Page 177 of 2889

(10) Install bolts into two of the threaded holes in
the companion flange 180É apart.
(11) Position Holder 6719 against the companion
flange and install a bolt and washer into one of the
remaining threaded holes. Tighten the bolts so the
Holder 6719 is held to the flange.
(12) Use Holder 6719 to hold companion flange
and remove the companion flange nut and washer.
(13) Remove the companion flange from the pinion
with Remover C-452 (Fig. 46).
(14) Remove the pinion from housing (Fig. 47).(15) Remove pinion seal with a pry tool or slide-
hammer mounted screw.
(16) Remove oil slinger if equipped and front pin-
ion bearing.
(17) Remove front pinion bearing cup with
Remover C-4345 and Handle C±4171 (Fig. 48).
Fig. 45 Ring Gear
1 - CASE
2 - RING GEAR
3 - RAWHIDE HAMMER
Fig. 46 Companion Flange
1 - COMPANION FLANGE
2 - REMOVER
Fig. 47 Pinion Gear
1 - RAWHIDE HAMMER
Fig. 48 Front Pinion Bearing Cup
1 - REMOVER
2 - HANDLE
3 - 104 REAR AXLE-91/4BR/BE
PINION GEAR/RING GEAR/TONE RING (Continued)
Page 178 of 2889

(18) Remove the rear bearing cup from housing
(Fig. 49) with Remover C-4307 and Handle C±4171.
(19) Remove the collapsible preload spacer (Fig.
50).(20) Remove rear bearing from the pinion (Fig. 51)
with Puller/Press C-293-PA and Adapters C-293-47.
(21) Remove depth shims from the pinion shaft
and record shim thickness.
INSTALLATION
NOTE: The ring gear and pinion are serviced in a
matched set. Do not replace the pinion without
replacing the ring gear. If ring and pinion gears or
bearings are replaced, Refer to Adjustments for Pin-
ion Gear Depth Setting.
(1) Apply Mopar Door Ease or stick lubricant to
outside surface of bearing cup.
(2) Install rear pinion bearing cup (Fig. 52) with
Installer C-4308 and Driver Handle C-4171 and ver-
ify cup is seated.
(3) Apply Mopar Door Ease or stick lubricant to
outside surface of bearing cup.
(4) Install front pinion bearing cup (Fig. 53) with
Installer D-130 and Handle C-4171 and verify cup is
seated.
(5) Install front pinion bearing.
(6) Apply a light coating of gear lubricant on the
lip of pinion seal. Install seal with Installer
C-4076±B and Handle C-4735-1 (Fig. 54).
(7) Place the proper thickness depth shim on the
pinion shaft.
Fig. 49 Rear Pinion Bearing Cup
1 - DRIVER
2 - HANDLE
Fig. 50 Collapsible Spacer
1 - COLLAPSIBLE SPACER
2 - SHOULDER
3 - PINION GEAR
4 - DEPTH SHIM
5 - REAR BEARING
Fig. 51 Rear Pinion Bearing
1 - PULLER
2 - VISE
3 - ADAPTERS
4 - PINION SHAFT
BR/BEREAR AXLE - 9 1/4 3 - 105
PINION GEAR/RING GEAR/TONE RING (Continued)
Page 179 of 2889
(8) Install the rear bearing on the pinion (Fig. 55)
with Installer 6448 and a press.
Fig. 52 Rear Pinion Bearing Cup
1 - INSTALLER
2 - HANDLE
Fig. 53 Front Pinion Bearing Cup
1 - INSTALLER
2 - HANDLE
Fig. 54 Pinion Seal
1 - HANDLE
2 - DIFFERENTIAL HOUSING
3 - INSTALLER
Fig. 55 Rear Pinion Bearing
1 - PRESS
2 - INSTALLER
3 - PINION GEAR
4 - REAR PINION BEARING
3 - 106 REAR AXLE-91/4BR/BE
PINION GEAR/RING GEAR/TONE RING (Continued)
Page 180 of 2889

