2002 JEEP GRAND CHEROKEE torque

(10) Push and hold differential case to pinion gear
side of the housing and zero dial indicator (Fig. 15).
(11) Push and hold differential case to ring gear
side of the housing and record dial indicator reading
(Fig. 16).(12) Add 0.152 mm (0.006 in.) to the zero end play
total. This new total represents the thickness of
shims to compress or preload the new bearings when
the differential is installed.
(13) Rotate dial indicator out of the way on the
pilot stud.
(14) Remove differential case and dummy bearings
from the housing.
(15) Install the pinion gear in the housing. Install
the pinion yoke and establish the correct pinion
rotating torque.
(16) Install differential case and Dummy Bearings
D-348 in the housing.
(17) Install a single dummy shim in the ring gear
side. Install bearing caps and tighten bolts snug.
(18) Seat ring gear side dummy bearing (Fig. 13).
(19) Position the dial indicator plunger on a flat
surface between the ring gear bolt heads (Fig. 14).
(20) Push and hold differential case toward pinion
gear and zero dial indicator (Fig. 17).
Fig. 15 ZERO DIAL INDICATOR
1 - FORCE DIFFERENTIAL CASE TO PINION GEAR SIDE
2 - PILOT STUD
3 - INDICATOR EXTENSION
4 - DIAL INDICATOR FACE
Fig. 16 RECORED DIAL INDICATOR READING
1 - DIAL INDICATOR
2 - DIFFERENTIAL CASE TO RING GEAR SIDE
3 - DIFFERENTIAL HOUSING
Fig. 17 ZERO DIAL INDICATOR
1 - DIAL INDICATOR
2 - FORCE DIFFERENTIAL CASE TO PINION GEAR SIDE
3 - PINION GEAR
4 - DIFFERENTIAL HOUSING
5 - DIFFERENTIAL CASE
3 - 26 FRONT AXLE - 186FBIWJ
FRONT AXLE - 186FBI (Continued)

DIFFERENTIAL BEARING PRELOAD CHECK
The final check on the differential assembly before
installing the axles is torque to rotate pinion and dif-
ferential combined. This will verify the correct differ-
ential bearing preload.Torque to rotate the differential and pinion should
be the torque to rotate the pinion plus 0.79-1.24 N´m
(7-11 in. lbs.).
SPECIFICATIONS
AXLE SPECIFICATIONS
DESCRIPTION SPECIFICATION
Axle Ratio 3.31, 3.55, 3.73, 3.91
Differential Side Gear Clearance 0.13-0.20 mm (0.005-0.008 in.)
Differential Bearing Preload 0.152 mm (0.006 in.)
Ring Gear Diameter 186 mm (7.33 in.)
Ring Gear Backlash 0.13-0.20 mm (0.005-0.008 in.)
Pinion Gear Std. Depth 92.08 mm (3.625 in.)
Pinion Bearing Preload - Original Bearings 1-2 N´m (10-20 in. lbs.)
Pinion Bearing Preload - New Bearings 1.7-3.4 N´m (15-30 in. lbs.)
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Fill Hole Plug 34 25 -
Differential Cover Bolts 41 30 -
Bearing Cap Bolts 61 45 -
Ring Gear Bolts 108 80 -
Axle Nut 237 175 -
Hub Bearing Bolts 102 75 -
3 - 30 FRONT AXLE - 186FBIWJ
FRONT AXLE - 186FBI (Continued)

INSTALLATION
(1) Pack the bearing caps 1/3 full of wheel bearing
lubricant. Apply extreme pressure (EP), lithium-base
lubricant to aid in installation.
(2) Position the spider in the yoke. Insert the seals
and bearings, then tap bearing caps into the yoke
bores far enough to hold the spider in position.
(3) Place the socket (driver) against one bearing
cap. Position the yoke with the socket in a vise.
(4) Tighten the vise to force the bearing caps into
the yoke. Force the caps enough to install the retain-
ing clips.
(5) Install the bearing cap retaining clips.
(6) Install axle shaft.
PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assemblies.
(3) Remove brake rotors and calipers, refer to 5
Brakes for procedures.
(4) Mark propeller shaft and pinion companion
flange for installation reference.
(5) Remove the propeller shaft from the pinion
companion flange.
(6) Rotate the pinion gear a minimum of ten times
and verify the pinion rotates smoothly.
(7) Record torque necessary to rotate the pinion
gear with a inch pound torque wrench.
(8) Using a short piece of pipe and Spanner
Wrench 6958 to hold the pinion companion flange
and remove the pinion nut and washer.
(9) Remove pinion companion flange with Remover
C-452 and Flange Wrench C-3281.
(10) Remove pinion seal with Remover 7794-A and
a slide hammer (Fig. 31).
INSTALLATION
(1) Apply a light coating of gear lubricant on the
lip of pinion seal. Install seal with an appropriate
installer (Fig. 32).
(2) Install pinion companion flange on the pinion
gear with Installer W-162-D, Cup 8109 and Wrench
6958.
CAUTION: Never exceed the minimum tightening
torque 298 N´m (220 ft. lbs.) while installing pinion
nut at this point. Damage to collapsible spacer or
bearings may result.
(3) Install the pinion washer and anewnut on
the pinion gear.Tighten the nut only enough to
remove the shaft end play.
Fig. 29 AXLE SHAFT OUTER U-JOINT
1 - SHAFT YOKE
2 - BEARING CAP
3 - SNAP RINGS
4 - BEARING CAP
5 - SPINDLE YOKE
6 - BEARING
7 - BEARING CAP
8 - SNAP RINGS
9 - BEARING CAP
Fig. 30 YOKE BEARING CAP
1 - LARGE-DIAMETER SOCKET
2 - VISE
3 - SMALL-DIAMETER SOCKET
WJFRONT AXLE - 186FBI 3 - 37
AXLE - U-JOINT (Continued)

