2002 JEEP GRAND CHEROKEE track bar

Condition Possible Causes Correction
Axle Noise 1. Insufficient lubricant. 1. Fill differential with the correct
fluid type and quantity.
2. Improper ring gear and pinion
adjustment.2. Check ring gear and pinion
contact pattern.
3. Unmatched ring gear and pinion. 3. Replace gears with a matched
ring gear and pinion.
4. Worn teeth on ring gear and/or
pinion.4. Replace ring gear and pinion.
5. Loose pinion bearings. 5. Adjust pinion bearing pre-load.
6. Loose differential bearings. 6. Adjust differential bearing
pre-load.
7. Mis-aligned or sprung ring gear. 7. Measure ring gear run-out.
Replace components as necessary.
8. Loose differential bearing cap
bolts.8. Inspect differential components
and replace as necessary. Ensure
that the bearing caps are torqued
tot he proper specification.
9. Housing not machined properly. 9. Replace housing.
VARI-LOKT
(1) Park the vehicle on a level surface or raise
vehicle on hoist so that the vehicle is level.
(2) Remove the axle fill plug.
(3) Verify that the axle fluid level is correct. The
fluid level is correct if the fluid is level with the bot-
tom of the fill hole.
(4) Shift the transfer case into the 4WD full-time
position.
(5) Drive the vehicle in a tight circle for 2 minutes
at 5mph to fully prime the pump.
(6) Block the tires opposite the axle to be tested to
prevent the vehicle from moving.
(7) Shift the transfer case into the 4WD Low posi-
tion and the transmission into the Park position.
(8) Raise both the wheels of the axle to be tested
off of the ground.
(9) Rotate the left wheel by hand at a minimum of
one revolution per second while an assistant rotates
the right wheel in the opposite direction.
(10) The left wheel should spin freely at first and
then increase in resistance within 5 revolutions until
the wheels cannot be continuously rotated in opposite
directions.
(11) The Vari-loktdifferential has engaged prop-
erly if the wheels cannot be rotated in opposite direc-
tions for a moment. After the wheels stop rotating for
a moment, the fluid pressure will drop in the differ-
ential and the wheels begin to rotate once again.
(12) If the system does not operate properly,
replace the Vari-loktdifferential.
REMOVAL
(1) Raise and support the vehicle.
(2) Position a suitable lifting device under the
axle.
(3) Secure axle to lift.
(4) Remove the wheels and tires.
(5) Remove the brake calipers and rotors (Refer to
5 - BRAKES/HYDRAULIC/MECHANICAL/ROTORS
- REMOVAL) from the axle.
(6) Disconnect the wheel sensor wiring harness
from the vehicle wiring harness.
(7) Disconnect the vent hose from the axle shaft
tube.
(8) Mark propeller shaft and yoke/pinion flange for
installation alignment reference.
(9) Remove propeller shaft.
(10) Disconnect stabilizer bar links at the axle.
(11) Disconnect shock absorbers from axle brack-
ets.
(12) Disconnect track bar.
(13) Disconnect the tie rod and drag link from the
steering knuckle.
(14) Disconnect the steering damper from the axle
bracket.
(15) Disconnect the upper and lower suspension
arms from the axle brackets.
(16) Lower the lifting device enough to remove the
axle. The coil springs will drop with the axle.
(17) Remove the coil springs from the axle.
3 - 20 FRONT AXLE - 186FBIWJ
FRONT AXLE - 186FBI (Continued)

INSTALLATION
CAUTION: The weight of the vehicle must be sup-
ported by the springs before suspension arms and
track bar fasteners can be tightened. If springs are
not at their normal ride position, ride height and
handling could be affected.
(1) Install the springs and retainer clips. Tighten
the retainer bolts to 21 N´m (16 ft. lbs.).
(2) Support the axle on a lifting device and posi-
tion axle under the vehicle.
(3) Raise the axle and align it with the spring
pads.
(4) Position the upper and lower suspension arms
in the axle brackets. Loosely install bolts and nuts to
hold suspension arms to the axle brackets.
(5) Install vent hose to the axle shaft tube.
(6) Install track bar in the axle bracket and install
the bolt loosely.