(9) Install anewcollapsible preload spacer on pin-
ion shaft and install the pinion into the housing (Fig.
56).
(10) Install companion flange with Installer
C-3718 and Holder 6719.
(11) Install bolts into two of the threaded holes in
the companion flange 180É apart.
(12) Position Holder 6719 against the companion
flange and install a bolt and washer into one of the
remaining threaded holes. Tighten the bolts so the
Holder 6719 is held to the flange.
(13) Install the companion flange washer and a
new nut on the pinion and tighten the pinion nut
until there is zero bearing end-play.
(14) Tighten the nut to 285 N´m (210 ft. lbs.) (Fig.
57).CAUTION: Never loosen pinion nut to decrease pin-
ion bearing rotating torque and never exceed spec-
ified preload torque. If preload torque or rotating
torque is exceeded a new collapsible spacer must
be installed.
(15) Slowly tighten the nut in 6.8 N´m (5 ft. lbs.)
increments until the desired rotating torque is
achieved. Measure the rotating torque frequently to
avoid over crushing the collapsible spacer (Fig. 58).
(16) Check bearing rotating torque with an inch
pound torque wrench (Fig. 58). The torque necessary
to rotate the pinion should be:
²Original Bearings: 1 to 3 N´m (10 to 20 in. lbs.).
²New Bearings: 2 to 5 N´m (15 to 35 in. lbs.).
(17) Position exciter ring on differential case.
(18) Using a brass drift, slowly and evenly tap the
exciter ring into position.
Fig. 56 Collapsible Preload Spacer
1 - COLLAPSIBLE SPACER
2 - SHOULDER
3 - PINION GEAR
4 - DEPTH SHIM
5 - REAR BEARINGFig. 57 Pinion Nut
1 - DIFFERENTIAL HOUSING
2 - HOLDER
3 - TORQUE WRENCH
BR/BEREAR AXLE - 9 1/4 3 - 107
PINION GEAR/RING GEAR/TONE RING (Continued)
Page 181 of 2889
(19) Position ring gear on the differential case and
start two ring gear bolts. This will provide case-to-
ring gear bolt hole alignment.
(20) Invert the differential case in the vise.
(21) Installnewring gear bolts and alternately
tighten to 156 N´m (115 ft. lbs.) (Fig. 59).
CAUTION: Do not reuse the bolts that held the ring
gear to the differential case. The bolts can fracture
causing extensive damage.
(22) Install differential in axle housing and verify
gear mesh and contact pattern.(23) Install axle shafts.
(24) Install wheel and tire assemblies.
(25) Install differential cover and fill with gear
lubricant.
(26) Install propeller shaft wtih reference marks
aligned.
(27) Remove support and lower vehicle.
Fig. 58 Pinion
1 - COMPANION FLANGE
2 - TORQUE WRENCHFig. 59 Ring Gear Bolts
1 - TORQUE WRENCH
2 - RING GEAR BOLTS
3 - RING GEAR
4 - DIFFERENTIAL CASE
3 - 108 REAR AXLE-91/4BR/BE
PINION GEAR/RING GEAR/TONE RING (Continued)
Page 182 of 2889

REAR AXLE - 248RBI
TABLE OF CONTENTS
page page
REAR AXLE - 248RBI
DESCRIPTION..........................109
OPERATION............................109
DIAGNOSIS AND TESTING.................111
AXLE...............................111
REMOVAL.............................113
INSTALLATION..........................114
ADJUSTMENTS.........................114
SPECIFICATIONS........................122
SPECIAL TOOLS........................122
AXLE SHAFTS
REMOVAL.............................125
INSTALLATION..........................125
AXLE BEARINGS
REMOVAL.............................125
INSTALLATION..........................125
PINION SEAL
REMOVAL.............................125INSTALLATION..........................125
DIFFERENTIAL
REMOVAL.............................127
DISASSEMBLY..........................128
ASSEMBLY............................128
INSTALLATION..........................129
DIFFERENTIAL - TRAC-LOK
DIAGNOSIS AND TESTING................130
TRAC-LOK...........................130
DISASSEMBLY..........................130
ASSEMBLY............................132
DIFFERENTIAL CASE BEARINGS
REMOVAL.............................134
INSTALLATION..........................134
PINION GEAR/RING GEAR/TONE RING
REMOVAL.............................135
INSTALLATION..........................137
REAR AXLE - 248RBI
DESCRIPTION
The Rear Beam-design Iron (RBI) axle housings
consist of an iron center casting (differential housing)
with axle shaft tubes extending from either side. The
tubes are pressed in to form a one-piece axle housing.
The integral type housing, hypoid gear design has
the centerline of the pinion set below the centerline
of the ring gear.
The axles are equipped with full-floating axle
shafts, meaning that loads are supported by the axle
housing tubes. The full-float axle shafts are retained
by bolts attached to the hub. The hub rides on two
bearings at the outboard end of the axle tube. The
axle shafts can be removed without disturbing or
removing the wheel bearings. The wheel bearings are
opposed tapered roller bearings and are contained in
the hub assembly.
The removable, stamped steel cover provides a
means for inspection and service without removing
the complete axle from the vehicle. A small, stamped
metal axle gear ratio identification tag is attached to
the housing cover via one of the cover bolts. This tag
also identifies the number of ring and pinion teeth.
The rear wheel anti-lock (RWAL) brake speed sen-
sor is attached to the top, forward exterior of the dif-
ferential housing. A seal is located between the
sensor and the wire harness connector. The seal mustbe in place when the wire connector is connected to
the sensor. The RWAL brake exciter ring is press-fit-
ted onto the differential case against the ring gear
flange.
The differential case for the standard differentials
and the Trac-lokydifferential are a one-piece design.
The differential pinion mate shaft is retained with a
roll pin. Differential bearing preload and ring gear
backlash are adjusted by the use of shims located
between the differential bearing cones and case. Pin-
ion bearing preload is set and maintained by the use
of a solid shims.
OPERATION
STANDARD DIFFERENTIAL
The axle receives power from the transmission/
transfer case through the rear propeller shaft. The
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.
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
BR/BEREAR AXLE - 248RBI 3 - 109
Page 183 of 2889