CAUTION: Never loosen pinion nut to decrease pin-
ion rotating torque and never exceed specified pre-
load torque. If preload torque or rotating torque is
exceeded a new collapsible spacer must be
installed.
(4) Rotate pinion a minimum of ten time and ver-
ify pinion rotates smoothly. Rotate the pinion shaft
with an inch pound torque wrench. Rotating torque
should be equal to the reading recorded during
removal plus 0.56 N´m (5 in. lbs.) (Fig. 33).
(5) If the rotating torque is low, use Spanner
Wrench 6958 to hold the pinion companion flange
(Fig. 34), and tighten the pinion shaft nut in 6.8 N´m
(5 ft. lbs.) increments until proper rotating torque is
achieved.
CAUTION: If maximum tightening torque is reached
prior to reaching the required rotating torque, thecollapsible spacer may have been damaged.
Replace the collapsible spacer.
Fig. 31 PINION SEAL
1 - REMOVER
2 - SLIDE HAMMER
3 - PINION SEAL
Fig. 32 PINION SEAL
1 - HANDLE
2 - INSTALLER
Fig. 33 PINION ROTATION TORQUE
1 - PINION YOKE/COMPANION FLANGE
2 - INCH POUND TORQUE WRENCH
Fig. 34 PINION SHAFT NUT
1 - PINION FLANGE
2 - FRONT AXLE
3 - SPANNER WRENCH
3 - 38 FRONT AXLE - 186FBIWJ
PINION SEAL (Continued)

(6) Install propeller shaft with installation refer-
ence marks aligned.
(7) Fill differential with gear lubricant.
(8) Install brake rotors and calipers.
(9) Install wheel and tire assemblies.
(10) Lower the vehicle.
COLLAPSIBLE SPACER
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assemblies.
(3) Remove brake rotors and calipers. Refer to 5
Brakes for procedures.
(4) Mark the propeller shaft and pinion companion
flange for installation reference.
(5) Remove propeller shaft from the pinion com-
panion flange.
(6) Rotate pinion gear a minimum of ten times and
verify pinion rotates smoothly.
(7) Record pinion gear rotating torque with a
torque wrench for installation reference.
(8) Remove pinion nut and washer. Using a short
piece of pipe and Spanner Wrench 6958 to hold the
pinion companion flange.
(9) Remove pinion companion flange with Remover
C-452 and Flange Wrench C-3281.
(10) Remove pinion shaft seal with Remover
7794-A and slide hammer (Fig. 35).
(11) Remove front pinion bearing using a pair of
pick tools to pull the bearing straight off pinion
shaft.NOTE: If bearing becomes bound on the pinion
shaft, lightly tap the end of the pinion gear with a
rawhide/rubber mallet.
(12) Remove the collapsible spacer.
INSTALLATION
(1) Install anewcollapsible preload spacer on pin-
ion shaft.
(2) Install pinion front bearing.
(3) Apply a light coating of gear lubricant on the
lip of pinion seal. Install seal with an appropriate
installer (Fig. 36).
(4) Install pinion companion flange with Installer
W-162-D, Cup 8109 and Flange Holder 6958.
(5) Install pinion washer and anewnut on the
pinion gear. Tighten the nut to 298 N´m (220 ft. lbs.)
minimum.Do not overtighten.Maximum torque is
500 N´m (368 ft. lbs.).
CAUTION: Never loosen pinion nut to decrease pin-
ion rotating torque and never exceed specified pre-
load torque. If preload torque is exceeded a new
collapsible spacer must be installed.
(6) Using Spanner Wrench 6958, a length of 1 in.
pipe and a torque wrench set at 500 N´m (368 ft. lbs.)
crush collapsible spacer until bearing end play is
taken up (Fig. 37).
(7) Slowly tighten the nut in 6.8 N´m (5 ft. lbs.)
increments until the required rotating torque is
achieved. Measure the rotating torque frequently to
avoid over crushing the collapsible spacer.
(8) Rotate pinion gear a minimum of ten times and
verify pinion rotates smoothly. Check rotating torque
with an inch pound torque wrench. The rotating
torque should be the amount recorded during
removal plus:
²Original Bearings: 0.56 N´m (5 in. lbs.).
Fig. 35 PINION SEAL PULLER
1 - REMOVER
2 - SLIDE HAMMER
3 - PINION SEAL
Fig. 36 PINION SEAL INSTALLER
1 - HANDLE
2 - INSTALLER
WJFRONT AXLE - 186FBI 3 - 39
PINION SEAL (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