Brake JEEP GRAND CHEROKEE 2003 WJ / 2.G Owner's Manual

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 lifting device under the axle and
secure axle.
(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.
WJREAR AXLE - 198RBI 3 - 55
REAR AXLE - 198RBI (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)

AXLE SHAFTS
REMOVAL
(1) Place transmission in neutral.
(2) Raise and support vehicle.
(3) Remove wheel and tire assembly.
(4) Remove brake caliper and rotor.
(5) Remove nuts holding axle retainer plate to axle
tube from the rear of the axle flange.
(6) Pull axle shaft from the axle with Slide Ham-
mer 7420 and Adapter 6790. Mount the adapter to
the axle with lug nuts.
NOTE: The axle bearing race is normally loose in
the axle tube.
INSTALLATION
(1) Insall axle into the axle tube with the flat area
of the retainer plate upward.
(2) Insert retaining plate studs into the brake
backing plate and axle tube flange.
(3) Install retainer nuts and tighten nuts to 61
N´m (45 ft. lbs.).
(4) Install the brake rotor and caliper.
(5) Install wheel and tire.
(6) Check and fill the differential with gear lubri-
cant.
(7) Lower vehicle.
AXLE BEARINGS/SEALS
REMOVAL
(1) Remove axle shaft from vehicle.
NOTE: The axle bearing race is normally loose in
the axle tube.
(2) Drill a shallow hole into soft steel axle bearing
retaining ring with a 3/8 in. drill bit (Fig. 25). Use a
drill depth stop to avoid marking the axle.
(3) With a cold chisel cut the retaining ring across
drilled hole. (Fig. 26)
(4) Slide retaining ring from axle shaft.
Fig. 25 DRILL RETAINING RING
1 - DRILL BIT
2 - AXLE
3 - RETAINING PLATE
4 - RETAINING RING
Fig. 26 RETAINING RING
1 - AXLE
2 - COLD CHISEL
3 - VISE
4 - RETAINING RING
WJREAR AXLE - 198RBI 3 - 69

(7) Press metal retaining ring onto axle shaft with
Installer 7913 and a press (Fig. 30).
(8) Install axle in vehicle.
PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assemblies.
(3) Remove brake calipers and rotors.
(4) Mark propeller shaft and pinion yoke for
installation reference.
(5) Remove propeller shaft from the yoke.
(6) Rotate pinion gear a minimum of ten times and
verify pinion rotates smoothly.
(7) Record rotating torque of the pinion gear with
an inch pound dial-type torque wrench, for installa-
tion reference.
(8) Hold the pinion yoke with Spanner Wrench
6958 and remove the pinion nut and washer (Fig.
31).
(9) Remove pinion yoke with Remover C-452 and
Wrench C-3281 (Fig. 32).
(10) Remove pinion gear seal with Remover
7794-A and slide hammer (Fig. 33).
INSTALLATION
(1) Apply a light coating of gear lubricant on the
lip of pinion seal and install seal with an appropriate
installer (Fig. 34).
(2) Install yoke on pinion gear with Screw 8112,
Cup 8109 and Spanner Wrench 6958 (Fig. 35).
CAUTION: Do not exceed the minimum tightening
torque 271 N´m (200 ft. lbs.) when installing the pin-
ion yoke at this point. Damage to the collapsible
spacer or bearings may result.
(3) Install yoke washer and anewnut on the pin-
ion gear and tighten the nut until there is zero bear-
ing end-play.
Fig. 30 BEARING RETAINING RING
1 - PRESS
2 - AXLE
3 - AXLE BEARING
4 - INSTALLER
5 - METAL RETAINING RING
Fig. 31 PINION YOKE HOLDER
1 - PIPE
2 - PINION YOKE
3 - SPANNER WRENCH
4 - LOWER CONTROL ARM
Fig. 32 PINION YOKE
1 - FLANGE WRENCH
2 - YOKE
3 - YOKE PULLER
WJREAR AXLE - 198RBI 3 - 71
AXLE BEARINGS/SEALS (Continued)

