tires JEEP WRANGLER UNLIMITED 2008 Owners Manual

21. Odometer/Trip Odometer Reset Button
Press this button to change the display from odometer to
either of two trip odometer settings. Trip A or Trip B will
appear when in the trip odometer mode. Press and hold
the button for two seconds to reset the trip odometer to 0
miles or kilometers. The odometer must be in trip mode
to reset.
22. Transmission Range Indicator
This display indicator shows the automatic transmission
gear selection.
23. Tire Pressure Monitoring Telltale LightEach tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recommended
by the vehicle manufacturer on the vehicle
placard or tire inflation pressure label. (If your vehicle
has tires of a different size than the size indicated on the vehicle placard or tire inflation pressure label, you should
determine the proper tire inflation pressure for those
tires.)
As an added safety feature, your vehicle has been
equipped with a tire pressure monitoring system (TPMS)
that illuminates a low tire pressure telltale when one or
more of your tires is significantly under-inflated. Accord-
ingly, when the low tire pressure telltale illuminates, you
should stop and check your tires as soon as possible, and
inflate them to the proper pressure. Driving on a signifi-
cantly under-inflated tire causes the tire to overheat and
can lead to tire failure. Under-inflation also reduces fuel
efficiency and tire tread life, and may affect the vehicle’s
handling and stopping ability.
Please note that the TPMS is not a substitute for proper
tire maintenance, and it is the driver ’s responsibility to
maintain correct tire pressure, even if under-inflation has
not reached the level to trigger illumination of the TPMS
low tire pressure telltale.

rear wheels to rotate at the same speed. This is accom-
plished by simply moving the shift lever to one of these
positions. The 4H and 4L positions are intended for loose,
slippery road surfaces only, and not intended for normal
driving. Driving in the 4H and 4L positions on hard
surfaced roads will cause increased tire wear and damage
to the driveline components.
The 4WD Indicator Light (located in the instrument
cluster) alerts the driver that the vehicle is in four-wheel
drive, and the front and rear driveshafts are locked
together. The light will illuminate when the transfer case
is shifted into the 4H position.
NOTE:Do not attempt to shift when only the front or
rear wheels are spinning. The transfer case is not
equipped with a synchronizer, and the front and rear
driveshaft speeds must be equal for a shift to take place.
Shifting while only the front or rear wheels are spinning
can cause damage to the transfer case. When operating your vehicle in 4L, the engine speed will
be approximately three times (four times for Rubicon
models) that of the 2H or 4H positions at a given road
speed. Take care not to overspeed the engine.
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
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.
286 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 2nd
gear (manual transmission), or DRIVE (automatic trans-
mission), with the transfer case in the 4L (Low) position
to maintain your momentum. If you start to slow to a
stop, try turning your steering wheel no more than a 1/4
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 is using the appropriate tirepressure, accelerating slowly, avoiding abrupt maneu-
vers 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 han-
dling, while driving on the soft sand, but you must return
the tires to normal air pressure before driving on pave-
ment or other hard surfaces. Be sure you have a way to
reinflate the tires prior to reducing the pressure.

branches or other obstacles on the path? Can you safely
recover the vehicle if something goes wrong? If every-
thing looks good and you feel confident, shift the trans-
mission into a lower gear with 4L (Low) engaged, and
proceed with caution maintaining your momentum as
you climb the hill.
Driving Up Hill
Once you have determined your ability to proceed and
have shifted into the appropriate gear, line your vehicle
up for the straightest possible run. Accelerate with an
easy constant throttle and apply more power as you start
up the hill. Do not race forward into a steep grade, the
abrupt change of grade could cause you to lose control. If
the front end begins to bounce, ease off the throttle
slightly to bring all four tires back on the ground. As you
approach the crest of the hill, ease off the throttle and
slowly proceed over the top. If the wheels start to slip as
you approach the crest of a hill, ease off the accelerator
and maintain headway by turning the steering wheel nomore than a 1/4 turn quickly back and forth. This will
provide a fresh
biteinto the surface and will usually
provide enough traction to complete the climb. If you do
not make it to the top, place the vehicle in REVERSE and
back straight down the grade using engine resistance
along with the vehicle brakes.

