stall JEEP GRAND CHEROKEE 2003 WJ / 2.G Repair Manual

DISASSEMBLY
(1) Remove the ring gear.
(2) Drive out the roll pin holding pinion gear mate
shaft with a hammer and punch (Fig. 43).
(3) Remove pinion gear mate shaft from the differ-
ential case and the pinion mate gears.
(4) Rotate differential side gears and remove the
pinion mate gears and thrust washers (Fig. 44).
(5) Remove differential side gears and thrust
washers.
ASSEMBLY
(1) Install differential side gears and thrust wash-
ers.
(2) Install pinion mate gears and thrust washers.
(3) Install pinion gear mate shaft. Align the roll
pin holes in shaft and the differential case.
(4) Install the roll pin in the differential case (Fig.
45).
(5) Install the ring gear.
(6) Lubricate all differential components with
hypoid gear lubricant.
Fig. 43 MATE SHAFT ROLL PIN
1 - PUNCH
2 - LOCKPIN
3 - MATE SHAFT
Fig. 44 PINION MATE GEAR
1 - THRUST WASHER
2 - SIDE GEAR
3 - PINION MATE GEAR
Fig. 45 MATE SHAFT ROLL PIN
1 - PUNCH
2 - PINION MATE SHAFT
3 - MATE SHAFT LOCKPIN
3 - 42 FRONT AXLE - 186FBIWJ
DIFFERENTIAL (Continued)

INSTALLATION
NOTE: If replacement differential bearings or differ-
ential case are being installed, differential side
bearing shim requirements may change. Refer to
Adjustments (Differential Bearing Preload and Gear
Backlash) to determine the proper shim selection.
(1) Position Spreader W-129-B with Adapter Kit
6987B on differential locating holes. Install hold
down clamps and tighten the tool turnbuckle finger-
tight.
(2) Install a Pilot Stud C-3288-B at the left side of
the differential housing. Attach Dial Indicator C-3339
to pilot stud. Load the indicator plunger against the
opposite side of the housing and zero the indicator.
(3) Spread the housing enough to install the case
in the housing. Measure the distance with the dial
indicator.
CAUTION: Never spread the housing over 0.50 mm
(0.020 in). If housing is over-spread, it could dis-
torted and damaged the housing.
(4) Remove the dial indicator.
(5) Install differential case in the housing (Fig.
46). Make sure the differential bearing cups remain
on the bearings and the preload shims remain
between the face of the bearing cup and housing. Tap
the differential case to ensure the bearings cups and
shims are fully seated in the housing.
CAUTION: On a Vari-lokTdifferential the oil feed
tube must be pointed at the bottom of the housing.
If differential is installed with the oil feed tube
pointed at the top, the anti-rotation tabs will be
damaged.
(6) Install the bearing caps at their original loca-
tions (Fig. 47).
(7) Loosely install differential bearing cap bolts.
(8) Remove axle housing spreader.
(9) Tighten the bearing cap bolts to 61 N´m (45 ft.
lbs.).
(10) Install the hub bearings and axle shafts.
Fig. 46 DIFFERENTIAL CASE REMOVAL
1 - DIFFERENTIAL HOUSING
2 - DIFFERENTIAL CASE
3 - BEARING CUPS
Fig. 47 Bearing Cap Reference
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
WJFRONT AXLE - 186FBI 3 - 43
DIFFERENTIAL (Continued)

