2002 JEEP GRAND CHEROKEE Rear axle

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)

DIFFERENTIAL & DRIVELINE
TABLE OF CONTENTS
page page
PROPELLER SHAFT......................1
FRONT TUBE AXLE......................14
FRONT AXLE - 186FBI....................15REAR AXLE - 198RBI.....................50
REAR AXLE - 226RBA....................90
PROPELLER SHAFT
TABLE OF CONTENTS
page page
PROPELLER SHAFT
DIAGNOSIS AND TESTING................1
STANDARD PROCEDURES................3
SPECIFICATIONS........................5
SPECIAL TOOLS........................5
PROPELLER SHAFT - FRONT
REMOVAL.............................6
INSTALLATION..........................6
PROPELLER SHAFT - FRONT 4.7L
REMOVAL.............................6INSTALLATION..........................7
PROPELLER SHAFT - REAR
REMOVAL.............................7
INSTALLATION..........................7
SINGLE CARDAN UNIVERSAL JOINTS
DISASSEMBLY..........................8
ASSEMBLY.............................9
DOUBLE CARDAN UNIVERSAL JOINTS
DISASSEMBLY..........................9
ASSEMBLY............................10
PROPELLER SHAFT
DIAGNOSIS AND TESTING
VIBRATION
Tires that are out-of-round, or wheels that are
unbalanced, will cause a low frequency vibration.
(Refer to 22 - TIRES/WHEELS - DIAGNOSIS AND
TESTING)
Brake rotors that are unbalanced will cause a
harsh, low frequency vibration. (Refer to 5 - BRAKES
- DIAGNOSIS AND TESTING)Driveline vibration can also result from loose or
damaged engine mounts.
Propeller shaft vibration increases as the vehicle
speed is increased. A vibration that occurs within a
specific speed range is not usually caused by a pro-
peller shaft being unbalanced. Defective universal
joints, or an incorrect propeller shaft angle, are usu-
ally the cause of such a vibration.
WJDIFFERENTIAL & DRIVELINE 3 - 1

DRIVELINE VIBRATION
Drive Condition Possible Cause Correction
Propeller Shaft Noise 1) Undercoating or other foreign material
on shaft.1) Clean exterior of shaft and wash with
solvent.
2) Loose U-joint clamp screws. 2) Install new clamps and screws and
tighten to proper torque.
3) Loose or bent U-joint yoke or
excessive runout.3) Install new yoke.
4) Incorrect driveline angularity. 4) Measure and correct driveline angles.
5) Rear spring center bolt not in seat. 5) Loosen spring u-bolts and seat center
bolt.
6) Worn U-joint bearings. 6) Install new U-joint.
7) Propeller shaft damaged or out of
balance.7) Installl new propeller shaft.
8) Broken rear spring. 8) Install new rear spring.
9) Excessive runout or unbalanced
condition.9) Re-index propeller shaft, test, and
evaluate.
10) Excessive drive pinion gear shaft
runout.10) Re-index propeller shaft and evaluate.
11) Excessive axle yoke deflection. 11) Inspect and replace yoke if necessary.
12) Excessive transfer case runout. 12) Inspect and repair as necessary.
Universal Joint Noise 1) Loose U-joint clamp screws. 1) Install new clamps and screws and
tighten to proper torque.
2) Lack of lubrication. 2) Replace U-joints as necessary.
BALANCE
NOTE: Removing and re-indexing the propeller
shaft 180É relative to the yoke may eliminate some
vibrations.
If propeller shaft is suspected of being unbalanced,
it can be verified with the following procedure:
(1) Raise the vehicle.
(2) Clean all the foreign material from the propel-
ler shaft and the universal joints.
(3) Inspect the propeller shaft for missing balance
weights, broken welds, and bent areas.If the pro-
peller shaft is bent, it must be replaced.
(4) Inspect the universal joints to ensure that they
are not worn, are properly installed, and are cor-
rectly aligned with the shaft.
(5) Check the universal joint clamp screws torque.
(6) Remove the wheels and tires. Install the wheel
lug nuts to retain the brake drums or rotors.
(7) Mark and number the shaft six inches from the
yoke end at four positions 90É apart.
(8) Run and accelerate the vehicle until vibration
occurs. Note the intensity and speed the vibration
occurred. Stop the engine.(9) Install a screw clamp at position 1 (Fig. 1).
Fig. 1 CLAMP SCREW - POSITION 1
1 - CLAMP
2 - SCREWDRIVER
3 - 2 PROPELLER SHAFTWJ
PROPELLER SHAFT (Continued)

(10) Start the engine and re-check for vibration. If
there is little or no change in vibration, move the
clamp to one of the other three positions. Repeat the
vibration test.
(11) If there is no difference in vibration at the
other positions, the source of the vibration may not
be propeller shaft.
(12) If the vibration decreased, install a second
clamp (Fig. 2) and repeat the test.
(13) If the additional clamp causes an additional
vibration, separate the clamps (1/4 inch above and
below the mark). Repeat the vibration test (Fig. 3).
(14) Increase distance between the clamp screws
and repeat the test until the amount of vibration is
at the lowest level. Bend the slack end of the clamps
so the screws will not loosen.
(15) If the vibration remains unacceptable, apply
the same steps to the front end of the propeller shaft.
(16) Install the wheel and tires. Lower the vehicle.RUNOUT
(1) Remove dirt, rust, paint, and undercoating
from the propeller shaft surface where the dial indi-
cator will contact the shaft.
(2) The dial indicator must be installed perpendic-
ular to the shaft surface.
(3) Measure runout at the center and ends of the
shaft sufficiently far away from weld areas to ensure
that the effects of the weld process will not enter into
the measurements.
(4) Refer to Runout Specifications chart.
(5) If the propeller shaft runout is out of specifica-
tion, remove the propeller shaft, index the shaft 180É,
and re-install the propeller shaft. Measure shaft
runout again.
(6) If the propeller shaft runout is now within
specifications, mark the shaft and yokes for proper
orientation.
(7) If the propeller shaft runout is not within spec-
ifications, verify that the runout of the transmission/
transfer case and axle are within specifications.
Correct as necessary and re-measure propeller shaft
runout.
(8) Replace the propeller shaft if the runout still
exceeds the limits.
RUNOUT SPECIFICATIONS
Front of Shaft 0.020 in. (0.50 mm)
Center of Shaft 0.025 in. (0.63 mm)
Rear of Shaft 0.020 in. (0.50 mm)
note:
Measure front/rear runout approximately 3 inches (76
mm) from the weld seam at each end of the shaft
tube for tube lengths over 30 inches. For tube lengths
under 30 inches, the maximum allowed runout is
0.020 in. (0.50 mm) for the full length of the tube.
STANDARD PROCEDURES
This procedure applies to both the front propeller
shafts and the rear propeller shaft. To obtain the
front (output) angle on the C/V front propeller shaft,
the inclinometer is placed on the machined ring of
the pinion flange. To obtain the propeller shaft angle
measurement on the C/V front propeller shaft, the
inclinometer is placed on the propeller shaft tube.
PROPELLER SHAFT ANGLE
(1) Raise and support the vehicle at the axles as
level as possible. Allow the wheels and propeller
shaft to turn.
(2) Remove any external bearing snap rings from
universal joint if equipped, so the inclinometer base
will sits flat.
Fig. 2 TWO CLAMP SCREWS
Fig. 3 CLAMP SCREWS SEPARATED
1 - ó INCH
WJPROPELLER SHAFT 3 - 3
PROPELLER SHAFT (Continued)