Page 97 of 2255
(9) Remove pinion gear from housing (Fig. 49).
(10) Remove pinion seal with a pry bar or screw
mounted slide hammer.
(11) Remove oil slinger and front pinion bearing.
(12) Remove front pinion bearing cup with Driver
D-158 and Handle C-4171 (Fig. 50).(13) Remove rear bearing cup with remover D-162
and Handle C-4171 (Fig. 51).
(14) Remove collapsible preload spacer (Fig. 52).
Fig. 50 FRONT PINION BEARING CUP
1 - REMOVER
2 - HANDLE
Fig. 49 PINION GEAR REMOVAL
1 - RAWHIDE HAMMER
Fig. 51 REAR PINION BEARING CUP
1 - DRIVER
2 - HANDLE
Fig. 52 COLLAPSIBLE SPACER
1 - COLLAPSIBLE SPACER
2 - SHOULDER
3 - PINION GEAR
4 - OIL SLINGER
5 - REAR BEARING
3 - 42 FRONT AXLE - 248FBIBR/BE
PINION GEAR/RING GEAR (Continued)
Page 98 of 2255

(15) Remove rear pinion bearing from pinion with
Puller C-293-PA and Adapters C-293-37 (Fig. 53).
(16) Remove pinion depth shims from the pinion
shaft and record thickness.
INSTALLATION
NOTE: Pinion depth shims are placed between the
rear pinion bearing cone and pinion gear to achieve
proper ring and pinion gear mesh. If ring and pinion
gears are reused, the original pinion depth shim
can be used. Refer to Adjustments (Pinion Gear
Depth) to select the proper shim thickness if ring
and pinion gears are replaced.
(1) Apply Mopar Door Ease stick lubricant or
equivalent to outside surface of bearing cups.
(2) Install rear pinion bearing cup with Installer
D-111 and Handle C-4171 (Fig. 54) and verify cup is
seated.
(3) Install front pinion bearing cup with Installer
D-146 and Handle C-4171 (Fig. 55) and verify cup is
seated.
(4) Install pinion front bearing, oil slinger. Apply a
light coating of gear lubricant on the lip of pinion
seal.
Fig. 53 REAR PINION BEARING
1 - PULLER
2 - VISE
3 - ADAPTERS
4 - PINION SHAFT
Fig. 54 REAR PINION BEARING CUP
1 - INSTALLER
2 - HANDLE
Fig. 55 FRONT PINION BEARING CUP
1 - INSTALLER
2 - HANDLE
BR/BEFRONT AXLE - 248FBI 3 - 43
PINION GEAR/RING GEAR (Continued)
Page 99 of 2255
(5) Install pinion seal with an appropriate installer
(Fig. 56).
(6) Install proper thickness depth shim on the pin-
ion gear.
(7) Install rear bearing and oil slinger on pinion
gear with Installer C-3095-A (Fig. 57).
(8) Install anewcollapsible preload spacer on pin-
ion shaft (Fig. 58).
(9) Install pinion gear in housing.
(10) Install yoke with Installer C-3718 and Yoke
Holder 6719A (Fig. 59).
Fig. 56 PINION SEAL INSTALLER
1 - HANDLE
2 - INSTALLER
Fig. 57 REAR PINION BEARING
1 - PRESS
2 - INSTALLER
3 - PINION GEAR
4 - PINION REAR BEARING
Fig. 58 COLLAPSIBLE SPACER
1 - COLLAPSIBLE SPACER
2 - SHOULDER
3 - PINION GEAR
4 - OIL SLINGER
5 - REAR PINION BEARING
Fig. 59 PINION YOKE INSTALLER
1 - INSTALLER
2 - YOKE HOLDER
3 - 44 FRONT AXLE - 248FBIBR/BE
PINION GEAR/RING GEAR (Continued)
Page 100 of 2255

(11) Install yoke washer and anewnut on the
pinion gear. Tighten the nut to 291 N´m (215 ft. lbs.)
minimum.Do not over±tighten.Maximum torque
is 678 N´m (500 ft. lbs.).
CAUTION: Never loosen pinion gear nut to decrease
pinion preload torque and never exceed specified
preload torque. If preload torque is exceeded a new
collapsible spacer must be installed.
(12) Use Yoke Holder 6719A to hold the yoke (Fig.
60) and tighten the nut in 6.8 N´m (5 ft. lbs.) until
the rotating torque is achieved. Measure the preload
torque frequently to avoid over-tightening the nut.
(13) Check bearing preload torque with an inch
pound torque wrench (Fig. 61). The torque to rotate
the pinion gear should be:
²Original Bearings: 1 to 2 N´m (10 to 20 in. lbs.).
²New Bearings: 2.26 to 4.52 N´m (20 to 40 in.
lbs.).
(14) Invert differential case in a vise and start two
ring gear bolts. This will provide case-to-ring gear
bolt hole alignment.
(15) Installnewring gear bolts and alternately
tighten to 176 N´m (130 ft. lbs.). (Fig. 62).
CAUTION: Never reuse the ring gear bolts. The
bolts can fracture causing extensive damage.
(16) Install differential in axle housing and verify
gear mesh and contact pattern. Refer to Adjustments
(Gear Contact Pattern).
(17) Install differential cover and fill with lubri-
cant.
Fig. 60 PINION NUT
1 - PINION FLANGE
2 - YOKE HOLDING
3 - DIFFERENTIAL HOUSING
Fig. 61 Pinion Rotating Torque
1 -TORQUE WRENCH
2 - PINION YOKE
Fig. 62 RING GEAR BOLT
1 - TORQUE WRENCH
2 - RING GEAR BOLT
3 - RING GEAR
4 - CASE
BR/BEFRONT AXLE - 248FBI 3 - 45
PINION GEAR/RING GEAR (Continued)
Page 101 of 2255