(7) Install shock absorbers and tighten the bolts to
23 N´m (17 ft. lbs.).
(8) Install stabilizer bar links to the axle brackets
and tighten the nuts to 95 N´m (70 ft. lbs.).
(9) Install drag link and tie rod to the steering
knuckles.
(10) Install steering damper to the axle bracket
and tighten the nut to 75 N´m (55 ft. lbs.).
(11) Install the brake rotors (Refer to 5 - BRAKES/
HYDRAULIC/MECHANICAL/ROTORS - INSTALLA-
TION) and calipers.
(12) Connect the wheel speed sensor wiring har-
ness to the vehicle wiring harness.
(13) Align the previously made marks on the pro-
peller shaft and the yoke/pinion flange.
(14) Install propeller shaft to pinion flange bolts ,
if equipped.
(15) Install propeller shaft to yoke straps and
bolts, if equipped.
(16) Check and fill axle lubricant.
(17) Install the wheel and tire assemblies.
(18) Remove the lifting device from the axle and
lower the vehicle.
(19) Tighten the upper suspension arm nuts to 75
N´m (55 ft. lbs.). Tighten the lower suspension arm
nuts to 115 N´m (85 ft. lbs.).
(20) Tighten the track bar bolt at the axle bracket
to 100 N´m (74 ft. lbs.).
(21) Check the front wheel alignment.
ADJUSTMENTS
Ring and pinion gears are supplied as matched
sets only. The identifying numbers for the ring and
pinion gear are etched onto each gear (Fig. 3). A plus
(+) number, minus (±) number or zero (0) is etched
into the face of the pinion gear. This number is theamount (in thousandths of an inch) the depth varies
from the standard depth setting of a pinion etched
with a (0). The standard setting from the center line
of the ring gear to the back face of the pinion is 92.1
mm (3.625 in.). The standard depth provides the best
gear tooth contact pattern. Refer to Backlash and
Contact Pattern Analysis paragraph in this section
for additional information.
Compensation for pinion depth variance is
achieved with a select shim/oil slinger. The shims are
placed between the rear pinion bearing and the pin-
ion gear head (Fig. 4).
Fig. 3 PINION GEAR ID NUMBERS
1 - PRODUCTION NUMBERS
2 - DRIVE PINION GEAR DEPTH VARIANCE
3 - GEAR MATCHING NUMBER
Fig. 4 ADJUSTMENT SHIM LOCATIONS
1 - PINION DEPTH SHIM/OIL SLINGER
2 - DIFFERENTIAL BEARING SHIM
3 - RING GEAR
4 - DIFFERENTIAL BEARING SHIM
5 - COLLAPSIBLE SPACER
WJFRONT AXLE - 186FBI 3 - 21
FRONT AXLE - 186FBI (Continued)

(13) Separate rear axle ball joint from the upper
suspension arm with Remover 8278 (Fig. 4).
(14) Disconnect shock absorbers from axle.
(15) Disconnect track bar.
(16) Disconnect lower suspension arms from the
axle brackets.
(17) Separate the axle from the vehicle.
INSTALLATION
CAUTION: The weight of the vehicle must be sup-
ported by the springs before suspension arms and
track bar fasteners are tightened. If springs are not
at their normal ride position, vehicle ride height and
handling could be affected.
(1) Raise axle with lift and align coil springs.
(2) Install lower suspension arms in axle brackets.
Install nuts and bolts, do not tighten bolts at this
time.
(3) Install upper suspension arm on rear axle ball
joint.
(4) Install rear axle ball joint nut and tighten to
122 N´m (90 ft.lbs.) (Fig. 5).
(5) Install track bar and attachment bolts, do not
tighten bolts at this time.
(6) Install shock absorbers and tighten nuts to 60
N´m (44 ft. lbs.).(7) Install stabilizer bar links and tighten nuts to
36 N´m (27 ft. lbs.).
(8) Install wheel speed sensors.
(9) Connect parking brake cable to brackets and
lever.
(10) Install brake rotors and calipers.
(11) Install the brake hose to the axle junction
block.
(12) Install axle vent hose.
(13) Align propeller shaft and pinion yoke refer-
ence marks. Install U-joint straps and nuts tighten to
19 N´m (14 ft. lbs.).
(14) Install the wheels and tires.
(15) Add gear lubricant, if necessary.
(16) Remove support and lower the vehicle.