(6) If the rotating torque is low, use Spanner
Wrench 6958 to hold the pinion yoke (Fig. 37), and
tighten the pinion nut in 6.8 N´m (5 ft. lbs.) incre-
ments until the proper rotating torque is achieved.
CAUTION: If maximum tightening torque is reached
prior to reaching required rotating torque, the col-
lapsible spacer may have been damaged. Replace
the collapsible spacer.
(7) Install the propeller shaft with reference marks
aligned.
(8) Add gear lubricant to the differential if neces-
sary.
(9) Install brake rotors and calipers.
(10) Install wheel and tire assemblies.
(11) Lower the vehicle.
COLLAPSIBLE SPACER
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assemblies.
(3) Remove rear brake calipers and rotors.
(4) Mark propeller shaft and pinion yoke for
installation reference and remove propeller shaft.
(5) Rotate pinion gear a minimum of ten times and
verify pinion rotates smoothly.
(6) Record rotate torque of the pinion gear, with an
inch pound torque wrench.
(7) Hold pinion yoke with Spanner Wrench 6958
and remove pinion nut and washer (Fig. 38).
(8) Remove pinion yoke with Remover C-452 and
Wrench C-3281 (Fig. 39).(9) Remove pinion shaft seal with Remover 7794-A
and slide hammer (Fig. 40).
(10) Remove front pinion bearing using a pair of
pick tools to pull the bearing off the pinion gear
shaft.
NOTE: If the pinion bearing becomes bound on the
pinion shaft, lightly tap the end of the shaft with a
rawhide/rubber mallet.
(11) Remove the collapsible spacer.
INSTALLATION
(1) Install anewcollapsible spacer on pinion
shaft.
(2) Install pinion front bearing on the pinion shaft.
Fig. 37 PINION SHAFT NUT
1 - SPANNER WRENCH
2 - PIPE
3 - TORQUE WRENCH
Fig. 38 PINION YOKE HOLDER
1 - 1 in. PIPE
2 - PINION YOKE
3 - SPANNER WRENCH
4 - LOWER CONTROL ARM
Fig. 39 PINION YOKE PULLER
1 - WRENCH
2 - PINION YOKE
3 - PULLER
WJREAR AXLE - 198RBI 3 - 73
PINION SEAL (Continued)

(7) Check rotating torque with an inch pound
torque wrench (Fig. 44). The rotating torque of the
pinion gear should be, the reading recorded during
removal plus an additional 0.56 N´m (5 in. lbs.).
(8) Install propeller shaft with reference marks
align.
(9) Install rear brake calipers and rotors (Refer to
5 - BRAKES/HYDRAULIC/MECHANICAL/ROTORS
- INSTALLATION).
(10) Add gear lubricant, if necessary.
(11) Install wheel and tire assemblies.
(12) Remove supports and lower vehicle.
DIFFERENTIAL
REMOVAL
(1) Raise and support vehicle.
(2) Remove fill hole plug from the differential
housing cover.
(3) Remove differential housing cover and drain
fluid.
(4) Clean the housing cavity with flushing oil, light
engine oil or lint free cloth.
NOTE: Do not use water, steam, kerosene or gaso-
line for cleaning.
(5) Remove axle shafts.(6)
Note the reference letters stamped on the bearing
caps and housing machined sealing surface (Fig. 45).
(7) Loosen the differential bearing cap bolts.
(8) Position Spreader W-129-B with Adapter Kit
6987B on differential locating holes (Fig. 46). Install
holddown clamps and tighten the turnbuckle finger-
tight.
Fig. 44 PINION ROTATING TORQUE
1 - TORQUE WRENCH
2 - PINION YOKE
Fig. 45 BEARING CAP REFERENCE
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
Fig. 46 SPREADER LOCATION
1 - DIFFERENTIAL HOUSING
2 - DOWEL
3 - SAFETY HOLD DOWN
4 - SPREADER
5 - TURNBUCKLE
WJREAR AXLE - 198RBI 3 - 75
COLLAPSIBLE SPACER (Continued)