(11) Apply a bead 6.35mm (1/4 inch) of red Mopar
Silicone Rubber Sealant or equivalent to the housing
cover (Fig. 48).
CAUTION: If cover is not installed within 3 to 5 min-
utes, the cover must be cleaned and new RTV
applied or adhesion quality will be compromised.
(12) Install differential cover and tighten cover
bolts in a criss-cross pattern to 41 N´m (30 ft. lbs.).
(13) Fill differential with gear lubricant to bottom
of the fill plug hole.
(14) Tighten fill plug to 34 N´m (25 ft. lbs.).
(15) Remove support and lower the vehicle.
DIFFERENTIAL CASE
BEARINGS
REMOVAL
(1) Remove differential case from housing.
(2) Remove bearings from the differential case
with Puller C-293-PA, Adapters 8352 and Plug
SP-3289 (Fig. 49).
INSTALLATION
NOTE: If replacement differential side bearings or
differential case are being installed, differential side
bearing shim requirements may change. Refer to
Adjustments (Differential Bearing Preload and Gear
Backlash) to determine the proper shim selection.
CAUTION: Vari-lokTplenum must be fully seated
against the differential case prior to installing the
ring gear side differential bearing.
(1) Install differential side bearings with Handle
C-4171 and Installer C-3726-A (Fig. 50).
(2) Install differential in housing.
Fig. 48 DIFFERENTIAL COVER
1 - COVER
2 - SEALANT
3 - SEALANT BEADFig. 49 DIFFERENTIAL CASE BEARING
1 - ADAPTERS
2 - BEARING
3 - DIFFERENTIAL
4 - PLUG
5 - PULLER
3 - 44 FRONT AXLE - 186FBIWJ
DIFFERENTIAL (Continued)

PINION GEAR/RING GEAR
REMOVAL
NOTE: The ring gear and pinion are serviced as a
matched set. Nevar replace one gear without replac-
ing the other matching gear.
(1) Raise and support vehicle
(2) Mark pinion companion flange and propeller
shaft for installation alignment.
(3) Remove propeller shaft from pinion companion
flange and tie propeller shaft to underbody.
(4) Remove differential from axle housing.
(5) Place differential case in a vise with soft metal
jaw (Fig. 51).
(6) Remove bolts holding ring gear to differential
case.
NOTE: On Veri-LokTdifferential the side bearing
and oil feed plenum must be removed before
removing the ring gear bolts.
(7) Driver ring gear off the differential case with a
rawhide hammer (Fig. 51).(8) With Spanner Wrench 6958 and a short length
of 1 in. pipe, hold pinion companion flange and
remove pinion nut and washer (Fig. 52).
(9) Remove pinion companion flange from pinion
shaft with Remover C-452 and Flange Wrench
C-3281.
Fig. 50 DIFFERENTIAL CASE BEARING
1 - INSTALLER
2 - HANDLE
Fig. 51 RING GEAR
1 - DIFFERENTIAL CASE
2 - RING GEAR
3 - HAMMER
Fig. 52 Pinion Flange
1 - PINION FLANGE
2 - FRONT AXLE
3 - SPANNER WRENCH
WJFRONT AXLE - 186FBI 3 - 45
DIFFERENTIAL CASE BEARINGS (Continued)

(10) Remove pinion gear and collapsible spacer
from housing (Fig. 53).
(11) Remove front pinion bearing cup, bearing, oil
slinger and pinion seal with Remover D-158 and
Handle C-4171 (Fig. 54).(12) Remove rear pinion bearing cup (Fig. 55) with
Remover C-4307 and Handle C-4171.
(13) Remove collapsible preload spacer from pinion
gear (Fig. 56).
(14) Remove rear pinion bearing from the pinion
with Puller/Press C-293-PA and Adapters C-293-42
(Fig. 57). Remove oil slinger/pinion depth shim from
the pinion shaft and record thickness.
INSTALLATION
NOTE: Pinion depth shims are placed between the
rear pinion bearing cone and the pinion head to
achieve proper ring and pinion gear mesh. If ring
and pinion gears are reused, the pinion oil slinger/
depth shim should not require replacement. Refer
to Adujstments (Pinion Gear Depth) to select the
proper thickness shim before installing pinion gear.
(1) Apply Mopar Door Ease or equivalent lubricant
to outside surface of pinion bearing cups.
(2) Install rear bearing cup with Installer C-4308
and Handle C-4171 and verify cup is seated (Fig. 58).
(3) Install bearing cup with Installer D-144 and
Handle C-4171 (Fig. 59) and verify cup is seated.
(4) Install front pinion bearing, and oil slinger if
equipped.
Fig. 53 REMOVE PINION GEAR
1 - RAWHIDE HAMMER
Fig. 54 FRONT PINION BEARING CUP
1 - REMOVER
2 - HANDLE
Fig. 55 REAR PINION BEARING CUP
1 - REMOVER
2 - HANDLE
3 - 46 FRONT AXLE - 186FBIWJ
PINION GEAR/RING GEAR (Continued)