(17) Tighten lower suspension arm bolts to 177
N´m (130 ft. lbs.).
(18) Tighten track bar bolts to 100 N´m (74 ft.
lbs.).
ADJUSTMENTS
Ring and pinion gears are supplied as matched
sets only. The identifying numbers for the ring and
pinion gear are etched into the face of each gear (Fig.
6). A plus (+) number, minus (±) number or zero (0) is
etched into the face of the pinion gear. This number
is the amount (in thousandths of an inch) the depth
varies from the standard depth setting of a pinion
etched with a (0). The standard setting from the cen-
ter line of the ring gear to the back face of the pinion
is 96.850 mm (3.813 in.). The standard depth pro-
vides the best gear tooth contact pattern. Refer to
Backlash and Contact Pattern Analysis paragraph in
this section for additional information.
Fig. 4 REAR BALL JOINT
1 - REMOVER
2 - UPPER SUSPENSION ARM
3 - BALL JOINT STUD
Fig. 5 REAR BALL JOINT NUT
1 - UPPER SUSPENSION ARM
2 - REAR AXLE BALL JOINT
3 - REAR AXLE
3 - 56 REAR AXLE - 198RBIWJ
REAR AXLE - 198RBI (Continued)

(3) Remove the wheels and tires.
(4) Remove brake calipers and rotors.
(5) Disconnect parking brake cables from brackets
and lever.
(6) Remove wheel speed sensors.
(7) Remove brake hose at the axle junction block.
Do not disconnect the brake hydraulic lines at the
calipers.
(8) Disconnect the vent hose from the axle shaft
tube.
(9) Mark propeller shaft and yokes for installation
reference.
(10) Remove propeller shaft.
(11) Disconnect stabilizer bar links.
(12) Remove upper suspension arm rear axle ball
joint nut.
(13) Separate rear axle ball joint from the upper
suspension arm with Remover 8278 (Fig. 4).
(14) Disconnect shock absorbers from axle.
(15) Disconnect track bar.
(16) Disconnect lower suspension arms from the
axle brackets.
(17) Separate the axle from the vehicle.
INSTALLATION
CAUTION: The weight of the vehicle must be sup-
ported by the springs before suspension arms and
track bar fasteners are tightened. If springs are notat their normal ride position, vehicle ride height and
handling could be affected.
(1) Raise axle with lift and align coil springs.
(2) Install lower suspension arms in axle brackets.
Install nuts and bolts, do not tighten bolts at this
time.
(3) Install upper suspension arm on rear axle ball
joint.
(4) Install rear axle ball joint nut and tighten to
122 N´m (90 ft.lbs.) (Fig. 5).
(5) Install track bar and attachment bolts, do not
tighten bolts at this time.
(6) Install shock absorbers and tighten nuts to 60
N´m (44 ft. lbs.).
(7) Install stabilizer bar links and tighten nuts to
36 N´m (27 ft. lbs.).
(8) Install wheel speed sensors.
(9) Connect parking brake cable to brackets and
lever.
(10) Install brake rotors and calipers.
(11) Install the brake hose to the axle junction
block.
(12) Install axle vent hose.
(13) Align propeller shaft and pinion yoke refer-
ence marks. Install U-joint straps and nuts tighten to
19 N´m (14 ft. lbs.).
(14) Install the wheels and tires.
(15) Add gear lubricant, if necessary.
(16) Remove support and lower the vehicle.
(17) Tighten lower suspension arm bolts to 177
N´m (130 ft. lbs.).
(18) Tighten track bar bolts to 100 N´m (74 ft.
lbs.).
