four wheel drive JEEP WRANGLER 2008 JK / 3.G Owners Manual

INTRODUCTION
This is a specialized utility vehicle designed for both
on-road and off-road use. It can go places and perform
tasks for which conventional two-wheel drive enclosed
vehicles were not intended. It handles and maneuvers
differently from many passenger cars both on-road and
off-road, so take time to become familiar with your
vehicle.
The two-wheel drive utility vehicle was designed for
on-road use only. It is not intended for off-road driving
or use in other severe conditions suited for a four-wheel
drive vehicle.
Before you start to drive this vehicle, read the Owner’s
Manual. Be sure you are familiar with all vehicle controls,
particularly those used for braking, steering, transmis-
sion, and transfer case shifting. Learn how your vehicle
handles on different road surfaces. Your driving skills
will improve with experience. When driving off-road orworking the vehicle, don’t overload the vehicle or expect
the vehicle to overcome the natural laws of physics.
Always observe federal, state, provincial and local laws
wherever you drive.
As with other vehicles of this type, failure to operate this
vehicle correctly may result in loss of control or an
accident. Refer to “On-Road/Off-Road Driving Tips” in
Section 5 of this manual.
This manual has been prepared with the assistance of
service and engineering specialists to acquaint you with
the operation and maintenance of your vehicle. It is
supplemented by a Warranty Information Booklet and
various customer-oriented documents. You are urged to
read these publications carefully. Following the instruc-
tions and recommendations in this manual will help
assure safe and enjoyable operation of your vehicle.
4 INTRODUCTION

15. Tachometer
This light indicates the engine speed in revolutions per
minute (RPM).
CAUTION!
Do not operate the engine with the tachometer
pointer in the red area. Engine damage will occur.
16. Engine Coolant Temperature Warning Light This light warns of an overheated engine condi-
tion. If the engine is critically hot, a warning chime
will sound 10 times. After the chime turns off, the
engine will still be critically hot until the light goes out.
17. Sentry Key/Security Alarm Indicator Light — If
Equipped
Refer to “Sentry Key Immobilizer System” or “Vehicle
Security Alarm” in Section 2 of this manual. 18. Coolant Temperature Gauge
Indicates engine coolant temperature. The red
zone to the far right indicates possible overheat-
ing. Seek your authorized dealer immediately if
the gauge operates in the red zone. On U.S. vehicles, the
temperature is indicated in degrees fahrenheit; and on
Canadian vehicles in degrees centigrade.
19. Cruise Indicator Light This light shows when the electronic speed
control system is turned on.
20. 4WD Indicator Light — If Equipped This light alerts the driver that the vehicle is in
the four-wheel drive mode, and the front and
rear driveshafts are mechanically locked to-
gether forcing the front and rear wheels to
rotate at the same speed.
UNDERSTANDING YOUR INSTRUMENT PANEL 209
4

Four–Wheel Drive Operation (Command-Trac™
Or Rock-Trac™) — If Equipped .............285
▫ Operating Instructions/Precautions .........285
▫ Shift Positions ........................287
▫ Shifting Procedure ....................288
 Trac-Lok™ Rear Axle — If Equipped .........289
 Axle Lock (Tru–Lok™) — Rubicon Models .....290
 Rear Axle Lock — 4WD Non-Rubicon Models
(If Equipped) ..........................291
 Electronic Sway Bar Disconnect — If Equipped . . 292
 On-Road Driving Tips ...................294
 Off-Road Driving Tips ...................294
▫ Side Step Removal — If Equipped .........294
▫ The Basics Of Off-Road Driving ...........296▫
When To Use 4L (Low) Range ............297
▫ Simultaneous Brake And Throttle Operation . . 297
▫ Driving In Snow, Mud And Sand ..........297
▫ Crossing Obstacles (Rocks And Other High
Points) .............................299
▫ Hill Climbing ........................301
▫ Driving Through Water .................304
▫ After Driving Off-Road .................307
 Parking Brake .........................308
 Anti-Lock Brake System ..................309
 Power Steering ........................311
 Tire Safety Information ...................313
▫ Tire Markings ........................313
268 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

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

when activation conditions are not met. The stabilizer/
sway bar should remain in 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. The front stabilizer bar
enhances vehicle stability and is necessary for main-
taining 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 or solid Sway Bar Indicator
Light. Once vehicle speed is reduced below 14 mph
(22 km/h), the system will once again attempt to
return to off-road mode.To disconnect the stabilizer/sway bar, shift to either 4H
or 4L (refer to “Four Wheel Drive Operation” in this
section) and press the SWAY BAR switch to obtain the
off-road position. The Sway Bar Indicator Light will flash
until the stabilizer/sway bar has been fully disconnected.
NOTE:
The stabilizer/sway bar may be torque locked
due to left and right suspension height differences. This
condition is due to driving surface differences or vehicle
loading. In order for the stabilizer/sway bar to
disconnect/reconnect, the right and left halves of the bar
must be aligned. This alignment may require that the
vehicle be driven onto level ground or rocked from side
to side.
To return to on-road mode, press the SWAY BAR switch
again.
STARTING AND OPERATING 293
5

