Page 407 of 554

NOTE:During snowplow usage on vehicles equipped
with an overhead console module, the outside tempera-
ture display will show higher temperatures than the
outside ambient temperature. The higher displayed tem-
perature is due to blocked or reduced airflow to the
underhood ambient temperature sensor by the snow-
plow. This is common, and outside temperature display
operation will return to normal when the snowplow is
removed.
General Maintenance
Snowplows should be maintained in accordance with the
plow manufacturer's instructions. Whenever the plow is
disconnected from the vehicle, coat the exposed angling
cylinder rods with chassis lubricant. The lift cylinder
should be extended upward and chassis lubricant ap-
plied to the lift rod. The hydraulic hoses interconnect to
keep the couplers clean.Keep all snowplow electrical connections and battery
terminals clean and free of corrosion.
When plowing snow, to avoid transmission and driv-
etrain damage, the following precautions should be ob-
served.
²Operate with transfer case in 4L when plowing small
or congested areas where speeds are not likely to
exceed 15 mph (24 km/h). At higher speeds operate in
4H.
²Do not shift the transmission unless the engine has
returned to idle and wheels have stopped. Make a
practice of stepping on the brake pedal before shifting
the transmission between forward and reverse.
NOTE:Change the automatic transmission fluid and
filter(s), refer to ªMaintenance Scheduleº in Section 8.
STARTING AND OPERATING 405
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Page 443 of 554
MAINTAINING YOUR VEHICLE
CONTENTS
mEngine CompartmentÐ 3.7L...............444
mEngine CompartmentÐ 4.7L...............445
mEngine CompartmentÐ 5.7L...............446
mOnboard Diagnostic System (OBD II).........447
NLoose Fuel Filler Cap Message............447
mEmissions Inspection And Maintenance
Programs............................448
mReplacement Parts......................449
mAuthorized Dealer Service................450mMaintenance Procedures..................450
NEngine Oil..........................451
NEngine Oil Filter......................454
NDrive Belts Ð Check Condition And Tension . . 454
NSpark Plugs (Gas Engines)...............454
NEngine Air Cleaner Filter................455
NEngine Fuel Filter.....................455
NCatalytic Converter....................455
NEmission-Related Components............457
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Page 455 of 554

NOTE:Vehicles equipped with a 5.7L engine must use
SAE 5W-20 oil. Failure to do so may result in improper
operation of the Multi-Displacement System (MDS). Re-
fer to ªMulti-Displacement Systemº under ªStarting and
Operatingº in Section 5.
NOTE:For 2500/3500 trucks with a 5.7L engine oper-
ating under a gross combined weight rating of 14,000 lbs.
or greater, SAE 5W-30 engine oil is recommended for all
operating temperatures.
Lubricants, which do not have both the engine oil certi-
fication mark and the correct SAE viscosity grade num-
ber, should not be used.
Synthetic Engine Oils
You may use synthetic engine oils if the recommended oil
quality requirements are met, and the recommended
maintenance intervals for oil and filter changes are
followed.
Materials Added to Engine Oil
The manufacturer strongly recommends against the ad-
dition of any additives (other than leak detection dyes) to
the engine oil. Engine oil is an engineered product and its
performance may be impaired by supplemental addi-
tives.
Disposing of Used Engine Oil and Oil Filters
Care should be taken in disposing of used engine oil and
oil filters from your vehicle. Used oil and oil filters,
indiscriminately discarded, can present a problem to the
environment. Contact your authorized dealer, service
station, or governmental agency for advice on how and
where used oil and oil filters can be safely discarded in
your area.
MAINTAINING YOUR VEHICLE 453
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Page 457 of 554

Engine Air Cleaner Filter
Follow the Maintenance Schedule for recommended En-
gine Air Cleaner Filter change intervals.
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.
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.
MAINTAINING YOUR VEHICLE 455
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Page 481 of 554