Fig. 4 REAR BALL JOINT
1 - REMOVER
2 - UPPER SUSPENSION ARM
3 - BALL JOINT STUD
Fig. 5 REAR BALL JOINT NUT
1 - UPPER SUSPENSION ARM
2 - REAR AXLE BALL JOINT
3 - REAR AXLE
3 - 96 REAR AXLE - 226RBAWJ
REAR AXLE - 226RBA (Continued)

POWER SEAT SYSTEM
TABLE OF CONTENTS
page page
POWER SEAT SYSTEM
DESCRIPTION
DESCRIPTION........................18
DESCRIPTION - MEMORY SYSTEM.......19
OPERATION
OPERATION - POWER SEAT SYSTEM.....20
OPERATION - MEMORY SYSTEM.........20
DIAGNOSIS AND TESTING
DIAGNOSIS & TESTING - POWER SEAT
SYSTEM............................20
DIAGNOSIS & TESTING - MEMORY
SYSTEM............................20
DRIVER SEAT SWITCH
DESCRIPTION.........................21
OPERATION...........................21
DIAGNOSIS AND TESTING - DRIVER SEAT
SWITCH............................22
REMOVAL.............................23
INSTALLATION.........................23
LUMBAR CONTROL SWITCH
DESCRIPTION.........................24
OPERATION...........................24
DIAGNOSIS AND TESTING - POWER LUMBAR
SWITCH............................24
REMOVAL.............................24
INSTALLATION.........................25
LUMBAR MOTOR
DESCRIPTION.........................25OPERATION...........................26
DIAGNOSIS AND TESTING - POWER LUMBAR
ADJUSTER..........................26
MEMORY SET SWITCH
DESCRIPTION.........................26
OPERATION...........................26
DIAGNOSIS AND TESTING - MEMORY
SWITCH............................27
REMOVAL.............................27
INSTALLATION.........................27
PASSENGER SEAT SWITCH
DESCRIPTION.........................27
OPERATION...........................28
DIAGNOSIS AND TESTING - PASSENGER
SEAT SWITCH........................28
REMOVAL.............................29
INSTALLATION.........................29
RECLINER MOTOR
DESCRIPTION.........................30
OPERATION...........................30
DIAGNOSIS AND TESTING - RECLINER
MOTOR .............................30
POWER SEAT TRACK
DESCRIPTION.........................31
OPERATION...........................32
DIAGNOSIS AND TESTING - POWER SEAT
TRACK.............................32
POWER SEAT SYSTEM
DESCRIPTION
DESCRIPTION
Driver and passenger power front seats are an
available factory-installed option for this vehicle. The
power seat system option allows the driver and front
seat passenger to electrically adjust their seating
positions for optimum control and comfort using the
power seat switches located on the outboard seat
cushion side shield of each front seat. The power seat
system receives battery current through a fuse in the
Power Distribution Center (PDC) and a circuit
breaker in the junction block so that the power seats
remain operational, regardless of the ignition switch
position.Four power seat options are offered on this vehicle,
depending upon the model. They are as follows:
²Six-way power drivers seat with manual
passenger seat- This power seat package is an
option on Laredo models equipped with cloth-
trimmed seats and includes a six-way adjustable
driver seat track with manual seat back recliners.
²Six-way power driver and passenger seat-
This power seat package is an option on Laredo mod-
els equipped with cloth or leather-trimmed seats and
includes six-way adjustable seat tracks with manual
seat back recliners. Heated Seats are available on
leather-trimmed seats.
²Ten-way power drivers seat with Memory
and Six-way power passenger seat- This power
seat package is standard on Limited models. This
option includes a six-way adjustable seat track with
power seat back recliners and power lumbar supports
for the driver and six-way only for the passenger.
8N - 18 POWER SEAT SYSTEMWJ

²Ten-way power drivers and passenger seats
with Memory- This power seat option is standard
on Overland models and optional on Limited models.
This option includes a six-way adjustable seat cush-
ion track with power seat back recliners and power
lumbar supports. Heated Seats are standard with
this option.
Refer toHeated Seat Systemfor more informa-
tion on the heated seat option. Refer toMemory
Systemin the Memory System section of this group
for more information on the memory system.
The power seat system includes the following com-
ponents:
²Power lumbar adjuster (ten-way power seat
only)
²Power lumbar switch (ten-way power seat only)
²Power seat recliner (ten-way power seat only)
²Power seat switch
²Power seat track.
Refer toPower Seatin Wiring Diagrams for com-
plete circuit diagrams. Following are general descrip-
tions of the major components in the power seat/
memory seat system.
DESCRIPTION - MEMORY SYSTEM
An electronic memory system is standard equip-
ment on the Limited model. The memory system is
able to store and recall the driver side power seat
positions (including the power recliner position), and
both outside power mirror positions for two drivers.
