
rear 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. 2).
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.
3). 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.
TRAC-LOKŸ DIFFERENTIAL
The Trac-lokŸ clutches are engaged by two concur-
rent forces. The first being the preload force exerted
through Belleville spring washers within the clutch
packs. The second is the separating forces generated
by the side gears as torque is applied through the
ring gear (Fig. 4).
Fig. 2 DIFFERENTIAL-STRAIGHT AHEAD DRIVING
1 - IN STRAIGHT AHEAD DRIVING EACH WHEEL ROTATES AT
100% OF CASE SPEED
2 - PINION GEAR
3 - SIDE GEAR
4 - PINION GEARS ROTATE WITH CASE
Fig. 3 DIFFERENTIAL-ON TURNS
1 - PINION GEARS ROTATE ON PINION SHAFT
Fig. 4 TRAC-LOK DIFFERENTIAL
1 - CASE
2 - RING GEAR
3 - DRIVE PINION
4 - PINION GEAR
5 - MATE SHAFT
6 - CLUTCH PACK
7 - SIDE GEAR
8 - CLUTCH PACK
3 - 50 REAR AXLE - 198RBIKJ
REAR AXLE - 198RBI (Continued)

(5) Assemble Dial Indicator C-3339 into Scooter
Block D-115-2 and secure set screw.
(6) Position Scooter Block/Dial Indicator flush on
the pinion height block. Hold scooter block and zero
the dial indicator.
(7) Slowly slide the scooter block across the pinion
height block over to the arbor (Fig. 14). Move the
scooter block till the dial indicator probe crests the
arbor bar and record the highest reading. If the dial
indicator can not achieve the zero reading, the rear
bearing cup or the pinion depth gauge set is not
installed correctly.
(8) Select a shim equal to the dial indicator read-
ing plus the drive pinion gear depth variance number
etched in the face of the pinion gear (Fig. 9) using
the opposite sign on the variance number. For exam-
ple, if the depth variance is ±2, add +0.002 in. to the
dial indicator reading.
(9) Remove the pinion depth gauge components
from the housing
DIFFERENTIAL BEARING PRELOAD
Differential side bearing preload and gear backlash
is achieved by selective shims inserted between the
bearing cup and the housing. The proper shim thick-
ness can be determined using slip-fit Dummy Bear-
ings D-348 in place of the differential side bearings
and a Dial Indicator C-3339. Before proceeding with
the differential bearing preload and gear backlash
measurements, measure the pinion gear depth and
prepare the pinion gear 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 sideplay is measured, the pinion gear is installed and the
gear backlash shim thickness is measured. The over-
all shim thickness is the total of the dial indicator
reading, starting point shim thickness and the pre-
load 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 differential (Fig. 15).
Fig. 13 GAUGE TOOLS IN HOUSING
1 - ARBOR DISC
2 - PINION BLOCK
3 - ARBOR
4 - PINION HEIGHT BLOCKFig. 14 Pinion Gear Depth Measurement
1 - ARBOR
2 - SCOOTER BLOCK
3 - DIAL INDICATOR
Fig. 15 Shim Locations
1 - PINION GEAR DEPTH SHIM
2 - DIFFERENTIAL BEARING SHIM
3 - RING GEAR
4 - DIFFERENTIAL BEARING SHIM
5 - COLLAPSIBLE SPACER
KJREAR AXLE - 198RBI 3 - 57
REAR AXLE - 198RBI (Continued)

