NOTE:Using the ªTOW HAULº or ªOD/OFFº range
while operating the vehicle under heavy operating con-
ditions will improve performance and extend transmis-
sion life by reducing excessive shifting and heat build up.
This action will also provide better engine braking.
The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than
45 minutes of continuous operation. See Maintenance
Schedule in section 8 of this manual for transmission
fluid change intervals.
NOTE:Check the automatic transmission fluid level
before towing.
Towing Tips Ð Tow/Haul (If Equipped)
To reduce potential for automatic transmission overheat-
ing, turn the ªTOW HAUL OD/OFFº feature ON when
driving in hilly areas or shift the transmission to Drive
position 2 on more severe grades.
Towing Tips Ð Electronic Speed Control (If
Equipped)
þ
Don't use in hilly terrain or with heavy loads.
þWhen using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
þUse speed control in flat terrain and with light loads to
maximize fuel efficiency.
Towing Tips Ð Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
þCity Driving
When stopped for short periods of time, put transmission
in neutral and increase engine idle speed.
þHighway Driving
Reduce speed.
STARTING AND OPERATING 399
5
NMaintenance-Free Battery................457
NAir Conditioner Maintenance.............459
NPower Steering Ð Fluid Check............460
NFront Suspension Ball Joints..............460
NSteering Linkage Ð Inspection............461
NHalf-Shaft Constant Velocity Joints.........461
NFront Prop Shaft Lubrication Ð
2500/3500 (4X4) Models................462
NBody Lubrication.....................462
NWindshield Wiper Blades................463
NWindshield Washers...................463
NExhaust System......................464NCooling System.......................465
NHoses And Vacuum/Vapor Harnesses.......470
NFuel System Connections................471
NBrake System........................471
NClutch Hydraulic System................474
NClutch Linkage.......................474
NRear Axle And 4X4 Front Driving Axle
Fluid Level..........................474
NTransfer Case........................475
NManual Transmission..................476
NAutomatic Transmission................476
NFront And Rear Wheel Bearings...........479
442 MAINTAINING YOUR VEHICLE
Manual Transmission
Lubricant Selection G238 (6-Speed Manual
Transmission Ð If Equipped)
This transmission is filled with manual transmission
fluid at the factory. This fluid does not require periodic
changing. If it is necessary to add or change fluid in this
transmission refer to Fluids, Lubricants and Genuine
Parts for correct fluid type. This is the only lubricant
recommended for use in the Getrag 238 transmission.
Lubricant Selection G56 (6-Speed Manual
Transmission Ð If Equipped)
Follow the Maintenance Schedule for recommended
transmission fluid change intervals. If it is necessary to
add or change fluid in this transmission refer to ªFluids,
Lubricants and Genuine Partsº for correct fluid type. This
is the only lubricant recommended for use in the G56
transmission.
Fluid Level Check ± All Manual Transmissions
This fluid level can be checked by removing the fill plug.
If the level of the lubricant is more than 1/4 in(6.4 mm)
below the bottom of the filler hole while the vehicle is on
level ground, enough lubricant should be added to bring
the level to the bottom of the filler hole.
Automatic Transmission
Selection Of Lubricant
It is important that the proper lubricant is used in the
transmission to assure optimum transmission perfor-
mance. Use only manufacturer 's recommended transmis-
sion fluid; refer to ªFluids, Lubricants and Genuine
Partsº in this section for correct fluid type. It is important
that the transmission fluid be maintained at the pre-
scribed level using the recommended fluid.
476 MAINTAINING YOUR VEHICLE
CAUTION!
Using a transmission fluid other than the manufac-
turer's recommended fluid may cause deterioration
in transmission shift quality and/or torque converter
shudder. Using a transmission fluid other than the
manufacturer's recommended fluid will result in
more frequent fluid and filter changes. Refer to
ªFluids, Lubricants and Genuine Partsº in this sec-
tion for correct fluid type.
Fluid Level Check
If equipped with a dipstick, use the following procedure.