Fig. 56 COLLAPSIBLE SPACER
1 - COLLAPSIBLE SPACER
2 - SHOULDER
3 - PINION GEAR
4 - DEPTH SHIM
5 - REAR BEARING
Fig. 57 REAR PINION BEARING
1 - PULLER
2 - VISE
3 - ADAPTERS
4 - PINION GEAR SHAFT
Fig. 58 REAR PINION BEARING CUP
1 - INSTALLER
2 - HANDLE
Fig. 59 FRONT PINION BEARING CUP
1 - INSTALLER
2 - HANDLE
WJFRONT AXLE - 186FBI 3 - 47
PINION GEAR/RING GEAR (Continued)

(5) Apply a light coating of gear lubricant on the
lip of pinion seal and install seal with an appropriate
installer (Fig. 60).
(6) Install rear pinion bearing and oil slinger/depth
shim onto the pinion shaft with Installer 6448 and a
press (Fig. 61).
(7) Install anewcollapsible spacer on pinion shaft
and install the pinion into the housing (Fig. 62).
(8) Install pinion companion flange, with Installer
W-162-B, Cup 8109 and Spanner Wrench 6958.(9) Install pinion washer and anewnut onto the
pinion gear and tighten the nut to 298 N´m (220 ft.
lbs.).Do not over-tighten.
CAUTION: Never loosen pinion gear nut to decrease
pinion rotating torque and never exceed specified
preload torque. If preload torque is exceeded a new
collapsible spacer must be installed.
(10) Use Flange Wrench 6958, a length of 1 in.
pipe and a torque wrench set at 500 N´m (368 ft. lbs.)
and crush collapsible spacer until bearing end play is
taken up (Fig. 63).
(11) Slowly tighten the nut in 6.8 N´m (5 ft. lb.)
increments until the required rotating torque is
achieved. Measure the rotating torque frequently to
avoid over crushing the collapsible spacer (Fig. 64).
(12) Rotate the pinion a minimum of ten times.
Verify pinion rotates smoothly and check rotating
torque with an inch pound torque wrench (Fig. 64).
Pinion gear rotating torque is:
²Original Bearings: 1 to 2.25 N´m (10 to 20 in.
lbs.).
²New Bearings: 1.7 to 3.4 N´m (15 to 30 in. lbs.).
(13) Invert the differential case and start two ring
gear bolts. This will provide case-to-ring gear bolt
hole alignment.
Fig. 60 PINION SEAL
1 - HANDLE
2 - INSTALLER
Fig. 61 REAR PINION BEARING
1 - INSTALLER
2 - OIL SLINGER
3 - PINION GEAR
4 - REAR PINION BEARING
5 - PRESS
Fig. 62 COLLAPSIBLE PRELOAD SPACER
1 - COLLAPSIBLE SPACER
2 - SHOULDER
3 - PINION GEAR
4 - DEPTH SHIM
5 - REAR BEARING
3 - 48 FRONT AXLE - 186FBIWJ
PINION GEAR/RING GEAR (Continued)

