cle turns. A worn pinion mate shaft can also cause a
snapping 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:
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 rear end
vibration. Do not overlook engine accessories, brack-
ets 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/BEFRONT AXLE - 248FBI 3 - 47
FRONT AXLE - 248FBI (Continued)
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.
3. End-play in pinion bearings. 3. Refer to pinion pre-load information
and correct as necessary.
4. Excessive gear backlash between the
ring gear and pinion.4. Check adjustment of the ring gear
and pinion backlash. Correct as
necessary.
5. Improper adjustment of pinion gear
bearings.5. Adjust the pinion bearings pre-load.
6. Loose pinion yoke nut. 6. Tighten the pinion yoke nut.
7. Scuffed gear tooth contact surfaces. 7. Inspect and replace 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.
3 - 48 FRONT AXLE - 248FBIBR/BE
FRONT AXLE - 248FBI (Continued)
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the wheels and tires.
(3) Remove the brake calipers and rotors. Refer to
Group 5, Brakes, for proper procedures.
(4) Remove ABS wheel speed sensors, if equipped.
Refer to Group 5, Brakes, for proper procedures.
(5) Disconnect the axle vent hose.
(6) Disconnect vacuum hose and electrical connec-
tor at disconnect housing.
(7) Remove the front propeller shaft.
(8) Disconnect the stabilizer bar links at the axle
brackets.
(9) Disconnect the shock absorbers from axle
brackets.
(10) Disconnect the track bar from the axle
bracket.
(11) Disconnect the tie rod and drag link from the
steering knuckles.
(12) Position the axle with a suitable lifting device
under the axle assembly.
(13) Secure axle to lifting device.
(14) Mark suspension alignment cams for installa-
tion reference.
(15) Disconnect the upper and lower suspension
arms from the axle bracket.
(16) Lower the axle. The coil springs will drop
with the axle.
(17) Remove the coil springs from the axle bracket.
INSTALLATION
CAUTION: Suspension components with rubber
bushings should be tightened with the weight of the
vehicle on the suspension, at normal height. If
springs are not at their normal ride position, vehicle
ride comfort could be affected and premature bush-
ing wear may occur. Rubber bushings must never
be lubricated.
(1) Support the axle on a suitable lifting device.
(2) Secure axle to lifting device.
(3) Position the axle under the vehicle.
(4) Install the springs, retainer clip and bolts.
(5) Raise the axle and align it with the spring
pads.
(6) Position the upper and lower suspension arms
in the axle brackets. Install bolts, nuts and align the
suspension alignment cams to the reference marks.
Do not tighten at this time.
(7) Connect the track bar to the axle bracket and
install the bolt. Do not tighten at this time.
(8) Install the shock absorber and tighten bolts to
121 N´m (89 ft. lbs.) torque.(9) Install the stabilizer bar link to the axle
bracket. Tighten the nut to 37 N´m (27 ft. lbs.)
torque.
(10) Install the drag link and tie rod to the steer-
ing knuckles and tighten the nuts to 88 N´m (65 ft.
lbs.) torque.
(11) Install the ABS wheel speed sensors, if
equipped. Refer to group 5, Brakes, for proper proce-
dures.
(12) Install the brake calipers and rotors. Refer to
Group 5, Brakes, for proper procedures.
(13) Connect the vent hose to the tube fitting.
(14) Connect vacuum hose and electrical connector
to disconnect housing.
(15) Install front propeller shaft.
(16) Check and add differential lubricant, if neces-
sary. Refer to Lubricant Specifications in this section
for lubricant requirements.
(17) Install the wheel and tire assemblies.
(18) Remove the supports and lower the vehicle.
(19) Tighten the upper suspension arm nuts at
axle to 121 N´m (89 ft. lbs.) torque. Tighten the
upper suspension arm nuts at frame to 84 N´m (62 ft.
lbs.) torque.
(20) Tighten the lower suspension arm nuts at
axle to 84 N´m (62 ft. lbs.) torque. Tighten the lower
suspension arm nuts at frame to 119 N´m (88 ft. lbs.)
torque.
(21) Tighten the track bar bolt at the axle bracket
to 176 N´m (130 ft. lbs.) torque.
(22) Check the front wheel alignment.ADJUSTMENTS
Ring and pinion gears are supplied as matched
sets only. The identifying numbers for the ring and
pinion gear are etched into the face of each gear (Fig.
4). A plus (+) number, minus (±) number or zero (0) is
etched into the face of the pinion gear. This number
is the amount (in thousandths of an inch) the depth
varies from the standard depth setting of a pinion
etched with a (0). The standard setting from the cen-
ter line of the ring gear to the back face of the pinion
is 127 mm (5.00 in.). The standard depth provides
the best gear tooth contact pattern. Refer to Back-
lash and Contact Pattern in this section for addi-
tional information.
Compensation for pinion depth variance is
achieved with a select shim/oil baffle. The shims are
placed between the rear pinion bearing and the pin-
ion gear head (Fig. 5).
