2002 JEEP GRAND CHEROKEE Oil feed tube

DIFFERENTIAL
Differential side bearing preload and gear backlash
is achieved by selective shims positioned behind the
differential side bearing cones. The proper shim
thickness can be determined using slip-fit Dummy
Bearings D-348 in place of the differential side bear-
ings and a Dial Indicator C-3339. Before proceeding
with the differential bearing preload and gear back-
lash measurements, measure the pinion gear depth
and prepare the pinion for installation. Establishing
proper pinion gear depth is essential to establishing
gear backlash and tooth contact patterns. After the
overall shim thickness to take up differential side
play is measured, the pinion is installed, and the
gear backlash shim thickness is measured. The over-
all shim thickness is the total of the dial indicator
reading and the preload specification added together.
The gear backlash measurement determines the
thickness of the shim used on the ring gear side of
the differential case. Subtract the gear backlash shim
thickness from the total overall shim thickness and
select that amount for the pinion gear side of the dif-
ferential (Fig. 9). Differential shim measurements
are performed with spreader W-129-B removed.
SHIM SELECTION
NOTE: It is difficult to salvage the differential side
bearings during the removal procedure. Install
replacement bearings if necessary.
(1) Remove differential side bearings from differ-
ential case.
(2) Install ring gear on differential case and
tighten bolts to specification.
(3) Install dummy side bearings D-348 on differen-
tial case.
(4) Install differential case in the housing.
CAUTION: When installing a Vari-LokTdifferential,
the oil feed tube must point to the bottom of the
housing. If differential is forced in with the oil feed
towards the top, the anti-rotation tabs will be dam-
aged.
(5) Record the thickness of Dummy Shims 8107.
Insert the shims between the dummy bearings and
the differential housing (Fig. 10).
Fig. 9 ADJUSTMENT SHIM LOCATIONS
1 - PINION DEPTH SHIM/OIL SLINGER
2 - DIFFERENTIAL BEARING SHIM
3 - RING GEAR
4 - DIFFERENTIAL BEARING SHIM
5 - COLLAPSIBLE SPACER
Fig. 10 DUMMY SHIM LOCATION
1 - DUMMY SHIM
2 - DIFFERENTIAL HOUSING
3 - DIFFERENTIAL CASE
4 - DUMMY BEARINGS
3 - 24 FRONT AXLE - 186FBIWJ
FRONT AXLE - 186FBI (Continued)

(21) Push and hold differential case to ring gear
side of the housing and record dial indicator reading
(Fig. 18). Add dummy shim thickness to this reading.
This will be the total shim thickness to achieve zero
backlash.
(22) Subtract 0.076 mm (0.003 in.) from the dial
indicator reading to compensate for backlash between
ring and pinion gears. This total is the thickness
shim required to achieve proper backlash.
(23) Subtract the backlash shim thickness from
the total preload shim thickness. The remainder is
the shim thickness required on the pinion side of the
axle housing.
(24) Rotate dial indicator out of the way on pilot
stud.(25) Remove differential case and dummy bearings
from the housing.
(26) Install side bearings and cups on differential
case.
(27) Install spreader W-129-B with Adapter Set
6987 on the housing and spread axle opening enough
to receive differential case.
(28) Place the bearing preload shims in the axle
housing, against the axle tubes.
(29) Install differential case into the housing.
CAUTION: When installing a Vari-LokTdifferential,
the oil feed tube must point to the bottom of the
housing. If differential is forced in with the oil feed
towards the top, the anti-rotation tabs will be dam-
aged.
(30) Remove spreader from the housing.
(31) Rotate the differential case several times to
seat the side bearings.
(32) Position the indicator plunger against a ring
gear tooth (Fig. 19).
Fig. 18 RECORED DIAL INDICATOR READING
1 - DIAL INDICATOR
2 - DIFFERENTIAL CASE TO RING GEAR SIDE
3 - PINION GEAR
4 - DIFFERENTIAL HOUSING
5 - DIFFERENTIAL CASE
Fig. 19 RING GEAR BACKLASH
1 - DIAL INDICATOR
WJFRONT AXLE - 186FBI 3 - 27
FRONT AXLE - 186FBI (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)

