2008 JEEP GRAND CHEROKEE four wheel drive

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 vehicles
were not intended. However, on-road ride and handling
will have a different feel from what drivers experience
with other vehicles, 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 this manual. Be
sure you are familiar with all vehicle controls, particu-
larly those used for braking, steering and transmission
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 it or expect it to
overcome the laws of nature. 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. Be sure to read ªOn-Road/Off-Road Driving
Tipsº 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 new 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

STARTING AND OPERATING
CONTENTS
mStarting Procedure......................275
NNormal Starting Ð Gasoline Engines.......276
NExtremely Cold Weather (Below220ÉF Or
229ÉC).............................276
NIf Engine Fails To Start.................277
NAfter Starting........................278
NNormal Starting Ð Diesel Engines.........278
mEngine Block Heater Ð If Equipped.........283
mAutomatic Transmission..................284NShift Lock Manual Override Ð If Equipped . . . 284
NBrake/Transmission Interlock System.......285
N5±Speed Automatic Transmission..........285
NGear Ranges.........................286
NRocking The Vehicle...................292
mFour-Wheel Drive Operation...............293
NQuadra-Trac ItOperating Instructions/
Precautions Ð If Equipped..............293
NQuadra-Trac IItOperating
Instructions/Precautions Ð If Equipped.....293
5

five rocking-motion cycles. This will minimize overheat-
ing and reduce the risk of transmission failure during
prolonged efforts to free a stuck vehicle.
CAUTION!
When ªrockingº a stuck vehicle by moving between
ªFirstº and R (Reverse), do not spin the wheels faster
than 15 mph (24 km/h), or drivetrain damage may
result.
FOUR-WHEEL DRIVE OPERATION
Quadra-Trac ITOperating
Instructions/Precautions Ð If Equipped
The Quadra-Trac Itis a single speed (HI range only)
transfer case which provides convenient full-time
4±wheel drive. No driver interaction is required. This
transfer case divides engine torque almost evenly with 48percent of engine torque to the front axle and 52 percent
of engine torque to the rear axle. The Brake Traction
Control System (BTC), which combines standard ABS
and Traction Control, provides resistance to any wheel
that is slipping to allow additional torque transfer to
wheels with traction.
NOTE:The Quadra-Trac Itsystem is not appropriate
for conditions where LOW range is recommended. Refer
to ªOff-Road Driving Tipsº in this section.
Quadra-Trac IITOperating
Instructions/Precautions Ð If Equipped
The Quadra-Trac IIttransfer case is fully automatic in the
normal driving 4 HI mode. The Quadra-Trac IIttransfer
case provides three mode positions Ð four wheel drive
high range, neutral, and four wheel drive low range.
This transfer case is fully automatic in the 4 HI mode.
This transfer case divides engine torque almost evenly
with 48 percent of engine torque to the front axle and 52
STARTING AND OPERATING 293
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percent of engine torque to the rear axle. When speed
differences are increased between the front and rear drive
shafts, the transfer case can transmit up to 100 percent of
available engine torque to the front or rear drive shafts.
When additional traction is required, the 4 LOW position
can be used to lock the front and rear driveshafts together
and force the front and rear wheels to rotate at the same
speed. The 4 LOW position is intended for loose, slippery
road surfaces only. Driving in the 4 LOW position on dry
hard surfaced roads may cause increased tire wear and
damage to driveline components.
When operating your vehicle in 4 LOW, the engine speed
is approximately three times that of the 4 HI position 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
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.
294 STARTING AND OPERATING