If a new gear set is being installed, note the depth
variance etched into both the original and replace-
ment pinion. Add or subtract this number from the
thickness of the original depth shim/oil slinger to
compensate for the difference in the depth variances.
Refer to the Depth Variance chart.
3 - 50 FRONT AXLE - 248FBIBR/BE
FRONT AXLE - 248FBI (Continued)
AXLE SHAFTS
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assembly.
(3) Remove brake caliper and rotor. Refer to
Brakes for procedures.
(4) Remove ABS wheel speed sensor if equipped.
Refer to Brakes for procedures.
(5) Remove the cotter pin and axle hub nut.
(6) Remove hub bearing bolts (Fig. 22) and remove
hub bearing from the steering knuckle.
(7) Remove brake dust shield from knuckle.(8) Remove axle shaft from the housing. Avoid
damaging the axle shaft oil seal.
INSTALLATION
(1) Clean axle shaft and apply a thin film of
Mopar Wheel Bearing Grease to the shaft splines,
seal contact surface, hub bore.
(2) Install axle shaft into the housing and differen-
tial side gears. Avoid damaging axle shaft oil seals in
the differential.
(3) Install dust shield and hub bearing on knuckle.
(4) Install hub bearing bolts and tighten to 170
N´m (125 ft. lbs.).
(5) Install axle washer and nut, tighten nut to 237
N´m (175 ft. lbs.). Align nut to next cotter pin hole
and install new cotter pin.
(6) Install ABS wheel speed sensor, brake rotor
and caliper. Refer to Brakes for proper procedures.
(7) Install wheel and tire assembly.
(8) Remove support and lower the vehicle.
AXLE SHAFTS -
INTERMEDIATE
REMOVAL - INTERMEDIATE AXLE
(1) Remove the vacuum shift motor housing.
(2) Remove the outer axle shaft.
(3) Remove the inner axle shaft seal from the shift
motor housing with a long drift or punch. Be careful
not to damage housing.
(4) Remove intermediate axle shaft and shift col-
lar.
(5) Remove the intermediate axle shaft bushing
(Fig. 23).
BLOCK, ADAPTER ± C-239-37
BLOCK, ADAPTER ± C-239-62
HOLDER, YOKE - 6719A
PINION DEPTH, SET ± 6730
Fig. 22 Hub and Knuckle
1 - KNUCKLE
2 - HUB BEARING
3 - 60 FRONT AXLE - 248FBIBR/BE
FRONT AXLE - 248FBI (Continued)
AXLE VACUUM MOTOR
DESCRIPTION
The disconnect axle control system consists of:
²Shift motor.
²Indicator switch.
²Vacuum switch.
²Vacuum harness (Fig. 27).
OPERATION
The shift motor receives a vacuum signal from the
switch mounted on the transfer case when the vehi-
cle operator wants to switch from two wheel drive
mode to four wheel drive mode, or vice versa. Whenthis signal is received, the shift motor begins to move
the shift fork and collar within the axle housing. In
the four wheel drive mode, the shift collar connects
the axle intermediate shaft to the axle shaft to sup-
ply engine power to both front wheels. In two wheel
drive mode, the shift collar is disengaged from the
intermediate shaft and the intermediate shaft is
allowed to free-spin. When the two shafts are disen-
gaged, the load on the engine is reduced, thereby pro-
viding better fuel economy and road handling.
Fig. 26 Seal Installation
1 - DIFFERENTIAL HOUSING
2 - POSITION FOR OPEN-END WRENCH
3 - SPECIAL TOOL 5041-2
4 - SPECIAL TOOL 8417
5 - SEAL
6 - SPECIAL TOOL 8411
Fig. 27 Vacuum Control System
1 - CHECK VALVE
2 - CONTROL SWITCH ON TRANSFER CASE
3 - AIR VENT FILTER
4 - AXLE SHIFT MOTOR
5 - INDICATOR SWITCH
3 - 62 FRONT AXLE - 248FBIBR/BE
AXLE SHAFT SEALS (Continued)
(5) Position the yoke with the sockets in a vise
(Fig. 31).
(6) Tighten the vise jaws to force the bearing cap
into the larger socket (receiver).
(7) Release the vise jaws. Remove the sockets and
bearing cap that was partially forced out of the yoke.
(8) Repeat the above procedure for the remaining
bearing cap and remove spider from the propeller
shaft yoke.
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. Tap the 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 calipers and rotors
(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 the amount of torque necessary to
rotate the pinion gear with a (in. lbs.) dial-type
torque wrench. Record the torque reading for instal-
lation reference.
(8) Remove the pinion yoke nut and washer. Use
Remover C-452 and Wrench C-3281 to remove the
pinion yoke (Fig. 32).
(9) Use suitable pry tool or slide hammer mounted
screw to remove the pinion shaft seal.
INSTALLATION
(1) Apply a light coating of gear lubricant on the
lip of pinion seal. Install seal with an appropriate
installer (Fig. 33).
