2008 JEEP WRANGLER automatic transmission

Overdrive can be locked out by pressing the O/D OFF
switch located on the center console. The O/D OFF
indicator light (on the switch) will illuminate to show
that the switch has been activated. When the indicator
light is on, Overdrive is locked out. Pressing the switch a
second time restores the Overdrive function. The lockout
feature is useful when towing a trailer or carrying a
heavy load.
2 (Second)
For moderate grades and to assist braking on dry pave-
ment or in mud and snow. Begins from a stop in low gear
with automatic upshift to 2nd gear. Will not shift to 3rd.
1 (First)
For hard pulling at low speeds in mud, sand, snow, or on
steep grades. Begins and stays in low gear with no
upshift. Provides engine compression braking at low
speeds.CAUTION!
•Before moving the shift lever out of PARK, you
must turn the ignition from LOCK so the steering
wheel and shift lever are released. Otherwise,
damage to steering column or shift lever could
result.
•Never race the engine with the brakes on and the
vehicle in gear, and never hold the vehicle on an
incline without applying the brakes. These prac-
tices can overheat and damage the transmission.
•When “rocking” a stuck vehicle by moving be-
tween DRIVE and REVERSE, do not spin the
wheels faster than 15 mph (24 km/h), or drivetrain
damage may result.
284 STARTING AND OPERATING

Torque Converter Clutch
A feature designed to improve fuel economy has been
added to the automatic transmission of this vehicle. A
clutch within the torque converter engages automatically
at calibrated speeds. This may result in a slightly differ-
ent feeling or response during normal operation in high
gear. When the vehicle speed drops or during accelera-
tion, the clutch automatically and smoothly disengages.
FOUR–WHEEL DRIVE OPERATION
(COMMAND-TRAC™ OR ROCK-TRAC™) — IF
EQUIPPED
Operating Instructions/Precautions
The transfer case provides four mode positions — 2H
(Two-wheel drive high range), 4H (Four-wheel drive high
range), N (Neutral), and 4L (Four-wheel drive low range).The transfer case is intended to be driven in the 2H
position for normal street and highway conditions such
as hard-surfaced roads.
In the event that additional traction is required, the
transfer case 4H and 4L positions can be used to lock the
front and rear driveshafts together, forcing the front and
4WD Shift Controls
STARTING AND OPERATING 285
5

4H to 4L or 4L to 4H
With the vehicle rolling at 2 to 3 mph (3 to 5 km/h), shift
an automatic transmission into NEUTRAL (N), or de-
press the clutch pedal on a manual transmission. While
the vehicle is coasting at 2 to 3 mph (3 to 5 km/h), shift
the transfer case lever firmly to the desired position. Do
not pause with the transfer case in N (Neutral).
NOTE:Shifting into or out of 4L is possible with the
vehicle completely stopped, however, difficulty may oc-
cur due to the mating teeth not being properly aligned.
Several attempts may be required for clutch teeth align-
ment and shift completion to occur. The preferred
method is with the vehicle rolling at 2 to 3 mph (3 to 5
km/h). Avoid attempting to engage or disengage 4L with
the vehicle moving faster than 2 to 3 mph (3 to 5 km/h).WARNING!
Failure to engage a position completely can cause
transfer case damage or loss of power and vehicle
control. You could have an injury accident. Do not
drive the vehicle unless the transfer case is fully
engaged.
TRAC-LOK™ REAR AXLE — IF EQUIPPED
The Trac-Lok™ rear axle provides a constant driving
force to both rear wheels and reduces wheel spin caused
by the loss of traction at one driving wheel. If traction
differs between the two rear wheels, the differential
automatically proportions the usable torque by providing
more torque to the wheel that has traction.
STARTING AND OPERATING 289
5

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.
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.
298 STARTING AND OPERATING