DISASSEMBLY
(1) Remove pinion shaft lock screw (Fig. 50).
(2) Remove pinion shaft.
(3) Rotate differential side gears and remove dif-
ferential pinions and thrust washers (Fig. 51).
(4) Remove differential side gears and thrust
washers.
ASSEMBLY
(1) Install differential side gears and thrust wash-
ers.
(2) Install differential pinion gears and thrust
washers.
(3) Install the pinion mate shaft.
(4) Align hole in the pinion mate shaft with the
hole in the differential case and install the pinion
mate shaft lock screw.
(5) Lubricate all differential components with
hypoid gear lubricant.
INSTALLATION
NOTE: If replacement differential bearings or differ-
ential case are being installed, differential side
bearing shim requirements may change. Refer
Adjustments (Differential Bearing Preload and Gear
Backlash) to determine the proper shim selection.
(1) Position Spreader W-129-B with Adapter set
6987 on differential housing locating holes. Install
the holddown 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.
CAUTION: Never spread the housing over 0.38 mm
(0.015 in). If housing is over-spread, it could be dis-
torted or damaged.
(3) Spread housing enough to install the case in
the housing.
(4) Remove the dial indicator.
(5) Install differential case in housing (Fig. 52).
Verify differential bearing cups remain in position on
the bearings and preload shims are between the face
of the bearing cup and the housing. Tap the differen-
tial case to ensure bearings cups and shims are
seated in the housing.
CAUTION: On a Vari-lokTdifferential the oil feed
tube must be pointed at the bottom of the housing
(Fig. 53). If differential is installed with the oil feed
tube pointed at the top, the anti-rotation tabs will be
damaged.
(6) Install bearing caps in their original locations
(Fig. 54).
(7) Loosely install differential bearing cap bolts.
(8) Remove axle housing spreader.
(9) Tighten bearing cap bolts in a criss-cross pat-
tern to 77 N´m (57 ft. lbs.).
(10) Install the axle shafts.
Fig. 50 SHAFT LOCK SCREW
1 - LOCK SCREW
2 - PINION SHAFT
Fig. 51 DIFFERENTIAL GEARS
1 - THRUST WASHER
2 - SIDE GEAR
3 - DIFFERENTIAL PINION
WJREAR AXLE - 198RBI 3 - 77
DIFFERENTIAL (Continued)

(11) Apply a 6.35mm (1/4 in.) bead of red Mopar
Silicone Rubber Sealant or equivalent to the housing
cover (Fig. 55).
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.
Fig. 52 SPREADER LOCATION
1 - DIFFERENTIAL HOUSING
2 - DOWEL
3 - SAFETY HOLD DOWN
4 - SPREADER
5 - TURNBUCKLE
Fig. 53 VARI-LOK
1 - ANTI-ROTATION TAB
2 - OIL FEED TUBE
Fig. 54 BEARING CAP REFERENCE
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
Fig. 55 DIFFERENTIAL COVER - TYPICAL
1 - COVER
2 - SEALANT
3 - SEALANT BEAD
3 - 78 REAR AXLE - 198RBIWJ
DIFFERENTIAL (Continued)