CAUTION!
Muddy waters can reduce the cooling system effec-
tiveness by depositing debris onto the radiator.
Crossing Ditches, Streams, Shallow Rivers Or
Other Flowing Water
Flowing water can be extremely dangerous. Never at-
tempt to cross a fast running 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. Eventhe slowest current can push the heaviest vehicle down-
stream 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!
Significant over or under-inflation of tires, or mixing
sizes of tires or wheels on the vehicle can lead to loss
of braking effectiveness.
The Anti-Lock Brake System conducts a low speed self-
test at about 12 mph (20 km/h). If for any reason, your
foot is on the brake when the vehicle reaches 12 mph (20
km/h), this check will be delayed until 25 mph (40
km/h).
The Anti-Lock Brake System pump motor runs during
the self-test, and during an ABS stop, to provide the
regulated hydraulic pressure. The motor pump makes a
low humming noise during operation, this is normal. During off-road use, loss of traction can temporarily
defeat the system and cause the warning light to illumi-
nate. Turn the ignition OFF and ON again to restore
Anti-Lock Brake System function.

Tire Identification Number (TIN)
The TIN may be found on one or both sides of the tire
however the date code may only be on one side. Tires with
white sidewalls will have the full TIN including date codelocated on the white sidewall side of the tire. Look for the
TIN on the outboard side of black sidewall tires as mounted
on the vehicle. If the TIN is not found on the outboard side
then you will find it on the inboard side of the tire.

Tire and Loading Information Placard
This placard tells you important information about
the
1) number of people that can be carried in the vehicle
2) total weight your vehicle can carry
3) tire size designed for your vehicle4) cold tire inflation pressures for the front, rear and
spare tires.
Loading
The vehicle maximum load on the tire must not exceed
the load carrying capacity of the tire on your vehicle. You
will not exceed the tire’s load carrying capacity if you
adhere to the loading conditions, tire size and cold tire
inflation pressures specified on the Tire and Loading
Information placard and the Vehicle Loading section of
this manual. Refer to “Vehicle Loading” in this section.
NOTE:
Under a maximum loaded vehicle condition,
gross axle weight ratings (GAWRs) for the front and rear
axles must not be exceeded. For further information on
GAWRs, vehicle loading and trailer towing. Refer to
“Vehicle Loading” in this section.
To determine the maximum loading conditions of your
vehicle, locate the statement “The combined weight of
occupants and cargo should never exceed XXX kg or XXX

Tread Wear Indicators
Tread wear indicators are in the original equipment tires
to help you in determining when your tires should be
replaced.These indicators are molded into the bottom of the tread
grooves and will appear as bands when the tread depth
becomes 1/16 inch (2 mm). When the indicators appear
in two or more adjacent grooves, the tire should be
replaced.
Many states have laws requiring tire replacement at this
point.
Life of Tire
The service life of a tire is dependent upon varying
factors including but not limited to:
•Driving style
•Tire pressure
•Distance driven

WARNING!
•Do not use a tire, wheel size or rating other than that
specified for your vehicle. Some combinations of
unapproved tires and wheels may change suspension
dimensions and performance characteristics, result-
ing in changes to steering, handling, and braking of
your vehicle. This can cause unpredictable handling
and stress to steering and suspension components.
You could lose control and have an accident resulting
in serious injury or death. Use only the tire and wheel
sizes with load ratings approved for your vehicle.
• Never use a tire with a smaller load index or capacity,
other than what was originally equipped on your
vehicle. Using a tire with a smaller load index could
result in tire overloading and failure. You could lose
control and have an accident.
• Failure to equip your vehicle with tires having ad-
equate speed capability can result in sudden tire
failure and loss of vehicle control.