WARNING!
If the engine stalls or you lose headway or cannot
make it to the top of a steep hill or grade, never
attempt to turn around. To do so may result in
tipping and rolling the vehicle, which may result in
severe injury. Always back carefully straight down a
hill in REVERSE gear. Never back down a hill in
NEUTRAL using only the vehicle brakes. Never
drive diagonally across a hill, always drive straight
up or down.
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 man-
ner. You should only drive through areas which are
designated and approved. You should tread lightly andavoid damage to the environment. You should know
your vehicles abilities and be able to recover it if some-
thing 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. Shift
into 1st gear (manual transmission), or DRIVE (automatic
transmission), with the transfer case in the 4L (Low)
position and proceed very slowly with a constant slow
speed {3 to 5 mph (5 to 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 inges-
tion.
304 STARTING AND OPERATING

PARKING BRAKE
To set the parking brake, pull the lever up as firmly as
possible. When the parking brake is applied with the
ignition ON, the Brake Warning Light in the instrument
cluster will light. To release the parking brake, pull up
slightly, press the center button, then lower the lever
completely.
NOTE:The instrument cluster Brake Warning Light
indicates only that the parking brake is applied. You must
be sure the parking brake is fully applied before leaving
the vehicle.
Be sure the parking brake is firmly set when parked, and
the shift lever is in the PARK position (automatic trans-
mission), or REVERSE, or 1st gear (manual transmission).
When parking on a hill, you should apply the parking
brake before placing the shift lever in PARK, otherwise
Parking Brake
308 STARTING AND OPERATING

the load on the transmission locking mechanism may
make it difficult to move the shifter out of PARK.
WARNING!
•Always fully apply the parking brake when leav-
ing your vehicle, or it may roll and cause damage
or injury. Also, be certain to leave an automatic
transmission in PARK, a manual transmission in
REVERSE or 1st gear. Failure to do so may allow
the vehicle to roll and cause damage or injury.
•Never leave children alone in a vehicle. Leaving
unattended children in a vehicle is dangerous for a
number of reasons. A child or others could be
seriously or fatally injured. Do not leave the key in
the ignition. A child could operate power win-
dows, other controls, or move the vehicle.When parking on a hill, turn the front wheels toward the
curb on a downhill grade and away from the curb on an
uphill grade.
The parking brake should always be applied whenever
the driver is not in the vehicle.
ANTI-LOCK BRAKE SYSTEM
The Anti-Lock Brake System (ABS) is designed to aid the
driver in maintaining vehicle control under adverse
braking conditions. The system operates with a separate
computer to modulate hydraulic pressure to prevent
wheel lock-up and help avoid skidding on slippery
surfaces.
All vehicle wheels and tires must be the same size and
type and tires must be properly inflated to produce
accurate signals for the computer.
STARTING AND OPERATING 309
5

Engine/
Transmission Axle Model GCWR (Gross
Combined Wt.Rating) Frontal Area Max. GTW
(Gross TrailerWt.) Max. Trailer
Tongue Wt. (See Note)
3.8L/Manual 3.21 2–Door X Model (4WD)4,987 lbs
(2 262 kg) 25 sq ft
(2.32 sq m) 1,000 lbs
(453 kg) 100 lbs (45 kg)
3.8L/Manual 3.73 2–Door X Model (4WD)5,987 lbs
(2 716 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
3.8L/
Automatic 3.73 2–Door X
Model (4WD) 6,032 lbs
(2 736 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
3.8L/Manual 3.21 2–Door Sahara Model (4WD)5,163 lbs
(2 342 kg) 25 sq ft
(2.32 sq m) 1,000 lbs
(453 kg) 100 lbs (45 kg)
3.8L/Manual 3.73 2–Door Sahara Model (4WD)6,163 lbs
(2 795 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
3.8L/
Automatic 3.73 2–Door Sahara
Model (4WD) 6,163 lbs
(2 795 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
3.8L/Manual 4.10 2–Door Rubi- con Model(4WD) 6,236 lbs
(2 829 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
STARTING AND OPERATING 349
5