2002 JEEP GRAND CHEROKEE Abs

REAR
TABLE OF CONTENTS
page page
REAR
DESCRIPTION.........................17
WARNING.............................17
DIAGNOSIS AND TESTING - REAR
SUSPENSION........................18
SPECIFICATIONS
TORQUE CHART......................18
SPECIAL TOOLS
REAR SUSPENSION...................19
LOWER CONTROL ARM
DESCRIPTION.........................19
OPERATION...........................19
REMOVAL.............................19
INSTALLATION.........................19
SHOCK
DESCRIPTION.........................19
OPERATION...........................19
REMOVAL.............................19
INSTALLATION.........................19
SPRING
DESCRIPTION.........................20OPERATION...........................20
REMOVAL.............................20
INSTALLATION.........................20
STABILIZER BAR
DESCRIPTION.........................21
OPERATION...........................21
REMOVAL.............................21
INSTALLATION.........................21
UPPER BALL JOINT
DESCRIPTION - UPPER SUSPENSION ARM,
BUSHINGS, AND BALL JOINT............21
OPERATION - UPPER SUSPENSION ARM,
BUSHINGS, AND BALL JOINT............21
REMOVAL.............................21
INSTALLATION.........................22
UPPER CONTROL ARM
DESCRIPTION.........................22
OPERATION...........................22
REMOVAL.............................22
INSTALLATION.........................23
REAR
DESCRIPTION
The rear suspension (Fig. 1) is comprised of :
²Drive axle
²Shock absorbers
²Coil springs
²Lower suspension arms
²Upper suspension arm
²Stabilizer bar
CAUTION: Suspension components with rubber/ure-
thane bushings should be tightened with the vehi-
cle at normal ride height. It is important to have the
springs supporting the weight of the vehicle when
the fasteners are torqued. This will maintain vehicle
ride comfort and prevent premature bushing wear.
WARNING
WARNING:: Suspension components with rubber
bushings must be tightened with the vehicle at nor-
mal ride height. It is important to have the springs
supporting the weight of the vehicle when the fas-
teners are torqued. If springs are not at their normalride position, vehicle ride comfort will be affected
and cause premature bushing wear.
Fig. 1 Rear Suspension
1 - SHOCK
2 - UPPER SUSPENSION ARM
3 - COIL SPRING
4 - STABILIZER BAR
5 - LOWER SUSPENSION ARM
WJREAR 2 - 17

DIAGNOSIS AND TESTING - REAR
SUSPENSION
CONDITION POSSIBLE CAUSES CORRECTION
VEHICLE INSTABILITY 1. Loose or worn wheel bearings. 1. Replace wheel bearings.
2. Loose, worn or bent suspension
components.2. Inspect, tighten or replace components
as necessary.
3. Tire pressure. 3. Adjust tire pressure.
VEHICLE PULLS TO ONE
SIDE1. Weak or broken spring. 1. Replace spring.
2. Alignment. 2. Align vehicle to specifications.
3.Tires. 3. Replace tires.
4. Brakes. 4. Repair as necassary.
KNOCKING, RATTLING
OR SQUEAKING1. Worn shock bushings. 1. Replace shock.
2. Loose shock mounting. 2. Tighten to specifications.
3. Shock valve. 3. Replace shock.
4. Loose upper ball joint. 4. Replace ball joint.
5. Loose, worn or bent suspension
components.5. Inspect, tighten or replace components
as necessary.
IMPROPER TRACKING 1. Loose, worn or bent suspension
components.1. Inspect, tighten or replace components
as necessary.
2. Bent axle. 2.Replace axle.
SPECIFICATIONS
TORQUE CHART
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Shock Absorber Upper Nut 108 80 Ð
Shock Absorber Lower Nut 115 85 Ð
Suspension Arm Upper Ball Joint Nut 142 105 Ð
Suspension Arm Upper Frame Bolts 100 74 Ð
Ball Joint Plate Bolts 136 100 Ð
Suspension Arms Lower Axle Bracket Nut 163 120 Ð
Suspension Arms Lower Frame Bracket Nut 156 115 Ð
Stabilizer Bar Retainer Bolts 54 40 Ð
Stabilizer Bar Bar Link Nut 54 40 Ð
Stabilizer Bar Bracket Link Nut 92 68 Ð
2 - 18 REARWJ
REAR (Continued)

