Page 406 of 532

Drive Belts (Gas Engines)
Belt tension is controlled by means of an automatic
tensioner. No belt tension adjustments are required.
However, belt and belt tensioner condition should be
inspected at the specified intervals and replaced if re-
quired. See your authorized dealer for service.
At the mileage indicated in the maintenance schedule, all
belts and tensioner should be checked for condition.
Improper belt tension can cause belt slippage and failure.
Belts should be inspected for evidence of cuts, cracks,
glazing or frayed cords and replaced if there is indication
of damage which could result in belt failure. Low gen-
erator belt tension can cause battery failure.
Also check belt routing to make sure there is no interfer-
ence between the belts and other engine components. Drive Belt (Diesel Engines)
Inspection
Check the belt for intersecting cracks.
• Transverse (across the belt width) cracks are accept-
able.
• Longitudinal (direction of belt length) cracks that
intersect with transverse cracks are NOT acceptable.
Replace the belt if it has unacceptable cracks, is frayed or
has pieces of material missing.
The engine speed sensor, located near the damper, should
be inspected for damage if a belt is frayed.
Engine Air Cleaner Filter (Gas Engines)
Under normal driving conditions, replace the air filter at
the intervals shown on Schedule “A”. If, however, you406 MAINTAINING YOUR VEHICLE
Page 413 of 532

mixture in excess of 5% can negatively impact the on-
engine fuel filter’s ability to separate water from the fuel,
resulting in high pressure fuel system corrosion or dam-
age.
NOTE: As sufficient testing as not been completed,
ethanol blends are not recommended or approved for use
with your Cummins Diesel equipped vehicle.
NOTE: In addition, commercially available fuel addi-
tives are not necessary for the proper operation of your
Cummins Diesel equipped vehicle.
Engine Fuel Filter (Gas Engines)
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. Spark Plugs (Gas Engines)
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.
Catalytic Converter (Gas Engines)
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. MAINTAINING YOUR VEHICLE 413
7
Page 418 of 532

Emission-Related Components (Gas Engines)
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 (Gas Engines)
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 imme-
diately 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
contain lead and lead compounds. Wash hands
after handling.418 MAINTAINING YOUR VEHICLE
Page 432 of 532

• Make sure that the radiator and coolant recovery
bottle overflow hoses are not kinked or obstructed.
• Keep the front of the radiator clean. If your vehicle is
equipped with air conditioning, keep the front of the
condenser clean, also.
• Do not change the thermostat for summer or winter
operation. If replacement is ever necessary, install
ONLY the correct type thermostat. Other designs may
result in unsatisfactory coolant performance, poor gas
mileage, and increased emissions.
Fan
Inspection
Check the fan for cracks and bent or broken blades. If any
of these conditions exist, you must replace the fan. Make
sure it is securely mounted. NOTE: This service procedure must be performed by a
trained service technician. Make arrangements with your
authorized Dodge Truck Dealer for this inspection.
Charge Air Cooler — Inter-Cooler (Diesel
Engines)
The charge air cooler is positioned between the radiator
and the air conditioner condenser. Air enters the engine
through the air cleaner and passes through the turbo-
charger where it is pressurized. This pressurized air
rapidly reaches high temperature. The air is then directed
through a hose to the charge air cooler and through
another hose to the intake manifold of the engine. The air
entering the engine has been cooled by about 50 to 100
degrees Fahrenheit. This cooling process enables more
efficient burning of fuel resulting in fewer emissions.
To guarantee optimum performance of the system, keep
the surfaces of the charge air cooler, condenser and
radiator clean and free of debris. Periodically check the432 MAINTAINING YOUR VEHICLE
Page 448 of 532
Noise Systems Maintenance Chart and Service Log Maintenance Log and Service Chart (Gas Engines)
Insert
Month, Day, Year under column mileage closest to the mileage at which service was performed.
MILES 6,000 12,000 18,000 24,000 30,000 36,000 42,000 48,000
KILOME-
TERS 9 600 19 000 29 000 36 000 48 000 58 000 67 000 77 000
Exhaust
system-
inspect
Air cleaner
assembly-
inspect
ODOM-
ETER
READING
PER-
FORMED
BY
PER-
FORMED
AT 448 MAINTAINING YOUR VEHICLE
Page 449 of 532
Noise Systems Maintenance Chart and Service Log Maintenance Log and Service Chart (Gas Engines)
Insert
Month, Day, Year under column mileage closest to the mileage at which service was performed.
MILES 54,000 60,000 66,000 72,000 78,000 84,000 90,000 96,000
KILOME-
TERS 87 000 96 000 106 000 116 000 126 000 135 000 145 000 154 000
Exhaust
system-
inspect
Air cleaner
assembly-
inspect
ODOM-
ETER
READING
PER-
FORMED
BY
PER-
FORMED
AT MAINTAINING YOUR VEHICLE 449
7