2004 JEEP GRAND CHEROKEE torque

STARTING AND OPERATING
CONTENTS
mStarting Procedures.....................176
NNormal Starting......................176
NExtreme Cold Weather (Below ±20ÉF (±29ÉC) . . 177
NIf Engine Fails To Start.................177
NAfter Starting........................178
mEngine Block Heater Ð If Equipped.........178
mAutomatic Transmission..................179
NBrake Transmission Shift Interlock System
(BTSI).............................180NElectronically Controlled Five Speed Automatic
Transmission (4.7L Engine Only)..........180
NProtect Mode - Electronically Controlled
Transmission (4.7L Engine Only)..........180
NGear Ranges.........................181
NOver Temperature Mode................185
NTorque Converter Clutch................185
NRocking The Vehicle...................186
mFour-Wheel Drive Operation...............186
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reaches the appropriate temperature. Refer to the ªNoteº
under ªTorque Converter Clutchº later in this section.
If the transmission temperature gets too hot, the trans-
mission may downshift out of Overdrive or engage
overdrive at higher vehicle speeds (4.7L engines only)
until the transmission cools down. After cooldown, Over-
drive will resume normal operation.
2ÐSecond
For driving slowly in heavy city traffic or on mountain
roads where more precise speed control is desirable. Use
it also when climbing long grades, and for engine brak-
ing when descending moderately steep grades. To pre-
vent excessive engine speed, do not exceed 45 mph (72
km/h) in this range.
1ÐFirst
For driving up very steep hills and for engine braking at
low speeds (25 mph (40 km/h) or less) when going
downhill. To prevent excessive engine speed do not
exceed 25 mph (40 km/h) in this range.
CAUTION!
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 practices
can cause overheating and damage to the transmis-
sion.
184 STARTING AND OPERATING

Over Temperature Mode
The transmission electronics constantly monitor the
transmission oil temperature. If the transmission gets too
hot, the transmission will change the way it shifts to help
control the condition. This may result in a slightly
different feeling or response during normal operation in
D (Drive) position. If the transmission becomes hot
enough the O/D OFF indicator light and TRANS OVER
TEMP warning light in the instrument cluster may come
on. After the transmission cools down, it will return to
normal operation.
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.NOTE:
²The torque converter clutch will not engage until the
transmission fluid and engine coolant are warm (usu-
ally after 1±3 miles (1.6±4.8 km) of driving). Because
engine speed is higher when the torque converter
clutch is not engaged, it may seem as if the transmis-
sion is not shifting into ªOverdriveº when cold. This is
considered a normal condition. Pressing the ªO/D
OFFº switch will show that the transmission is able to
shift into and out of ªOverdrive.º
²If the vehicle has not been driven for several days, the
first few seconds of operation after shifting the trans-
mission into gear may seem sluggish. This is due to the
transmission fluid partially draining from the torque
converter into the transmission. This is considered a
normal condition and will not cause damage to the
transmission. The torque converter will refill within 5
seconds of shifting from P (Park) into any other gear
position.
STARTING AND OPERATING 185
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induce a torque interrupt and allow full engagement of
the newly selected position. With the vehicle stationary, it
may be necessary to shift from D (Drive) to R (Reverse)
and back to D (Drive) after shifting. This will allow full
engagement of the newly selected position. Apply a
constant force when shifting the transfer case lever.
4 PART TIME to 4 FULL TIME or 4 FULL TIME to
4 PART TIME
Shifting between 4 PART TIME and 4 FULL TIME can be
made with the vehicle stopped or in motion. If the vehicle
is in motion, shifts can be made up to 55 mph (88 km/h).
With the vehicle in motion, two momentary releases of the
accelerator pedal may be required after shifting. This will
induce a torque interrupt and allow full engagement of
the newly selected position. With the vehicle stationary, it
may be necessary to shift from D (Drive) to R (Reverse)
and back to D (Drive) after shifting. This will allow full
engagement of the newly selected position. Apply a
constant force when shifting the transfer case lever.
4 FULL TIME to 4 LO or 4 LO to 4 FULL TIME
With the vehicle rolling at 2 to 3 mph (3 to 5 km/h), shift
the transmission into N (Neutral). 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 in
transfer case N (Neutral).
NOTE:Pausing in transfer case N (Neutral) in vehicles
equipped with an automatic transmission may require
shutting the engine OFF to avoid gear clash while
completing the shift. If difficulty occurs, shift the trans-
mission to N (Neutral), hold foot on brake, and turn the
engine OFF. Make shift to desired mode.
NOTE:Shifting into or out of 4LO is possible with the
vehicle completely stopped, however difficulty may oc-
cur due to the mating clutch teeth not being properly
aligned. Several attempts may be required for clutch
teeth alignment and shift completion to occur. The pre-
ferred method is with the vehicle rolling 2 to 3 mph (3 to
190 STARTING AND OPERATING