For vehicles with a radio connected to the Program-
mable Communications Interface (PCI) data bus net-
work, the memory system is also able to store and
recall up to twenty - ten AM and ten FM - radio sta-
tion presets for two drivers. The memory system also
will store and recall the last station listened to for
each driver, even if it is not one of the twenty preset
stations.
The memory system will automatically return to
all of these settings when the corresponding num-
bered and color-coded button (Driver 1 - Black, or
Driver 2 - Gray) of the memory switch on the driver
side front door trim panel is depressed, or when the
doors are unlocked using the corresponding num-
bered and color-coded (Driver 1 - Black, or Driver 2 -
Gray) Remote Keyless Entry (RKE) transmitter. A
customer programmable feature of the memory sys-
tem allows the RKE recall of memory features to be
disabled in cases where there are more than two
drivers of the vehicle.
The memory system also has a customer program-
mable easy exit feature that will move the driver
seat rearward 55 millimeters (two inches) or to the
end of its travel, whichever occurs first, when the key
is removed from the ignition switch lock cylinder.A Memory Seat Module (MSM) or Memory Heated
Seat Module (MHSM) are used on this model to con-
trol and integrate the many electronic functions and
features included in the memory system. On vehicles
equipped with the heated seat system option, the
MHSM also controls the functions and features of
that system.
The memory system includes the following compo-
nents:
²Memory seat module (or memory heated seat
module)
²Memory switch
²Position potentiometers on both outside power
mirrors
²Position potentiometers on the driver side power
seat track and power seat recliner motors.
²Radio receiver (if PCI data bus capable).
Certain functions and features of the memory sys-
tem rely upon resources shared with other electronic
modules in the vehicle over the Programmable Com-
munications Interface (PCI) data bus network. The
PCI data bus network allows the sharing of sensor
information. This helps to reduce wire harness com-
plexity, internal controller hardware, and component
sensor current loads. At the same time, this system
provides increased reliability, enhanced diagnostics,
and allows the addition of many new feature capabil-
ities. For diagnosis of these electronic modules or of
the PCI data bus network, the use of a DRBtscan
tool and the proper Diagnostic Procedures manual
are recommended.
The other electronic modules that may affect mem-
ory system operation are as follows:
²Body Control Module (BCM)- Refer toBody
Control Modulein Electronic Control Modules for
more information.
²Driver Door Module (DDM)- Refer toDoor
Modulein Electronic Control Modules for more
information.
²Electronic Vehicle Information Center
(EVIC)- Refer toElectronic Vehicle Information
Centerin Overhead Console Systems for more infor-
mation.
²Passenger Door Module (PDM)- Refer to
Door Modulein Electronic Control Modules for
more information.
²Powertrain Control Module (PCM)- Refer to
Powertrain Control Modulein Electronic Control
Modules for more information.
²Radio Receiver- Refer toRadio Receiverin
Audio Systems for more information.
Refer toHeated Seat Systemfor more informa-
tion on this system. Refer toRemote Keyless Entry
Systemin Power Lock Systems for more information
on the RKE system. Refer toPower Mirrorin
Power Mirror Systems for more information on the
WJPOWER SEAT SYSTEM 8N - 19
POWER SEAT SYSTEM (Continued)

of the electronic modules are sending and receiving
the proper messages on the PCI data bus, and that
the memory system is receiving the proper hard
wired inputs and relaying the proper hard wired out-
puts to perform its functions.
DRIVER SEAT SWITCH
DESCRIPTION
Two different power seat switches are used on this
vehicle, depending upon the optional power seat sys-
tem installed in the vehicle. The six-way power seats
are each equipped with a switch featuring three
switch control knobs ganged together on the outboard
seat cushion side shield (Fig. 1). The ten-way power
seats are each equipped with a switch featuring two
knobs ganged together on the outboard seat cushion
side shield (Fig. 2).
The switch units for both power seat types are
secured to the back of the seat cushion side shield
with two screws. However, the control knobs for the
six-way power seat switch unit remain installed dur-
ing switch unit removal and installation, while both
knobs for the ten-way power seat switch unit must
be removed.
The individual switches in both power seat switch
units cannot be repaired. If one switch is damaged or
faulty, the entire power seat switch unit must be
replaced.