7. Check for leaks. Release parking brake.
To prevent dirt and water from entering the transmission
after checking or replenishing fluid, make certain 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.
Automatic Transmission Fluid and Filter Change
Follow the Maintenance Schedule for recommended
transmission fluid and filter change intervals.
NOTE:If the transmission is disassembled for any
reason, the fluid and filter(s) should be changed.
It is important that proper lubricant is used in the
transmission. For the correct Fluid type, refer to ªFluids,
Lubricants and Genuine Partsº in this Section.
Special Additives
Automatic Transmission Fluid (ATF) is an engineered
product and its performance may be impaired by supple-
mental additives. Therefore, do not add any fluid addi-
tives to the transmission. The only exception to this
policy is the use of special dyes to aid in detecting fluid
leaks. In addition, avoid using transmission sealers as
they may adversely affect seals.
Front and Rear Wheel Bearings
Front Wheel Bearings
Front wheel bearings for all vehicles are sealed-for-life.
They do not require greasing or seal replacement. In
some instances, these bearings will ªpurgeº excess grease
and the bearing will look slightly wet. This is normal.
Periodic inspection for excess play is recommended.
MAINTAINING YOUR VEHICLE 479
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Page 483 of 554

Required Maintenance for Noise Control Systems
The following maintenance services must be performed
every six months or 6,000 mi (9 600 km), whichever
comes first, to assure proper operation of the noise
control systems. In addition, inspection and service
should be performed anytime a malfunction is observed
or suspected. Proper maintenance of the entire vehicle
will help the effectiveness of the noise control systems.
Air Cleaner Assembly
Inspect air cleaner housing for proper assembly and fit.
Make certain that the air cleaner is properly positioned
and the cover is tight. Check all hoses leading to the
cleaner for tightness. The gasket between the air cleaner
housing and throttle body must be intact and in good
condition. The engine air cleaner filter must also be clean
and serviced according to the instructions outlined in the
appropriate maintenance schedule.
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 incorpo-
rated 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.
AIR CLEANER
²Removal of the air cleaner.
²Inverting the air cleaner lid.
²Removal of the air ducting.
MAINTAINING YOUR VEHICLE 481
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Page 519 of 554
Perform Maintenance Every(Where time and mileage
are listed, follow the interval that occurs first.)
Maintenance Items Miles Kilometers or Months
Change the engine oil and engine oil filter. 6,000 10 000 6
Rotate Tires. 6,000 10 000 6
Lubricate outer tie rod ends 2500/3500 (4X4) models
only.6,000 10 000 6
Lube Front Drive Shaft Fitting (2500/3500, 4x4 only). 6,000 10 000 6
If using your vehicle for any of the following: Dusty
or off-road conditions. Inspect the engine air cleaner
filter, replace if necessary.12,000 20 000 12
Inspect the brake linings, replace if necessary. 12,000 20 000 12
Inspect the front & rear axle fluid, change if using
your vehicle for police, taxi, fleet, off-road or frequent
trailer towing.18,000 30 000 18
Inspect the CV Joints. Perform the first inspection at
12,000 miles (20 000 km) or 12 months.24,000 40 000 24
MAINTENANCE SCHEDULES 517
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Page 520 of 554
Perform Maintenance Every(Where time and mileage
are listed, follow the interval that occurs first.)
Maintenance Items Miles Kilometers or Months
Inspect Exhaust System. Perform the first inspection at
12,000 miles (20 000 km) or 12 months.24,000 40 000 24
Inspect the front suspension, tie rod ends and boot
seals, replace if necessary.24,000 40 000 24
Replace the engine air cleaner filter. 30,000 50 000 30
Inspect the transfer case fluid. 30,000 50 000 30
Replace the top row of spark plugs on 4.7L engines. **30,000 50 000 30
Replace the spark plugs on 3.7L and 5.7L engines.30,000 50 000 30
Change the automatic transmission fluid & filter if
using your vehicle for any of the following: police,
taxi, fleet or frequent trailer towing.60,000 100 000 60
Change the transfer case fluid if using your vehicle for
any of the following: police, taxi, fleet, off-road or fre-
quent trailer towing.60,000 100 000 60
518 MAINTENANCE SCHEDULES
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