen or remove pressure cap to
cool an overheated engine! The coolant is under
pressure and severe scalding could result.
Drain, Flush And Refill
At intervals shown on the Maintenance Schedules, the
system should be drained, flushed and refilled. Refer to
your dealer or consult a service manual for proper
procedures.
Adding Coolant
When adding coolant, or refilling the system, a minimum
solution of 50% recommended HOAT ethylene glycol
engine coolant (antifreeze) and distilled water should be
used. Use higher concentrations (not to exceed 70%) if
temperatures below 34°F (37°C) are anticipated.
Use only high purity water such as distilled or deionized
water when mixing the water/engine coolant solution.
The use of lower quality water will reduce the amount of
corrosion protection in the engine cooling system.
NOTE: It is the owner’s responsibility to maintain the
proper level of protection against freezing according to
the temperatures occurring in the area where the vehicle
is operated.
NOTE: Mixing coolant types will decrease the life of the
engine coolant and will require more frequent coolant
changes.
MAINTAINING YOUR VEHICLE 447
7