WARNING!
You or others could be injured if you leave the
vehicle unattended with the transfer case in the N
(Neutral) position without first fully engaging the
parking brake. The transfer case N (Neutral) position
disengages both the front and rear driveshafts 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.
Shift Positions
For additional information on the appropriate use of each
transfer case mode position, see the information below:
4HI
Four Wheel Drive High Range Ð All roads surfaces such
as ice, snow, gravel, sand, and dry hard pavement.
N (Neutral)
Neutral Ð Disengages both the front and rear driveshafts
from the powertrain. To be used for flat towing behind
another vehicle. Refer to ªRecreational Towingº in Sec-
tion 5 of this manual.
4 LOW
Four Wheel Drive Low Range Ð Low speed 4 wheel
drive. Locks the front and rear driveshafts together.
Forces the front and rear wheels to rotate at the same
speed. Additional traction and maximum pulling power
for loose, slippery road surfaces only. Do not exceed 25
mph (40 km/h).
STARTING AND OPERATING 295
5

and/or the flow rate is reduced. If you must cross
flowing water avoid depths in excess of 9 inches. The
flowing water can erode the streambed causing your
vehicle to sink into deeper water. Determine exit point(s)
that are downstream of your entry point to allow for
drifting.
Standing Water
Avoid driving in standing water deeper than 20 inches,
and reduce speed appropriately to minimize wave ef-
fects. Maximum speed in 20 inches of water is less than 5
mph (8 km/h).
Maintenance
After driving through deep water, inspect your vehicle
fluids and lubricants (engine oil, transmission oil, axle,
transfer case) to assure the fluids have not been contami-
nated. Contaminated fluid (milky, foamy in appearance)
should be flushed/changed as soon as possible to pre-
vent component damage.Driving In Snow, Mud and Sand
In heavy snow, when pulling a load, or for additional
control at slower speeds, shift the transmission to a low
gear and shift the transfer case to 4WD LOW if necessary.
Refer to ªFour-Wheel Drive Operationº in this section.
Do not shift to a lower gear than necessary to maintain
forward motion. Over-revving the engine can spin the
wheels and traction will be lost.
Avoid abrupt downshifts on icy or slippery roads, be-
cause engine braking may cause skidding and loss of
control.
Hill Climbing
NOTE:Before attempting to climb a hill, determine the
conditions at the crest and/or on the other side.
Before climbing a steep hill,shift the transmission to a
lower gear and shift the transfer case to 4WD LOW. Use
first gear and 4WD LOW for very steep hills.
STARTING AND OPERATING 301
5

If you stall or begin to lose forward motionwhile
climbing a steep hill, allow your vehicle to come to a stop
and immediately apply the brakes. Restart the engine
and shift to R (Reverse). Back slowly down the hill
allowing the compression braking of the engine to help
regulate your speed. If the brakes are required to control
vehicle speed, apply them lightly and avoid locking or
skidding the tires.
WARNING!
If the engine stalls, you lose forward motion, 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. Always back care-
fully straight down a hill in R (Reverse) gear. Never
back down a hill in N (Neutral) using only the brake.Remember, never drive diagonally across a hill-always
drive straight up or down.
If the wheels start to slip as you approach the crest of a
hill, ease off the accelerator and maintain forward motion
by turning the front wheels slowly. This may provide a
fresh ªbiteº into the surface and will usually provide
traction to complete the climb.
Traction Downhill
Shift the transmission into a low gear and the transfer
case to 4WD LOW range. Let the vehicle go slowly down
the hill with all four wheels turning against engine
compression drag. This will permit you to control the
vehicle speed and direction.
When descending mountains or hills, repeated braking
can cause brake fade with loss of braking control. Avoid
repeated heavy braking by downshifting the transmis-
sion whenever possible.
302 STARTING AND OPERATING

NOTE:Increased noise levels at the end of the steering
wheel travel are considered normal and do not indicate
that there is a problem with the power steering system.
Upon initial start-up in cold weather, the power steering
pump may make noise for a short amount of time. This is
due to the cold, thick fluid in the steering system. This
noise should be considered normal, and it does not in any
way damage the steering system.
WARNING!
Continued operation with reduced power steering
assist could pose a safety risk to yourself and others.
Service should be obtained as soon as possible.
CAUTION!
Prolonged operation of the steering system at the end
of the steering wheel travel will increase the steering
fluid temperature and it should be avoided when
possible. Damage to the power steering pump may
occur.
MULTI DISPLACEMENT SYSTEM (MDS) Ð 5.7L
Engine Only
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:The MDS system may take some time to return
to full functionality after a battery disconnect.
STARTING AND OPERATING 309
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