2010 JEEP GRAND CHEROKEE wheel torque

the transmission may not shift into the top Overdrive
gear (normal fifth gear) until the transmission fluid
and engine coolant are warm.
•If the vehicle has not been driven in several days, the
first few seconds of operation after shifting the trans-
mission into gear may seem sluggish. This is due to the
fluid partially draining from the torque converter into
the transmission. This condition is normal and will not
cause damage to the transmission. The torque con-
verter will refill within five seconds of shifting from
PARK into any other gear position.
Rocking the Vehicle
If the vehicle becomes stuck in snow, sand, or mud, it can
often be moved by a rocking motion. Move the shift lever
between DRIVE and REVERSE, while applying slight
pressure to the accelerator.NOTE:
The Electronic Stability Program (ESP) and
Traction Control System (TCS) (if equipped) should be
turned OFF before attempting to rock the vehicle. Refer
to “Electronic Brake Control System” in “Starting and
Operating” for further information.
The least amount of accelerator pedal pressure to main-
tain the rocking motion, without spinning the wheels or
racing the engine, is most effective. Racing the engine or
spinning the wheels, due to the frustration of not freeing
the vehicle, may lead to transmission overheating and
failure. Allow the engine to idle with the shift lever in
NEUTRAL for at least one minute after every five
rocking-motion cycles. This will minimize overheating
and reduce the risk of transmission failure during pro-
longed efforts to free a stuck vehicle.
252 STARTING AND OPERATING

CAUTION!
When “rocking” a stuck vehicle by moving between
“First” and REVERSE, do not spin the wheels faster
than 15 mph (24 km/h) or drivetrain damage may
result.
FOUR-WHEEL DRIVE OPERATION
Quadra-Trac IOperating Instructions/
Precautions – If Equipped
The Quadra-Trac I is a single-speed (HI range only)
transfer case, which provides convenient full-time four–
wheel drive. No driver interaction is required. The Brake
Traction Control (BTC) System, 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 I system is not appropriate
for conditions where 4WD LOW range is recommended.
Refer to “Off-Road Driving Tips” in “Starting and Oper-
ating” for further information.
Quadra-Trac II Operating Instructions/
Precautions – If Equipped
The Quadra-Trac II transfer case is fully automatic in the
normal driving 4WD HI mode. The Quadra-Trac II
transfer case provides three mode positions:
•4WD HI
•NEUTRAL
•4WD LOW
This transfer case is fully automatic in the 4WD HI mode.
5
STARTING AND OPERATING 253

NOTE:If shift conditions/interlocks are not met, a
“CHECK SHIFT PROCEDURES” message will flash from
the Electronic Vehicle Information Center (EVIC). Refer
to “Electronic Vehicle Information Center (EVIC)” in
“Understanding Your Instrument Panel” for further
information.
Quadra-Drive II System – If Equipped
The optional Quadra-Drive II System features three
torque transfer couplings. The couplings include Elec-
tronic Limited-Slip Differential (ELSD) front and rear
axles and Quadra-Trac II transfer case. The optional
ELSD axles are fully automatic and require no driver
input to operate. Under normal driving conditions, the
units function as standard axles, balancing torque evenly
between left and right wheels. With a traction difference
between left and right wheels, the coupling will sense a
speed difference. As one wheel begins to spin faster than
the other, torque will automatically transfer from the
wheel that has less traction, to the wheel that has traction. While the transfer case and axle couplings differ in
design, their operation is similar. Follow the Quadra-Trac
II
transfer case shifting information, preceding this
section, for shifting this system.
ON-ROAD DRIVING TIPS
Utility vehicles have higher ground clearance and a
narrower track to make them capable of performing in a
wide variety of off-road applications. Specific design
characteristics give them a higher center of gravity than
ordinary cars.
An advantage of the higher ground clearance is a better
view of the road, allowing you to anticipate problems.
They are not designed for cornering at the same speeds as
conventional two-wheel drive vehicles any more than
low-slung sports cars are designed to perform satisfacto-
rily in off-road conditions. If at all possible, avoid sharp
258 STARTING AND OPERATING

Traction Downhill
Shift the transmission into a low gear, and the transfer
case into 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.
After Driving Off-Road
Off-road operation puts more stress on your vehicle than
does most on-road driving. After going off-road, it is
always a good idea to check for damage. That way you
can get any problems taken care of right away and have
your vehicle ready when you need it.
•Completely inspect the underbody of your vehicle.
Check the tires, body structure, steering, suspension,
and exhaust system for damage.
•Check threaded fasteners for looseness, particularly on
the chassis, drivetrain components, steering, and sus-
pension. Retighten them, if required, and torque to the
values specified in the Service Manual.
•Check for accumulations of plants or brush. These
things could be a fire hazard. They might hide damage
to fuel lines, brake hoses, axle pinion seals, and
propeller shafts.
•After extended operation in mud, sand, water, or
similar dirty conditions, have brake rotors, wheels,
brake linings, and axle yokes inspected and cleaned as
soon as possible.
262 STARTING AND OPERATING

