NOTE:To select the proper gear position for maximum
deceleration (engine braking), simply push and hold the
ERS (-) switch. The transmission will shift to the range
from which the vehicle can best be slowed down.
CAUTION!
When using ERS for engine braking while descending
steep grades, be careful not to overspeed the engine.
Apply the brakes as needed to prevent engine over-
speed.
Overdrive Operation
The automatic transmission includes an electronically con-
trolled Overdrive (fifth and sixth gears). The transmission
will automatically shift into Overdrive if the following
conditions are present:
• The gear selector is in the DRIVE position.
• The transmission fluid has reached an adequate tem-
perature.
• The engine coolant has reached an adequate tempera-
ture. •
Vehicle speed is sufficiently high.
• The TOW/HAUL switch has not been activated.
• The driver is not heavily pressing the accelerator.
When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting occurs,
push the TOW/HAUL switch to activate TOW/HAUL
mode. This will improve performance and reduce the
potential for transmission overheating or failure due to
excessive shifting. When operating in TOW/HAUL mode,
transmission upshifts are delayed, and the transmission
will automatically downshift (for engine braking) when the
throttle is closed and/or during steady braking maneu-
vers.
322 STARTING AND OPERATING
Driving Through Water
Extreme care should be taken crossing any type of water.
Water crossings should be avoided if possible and only be
attempted when necessary, in a safe responsible manner.
You should only drive through areas which are designated
and approved. You should tread lightly and avoid damage
to the environment. You should know your vehicle’s
abilities and be able to recover it if something goes wrong.
You should never stop or shut a vehicle off when crossing
deep water unless you ingested water into the engine air
intake. If the engine stalls do not attempt to restart it.
Determine if it has ingested water first. The key to any
crossing is low and slow. You want to use first gear in 4L
(Low Range) and proceed very slowly with a constant slow
speed (3-5 mph [5–8 km/h] maximum) and light throttle.
Keep the vehicle moving; do not try to accelerate through
the crossing. After crossing any water higher than the
bottom of the axle differentials, you should inspect all of
the vehicle fluids for signs of water ingestion.
CAUTION!
Water ingestion into the axles, transmission, transfer
case, engine or vehicle interior can occur if you drive
(Continued)
CAUTION!(Continued)
too fast or through too deep of water. Water can cause
permanent damage to engine, driveline or other ve-
hicle components and your brakes will be less effec-
tive once wet and/or muddy.
• Before You Cross Any Type Of Water – As you ap-
proach any type of water you need to determine if you
can cross it safely and responsibly. If necessary, get out
and walk through the water or probe it with a stick. You
need to be sure of its depth, approach angle, current and
bottom condition. Be careful of murky or muddy waters,
check for hidden obstacles. Make sure you will not be
intruding on any wildlife and you can recover the
vehicle if necessary. The key to a safe crossing is the
water depth, current and bottom conditions. On soft
bottoms the vehicle will sink in, effectively increasing
the water level on the vehicle. Be sure to consider this
when determining the depth and the ability to safely
cross.
• Crossing Puddles, Pools, Flooded Areas Or Other
Standing Water – Puddles, pools, flooded or other
standing water areas normally contain murky or muddy
waters. These water types normally contain hidden
obstacles and make it difficult to determine an accurate
370 STARTING AND OPERATING
Towing Tips
Before setting out on a trip, practice turning, stopping, and
backing up the trailer in an area located away from heavy
traffic.
Automatic Transmission
The DRIVE range can be selected when towing. The
transmission controls include a drive strategy to avoid
frequent shifting when towing. However, if frequent shift-
ing does occur while in DRIVE, select TOW/HAUL mode
or select a lower gear range (using the Electronic Range
Select (ERS) shift control).
NOTE:Using TOW/HAUL mode or selecting a lower
gear range (using the ERS shift control) while operating the
vehicle under heavy loading conditions will improve per-
formance and extend transmission life by reducing exces-
sive shifting and heat build up. This action will also
provide better engine braking.