(15) Invert the differential case in the vise.
(16) Installnewring gear bolts and alternately
tighten to 136 N´m (100 ft. lbs.) (Fig. 88).
CAUTION: Never reuse the ring gear bolts. The
bolts can fracture causing extensive damage.
(17) Install differential in housing and verify dif-
ferential bearing preload, gear mesh and contact pat-
tern. Refer to Ajustments for procedure.
CAUTION: When installing a Vari-lokTdifferential
(Fig. 89), the oil feed tube must point to the bottom
of the housing. If differential is installed with the oil
feed tube pointed toward the top, the anti-rotation
tabs will be damaged.
(18) Install differential cover and fill with gear
lubricant.
(19) Install the propeller shaft with the reference
marks aligned.
(20) Remove supports and lower vehicle.
Fig. 87 PINION ROTATING TORQUE
1 - PINION YOKE/COMPANION FLANGE
2 - INCH POUND TORQUE WRENCH
Fig. 88 RING GEAR
1 - TORQUE WRENCH
2 - RING GEAR BOLT
3 - RING GEAR
4 - CASE
Fig. 89 VARI-LOK
1 - ANTI-ROTATION TAB
2 - OIL FEED TUBE
WJREAR AXLE - 198RBI 3 - 89
PINION GEAR/RING GEAR (Continued)

DISASSEMBLY
(1) Remove pinion shaft lock screw (Fig. 50).
(2) Remove pinion shaft.
(3) Rotate differential side gears and remove dif-
ferential pinions and thrust washers (Fig. 51).
(4) Remove differential side gears and thrust
washers.
ASSEMBLY
(1) Install differential side gears and thrust wash-
ers.
(2) Install differential pinion gears and thrust
washers.
(3) Install the pinion mate shaft.
(4) Align hole in the pinion mate shaft with the
hole in the differential case and install the pinion
mate shaft lock screw.
(5) Lubricate all differential components with
hypoid gear lubricant.
INSTALLATION
NOTE: If replacement differential bearings or differ-
ential case are being installed, differential side
bearing shim requirements may change. Refer
Adjustments (Differential Bearing Preload and Gear
Backlash) to determine the proper shim selection.
(1) Position Spreader W-129-B with Adapter set
6987 on differential housing locating holes. Install
the holddown 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.
CAUTION: Never spread the housing over 0.38 mm
(0.015 in). If housing is over-spread, it could be dis-
torted or damaged.
(3) Spread housing enough to install the case in
the housing.
(4) Remove the dial indicator.
(5) Install differential case in housing (Fig. 52).
Verify differential bearing cups remain in position on
the bearings and preload shims are between the face
of the bearing cup and the housing. Tap the differen-
tial case to ensure bearings cups and shims are
seated in the housing.
CAUTION: On a Vari-lokTdifferential the oil feed
tube must be pointed at the bottom of the housing
(Fig. 53). If differential is installed with the oil feed
tube pointed at the top, the anti-rotation tabs will be
damaged.
(6) Install bearing caps in their original locations
(Fig. 54).
(7) Loosely install differential bearing cap bolts.
(8) Remove axle housing spreader.
(9) Tighten bearing cap bolts in a criss-cross pat-
tern to 77 N´m (57 ft. lbs.).
(10) Install the axle shafts.
Fig. 50 SHAFT LOCK SCREW
1 - LOCK SCREW
2 - PINION SHAFT
Fig. 51 DIFFERENTIAL GEARS
1 - THRUST WASHER
2 - SIDE GEAR
3 - DIFFERENTIAL PINION
WJREAR AXLE - 226RBA 3 - 117
DIFFERENTIAL (Continued)

(11) Apply a 6.35mm (1/4 in.) bead of red Mopar
Silicone Rubber Sealant or equivalent to the housing
cover (Fig. 55).
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.
Fig. 52 SPREADER LOCATION
1 - DIFFERENTIAL HOUSING
2 - DOWEL
3 - SAFETY HOLD DOWN
4 - SPREADER
5 - TURNBUCKLE
Fig. 53 VARI-LOK
1 - ANTI-ROTATION TAB
2 - OIL FEED TUBE
Fig. 54 BEARING CAP REFERENCE
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
Fig. 55 DIFFERENTIAL COVER - TYPICAL
1 - COVER
2 - SEALANT
3 - SEALANT BEAD
3 - 118 REAR AXLE - 226RBAWJ
DIFFERENTIAL (Continued)