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.TRAC-LOKYDIFFERENTIAL
The Trac-lokyclutches 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. 3).
The Trac-lokydesign provides the differential
action needed for turning corners and for driving
straight ahead during periods of unequal traction.
When one wheel looses traction, the clutch packs
transfer additional torque to the wheel having the
most traction. Trac-lokydifferentials resist wheel
spin on bumpy roads and provide more pulling power
when one wheel looses traction. Pulling power is pro-
vided continuously until both wheels loose traction. If
both wheels slip due to unequal traction, Trac-loky
operation is normal. In extreme cases of differences
Fig. 1 Differential Operation - 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. 2 Differential Operation - On Turns
1 - PINION GEARS ROTATE ON PINION SHAFT
Fig. 3 Trac-lokYLimited Slip 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 - 110 REAR AXLE - 248RBIBR/BE
REAR AXLE - 248RBI (Continued)
Page 184 of 2889

of traction, the wheel with the least traction may
spin.
DIAGNOSIS AND TESTING - AXLE
GEAR NOISE
Axle gear noise can be caused by insufficient lubri-
cant, incorrect backlash, incorrect pinion depth, tooth
contact, worn/damaged gears, or the carrier housing
not having the proper offset and squareness.
Gear noise usually happens at a specific speed
range. The noise can also occur during a specific type
of driving condition. These conditions are accelera-
tion, deceleration, coast, or constant load.
When road testing, first warm-up the axle fluid by
driving the vehicle at least 5 miles and then acceler-
ate the vehicle to the speed range where the noise is
the greatest. Shift out-of-gear and coast through the
peak-noise range. If the noise stops or changes
greatly:
²Check for insufficient lubricant.
²Incorrect ring gear backlash.
²Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehi-
cle turns. A worn pinion shaft can also cause a snap-
ping or a knocking noise.
BEARING NOISE
The axle shaft, differential and pinion bearings can
all produce noise when worn or damaged. Bearing
noise can be either a whining, or a growling sound.
Pinion bearings have a constant-pitch noise. This
noise changes only with vehicle speed. Pinion bearing
noise will be higher pitched because it rotates at a
faster rate. Drive the vehicle and load the differen-
tial. If bearing noise occurs, the rear pinion bearing
is the source of the noise. If the bearing noise is
heard during a coast, the front pinion bearing is the
source.
Worn or damaged differential bearings usually pro-
duce a low pitch noise. Differential bearing noise is
similar to pinion bearing noise. The pitch of differen-
tial bearing noise is also constant and varies only
with vehicle speed.
Axle shaft bearings produce noise and vibration
when worn or damaged. The noise generally changes
when the bearings are loaded. Road test the vehicle.Turn the vehicle sharply to the left and to the right.
This will load the bearings and change the noise
level. Where axle bearing damage is slight, the noise
is usually not noticeable at speeds above 30 mph.
LOW SPEED KNOCK
Low speed knock is generally caused by a worn
U-joint or by worn side±gear thrust washers. A worn
pinion shaft bore will also cause low speed knock.
VIBRATION
Vibration at the rear of the vehicle is usually
caused by a:
²Damaged drive shaft.
²Missing drive shaft balance weight(s).
²Worn or out-of-balance wheels.
²Loose wheel lug nuts.
²Worn U-joint(s).
²Loose/broken springs.
²Damaged axle shaft bearing(s).
²Loose pinion gear nut.
²Excessive pinion yoke run out.
²Bent axle shaft(s).
Check for loose or damaged front-end components
or engine/transmission mounts. These components
can contribute to what appears to be a rearend vibra-
tion. Do not overlook engine accessories, brackets
and drive belts.
All driveline components should be examined
before starting any repair.
(Refer to 22 - TIRES/WHEELS - DIAGNOSIS AND
TESTING)
DRIVELINE SNAP
A snap or clunk noise when the vehicle is shifted
into gear (or the clutch engaged), can be caused by:
²High engine idle speed.
²Transmission shift operation.
²Loose engine/transmission/transfer case mounts.
²Worn U-joints.
²Loose spring mounts.
²Loose pinion gear nut and yoke.
²Excessive ring gear backlash.
²Excessive side gear to case clearance.
The source of a snap or a clunk noise can be deter-
mined with the assistance of a helper. Raise the vehi-
cle on a hoist with the wheels free to rotate. Instruct
the helper to shift the transmission into gear. Listen
for the noise, a mechanics stethoscope is helpful in
isolating the source of a noise.
BR/BEREAR AXLE - 248RBI 3 - 111
REAR AXLE - 248RBI (Continued)