5 km/h). Avoid attempting to engage or disengage 4LO
with the vehicle moving faster than 2 to 3 mph (3 to 5
km/h).
Quadra-Trac IITOperating
Instructions/Precautions Ð If Equipped
The Quadra-Trac IIttransfer case is fully automatic in the
normal driving 4 ALL TIME mode. The Quadra-Trac IIt
transfer 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 ALL TIME
mode. The 4 ALL TIME mode transmits torque to the rear
axle during normal driving, similar to a rear wheel drive
vehicle. When speed difference is increased between the
front and rear driveshafts the majority of engine torque
can be transmitted to the front driveshaft.
When additional traction is required, the 4LO position
can be used to lock the front and rear driveshafts togetherand force the front and rear wheels to rotate at the same
speed. The 4LO position is intended for loose, slippery
road surfaces only. Driving in the 4LO position on dry
hard surfaced roads may cause increased tire wear and
damage to driveline components.
When operating your vehicle in 4LO, the engine speed is
approximately three times that of the 4 ALL TIME
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.
STARTING AND OPERATING 191
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Quadra-DriveTSystem Ð If Equipped
The optional Quadra-DrivetSystem features three
torque transfer couplings. The couplings include Vari-
Lok front and rear axles and Quadra-Trac IIttransfer
case. The optional Vari-Lok 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 automati-
cally 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 IIttransfer case shifting infor-
mation, preceding this section, for shifting this system.
VARI-LOK FRONT AND REAR AXLES Ð IF
EQUIPPED
The optional Vari-Lok axle is fully automatic and requires
no driver input to operate. Under normal driving condi-
tions the unit functions as a standard axle 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 automati-
cally transfer from the wheel that has less traction to the
wheel that has traction.
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 ªBrake Warning Lightº in the instru-
ment cluster will light.
194 STARTING AND OPERATING

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.
²Completely inspect the underbody of your vehicle.
Check tires, body structure, steering, suspension, and
exhaust system for damage.
²Check 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.
²Check 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.
²After 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.
WARNING!
Abrasive material in any part of the brakes may
cause excessive wear or unpredictable braking. You
might not have full braking power when you need it
to prevent an accident. If you have been operating
your vehicle in dirty conditions, get your brakes
checked and cleaned as necessary.
²If you experience unusual vibration after driving in
mud, slush or similar conditions, check the wheels for
impacted material. Impacted material can cause a
wheel imbalance and freeing the wheels of it will
correct the situation.
202 STARTING AND OPERATING

9. Tighten the lug nuts securely in a crisscross pattern.
Have an authorized service technician check that the
torque is 85-115 ft.lbs. (115-156 N´m) as soon as possible.
10. Secure the jack, lug wrench, jack handle and tire in
the proper locations.WARNING!
²A loose tire or jack thrown forward in a collision
or hard stop could injure someone in the vehicle.
Always stow the jack parts and the extra tire and
wheel in the places provided.
²Carefully follow these tire changing warnings to
help prevent personal injury or damage to your
vehicle:
²Always park on a firm, level surface as far from the
edge of the roadway as possible before raising the
vehicle.
²Block the wheel diagonally opposite the wheel to be
raised.
²Apply the parking brake firmly before jacking.
²Never start the engine with the vehicle on a jack.
WHAT TO DO IN EMERGENCIES 245
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