•The TPMS is not a substitute for proper tire mainte-
nance, 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 Tire
Pressure Monitoring Telltale Light.
•Seasonal temperature changes will affect tire pressure,
and the TPM System will monitor the actual tire
pressure in the tire.
Base System
The Tire Pressure Monitor System (TPMS) uses wireless
technology with wheel rim-mounted electronic sensors to
monitor tire pressure levels. Sensors, mounted to each
wheel as part of the valve stem, transmit tire pressure
readings to the Receiver Module.
NOTE:It is particularly important, for you to check the
tire pressure in all of your tires regularly and to maintain
the proper pressure. The Tire Pressure Monitor System (TPMS) consists of the
following components:
•Receiver Module
•Four Tire Pressure Monitoring Sensors
•Tire Pressure Monitoring Telltale Light
A tire pressure monitoring sensor is located in the spare
wheel if the vehicle is equipped with a matching full size
spare wheel and tire assembly. The matching full size
spare tire can be used in place of any of the four road
tires. A low spare tire will not cause the Tire Pressure
Monitoring Telltale Light to illuminate or the chime to
sound. The Tire Pressure Monitoring Telltale Light will
illuminate in the instrument cluster, and an au-
dible chime will be activated when one or more of
the four active road tire pressures are low. Should this
occur, you should stop as soon as possible, check the
STARTING AND OPERATING 333
5

NOTE:If your vehicle is not equipped with a matching
full-size spare wheel and tire assembly, it does not have a
tire pressure monitoring sensor in the spare tire. The
TPMS will not be able to monitor the tire pressure. If you
install the spare tire in place of a road tire that has a
pressure below the low-pressure warning limit, upon the
next ignition key cycle, a chime will sound and the Tire
Pressure Monitoring Telltale Light will turn ON. After
driving the vehicle for up to 10 minutes above 15 mph (25
km/h), the Tire Pressure Monitoring Telltale Light will
flash on and off for 75 seconds and then remain on solid.
For each subsequent ignition key cycle, a chime will
sound and the Tire Pressure Monitoring Telltale Light
will flash on and off for 75 seconds and then remain on
solid. Once you repair or replace the original road tire,
and reinstall it on the vehicle in place of the spare tire, the
TPMS will update automatically and the Tire Pressure
Monitoring Telltale Light will turn OFF, as long as no tire
pressure is below the low-pressure warning limit in any of the four active road tires. The vehicle may need to be
driven for up to 10 minutes above 15 mph (25 km/h) in
order for the TPMS to receive this information.
General Information
This device complies with part 15 of the FCC rules and
RSS 210 of Industry Canada. Operation is subject to the
following conditions:
•This device may not cause harmful interference.
•This device must accept any interference received,
including interference that may cause undesired op-
eration.
The tire pressure sensors are covered under one of the
following licenses:
United States ..................... KR5S120123
Canada ........................ 2671-S120123
STARTING AND OPERATING 335
5

WARNING!
Improper towing can lead to an injury accident.
Follow these guidelines to make your trailer towing
as safe as possible:
Make certain that the load is secured in the trailer
and will not shift during travel. When trailering
cargo that is not fully secured, dynamic load shifts
can occur that may be difficult for the driver to
control. You could lose control of your vehicle and
have an accident.
•When hauling cargo or towing a trailer, do not over-
load your vehicle or trailer. Overloading can cause a
loss of control, poor performance or damage to brakes,
axle, engine, transmission, steering, suspension, chas-
sis structure or tires.
•Safety chains must always be used between your
vehicle and trailer. Always connect the chains to the
frame or hook retainers of the vehicle hitch. Cross the
chains under the trailer tongue and allow enough
slack for turning corners.
•Vehicles with trailers should not be parked on a grade.
When parking, apply the parking brake on the tow
vehicle. Put the tow vehicle automatic transmission in
PARK. With a manual transmission, shift the transmis-
sion into 1st gear. And with four-wheel-drive vehicles,
make sure the transfer case is not in N (Neutral).
Always, block orchockthe trailer wheels.
•GCWR must not be exceeded.
•Total weight must be distributed between the tow
vehicle and the trailer such that the following four
ratings are not exceeded:
1. GVWR
354 STARTING AND OPERATING

Engine Oil........................... 385
Finish Care ............................ 407
Flashers Hazard Warning ....................... 364
Turn Signal ..................... 207,421,422
Flooded Engine Starting ................... 273
Fluid Capacities ......................... 424
Fluid Level Checks ...................... 405
Automatic Transmission ................. 401
Engine Oil ........................... 383
Manual Transmission ................... 404
Power Steering ........................ 391
Fluids, Lubricants and Genuine Parts .......... 425
Fog Light Service ........................ 422
Fog Lights ........................... 99,422
Fold and Tumble Rear Seat .................. 89
Folding Rear Seat ........................ 92
Folding Windshield ...................... 191
Four Wheel Drive ....................... 285 Shifting
............................. 287
Four Wheel Drive Operation ................ 285
Four-Way Hazard Flasher .................. 364
Front Axle (Differential) ................... 405
Fuel ................................. 336
Filler Cap (Gas Cap) .................... 340
Filter ............................... 388
Gasoline ............................ 336
Gauge .............................. 206
Materials Added ....................... 338
Octane Rating ........................ 336
Requirements ......................... 424
Tank Capacity ........................ 424
Fuel System Caution ................... 338,341
Fuses ................................ 413
Gas Cap (Fuel Filler Cap) ...............340,380
Gasoline (Fuel) ......................... 336
Gasoline, Reformulated ................... 336
INDEX 451
10