
Operating Tips
NOTE:Refer to the chart at the end of this section for
suggested control settings for various weather conditions.
Summer Operation
The engine cooling system must be protected with a
high-quality antifreeze coolant to provide proper corrosion
protection and to protect against engine overheating. OAT
coolant (conforming to MS.90032) is recommended. Refer
to “Maintenance Procedures” in “Maintaining Your Ve-
hicle” for proper coolant selection.
Winter Operation
To ensure the best possible heater and defroster perfor-
mance, make sure the engine cooling system is functioning
properly and the proper amount, type, and concentration
of coolant is used. Refer to “Maintenance Procedure” in
“Maintaining Your Vehicle” for proper coolant selection.
Use of the air Recirculation mode during Winter months is
not recommended because it may cause window fogging.
Vacation/Storage
Any time you store your vehicle or keep it out of service
(i.e., vacation) for two weeks or more, run the air condi-
tioning system at idle for about five minutes in fresh air
with the blower setting in high. This will ensure adequate
system lubrication to minimize the possibility of compres-
sor damage when the system is started again.
Window Fogging
Vehicle windows tend to fog on the inside of the glass in
mild, rainy and/or humid weather. Windows may frost on
the inside of the glass in very cold weather. To clear the
windows, select Defrost or Mix mode and increase the
front blower speed. Do not use the Recirculation mode
without A/C for long periods, as fogging may occur.
NOTE: Automatic Temperature Controls (ATC) will auto-
matically adjust the climate control settings to reduce or
eliminate window fogging on the front windshield. When
this occurs, recirculation will be unavailable.
346 UNDERSTANDING YOUR INSTRUMENT PANEL

Outside Air Intake
Make sure the air intake, located directly in front of the
windshield, is free of obstructions such as leaves. Leaves
collected in the air intake may reduce airflow, can cause
odor, and if they enter the plenum they could plug the
water drains. In Winter months make sure the air intake is
clear of ice, slush and snow.
Cabin Air Filter
The climate control system has a cabin air filter that filters
out dust and pollen from the air. Refer to “Maintenance
Procedures” in “Maintaining Your Vehicle” for filter re-
placement instructions.
4
UNDERSTANDING YOUR INSTRUMENT PANEL 347

Normal Ride Height (NRH)– This is the standard position
of the suspension and is meant for normal driving. It will
automatically adjust to maintain the rear ride height as
conditions change.
Alternate Trailer Height (ATH) – Lowers the vehicle
approximately 1 in (25 mm) for a level truck, to be used as
required while trailer towing. It will automatically adjust
to maintain the rear ride height as conditions change.
Trailer Decoupling/Unloading - The air suspension sys-
tem will load level (lower/exhaust only) for up to 10 min-
utes after the vehicle is turned off. This allows for easy
removal of a trailer and/or load from the back of the truck
by maintaining the ride height. After 10 minutes you will
need to turn the ignition to the run position for the air
suspension to maintain ride height. If the air suspension
system is disabled using the settings menu (Tire Jack Mode,
Transport Mode or Alignment Mode) the system will
remain disabled when the vehicle is turned off. Reactivat-
ing the air suspension can be accomplished via the settings
menu or driving the vehicle above 5 mph (8 km/h) for Tire
Jack Mode or Alignment Mode and 16 mph (26 km/h) for
Transport Mode. NOTE:
•
Most 3500 models will not lower to Alternate Trailer
Height (ATH) when unloaded.
• Refer to “Trailer Towing” in “Starting And Operating”
for further information.
Ignition OFF Behavior
For a predetermined amount of time after the ignition is off
the air suspension may adjust to maintain a proper appear-
ance.
WARNING!
The air suspension system uses a high pressure vol-
ume of air to operate the system. To avoid personal
injury or damage to the system, see your authorized
dealer for service.
5
STARTING AND OPERATING 451

This system is controlled by the electronic control sway bar
switch located on the instrument panel.
The switch has two positions; On-Road and Off-Road. The
system is normally in the On-Road mode, indicated by a
solid green light. The stabilizer/sway bar should remain in
the On-Road mode during normal driving conditions.WARNING!
Do not disconnect the stabilizer bar and drive on hard
surfaced roads or at speeds above 18 mph (29 km/h),
you may lose control of the vehicle, which could result
in serious injury or death. The front stabilizer bar
enhances vehicle stability and assists in maintaining
control of the vehicle. The system monitors vehicle
speed and will attempt to reconnect the stabilizer bar
at speeds over 18 mph (29 km/h). This is indicated by a
flashing off road light and solid on road light. Once
vehicle speed is reduced below 14 mph (22 km/h), the
system will attempt to return to the Off-Road mode.
To disconnect the stabilizer/sway bar, shift to either 4HI or
4LO as shown in “Four Wheel Drive Operation” and push
the right hand Off Road stabilizer/sway bar button to
obtain the Off-Road position. The amber indicator light
will flash until the stabilizer/sway bar has been fully
disconnected.
Sway Bar Disconnect Buttons
456 STARTING AND OPERATING

