▫Tire Identification Number (TIN) ...........533
▫ Tire Terminology And Definitions ..........534
▫ Tire Loading And Tire Pressure ...........535
TIRES — GENERAL INFORMATION ........540
▫ Tire Pressure ....................... .540
▫ Tire Inflation Pressures .................541
▫ Tire Pressures For High Speed Operation . . . .543
▫ Radial Ply Tires ..................... .543
▫ Tire Types .......................... .544
▫ Run Flat Tires — If Equipped .............545
▫ Spare Tires — If Equipped ...............546
▫ Tire Spinning ....................... .548
▫ Tread Wear Indicators ..................548 ▫
Life Of Tire ........................ .549
▫ Replacement Tires .....................550
SUPPLEMENTAL TIRE PRESSURE INFORMATION
— IF EQUIPPED ...................... .551
TIRE CHAINS (TRACTION DEVICES) .......552
TIRE ROTATION RECOMMENDATIONS .....554
▫ Directional Tires — If Equipped ...........555
▫ Dual Rear Wheels — If Equipped ..........555
TIRE PRESSURE MONITOR SYSTEM (TPMS) . .557
▫ Base System ........................ .560
▫ Premium System — If Equipped ...........562
▫ Tire Pressure Information System (TPIS) 3500
Series Trucks ........................ .566
▫ General Information ...................567
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STARTING AND OPERATING 381
in four-wheel drive and that the front and rear drive-
shafts are locked together. This light will illuminate when
the transfer case is shifted into either the 4H or 4L
position. There is no light for the 2H or NEUTRAL
positions on some models.
When operating your vehicle in 4L, the engine speed is
approximately three times that of the 2H or 4H positions
at a given road speed. Take care not to overspeed the
engine and do not exceed 25 mph (40 km/h).
Proper operation of four-wheel drive vehicles depends
on tires of equal size, type and circumference on each
wheel. Any difference will adversely affect shifting and
can cause damage to the drivetrain.
NOTE:Do not attempt to make a shift while only the
front or rear wheels are spinning. The front and rear
driveshaft speeds must be equal for the shift to take
place. Shifting while only the front or rear wheels are
spinning can cause damage to the transfer case. Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
NOTE:
Delayed shifts out of four-wheel drive may be
experienced due to uneven tire wear, low or uneven tire
pressures, excessive vehicle loading, or cold tempera-
tures.
WARNING!
You or others could be injured or killed if you leave
the vehicle unattended with the transfer case in the
NEUTRAL position without first fully engaging the
parking brake. The transfer case NEUTRAL position
disengages both the front and rear drive shafts from
the powertrain and will allow the vehicle to move
regardless of the transmission position. The parking
brake should always be applied when the driver is
not in the vehicle.
430 STARTING AND OPERATING
NOTE:If equipped with a touch screen radio all
enabling/disabling of air suspension features must be
done through the radio. Refer to “Uconnect® Access
Settings” in “Understanding Your Instrument Panel” for
further information.
WARNING!
The air suspension system uses a high pressure
volume of air to operate the system. To avoid per-
sonal injury or damage to the system, see your
authorized dealer for service.
Air Suspension Modes
The Air Suspension system has multiple modes to protect
the system in unique situations:
Tire/Jack Mode
To assist with changing a spare tire, the air suspension
system has a feature which allows the automatic leveling to be disabled. Refer to “Electronic Vehicle Information
Center (EVIC)” in “Understanding Your Instrument
Panel” for further information.
NOTE:
This mode is intended to be enabled with engine
running.
Transport Mode
To assist with flat bed towing, the air suspension system
has a feature which will put the vehicle into Entry/Exit
height and disable the automatic load leveling system.
Refer to “Electronic Vehicle Information Center (EVIC)”
in “Understanding Your Instrument Panel” for further
information.
NOTE: This mode is intended to be enabled with engine
running.
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STARTING AND OPERATING 455
including towing a trailer. The trailer button will blink
continuously until trailer height has been achieved.
The system requires that the ignition be in ON/RUN
position or the engine running for all user requested
changes.