If your vehicle has a capped dipstick tube, it is sealed and
should not be tampered with. Your authorized dealer has
the proper tools to ensure that the fluid level is set
properly. The fluid level should be checked when theengine is fully warmed up and the fluid in the transmis-
sion is at normal operating temperature. Operation of the
transmission with an improper fluid level will greatly
reduce the life of the transmission and of the fluid. Check
the fluid level whenever the vehicle is serviced.
Fluid Level Check ± 545RFE/42RLE
Check the fluid level while the transmission is at normal
operating temperature 82ÉC (180ÉF). This occurs after at
least 15 mi (25 km) of driving. At normal operating
temperature the fluid cannot be held comfortably be-
tween the fingertips.
To check the automatic transmission fluid level properly,
the following procedure must be used:
1. Operate the engine at idle speed and normal operating
temperature.
2. The vehicle must be on level ground.
MAINTAINING YOUR VEHICLE 477
7
3. Fully apply the parking brake and press the brake
pedal.
4. Place the gear selector momentarily in each gear
position ending with the lever in PARK.
5. Remove the dipstick, wipe it clean and reinsert it until
seated.
6. Remove the dipstick again and note the fluid level on
both sides. The fluid level should be between the ªHOTº
(upper) reference holes on the dipstick at normal operat-
ing temperature. Verify that solid coating of oil is seen on
both sides of the dipstick. If the fluid is low, add as
required into the dipstick tube.Do not overfill.After
adding any quantity of oil through the oil fill tube, wait
a minimum of two minutes for the oil to fully drain into
the transmission before rechecking the fluid level.NOTE:If it is necessary to check the transmissionbelow
the operating temperature, the fluid level should be
between the two ªCOLDº (lower) holes on the dipstick
with the fluid at approximately 70ÉF (21ÉC) (room tem-
perature). If the fluid level is correctly established at
room temperature, it should be between the ªHOTº
(upper) reference holes when the transmission reaches
180ÉF (82ÉC). Remember it is best to check the level at the
normal operating temperature.
CAUTION!
Be aware that if the fluid temperature is below 50ÉF
(10ÉC) it may not register on the dipstick. Do not add
fluid until the temperature is elevated enough to
produce an accurate reading.
478 MAINTAINING YOUR VEHICLE
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
7
²Change your engine oil more often if you drive your
vehicle off-road for an extended period of time.
²Under no circumstances should oil change intervals
exceed 6,000 miles (10,000 km) or 6 months, whichever
comes first.
Your dealer will reset the oil change indicator message
after completing the scheduled oil change. If this sched-
uled oil change is performed by someone other than your
dealer the message can be reset by referring to the steps
described under ªOdometer/Trip Odometerº under ªIn-
strument Cluster Descriptionº in Section 4 of this
manual.
At Each Stop for Fuel
²Check the engine oil level about 5 minutes after a fully
warmed engine is shut off. Checking the oil level whilethe vehicle is on level ground will improve the accu-
racy of the oil level reading. Add oil only when the
level is at or below the ADD or MIN mark.
²Check the windshield washer solvent and add if
required.
Once a Month
²Check tire pressure and look for unusual wear or
damage.
²Inspect the battery and clean and tighten the terminals
as required.
²Check the fluid levels of coolant reservoir, brake
master cylinder, power steering and transmission and
add as needed.
²Check all lights and other electrical items for correct
operation.
MAINTENANCE SCHEDULES 515
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At Each Oil Change
²Change the engine oil filter.
²Inspect the brake hoses and lines.
²Check the Manual Transmission fluid level.
CAUTION!
Failure to perform the required maintenance items
may result in damage to the vehicle.
Required Maintenance Intervals
NOTE:** Vehicles built with the 4.7L engine are
equipped with sixteen spark plugs, one set is located on
the top of the engine under the coils and the second set is
located on the side of the engine.
The spark plugs located under the coils are a standard
plug and must be changed every 30,000 miles (50 000 km)
The spark plugs located on the side of the engine are a
premium plug and must be changed every 102,000 miles
(170 000 km).
516 MAINTENANCE SCHEDULES
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