(8) Thread Pilot Stud C-3288-B into rear cover bolt
hole below ring gear (Fig. 19).
(9) Attach Dial Indicator C-3339 to the pilot stud
and position indicator plunger on a flat surface of the
ring gear bolt head (Fig. 19).
(10) Push the differential case firmly to the pinion
gear side of the housing (Fig. 20) and zero dial indi-
cator.
(11) Push differential case firmly to the ring gear
side and record dial indicator reading (Fig. 21).
(12) Add the dial indicator reading to the starting
point shim thickness to determine total shim thick-
ness to achieve zero differential end play.
(13) Add 0.2 mm (0.008 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.
(14) Rotate dial indicator out of the way.
(15) Remove differential case, dummy bearings
and starting point shims from the housing.
(16) Install pinion gear in the housing. Install the
yoke and establish the correct pinion rotating torque.
(17) Install differential case and dummy bearings
in the housing (without shims) and tighten retaining
cap bolts.
(18) Position the dial indicator plunger on a flat
surface between the ring gear bolt heads (Fig. 19).(19) Push and hold differential case toward pinion
gear.
(20) Zero dial indicator face to pointer.
(21) Push and hold differential case to ring gear
side of the housing and record dial indicator reading.
(22) Subtract 0.05 mm (0.002 in.) from the dial
indicator reading to compensate for backlash between
ring and pinion gears. This total is the thickness of
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
housing.
Fig. 19 DIFFERENTIAL SIDE PLAY
1 - DIFFERENTIAL CASE
2 - DIFFERENTIAL HOUSING
3 - PILOT STUD
4 - DIAL INDICATOR
Fig. 20 ZERO DIAL INDICATOR
1 - FORCE CASE TO PINION SIDE
2 - PILOT STUD
3 - DIAL INDICATOR EXTENSION
4 - DIAL INDICATOR
Fig. 21 RECORD DIAL INDICATOR
1 - DIAL INDICATOR
2 - FORCE CASE TO RING GEAR SIDE
3 - DIFFERENTIAL HOUSING
KJREAR AXLE - 198RBI 3 - 59
REAR AXLE - 198RBI (Continued)

PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assemblies.
(3) Remove rear brake rotors drums.
(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) Measure and record torque to rotate the pinion
gear with an inch pound dial-type torque wrench.
(8) With a short piece of pipe and Spanner Wrench
6958 remove the pinion nut and washer (Fig. 31).
(9) Remove pinion companion flange with Remover
C-452 and Flange Wrench C-3281. (Fig. 32)
(10) Remove pinion seal with Remover 7794-A and
a slide hammer (Fig. 33).
INSTALLATION
(1) Apply a light coating of gear lubricant on the
lip of pinion seal. Install seal with an appropriate
seal installer (Fig. 34).
(2) Install yoke on the pinion gear with Installer
C-3718 and Spanner Wrench 6958 (Fig. 35).(3) Install anewnut on the pinion gear.Tighten
the nut only enough to remove the shaft end
play.
CAUTION: Do not exceed the minimum torque 271
N´m (200 ft. lbs.) when installing the pinion yoke
retaining nut at this point. Damage to collapsible
spacer or bearings may result.
(4) Rotate the pinion a minimum of ten times and
verify pinion rotates smoothly.
(5) Measure and recore pinion torque to rotate
with an inch pound torque wrench. Torque to rotate
should be equal to the reading recorded during
removal, plus 0.56 N´m (5 in. lbs.) (Fig. 36).
Fig. 31 YOKE SPANNER WRENCH
1 - PINION YOKE
2 - WRENCH
3 - PIPE
Fig. 32 PINION YOKE REMOVER
1 - WRENCH
2 - YOKE
3 - REMOVER
Fig. 33 PINION SEAL REMOVER
1 - REMOVER
2 - SLIDE HAMMER
3 - PINION SEAL
3 - 68 REAR AXLE - 198RBIKJ

(8) Fill differential with gear lubricant.
(9) Install the brake drums
(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 drums.
(4) Mark the propeller shaft and pinion yoke for
installation reference.
(5) Remove the propeller shaft from the yoke.
(6) Rotate the pinion gear three or four times.
(7) Measure and record torque to rotate the pinion
gear with an inch pound dial-type torque wrench.
(8) Hold pinion yoke with Spanner Wrench 6958
and remove pinion nut and washer.
(9) Remove the pinion yoke with Remover C-452
and Flange Wrench C-3281 (Fig. 38).
(10) Remove pinion shaft seal with a pry tool or a
slide hammer mounted screw.
(11) Remove front pinion bearing using a pair of
pick tools. Pull the bearing straight off the pinion
gear shaft. If the bearing becomes bound on the pin-
ion shaft, lightly tap the end of the pinion gear with
a rawhide/rubber hammer.
(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 and install anewseal with an
appropriate installer (Fig. 39).
(4) Install yoke with Screw 8112, Cup 8109 and
Spanner Wrench 6958 (Fig. 40).
(5) Install yoke washer andnewnut on the pinion
gear. Tighten the nut to 271 N´m (200 ft. lbs.).
CAUTION: Never loosen pinion gear nut to decrease
pinion gear bearing rotating torque and never
exceed specified preload torque. If preload torque
or rotating torque is exceeded a new collapsible
spacer must be installed.
Fig. 38 PINION YOKE
1 - FLANGE WRENCH
2 - YOKE
3 - REMOVER
Fig. 39 PINION SEAL
1 - HANDLE
2 - INSTALLER
Fig. 40 PINION YOKE INSTALLER
1 - INSTALLER
2 - PINION YOKE
3 - WRENCH
3 - 70 REAR AXLE - 198RBIKJ
PINION SEAL (Continued)