(2) Install yoke on the pinion gear with Installer
C-3718 and Holder 6719 (Fig. 34).
CAUTION: Do not exceed the minimum tightening
torque when installing the pinion yoke retaining
nut. Damage to collapsible spacer or bearings may
result.
Fig. 30 Axle Shaft Outer UÐJoint
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. 31 Yoke Bearing Cap
1 - LARGE-DIAMETER SOCKET WRENCH
2 - VISE
3 - SMALL-DIAMETER SOCKET WRENCH
3 - 66 FRONT AXLE - 248FBIBR/BE
SINGLE CARDAN UNIVERSAL JOINTS (Continued)
(3) Install a new nut on the pinion gear. Tighten
the nut only enough to remove the shaft end play.
(4) Rotate the pinion shaft using an inch pound
torque wrench. Rotating torque should be equal to
the reading recorded during removal, plus an addi-
tional 0.56 N´m (5 in. lbs.) (Fig. 35).
(5) If the rotating torque is to low, use Holder 6719
to hold the pinion yoke (Fig. 36), and tighten the pin-
ion shaft nut in 6.8 N´m (5 ft. lbs.) until proper rotat-
ing torque is achieved.
(6) Align the installation reference marks and
attach the propeller shaft to the yoke.
(7) Check and add lubricant to axle, if necessary.
Refer to Lubricant Specifications in this section for
lubricant requirements.
(8) Install brake rotors and calipers.(9) Install wheel and tire assemblies.
(10) Lower the vehicle.
Fig. 32 Pinion
1 - YOKE HOLDER
2 - YOKE
3 - YOKE PULLER
Fig. 33 Pinion Seal Installation
1 - SPECIAL TOOL CÐ4171
2 - SPECIAL TOOL CÐ8108
Fig. 34 Install Pinion Yoke
1 - YOKE INSTALLER
2 - YOKE HOLDER
Fig. 35 Check Pinion Rotation
1 - PINION YOKE
2 - INCH POUND TORQUE WRENCH
BR/BEFRONT AXLE - 248FBI 3 - 67
PINION SEAL (Continued)
REAR AXLE-91/4
TABLE OF CONTENTS
page page
REAR AXLE-91/4
DESCRIPTION...........................77
OPERATION.............................77
DIAGNOSIS AND TESTING.................80
AXLE................................80
REMOVAL..............................83
INSTALLATION...........................84
ADJUSTMENTS..........................84
SPECIFICATIONS........................90
SPECIAL TOOLS.........................90
AXLE SHAFTS
REMOVAL..............................93
INSTALLATION...........................93
AXLE SHAFT SEALS
REMOVAL..............................94
INSTALLATION...........................94
AXLE BEARINGS
REMOVAL..............................94
INSTALLATION...........................95PINION SEAL
REMOVAL..............................95
INSTALLATION...........................95
DIFFERENTIAL
REMOVAL..............................96
DISASSEMBLY...........................97
ASSEMBLY.............................98
INSTALLATION...........................98
DIFFERENTIAL - TRAC-LOK
DIAGNOSIS AND TESTING.................98
TRAC-LOK............................98
DISASSEMBLY...........................99
ASSEMBLY............................101
DIFFERENTIAL CASE BEARINGS
REMOVAL.............................103
INSTALLATION..........................103
PINION GEAR/RING GEAR/TONE RING
REMOVAL.............................103
INSTALLATION..........................105
REAR AXLE-91/4
DESCRIPTION
The 9 1/4 Inch axle housings consist of a cast iron
center section with axle tubes extending from either
side. The tubes are pressed into and welded to the
differential housing to form a one-piece axle housing
(Fig. 1).
The axles have a vent hose to relieve internal pres-
sure caused by lubricant vaporization and internal
expansion.
The axles are equipped with semi-floating axle
shafts, meaning vehicle loads are supported by the
axle shaft and bearings. The axle shafts are retained
by C-locks in the differential side gears.
The removable, stamped steel cover provides a
means for inspection and service without removing
the complete axle from the vehicle.
The axle has a date tag and a gear ratio tag. The
tags are attached to the differential housing by a
cover bolt.
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 must
be 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 is a one-piece design. The dif-
ferential pinion shaft is retained with a screw. Differ-
ential bearing preload and ring gear backlash are set
and maintained by threaded adjusters at the outside
of the differential housing. Pinion bearing preload is
set and maintained by the use of a collapsible spacer.
Axles equipped with a Trac-Lokydifferential are
optional. A differential has a one-piece differential
case, and the same internal components as a stan-
dard differential, plus two clutch disc packs.
AXLE IDENTIFICATION
The axle differential cover can be used for identifi-
cation of the axle (Fig. 2). A ratio tag is attached to
the top of the differential cover.
OPERATION
The axle receives power from the transmission/
transfer case through the rear propeller shaft. The
rear propeller shaft is connected to the drive pinion
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 differential pinions and side gears. The
side gears are splined to the axle shafts.
BR/BEREAR AXLE - 9 1/4 3 - 77