SPECIAL TOOLS
REAR SUSPENSION
LOWER CONTROL ARM
DESCRIPTION
The lower suspension arms are hydroformed steel
and use voided oval bushings at each end of the arm.
OPERATION
The bushings provide isolation from the axle. The
arms mount to the unibody frame rail bracket and
the axle brackets. The arm and bushings provide
location and react to loads.
REMOVAL
(1) Raise the vehicle and support the rear axle.
(2) Remove the lower suspension arm nut and bolt
from the axle bracket (Fig. 2).
(3) Remove the nut and bolt (Fig. 2) from the
frame rail and remove the lower suspension arm.
INSTALLATION
(1) Position the lower suspension arm in the axle
bracket and frame rail bracket.
NOTE: The end of the arm with the oval bushing
attaches to the axle bracket.
(2) Install the axle bracket bolt and nut finger
tight.
(3) Install the frame rail bracket bolt and nut fin-
ger tight.
(4) Remove the supports and lower the vehicle.
(5) With the vehicle on the ground tighten the nut
at the frame to 156 N´m (115 ft. lbs.). Tighten the
nut at the axle bracket to 163 N´m (120 ft. lbs.).
SHOCK
DESCRIPTION
The top of the shock absorbers are bolted to the
body. The bottom of the shocks are bolted to the axle
brackets. The standard shocks have conventional
twin tube construction and are low pressure gas
charged. Gas charging prevents cavitation during
rough road operation. Up-Country shocks are mono
tube design and are high pressure gas charged.
OPERATION
The shock absorbers dampen jounce and rebound
motion of the vehicle over various road conditions
and limit suspension rebound travel.
REMOVAL
(1) Raise and support the vehicle. Position a
hydraulic jack under the axle to support the axle.
CAUTION: Do not allow the axle to hang from the
upper suspension arm ball joint.
(2) Remove the upper nut and bolt from the frame
bracket (Fig. 3).
(3) Remove the lower nut and bolt from the axle
bracket. Remove the shock absorber.
INSTALLATION
(1) Install the shock absorber in the frame bracket
and install the bolt and nut.
(2) Install the shock absorber in the axle bracket
and install the bolt and nut.
(3) Tighten the upper mounting nuts to 108 N´m
(80 ft. lbs.). Tighten the lower mounting nuts to 115
N´m (85 ft. lbs.).
(4) Remove the supports and lower the vehicle.
Remover 8278
Fig. 2 Lower Suspension Arm
1 - LOWER SUSPENSION ARM
2 - AXLE BRACKET
3 - FRAME BRACKET
WJREAR 2 - 19
REAR (Continued)