When towing a loaded trailer up steep grades at low
speeds (20 mph [32 km/h] or below), holding your vehicle
in first gear (using the ERS shift control) can help to avoid
transmission overheating.
If you regularly tow a trailer for more than 45 minutes of
continuous operation, then change the automatic transmis-
sion fluid and filter(s) as specified for police, taxi, fleet, or
Seven-Pin Connector
1 — Battery5 — Ground
2 — Backup Lamps 6 — Left Stop/Turn
3 — Right Stop/Turn 7 — Running Lamps
4 — Electric Brakes
6
STARTING AND OPERATING 431
Recreational Towing — Two-Wheel Drive Models
DO NOT flat tow this vehicle. Damage to the drivetrain
will result.
Recreational towing (for two-wheel drive models) is al-
lowedONLY if the rear wheels are OFFthe ground. This
may be accomplished using a tow dolly or vehicle trailer. If
using a tow dolly, follow this procedure:
NOTE: If vehicle is equipped with air suspension, ensure
the vehicle is set to Normal Ride Height.
1. Properly secure the dolly to the tow vehicle, following the dolly manufacturer’s instructions.
2. Drive the rear wheels onto the tow dolly.
3. Firmly apply the parking brake. Place automatic trans- mission in PARK, manual transmission in gear (not in
NEUTRAL).
4. Properly secure the rear wheels to the dolly, following the dolly manufacturer’s instructions.
5. Turn the ignition OFF and remove the key fob.
6. Install a suitable clamping device, designed for towing, to secure the front wheels in the straight position.
CAUTION!
•Towing with the rear wheels on the ground will
cause severe transmission damage. Damage from
improper towing is not covered under the New
Vehicle Limited Warranty.
• Do not disconnect the driveshaft because fluid may
leak from the transmission, causing damage to inter-
nal parts.
Recreational Towing — Four-Wheel Drive Models
NOTE: Both the manual shift and electronic shift transfer
cases must be shifted into NEUTRAL (N) for recreational
towing. Automatic transmissions must be shifted into
PARK for recreational towing. Manual transmissions must
be placed in gear (NOT in NEUTRAL) for recreational
towing. Refer to the following for the proper transfer case
NEUTRAL (N) shifting procedure for your vehicle.
CAUTION!
• DO NOT dolly tow any 4WD vehicle. Towing with
only one set of wheels on the ground (front or rear)
will cause severe transmission and/or transfer case
(Continued)
6
STARTING AND OPERATING 437
CAUTION!(Continued)
damage. Tow with all four wheels either ON the
ground, or OFF the ground (using a vehicle trailer).
• Tow only in the forward direction. Towing this
vehicle backwards can cause severe damage to the
transfer case.
• Before recreational towing, the transfer case must be
in NEUTRAL. To be certain the transfer case is fully
in NEUTRAL, perform the procedure outlined under
“Shifting Into NEUTRAL”. Internal transmission
damage will result, if the transfer case is not in
NEUTRAL during towing.
• Automatic transmissions must be placed in PARK,
and manual transmissions must be placed in gear
(not in Neutral) for recreational towing.
• Towing this vehicle in violation of the above require-
ments can cause severe transmission and/or transfer
case damage. Damage from improper towing is not
covered under the New Vehicle Limited Warranty.
• Do not disconnect the rear driveshaft because fluid
will leak from the transfer case, causing damage to
internal parts.
• Do not use a bumper-mounted clamp-on tow bar on
your vehicle. The bumper face bar will be damaged.
Shifting Into NEUTRAL (N)
Use the following procedure to prepare your vehicle for
recreational towing.
WARNING!
You or others could be injured or killed if you leave the
vehicle unattended with the transfer case in the NEU-
TRAL (N) position without first fully engaging the
parking brake. The transfer case NEUTRAL (N) posi-
tion disengages both the front and rear driveshafts
from the powertrain, and will allow the vehicle to roll,
even if the automatic transmission is in PARK (or
manual transmission is in gear). The parking brake
should always be applied when the driver is not in the
vehicle.
