Jeep Grand Cherokee WJ. Manual - part 12

CAUTION: Suspension components with rubber/
urethane bushings should be tightened with the
vehicle 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.

SHOCK ABSORBERS

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.

JOUNCE BUMPERS

DESCRIPTION

The jounce bumpers are mounted inside the coil

spring, between the axle and the frame rail, to min-
imize transmission of noise to the passenger com-
partment.

Fig. 1 Rear Suspension

1 – SHOCK
2 – UPPER SUSPENSION ARM
3 – COIL SPRING
4 – STABILIZER BAR
5 – LOWER SUSPENSION ARM

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SUSPENSION

OPERATION

The jounce bumpers are used to limit suspension

travel in compression.

COIL SPRINGS AND ISOLATORS

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.

LOWER SUSPENSION ARMS AND BUSHINGS

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.

UPPER SUSPENSION ARM, BUSHINGS, AND
BALL JOINT

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.

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.

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
SIDE

1. 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
SQUEAKING

1. 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.

SUSPENSION

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DESCRIPTION AND OPERATION (Continued)

CONDITION

POSSIBLE CAUSES

CORRECTION

IMPROPER TRACKING

1. Loose, worn or bent suspension
components.

1. Inspect, tighten or replace components
as necessary.

2. Bent axle.

2. Replace axle.

SERVICE PROCEDURES

SERVICE WARNINGS AND CAUTIONS

CAUTION: 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 normal
ride position, vehicle ride comfort will be affected
and cause premature bushing wear.

REMOVAL AND INSTALLATION

SHOCK ABSORBER

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. 2).

(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.

COIL SPRING

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. 3).

(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. 3).

(6) Remove and inspect the upper and lower

spring isolators (Fig. 3).

INSTALLATION

(1) Install the upper isolator.

Fig. 2 Shock Absorber

1 – SHOCK

Fig. 3 Coil Spring

1 – COIL SPRING
2 – ISOLATOR
3 – STABILIZER LINK
4 – ISOLATOR

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SUSPENSION

DIAGNOSIS AND TESTING (Continued)

(2) Install the lower isolator with the isolator loca-

tor nub in the axle pad hole (Fig. 4).

(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. 5).

(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.

LOWER SUSPENSION ARM

REMOVAL

(1) Raise the vehicle and support the rear axle.
(2) Remove the lower suspension arm nut and bolt

from the axle bracket (Fig. 6).

(3) Remove the nut and bolt (Fig. 6) 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.).

UPPER SUSPENSION ARM

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. 7).

Fig. 4 Isolator Locator Nub

1 – LOWER ISOLATOR
2 – LOCATOR NUB
3 – AXLE SPRING PAD

Fig. 5 Isolator Spring Locator - Typical

1 – LOWER ISOLATOR
2 – SPRING LOCATOR
3 – COIL SPRING

Fig. 6 Lower Suspension Arm

1 – LOWER SUSPENSION ARM
2 – AXLE BRACKET
3 – FRAME BRACKET

SUSPENSION

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REMOVAL AND INSTALLATION (Continued)

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