After the engine is turned off, it may be noticed that the
air suspension system operates briefly, this is normal. The
system is correcting the position of the vehicle to ensure
a proper appearance.
NOTE:If equipped with a touch screen radio all
enabling/disabling of air suspension features must be
done through the radio. Refer to “Uconnect® Access
Settings” in “Understanding Your Instrument Panel” for
further information.WARNING!
The air suspension system uses a high pressure
volume of air to operate the system. To avoid per-
sonal injury or damage to the system, see your
authorized dealer for service.
Air Suspension Modes
The Air Suspension system has multiple modes to protect
the system in unique situations:
Tire/Jack Mode
To assist with changing a spare tire, the air suspension
system has a feature which allows the automatic leveling
to be disabled. This mode is intended to be used with
engine running. Refer to “Electronic Vehicle Information
Center (EVIC)” in “Understanding Your Instrument
Panel” for further information.
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STARTING AND OPERATING 459
•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 mo-
mentum. 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
470 STARTING AND OPERATING
throttle lightly while holding a light brake pressure and
ease the vehicle up and over the object.
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
ensures 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
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STARTING AND OPERATING 471
stream or river even in shallow water. Fast moving
water can easily push your vehicle downstream
sweeping it out of control. Even in very shallow water,
a high current can still wash the dirt out from around
your tires putting you and your vehicle in jeopardy.
There is still a high risk of personal injury and vehicle
damage with slower water currents in depths greater
than the vehicle’s running ground clearance. You
should never attempt to cross flowing water which is
deeper than the vehicle’s running ground clearance.
Even the slowest current can push the heaviest vehicle
downstream out of control if the water is deep enough
to push on the large surface area of the vehicle’s body.
Before you proceed determine the speed of the current,
the water’s depth, approach angle, bottom condition
and if there are any obstacles, then cross at an angle
heading slightly upstream using the low and slow
technique.WARNING!
Never drive through fast moving deep water. It can
push your vehicle downstream, sweeping it out of
control. This could put you and your passengers at
risk of injury or drowning.
Airing Down For Off-Road Driving
Running lower tire pressure off-road can improve your
ride comfort and vehicle traction. Reducing the tire air
pressure allows the tire to bulge slightly, improving its
surface area for better flotation and ability to mold or
form to the ground contour. Different terrain, tires, and
vehicles require different tire pressure. Hard surfaces like
rock and heavier vehicles require higher pressures than
softer surfaces such as sand and lighter vehicles. You will
need to experiment to determine what is right for your
situation. It is easier and faster to let air out than it is to
478 STARTING AND OPERATING
replace it so, start high and lower it as required. Remem-
ber you must return the tires to normal air pressure
before driving on road or at highway conditions. Be sure
you have a way to return the tires to their normal on road
air pressure.
CAUTION!
Reduced tire pressure increases the risk of tire dam-
age and may cause tire unseating with total loss of air
pressure. To reduce the risk of tire unseating, while at
a reduced tire pressure, drive at slower speeds and
avoid sharp turns or abrupt maneuvers.
Vehicle Recovery
If you drive off-road, you may encounter a situation
where you will need to recover your vehicle. Vehicle
recovery should always be given consideration before
attempting a questionable obstacle. You should never gooff-road driving without the ability to recover your
vehicle from a situation. Having another vehicle with
you usually works best for most situations. The first
thing to do is assess the situation. Why are you stuck?
Are you hung up on something? Would it be easier to go
forward or to go backward? Can you still move the
vehicle? Is there an anchor point to winch to? Are you
alone or do you have another vehicle to help? Is there
high risk of vehicle damage during the recovery process?
Answering these questions will help you determine the
best method of recovery. If you can still move the vehicle
slightly and the only issue is slick ground, then rock
cycling your vehicle would be the first choice. If you have
ample room, an additional vehicle and there is low risk of
vehicle impingement on the surroundings, then using a
tow strap to the vehicle tow hooks would be fast and
easy. If the vehicle is severely hung up or in a situation
where great care needs to be taken during the recovery,
then nothing can do the job better than a winch. If you are
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