CAUTION!
It is necessary to follow these steps to be certain that
the transfer case is fully in NEUTRAL (N) before
recreational towing to prevent damage to internal
parts.
438 STARTING AND OPERATING
SERVICING AND MAINTENANCE
CONTENTS
SCHEDULED SERVICING .................517
▫ Maintenance Plan ..................... .518
▫ Heavy Duty Use Of The Vehicle ............522
ENGINE COMPARTMENT .................523
▫ 3.6L Engine ..........................523
▫ 5.7L Engine ..........................524
▫ 6.4L Engine ..........................525
▫ Checking Oil Level — Gas Engine ...........526
▫ Adding Washer Fluid ...................526
▫ Maintenance-Free Battery .................526
DEALER SERVICE .......................527
▫ Engine Oil — Gas Engine .................528
▫ Engine Oil Filter .......................530
▫ Engine Air Cleaner Filter .................531 ▫
Air Conditioner Maintenance ..............533
▫ Front Driveshaft Lubrication — 2500/3500
(Four-Wheel Drive Models Only) ............539
▫ Accessory Drive Belt Inspection ............540
▫ Body Lubrication ..................... .541
▫ Windshield Wiper Blades .................542
▫ Exhaust System ........................545
▫ Cooling System ........................546
▫ Brake System ........................ .552
▫ Automatic Transmission ..................553
▫ Rear Axle And 4x4 Front Driving Axle Fluid
Level ...............................556
▫ Transfer Case ........................ .557
HOISTING ............................558
TIRES ............................... .558
8
Severe Duty All Models
NOTE:Change Engine Oil at 4,000 miles (6,500 km) or 350
hours of engine run time if the vehicle is operated in a
dusty and off road environment or is operated predomi-
nantly at idle, or only very low engine RPM’s. This type of
vehicle use is considered Severe Duty.
Once A Month Or Before A Long Trip:
• Check engine oil level
• Check windshield washer fluid level
• Check tire pressure and look for unusual wear or
damage. Rotate tires at the first sign of irregular wear,
even if it occurs before the oil indicator system turns on.
• Check the fluid levels of the coolant reservoir, brake
master cylinder, power steering (2500/3500 Models
Only) and automatic transmission (six-speed only) and
fill as needed
• Check function of all interior and exterior lightsMaintenance Plan
Required Maintenance
Refer to the Maintenance Plan on the following pages for
required maintenance.
At Every Oil Change Interval As Indicated By Oil
Change Indicator System:
•Change oil and filter.
• Rotate the tires. Rotate at the first sign of irregular
wear, even if it occurs before the oil indicator
system turns on.
• Inspect battery and clean and tighten terminals as
required.
• Inspect automatic transmission fluid if equipped
with dipstick.
• Inspect brake pads, shoes, rotors, drums, hoses and
park brake.
• Inspect engine cooling system protection and hoses.
• Inspect exhaust system.
• Inspect engine air cleaner if using in dusty or
off-road conditions.
• Lube the front drive shaft fitting (2500/3500 (4x4)
models only).
518 SERVICING AND MAINTENANCE
Mileage or time passed (which-ever comes first)
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
110,000
120,000
130,000
140,000
150,000
Or Years: 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Or Kilometers:
32,000
48,000
64,000
80,000
96,000
112,000
128,000
144,000
160,000
176,000
192,000
208,000
224,000
240,000
Inspect the brake linings, replace
as necessary. XXX X X X X
Adjust parking brake as necessary. X X X X X X X
Inspect transfer case fluid. XX X
Additional Maintenance
Replace cabin air filter. XX X XX XX
Replace engine air filter. XX X X X
Replace spark plugs. ** X
Flush and replace the engine cool-
ant at 10 years or 150,000 miles
(240,000 km) whichever comes
first. XX
Change automatic transmission
fluid and filter(s) (six-speed auto-
matic only), if using your vehicle
for police, taxi, fleet, or frequent
trailer towing. XX
520 SERVICING AND MAINTENANCE