2003 JEEP GRAND CHEROKEE Brake

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)

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)

NOTE: It may be necessary to strike the upper con-
trol arm with a hammer to separate the ball joint
from the arm.
(6) Remove the upper suspension arm mounting
bolts and remove the arm (Fig. 14).
INSTALLATION
(1) Position the upper suspension arm in the
frame rail brackets.
(2) Install the mounting bolts and tighten to 100
N´m (74 ft. lbs.).
(3) Pull the arm down on the ball joint stud and
install anewnut. Tighten the nut to 142 N´m (105
ft. lbs.).(4) Install the park brake cables and brake hose to
the arm.
(5) Remove the supports and lower the vehicle.
Fig. 11 Park Brake Cables And Brake Hose
1 - UPPER SUSPENSION ARM
2 - REAR BRAKE HOSE
3 - PARK BRAKE CABLES
Fig. 12 Ball Joint Nut
1 - BALL JOINT NUT
2 - UPPER SUSPENSION ARM
Fig. 13 Separate Ball Joint
1 - REMOVER
2 - UPPER SUSPENSION ARM
3 - BALL JOINT STUD
Fig. 14 Upper Suspension Arm Mounting Bolt
1 - UPPER SUSPENSION ARM
2 - MOUNTING BOLT
WJREAR 2 - 23
UPPER CONTROL ARM (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)

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)

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)