SPRING
DESCRIPTION
The coil springs mount up in the wheelhouse which
is part of the unitized body bracket. A rubber dough-
nut isolator is located between the top of the spring
and the body. The bottom of the spring seats on a
axle isolator made of rubber with a steel insert. The
isolators provide road noise isolation
OPERATION
The coil springs control ride quality and maintain
proper ride height.
REMOVAL
(1) Raise and support the vehicle. Position a
hydraulic jack under the axle to support the axle.
(2) Remove the wheel and tire assemblies.
(3) Remove the stabilizer bar link from the stabi-
lizer bar (Fig. 4).
(4) Remove the shock absorber lower bolt from the
axle bracket.
(5) Lower the hydraulic jack and tilt the axle and
remove the coil spring (Fig. 4).
(6) Remove and inspect the upper and lower
spring isolators (Fig. 4).
INSTALLATION
(1) Install the upper isolator.
(2) Install the lower isolator with the isolator loca-
tor nub in the axle pad hole (Fig. 5).
(3) Pull down on the axle and position the coil
spring in the lower isolator.CAUTION: Ensure the spring is positioned on the
lower isolator with the end of the spring coil
against the isolator spring locator (Fig. 6).
(4) Raise the axle with the hydraulic jack.
(5) Install the shock absorber to the axle bracket
and tighten to specification.
(6) Install the stabilizer bar link to the stabilizer
bar.
(7) Install the wheel and tire assemblies.
(8) Remove the supports and lower the vehicle.
(9) Tighten the stabilizer bar links to specification.
Fig. 3 Shock Absorber
1 - SHOCKFig. 4 Coil Spring
1 - COIL SPRING
2 - ISOLATOR
3 - STABILIZER LINK
4 - ISOLATOR
Fig. 5 Isolator Locator Nub
1 - LOWER ISOLATOR
2 - LOCATOR NUB
3 - AXLE SPRING PAD
2 - 20 REARWJ
SHOCK (Continued)

STABILIZER BAR
DESCRIPTION
The stabilizer bar extends across the back side of
the rear axle. Links are connected between the bar
and frame rail brackets. The stabilizer bar and links
are isolated by rubber bushings.
OPERATION
The stabilizer bar is used to control vehicle body
roll, during turns. The bar helps control the vehicle
body in relationship to the suspension.
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the stabilizer bar links from stabilizer
bar and frame mount. (Fig. 7).
(3) Remove the stabilizer bar retainer bolts.
(4) Remove the stabilizer bar.
INSTALLATION
(1) Position the stabilizer bar on the axle and
install the retainers and bolts. Ensure the bar is cen-
tered with equal spacing on both sides. Tighten the
bolts to 54 N´m (40 ft. lbs.).
(2) Install the links to the stabilizer bar and frame
brackets.
(3) Tighten the nuts at the stabilizer bar to 54
N´m (40 ft. lbs.).
(4) Tighten the nuts at the frame brackets to 92
N´m (68 ft. lbs.).
(5) Remove support and lower the vehicle.
UPPER BALL JOINT
DESCRIPTION - UPPER SUSPENSION ARM,
BUSHINGS, AND BALL JOINT
The suspension arm uses vertical spool bushings to
isolate road noise. The suspension arm is bolted
through bushings to cage nuts in the body and a ball
joint plate to the top of the differential housing.
OPERATION - UPPER SUSPENSION ARM,
BUSHINGS, AND BALL JOINT
The upper suspension arm provides fore/aft and
lateral location of the rear axle. The suspension arm
travel is limited through the use of jounce bumpers
in compression and shock absorbers in rebound.
REMOVAL
(1) Raise and support the vehicle.
(2) Support the rear axle with a hydraulic jack.
(3) Remove the ball joint nut from the top of the
upper suspension arm (Fig. 8).
(4) Separate ball joint from the arm with Remover
8278 (Fig. 9).
NOTE: It may be necessary to strike the upper con-
trol arm with a hammer to separate the ball joint
from the arm.
(5) Remove the ball joint mounting bolts (Fig.
10)from the differential housing.
(6) Remove the ball joint from the differential
housing.
Fig. 6 Isolator Spring Locator - Typical
1 - LOWER ISOLATOR
2 - SPRING LOCATOR
3 - COIL SPRING
Fig. 7 Rear Stabilizer Bar
1 - LINK
2 - RETAINER
3 - BUSHING
4 - STABILIZER BAR
WJREAR 2 - 21
SPRING (Continued)