(14) Invert the differential case in the vise.
(15) Install new ring gear bolts and alternately
tighten to 108 N´m (80 ft. lbs.) (Fig. 65).
CAUTION: Never reuse the ring gear bolts. The
bolts can fracture causing extensive damage.
NOTE: If equipped with Veri-LokTdifferential install
oil feed plenum and side bearing.
(16) Install differential in housing and verify dif-
ferential bearing preload, gear mesh and contact pat-
tern. Refer to Adjustment for procedure.
(17) Install differential cover and fill with gear
lubricant.
(18) Install propeller shaft with reference marks
aligned.
(19) Remove supports and lower vehicle.
Fig. 63 Pinion Nut
1 - PINION FLANGE
2 - FRONT AXLE
3 - SPANNER WRENCH
Fig. 64 PINION ROTATING TORQUE
1 - TORQUE WRENCH
2 - PINION YOKE/FLANGE
Fig. 65 RING GEAR BOLTS
1 - TORQUE WRENCH
2 - RING GEAR BOLTS
3 - RING GEAR
4 - DIFFERENTIAL CASE
WJFRONT AXLE - 186FBI 3 - 49
PINION GEAR/RING GEAR (Continued)

REAR AXLE - 198RBI
TABLE OF CONTENTS
page page
REAR AXLE - 198RBI
DESCRIPTION.........................50
OPERATION...........................50
DIAGNOSIS AND TESTING................51
REMOVAL.............................55
INSTALLATION.........................56
ADJUSTMENTS........................56
SPECIFICATIONS.......................65
SPECIAL TOOLS.......................66
AXLE SHAFTS
REMOVAL.............................69
INSTALLATION.........................69
AXLE BEARINGS/SEALS
REMOVAL.............................69
INSTALLATION.........................70
PINION SEAL
REMOVAL.............................71
INSTALLATION.........................71
COLLAPSIBLE SPACER
REMOVAL.............................73INSTALLATION.........................73
DIFFERENTIAL
REMOVAL.............................75
DISASSEMBLY.........................77
ASSEMBLY............................77
INSTALLATION.........................77
DIFFERENTIAL-TRAC-LOC
DIAGNOSIS AND TESTING................79
DISASSEMBLY.........................79
CLEANING............................82
INSPECTION..........................82
ASSEMBLY............................82
DIFFERENTIAL CASE BEARINGS
REMOVAL.............................83
INSTALLATION.........................84
PINION GEAR/RING GEAR
REMOVAL.............................84
INSTALLATION.........................86
REAR AXLE - 198RBI
DESCRIPTION
The Rear Beam-design Iron (RBI) axle housing has
an iron center casting with axle shaft tubes extend-
ing from either side. The tubes are pressed into and
welded to the differential housing to form a one-piece
axle housing. The axles has semi-floating axle shafts,
meaning that loads are supported by the axle shaft
and bearings. The axle shafts are retained by bearing
retainer plates on the axles which are bolted to
flanges at the outboard end of the axle tubes.
The differential case is a one-piece design. Differ-
ential bearing preload and ring gear backlash is
adjusted by the use of selective spacer shims. Pinion
bearing preload is set and maintained by the use of a
collapsible spacer. A differential cover provides a
means for inspection and service.
Axles with optional Trac-Loktdifferential have a
one-piece differential case, and the same internal
components as a standard differential, plus two
clutch disc packs.
OPERATION
The axle receives power from the transmission/
transfer case through the rear propeller shaft. Therear propeller shaft is connected to the pinion gear
which rotates the differential through the gear mesh
with the ring gear bolted to the differential case. The
engine power is transmitted to the axle shafts
through the pinion mate and side gears. The side
gears are splined to the axle shafts.
STANDARD DIFFERENTIAL
During straight-ahead driving, the differential pin-
ion gears do not rotate on the pinion mate shaft. This
occurs because input torque applied to the gears is
divided and distributed equally between the two side
gears. As a result, the pinion gears revolve with the
pinion mate shaft but do not rotate around it (Fig. 1).
When turning corners, the outside wheel must
travel a greater distance than the inside wheel to
complete a turn. The difference must be compensated
for to prevent the tires from scuffing and skidding
through turns. To accomplish this, the differential
allows the axle shafts to turn at unequal speeds (Fig.
2). In this instance, the input torque applied to the
pinion gears is not divided equally. The pinion gears
now rotate around the pinion mate shaft in opposite
directions. This allows the side gear and axle shaft
attached to the outside wheel to rotate at a faster
speed.
3 - 50 REAR AXLE - 198RBIWJ

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)