OPERATION
The power seat tracks of both the six-way and the
ten-way power seat systems can be adjusted in six
different ways using the power seat switches. The
ten-way system has the additional power seat
recliner switch integral to the power seat switch and
also has a separate, stand-alone switch to control the
power lumbar adjuster. See the owner's manual in
the vehicle glove box for more information on the
power seat switch functions and the seat adjusting
procedures.
When a power switch control knob or knobs are
actuated, a battery feed and a ground path are
applied through the switch contacts to the power seat
track or recliner adjuster motor. The selected
adjuster motor operates to move the seat track or
recliner through its drive unit in the selected direc-
tion until the switch is released, or until the travel
limit of the adjuster is reached. When the switch is
moved in the opposite direction, the battery feed and
ground path to the motor are reversed through the
switch contacts. This causes the adjuster motor to
run in the opposite direction.
No power seat switch should be held applied in any
direction after the adjuster has reached its travel
limit. The power seat adjuster motors each contain a
self-resetting circuit breaker to protect them from
overload. However, consecutive or frequent resetting
of the circuit breaker must not be allowed to con-
tinue, or the motor may be damaged.
Fig. 1 Six-Way Power Seat Switches - Typical
1 - OUTBOARD SEAT CUSHION SIDE SHIELD
2 - POWER SEAT TRACK SWITCHES
3 - MECHANICAL SEAT BACK RECLINER LEVER
Fig. 2 Ten-Way Power Seat Switches - Typical
1 - OUTBOARD CUSHION SIDE SHIELD
2 - POWER SEAT RECLINER SWITCH
3 - POWER SEAT TRACK SWITCH
4 - POWER LUMBAR SWITCH
WJPOWER SEAT SYSTEM 8N - 21
POWER SEAT SYSTEM (Continued)

LUMBAR CONTROL SWITCH
DESCRIPTION
The ten-way power seat option includes an electri-
cally operated lumbar support mechanism. A single
two-way momentary power lumbar switch is located
on the outboard seat cushion side shield of each front
seat, just forward of the other power seat switches
(Fig. 8). The power lumbar switch is secured to the
back of the seat cushion side shield with two screws,
and the switch paddle protrudes through a hole to
the outside of the shield. The switch paddle is located
in a shallow depression molded into the outer surface
of the seat cushion side shield that helps to shroud it
from unintentional actuation when entering or leav-
ing the vehicle.
The power lumbar switches cannot be adjusted or
repaired and, if faulty or damaged, they must be
replaced.
OPERATION
When the power lumbar switch paddle is actuated,
a battery feed and a ground path are applied through
the switch contacts to the power lumbar adjuster
motor. The motor operates to move the lumbar
adjuster through its drive unit in the selected direc-
tion until the switch is released, or until the travel
limit of the adjuster is reached. When the switch is
moved in the opposite direction, the battery feed and
ground path to the motor are reversed through the
switch contacts. This causes the motor to run in the
opposite direction.
The power lumbar switch should not be held
applied in either direction after the adjuster hasreached its travel limit. The power lumbar adjuster
motor contains a self-resetting circuit breaker to pro-
tect it from overload. However, consecutive or fre-
quent resetting of the circuit breaker must not be
allowed to continue, or the motor may be damaged.
DIAGNOSIS AND TESTING - POWER LUMBAR
SWITCH
For complete circuit diagrams, refer toWiring
Diagrams.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the power lumbar switch from the out-
board seat cushion side shield. Refer to the procedure
in this section of the manual.
(3) Use an ohmmeter to test the continuity of the
power lumbar switch in each switch position. See the
Power Lumbar Switch Continuity chart (Fig. 9). If
OK, refer toPower Lumbar Adjuster Diagnosis
and Testingin this group. If not OK, replace the
faulty power lumbar switch.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
Fig. 8 Ten-Way Power Seat Switches
1 - OUTBOARD CUSHION SIDE SHIELD
2 - POWER SEAT RECLINER SWITCH
3 - POWER SEAT TRACK SWITCH
4 - POWER LUMBAR SWITCH
Fig. 9 Power Lumbar Switch
POWER LUMBAR SWITCH
LEFT SWITCH
POSITIONRIGHT
SWITCH
POSITIONCONTINUITY
BETWEEN
Off Off 2-4, 3-5
Forward Rearward 3-5, 4-6
Rearward Forward 2-4, 3-6
8N - 24 POWER SEAT SYSTEMWJ