REAR AXLE - 248RBI
TABLE OF CONTENTS
page page
REAR AXLE - 248RBI
DESCRIPTION.........................46
OPERATION...........................46
DIAGNOSIS AND TESTING - AXLE..........47
REMOVAL.............................51
INSTALLATION.........................51
ADJUSTMENTS........................51
SPECIFICATIONS
REAR AXLE - 248RBI..................59
SPECIAL TOOLS
REAR AXLE - 248RBI..................59
AXLE SHAFTS
REMOVAL.............................62
INSTALLATION.........................62
AXLE BEARINGS
REMOVAL.............................62
INSTALLATION.........................62
PINION SEAL
REMOVAL.............................63INSTALLATION.........................63
DIFFERENTIAL
REMOVAL.............................64
DISASSEMBLY.........................65
ASSEMBLY............................66
INSTALLATION.........................66
DIFFERENTIAL - TRAC-LOK
DIAGNOSIS AND TESTING - TRAC-LOKT.....67
DISASSEMBLY.........................68
ASSEMBLY............................70
DIFFERENTIAL CASE BEARINGS
REMOVAL.............................72
INSTALLATION.........................72
PINION GEAR/RING GEAR/TONE RING
REMOVAL.............................73
INSTALLATION.........................75
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 into the differential housing and welded. The
axles are equipped with full-floating axle shafts, meaning
that loads are supported by the axle housing tubes.
The differential case for the standard differentials
and the Trac-loktdifferential are a one-piece design.
Differential bearing preload and ring gear backlash
are adjusted by the use of shims located between the
differential bearing cones and case. Pinion bearing
preload is set and maintained by the use of a collaps-
ible spacer. The removable, stamped steel cover pro-
vides a means for inspection and service.
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 shaftsthrough 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
gears. As a result, the pinion gears revolve with the
pinion mate shaft but do not rotate around it (Fig. 1).Fig. 1 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
3 - 46 REAR AXLE - 248RBIBR/BE
Page 102 of 2255

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-LOKTDIFFERENTIAL
The differential clutches are engaged by two con-
current forces. The first being the preload force
exerted through Belleville spring washers within the
clutch packs. The second is the separating forces gen-
erated by the side gears as torque is applied through
the ring gear (Fig. 3).
This design 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. The
differential resist wheel spin on bumpy roads and
provide more pulling power when one wheel looses
traction. Pulling power is provided continuously until
both wheels loose traction. If both wheels slip due to
unequal traction, Trac-loktoperation is normal. In
extreme cases of differences 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, toothcontact, 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-
Fig. 2 DIFFERENTIAL ON TURNS
1 - PINION GEARS ROTATE ON PINION SHAFTFig. 3 TRAC-LOK LIMITED 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
BR/BEREAR AXLE - 248RBI 3 - 47
REAR AXLE - 248RBI (Continued)
Page 103 of 2255

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.
NOTE: All driveline components should be exam-
ined before starting any repair.
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.
3 - 48 REAR AXLE - 248RBIBR/BE
REAR AXLE - 248RBI (Continued)
Page 104 of 2255

DIAGNOSTIC CHART
Condition Possible Causes Correction
Wheel Noise 1. Wheel loose. 1. Tighten loose nuts.
2. Faulty, brinelled wheel bearing. 2. Replace bearing.
Axle Shaft Noise 1. Misaligned axle tube. 1. Inspect axle tube alignment.
Correct as necessary.
2. Bent or sprung axle shaft. 2. Inspect and correct as necessary.
Axle Shaft Broke 1. Misaligned axle tube. 1. Replace the broken shaft after
correcting tube mis-alignment.
2 Vehicle overloaded. 2. Replace broken shaft and avoid
excessive weight on vehicle.
3. Erratic clutch operation. 3. Replace broken shaft and avoid
or correct erratic clutch operation.
4. Grabbing clutch. 4. Replace broken shaft and inspect
and repair clutch as necessary.
Differential Cracked 1. Improper adjustment of the
differential bearings.1. Replace case and inspect gears
and bearings for further damage.
Set differential bearing pre-load
properly.
2. Excessive ring gear backlash. 2. Replace case and inspect gears
and bearings for further damage.
Set ring gear backlash properly.
3. Vehicle overloaded. 3. Replace case and inspect gears
and bearings for further damage.
Avoid excessive vehicle weight.
4. Erratic clutch operation. 4. Replace case and inspect gears
and bearings for further damage.
Avoid erratic use of clutch.
Differential Gears Scored 1. Insufficient lubrication. 1. Replace scored gears. Fill
differential with the correct fluid type
and quantity.
2. Improper grade of lubricant. 2. Replace scored gears. Fill
differential with the correct fluid type
and quantity.
3. Excessive spinning of one
wheel/tire.3. Replace scored gears. Inspect all
gears, pinion bores, and shaft for
damage. Service as necessary.
BR/BEREAR AXLE - 248RBI 3 - 49
REAR AXLE - 248RBI (Continued)