•Mud – Deep mud creates a great deal of suction around
the tires and is very difficult to get through. You should
use 4LO (Low Range) with a gear low enough to
maintain your momentum without shifting. If you start
to slow to a stop, try turning your steering wheel no
more than a ¼ turn quickly back and forth for additional
traction. Mud holes pose an increased threat of vehicle
damage and getting stuck. They are normally full of
debris from previous vehicles getting stuck. As a good
practice before entering any mud hole, get out and
determine how deep it is, if there are any hidden
obstacles and if the vehicle can be safely recovered if
stuck.
• Sand – Soft sand is very difficult to travel through with
full tire pressure. When crossing soft sandy spots in a
trail maintain your vehicle’s momentum and do not
stop. The key to driving in soft sand using the appro-
priate tire pressure, accelerating slowly, avoiding abrupt
maneuvers and maintaining the vehicle’s momentum. If
you are going to be driving on large soft sandy areas or
dunes, reduce your tire pressure to a minimum of 15 psi
(103 kPa) to allow for a greater tire surface area. Reduced
tire pressure will drastically improve your traction and
handling, while driving on the soft sand, but you must
return the tires to normal air pressure before driving on pavement or other hard surfaces. Be sure you have a
way to air the tires back up prior to reducing the
pressure.
CAUTION!
Reduced tire pressures may cause tire unseating and
total loss of air pressure. To reduce the risk of tire
unseating, while at a reduced tire pressure, reduce your
speed and avoid sharp turns or abrupt maneuvers.
Crossing Obstacles (Rocks And Other High Points)
While driving off road, you will encounter many types of
terrain. These varying types of terrain bring different types
of obstacles. Before proceeding review the path ahead to
determine the correct approach and your ability to safely
recover the vehicle if something goes wrong. Keeping a
firm grip on the steering wheel, bring the vehicle to a
complete stop and then inch the vehicle forward until it
makes contact with the object. Apply the throttle lightly
while holding a light brake pressure and ease the vehicle
up and over the object.
460 STARTING AND OPERATING

WARNING!
Crossing obstacles can cause abrupt steering system
loading which could cause you to loose control of your
vehicle.
Using A Spotter
There are many times where it is hard to see the obstacle or
determine the correct path. Determining the correct path
can be extremely difficult when you are confronting many
obstacles. In these cases have someone guide you over,
through, or around the obstacle. Have the person stand a
safe distance in front of you where they can see the
obstacle, watch your tires and undercarriage, and guide
you through.
Crossing Large Rocks
When approaching large rocks, choose a path which en-
sures you drive over the largest with your tires. This will
lift your undercarriage over the obstacle. The tread of the
tire is tougher and thicker than the side wall and is
designed to take the abuse. Always look ahead and make
every effort to cross the large rocks with your tires.
CAUTION!
•Never attempt to straddle a rock that is large enough
to strike your axles or undercarriage.
• Never attempt to drive over a rock which is large
enough to contact the door sills.
Crossing A Ravine, Gully, Ditch, Washout Or Rut
When crossing a ravine, gully, ditch, washout or a large rut,
the angled approach is the key to maintaining your vehi-
cle’s mobility. Approach these obstacles at a 45-degree
angle and let each tire go through the obstacle indepen-
dently. You need to use caution when crossing large
obstacles with steep sides. Do not attempt to cross any
large obstacle with steep sides at an angle great enough to
put the vehicle at risk of a rollover. If you get caught in a
rut, dig a small trench to the right or left at a 45-degree
angle ahead of the front tires. Use the removed dirt to fill
the rut ahead of the turnout you just created. You should
now be able to drive out following the trench you just
created at a 45-degree angle.
5
STARTING AND OPERATING 461

Rigging Techniques
Various winching situations will require application of
other winching techniques. These could range from too
little distance to achieve maximum pull using straight line
rigging, simply increasing pulling power, or maintaining a
straight-line pulling situation. You will have to assess what
technique is correct for your situation. Thinksafetyat all
times.
How To Change The Pulling Direction
All winching operations should have a straight line from
the winch to the object being pulled. This minimizes the
wire rope collecting on one side of the drum affecting
pulling efficiency and damaging wire rope. A snatch block,
secured to a point directly in front of the vehicle will enable
you to change your pulling direction while still allowing
the wire rope to be at 90° to wind properly onto the
spooling drum.
Increasing Pulling Power
In some cases, you may find yourself needing more pulling
power. The use of snatch blocks increases mechanical
advantage and that increases your pulling power.
Change Pulling Directions
5
STARTING AND OPERATING 489

Power Steering Fluid Check — 2500/3500 Models
Checking the power steering fluid level at a defined service
interval is not required. The fluid should only be checked
if a leak is suspected, abnormal noises are apparent,
and/or the system is not functioning as anticipated. Coor-
dinate inspection efforts through an authorized dealer.
CAUTION!
Do not use chemical flushes in your power steering
system as the chemicals can damage your power steer-
ing components. Such damage is not covered by the
New Vehicle Limited Warranty.
WARNING!
Fluid level should be checked on a level surface and
with the engine off to prevent injury from moving
parts and to ensure accurate fluid level reading. Do not
overfill. Use only manufacturer’s recommended power
steering fluid.
If necessary, add fluid to restore to the proper indicated
level. With a clean cloth, wipe any spilled fluid from all
surfaces. Refer to “Fluids, Lubricants, And Genuine Parts”
in “Maintaining Your Vehicle” for further information.
FUEL SAVER TECHNOLOGY 5.7L/6.4L ENGINES
ONLY — IF EQUIPPED
This feature offers improved fuel economy by shutting off
four of the engine’s eight cylinders during light load and
cruise conditions. The system is automatic with no driver
inputs or additional driving skills required.
NOTE: This system may take some time to return to full
functionality after a battery disconnect.
PARKING BRAKE
Before leaving the vehicle, make sure that the parking
brake is fully applied. Also, be certain to leave the trans-
mission in PARK.
The foot operated parking brake is located below the lower
left corner of the instrument panel. To apply the park
brake, firmly push the park brake pedal fully. To release the
parking brake, pull the parking brake release handle.
492 STARTING AND OPERATING