INSTALLATION
(1) Install the ball joint on the differential hous-
ing.
(2) Install the ball joint mounting bolts and
tighten to 136 N´m (100 ft. lbs.).
(3) Raise the rear axle with a hydraulic jack to
align the upper arm with the ball joint.(4) Pull the arm down on the ball joint stud and
install anewnut. Tighten the nut to 142 N´m (105
ft. lbs.).
(5) Remove the supports and lower the vehicle.
UPPER CONTROL ARM
DESCRIPTION
The suspension arm uses vertical spool bushings to
isolate road noise. The suspension arm is bolted
through bushings to cage nuts in the body and a ball
joint plate to the top of the differential housing.
OPERATION
The upper suspension arm provides fore/aft and
lateral location of the rear axle. The suspension arm
travel is limited through the use of jounce bumpers
in compression and shock absorbers in rebound.
REMOVAL
(1) Raise and support the vehicle.
(2) Support the rear axle with a hydraulic jack.
(3) Remove the park brake cables and brake hose
from the arm (Fig. 11).
(4) Remove the ball joint nut from the top of the
upper suspension arm (Fig. 12).
(5) Separate ball joint from the arm with Remover
8278 (Fig. 13).
Fig. 8 Ball Joint Nut
1 - BALL JOINT NUT
2 - UPPER SUSPENSION ARM
Fig. 9 Separate Ball Joint
1 - REMOVER
2 - UPPER SUSPENSION ARM
3 - BALL JOINT STUD
Fig. 10 Ball Joint Mounting Bolts
1 - BALL JOINT
2 - MOUNTING BOLTS
2 - 22 REARWJ
UPPER BALL JOINT (Continued)

FRONT TUBE AXLE
TABLE OF CONTENTS
page page
FRONT TUBE AXLE
REMOVAL.............................14INSTALLATION.........................14
FRONT TUBE AXLE
REMOVAL
(1) Raise and support the vehicle.
(2) Position a lifting device under the axle and
secure axle to lift.
(3) Remove the wheels and tires.
(4) Remove the brake rotors (Refer to 5 - BRAKES/
HYDRAULIC/MECHANICAL/ROTORS - REMOVAL)
and calipers.
(5) Disconnect wheel sensor wiring harness from
the vehicle wiring harness.
(6) Remove stabilizer bar links at the axle.
(7) Remove shock absorbers from axle brackets.
(8) Removet track bar.
(9) Remove tie rod and drag link from the steering
knuckle.
(10) Remove steering damper from the axle
bracket.
(11) Remove upper and lower suspension arms
from the axle brackets.
(12) Lower the lift enough to remove the axle. The
coil springs will drop with the axle.
(13) Remove the coil springs from the axle.
INSTALLATION
CAUTION: The weight of the vehicle must be sup-
ported by the springs before suspension arms and
track bar fasteners are tightened. If not at their nor-mal ride position, ride height and handling could be
affected.
(1) Install springs and retainer clips and tighten
retainer bolts to 21 N´m (16 ft. lbs.).
(2) Lift and position axle under the vehicle and
align it with the spring pads.
(3) Position upper and lower suspension arms in
the axle brackets and loosely install bolts and nuts.
(4) Install track bar to the axle bracket and loosely
install bolt.
(5) Install shock absorbers and tighten bolts to 23
N´m (17 ft. lbs.).
(6) Install stabilizer bar links to the axle brackets
and tighten nuts to 95 N´m (70 ft. lbs.).
(7) Install drag link and tie rod to the steering
knuckles.
(8) Install steering damper to the axle bracket and
tighten nut to 75 N´m (55 ft. lbs.).
(9) Install the brake rotors and calipers.
(10) Connect wheel speed sensor wiring harness, if
equipped.
(11) Install the wheel and tire assemblies.
(12) Remove lift from the axle and lower the vehi-
cle.
(13) Tighten upper suspension arm nuts to 75 N´m
(55 ft. lbs.). Tighten lower suspension arm nuts to
115 N´m (85 ft. lbs.).
(14) Tighten track bar bolt at the axle bracket to
100 N´m (74 ft. lbs.).
(15) Check the front wheel alignment.
3 - 14 FRONT TUBE AXLEWJ

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)