WARNING!
The ABS cannot prevent the natural laws of physics
from acting on the vehicle, nor can it increase the
traction afforded by prevailing road conditions. The
ABS cannot prevent accidents, including those re-
sulting from excessive speed in turns, driving on
very slippery surfaces, or hydroplaning. Only a safe,
attentive, and skillful driver can prevent accidents.
The capabilities of an ABS-equipped vehicle must
never be exploited in a reckless or dangerous manner
which could jeopardize the user’s safety or the safety
of others.
Traction Control System (TCS)
This system monitors the amount of wheel spin of each of
the driven wheels. If wheel spin is detected, brake
pressure is applied to the slipping wheel(s) and engine
power is reduced to provide enhanced acceleration andstability. A feature of the TCS system functions similar to
a limited-slip differential and controls the wheel spin
across a driven axle. If one wheel on a driven axle is
spinning faster than the other, the system will apply the
brake of the spinning wheel. This will allow more engine
torque to be applied to the wheel that is not spinning.
This feature remains active even if TCS and ESP are in
either the “Partial Off” or “Full Off” modes. Refer to
“Electronic Stability Program (ESP)” in this section for
more information.
Brake Assist System (BAS)
The BAS is designed to optimize the vehicle’s braking
capability during emergency braking maneuvers. The
system detects an emergency braking situation by sens-
ing the rate and amount of brake application and then
applies optimum pressure to the brakes. This can help
reduce braking distances. The BAS complements the
anti-lock brake system (ABS). Applying the brakes very
quickly results in the best BAS assistance. To receive the
5
STARTING AND OPERATING 271

WARNING!
If the driveshaft is removed, the vehicle can roll even
if the transmission is in PARK, which could cause
serious injury or death.
The parking brake must be firmly engaged and the
wheels chocked during driveshaft removal and installa-
tion. The parking brake must remain engaged unless the
vehicle is securely and properly connected to the tow
vehicle, or the driveshaft is completely reinstalled. See
your authorized dealer for proper driveshaft removal
and reinstallation procedures, including flange
orientation/alignment, use of thread-locking compound,
proper bolt torque specifications, etc.
Towing — Quadra-Trac I (Single-Speed Transfer
Case) Four-Wheel Drive Models
Recreational towing is not allowed. This model does not
have a NEUTRAL position in the transfer case.
Towing — Quadra–Trac II /Quadra–DriveII
Four-Wheel Drive Models
CAUTION!
Front or rear wheel lifts should not be used. Internal
damage to the transmission or transfer case will occur
if a front or rear wheel lift is used when recreational
towing.
NOTE: The transfer case must be in the NEUTRAL
position, and the transmission must be in the PARK
position for recreational towing.5
STARTING AND OPERATING 339

WARNING!
Raising the vehicle higher than necessary can make
the vehicle less stable. It could slip off the jack and
hurt someone near it. Raise the vehicle only enough
to remove the tire.
6. Remove the lug nuts and wheel.
7. Position the spare wheel/tire on the vehicle and install
the lug nuts with the cone-shaped end toward the wheel.
Lightly tighten the nuts. To avoid the risk of forcing the
vehicle off the jack, do not tighten the nuts fully until the
vehicle has been lowered.
8. Lower the vehicle by turning the jack screw counter-
clockwise, and remove the jack and wheel blocks.
9. Finish tightening the lug nuts. Push down on the
wrench while tightening for increased leverage. Alternate
nuts until each nut has been tightened twice. The correct wheel nut tightness is 95 ft lbs (130 N·m). If in doubt
about the correct tightness, have them checked with a
torque wrench by your authorized dealer or at a service
station.
10. Lower the jack to its fully closed position.
WARNING!
A loose tire or jack, thrown forward in a collision or
hard stop could endanger the occupants of the ve-
hicle. Always stow the jack parts and the spare tire in
the places provided.
11. Secure the tire, jack, and tools in their proper loca-
tions.
NOTE: A tire should be stowed with the “beauty” side
up. Storing the tire upside down may result in scratching
or damage to the wheel face. Continue winching up the
tire until you hear the winch “ratchet” three times.
354 WHAT TO DO IN EMERGENCIES

Spinning............................ 299
Tread Wear Indicators ................... 300
Wheel Mounting ...................... 354
Tongue Weight/Trailer Weight .............. 331
Torque Converter Clutch .................. 251
Tow Hooks, Emergency ................... 359
Tow/Haul Indicator Light ................. 165
Towing ............................ 324,359
Disabled Vehicle ....................... 359
Guide .............................. 330
Recreational .......................... 338
Weight .............................. 330
Traction Control ......................... 271
Trailer Sway Control (TSC) ................. 278
Trailer Towing .......................... 324
Cooling System Tips .................... 338
Hitches ............................. 328
Minimum Requirements ................. 332
Trailer and Tongue Weight ............... 331 Wiring
.............................. 335
Trailer Towing Guide ..................... 330
Trailer Weight .......................... 330
Transfer Case ........................... 388
Maintenance ......................... 388
Transmission Automatic ........................ 245,389
Maintenance ......................... 389
Shifting ............................. 243
Transmitter Battery Service
(Remote Keyless Entry) .................... 24
Transmitter, Garage Door Opener (HomeLink) . . 128
Transmitter Programming
(Remote Keyless Entry) .................... 20
Transmitter, Remote Keyless Entry (RKE) ........ 20
Tread Wear Indicators .................... 300
Turn Signals ................... 107,159,409,410
UCI Connector ......................... 209
10
INDEX 463