(6) Using yoke with Spanner Wrench 6958 and a
torque wrench set at 474 N´m (350 ft. lbs.), (Fig. 41)
slowly tighten the nut in 6.8 N´m (5 ft. lbs.) incre-
ments until the rotating torque is achieved. Measure
the rotating torque frequently to avoid over crushing
the collapsible spacer (Fig. 42).
NOTE: If more than 474 N´m (350 ft. lbs.) torque is
required to crush the collapsible spacer, the spacer
is defective and must be replaced.
(7) Check rotating torque with an inch pound
torque wrench (Fig. 42). 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
aligned.
(9) Install rear brake drums.
(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 differential cover and drain fluid.
(3) 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.
(4) Remove axle shafts.
(5)
Note the reference letters stamped on the bearing
caps and housing machined sealing surface (Fig. 43).
Fig. 41 YOKE SPANNER WRENCH
1 - PINION YOKE
2 - WRENCH
3 - PIPE
Fig. 42 PINION ROTATING TORQUE
1 - TORQUE WRENCH
2 - PINION YOKE
Fig. 43 BEARING CAP IDENTIFICATION
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
KJREAR AXLE - 198RBI 3 - 71
COLLAPSIBLE SPACER (Continued)

(6) Assemble Threaded Adapter 6960-1 into top
side gear. Thread Forcing Screw C-6960-4 into
adapter until it becomes centered in adapter plate.
(7) Position a small screw driver in slot of
Threaded Adapter Disc 6960-3 (Fig. 56) to prevent
adapter from turning.
(8) Install Forcing Screw 6960-4 and tighten screw
to 122 N´m (90 ft. lbs.) maximum to compress
Belleville springs in clutch packs (Fig. 57).
(9) With a feeler gauge remove thrust washers
from behind the pinion gears (Fig. 58).
Fig. 56 THREAD ADAPTER DISC
1 - SOCKET
2 - SLOT IN ADAPTER
3 - SCREWDRIVER
4 - STEP PLATE
5 - THREADED ROD
6 - ADAPTER DISC
Fig. 57 COMPRESS BELLEVILLE SPRING
1 - TORQUE WRENCH
2 - FORCING SCREW
3 - DIFFERENTIAL CASE
Fig. 58 PINION GEAR THRUST WASHER
1 - THRUST WASHER
2 - FEELER GAUGE
3 - 76 REAR AXLE - 198RBIKJ
DIFFERENTIAL - TRAC-LOK (Continued)

(16) Remove rear bearing from the pinion with
Puller/Press C-293-PA and Adapters C-293-39 (Fig.
74).
(17) Remove depth shims from pinion gear shaft
and record shim thickness.
INSTALLATION
NOTE: A pinion depth shim/oil slinger is placed
between the rear pinion bearing cone and the pin-
ion head to achieve proper ring gear and pinion
mesh. If ring gear and pinion are reused, the pinion
depth shim/oil slinger should not require replace-
ment. Refer to Adjustment (Pinion Gear Depth) to
select the proper thickness shim/oil slinger if ring
and pinion gears are replaced.
(1) Apply MopartDoor Ease or equivalent lubri-
cant to outside surface of bearing cup.
(2) Install pinion rear bearing cup with Installer
C-146 and Driver Handle C-4171 (Fig. 75) and verify
cup is seated.
(3) Apply MopartDoor Ease or equivalent lubri-
cant to outside surface of bearing cup.
(4) Install pinion front bearing cup with Installer
D-130 and Handle C-4171 (Fig. 76) and verify cup is
seated.
(5) Install pinion front bearing and oil slinger, if
equipped.
Fig. 74 REAR PINION BEARING PULLER
1 - PULLER
2 - VISE
3 - ADAPTERS
4 - PINION GEAR SHAFT
Fig. 75 REAR PINION BEARING CUP
1 - INSTALLER
2 - HANDLE
Fig. 76 FRONT PINION BEARING CUP
1 - INSTALLER
2 - HANDLE
3 - 82 REAR AXLE - 198RBIKJ
PINION GEAR/RING GEAR/TONE RING (Continued)