(12) Install cover and tighten bolts in a criss-cross
pattern to 41 N´m (30 ft. lbs.).
(13) Refill the differential with Mopar Hypoid
Gear Lubricant or equivalent to bottom of the fill
plug hole.
(14) Install fill hole plug.
(15) Remove support and lower the vehicle.
DIFFERENTIAL-TRAC-LOC
DIAGNOSIS AND TESTING
The most common problem is a chatter noise when
turning corners. Before removing the unit for repair,
drain, flush and refill the axle with the specified
lubricant. A container of Mopar Trac-loktLubricant
(friction modifier) should be added after repair ser-
vice or during a lubricant change.
After changing the lubricant, drive the vehicle and
make 10 to 12 slow, figure-eight turns. This maneu-
ver will pump lubricant through the clutches. This
will correct the condition in most instances. If the
chatter persists, clutch damage could have occurred.
DIFFERENTIAL TEST
The differential can be tested without removing the
differential case by measuring rotating torque. Make
sure brakes are not dragging during this measure-
ment.
(1) Place blocks in front and rear of both front
wheels.
(2) Raise one rear wheel until it is completely off
the ground.
(3) Engine off, transmission in neutral, and park-
ing brake off.
(4) Remove wheel and bolt Special Tool 6790 or
equivalent tool to studs.
(5) Use torque wrench on special tool to rotate
wheel and read rotating torque (Fig. 56).
(6) If rotating torque is less than 41 N´m (56 ft.
lbs.) or more than 271 N´m (200 ft. lbs.) on either
wheel the unit should be serviced.
DISASSEMBLY
(1) Clamp side gear Holding Fixture 6965 in a vise
and position the differential case on the Holding Fix-
ture (Fig. 57).
Fig. 56 ROTATING TORQUE TEST
1 - SPECIAL TOOL WITH BOLT IN CENTER HOLE
2 - TORQUE WRENCH
Fig. 57 DIFFERENTIAL CASE FIXTURE
1 - HOLDING FIXTURE
2 - VISE
3 - DIFFERENTIAL
WJREAR AXLE - 198RBI 3 - 79
DIFFERENTIAL (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)

AXLE SHAFTS
REMOVAL
(1) Place transmission in neutral.
(2) Raise and support vehicle.
(3) Remove wheel and tire assembly.
(4) Remove brake caliper and rotor.
(5) Remove nuts holding axle retainer plate to axle
tube from the rear of the axle flange.
(6) Pull axle shaft from the axle with Slide Ham-
mer 7420 and Adapter 6790. Mount the adapter to
the axle with lug nuts.
NOTE: The axle bearing race is normally loose in
the axle tube.
INSTALLATION
(1) Insall axle into the axle tube with the flat area
of the retainer plate upward.
(2) Insert retaining plate studs into the brake
backing plate and axle tube flange.
(3) Install retainer nuts and tighten nuts to 61
N´m (45 ft. lbs.).
(4) Install the brake rotor and caliper.
(5) Install wheel and tire.
(6) Check and fill the differential with gear lubri-
cant.
(7) Lower vehicle.
AXLE BEARINGS/SEALS
REMOVAL
(1) Remove axle shaft from vehicle.
NOTE: The axle bearing race is normally loose in
the axle tube.
(2) Drill a shallow hole into soft steel axle bearing
retaining ring with a 3/8 in. drill bit (Fig. 25). Use a
drill depth stop to avoid marking the axle.
(3) With a cold chisel cut the retaining ring across
drilled hole. (Fig. 26)
(4) Slide retaining ring from axle shaft.
Fig. 25 DRILL RETAINING RING
1 - DRILL BIT
2 - AXLE
3 - RETAINING PLATE
4 - RETAINING RING
Fig. 26 RETAINING RING
1 - AXLE
2 - COLD CHISEL
3 - VISE
4 - RETAINING RING
WJREAR AXLE - 226RBA 3 - 109

(7) Press metal retaining ring onto axle shaft with
Installer 7913 and a press (Fig. 30).
(8) Install axle in vehicle.
PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assemblies.
(3) Remove rear brake calipers and rotors.
(4) Mark propeller shaft and pinion yoke for
installation reference.
(5) Remove the propeller shaft from the yoke.
(6) Rotate pinion gear three or four times and ver-
ify that pinion rotates smoothly.
(7) Record torque necessary to rotate the pinion
gear with a inch pound dial-type torque wrench.
(8) Using a short piece of pipe and Spanner
Wrench 6958 to hold the pinion yoke and remove pin-
ion nut and washer (Fig. 31).
(9) Remove pinion companion flange with Remover
C-452 and Flange Wrench C-3281. (Fig. 32)
Fig. 30 BEARING RETAINING RING
1 - PRESS
2 - AXLE
3 - AXLE BEARING
4 - INSTALLER
5 - METAL RETAINING RING
Fig. 31 Pinion Yoke Holder
1 - PIPE
2 - PINION YOKE
3 - SPANNER WRENCH
4 - LOWER CONTROL ARM
Fig. 32 Pinion Yoke Remover
1 - FLANGE WRENCH
2 - YOKE
3 - YOKE PULLER
WJREAR AXLE - 226RBA 3 - 111
AXLE BEARINGS/SEALS (Continued)