Page 81 of 2255
Fig. 20 GEAR TOOTH CONTACT PATTERNS
3 - 26 FRONT AXLE - 248FBIBR/BE
FRONT AXLE - 248FBI (Continued)
Page 82 of 2255
SPECIFICATIONS
FRONT AXLE - 248FBI
AXLE SPECIFICATIONS
DESCRIPTION SPECIFICATION
Axle Ratio 3.54, 4.10
Ring Gear Diameter 248 mm (9.75 in.)
Ring Gear Backlash 0.12-0.20 mm (0.005-0.008 in.)
Pinion Gear Standard Depth 127 mm (5.000 in.)
Pinion Bearing Preload - Original Bearing 1-2 N´m (10-20 in. lbs.)
Pinion Bearing Preload - New Bearing 2.26-4.52 N´m (20-40 in. lbs.)
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Fill Hole Plug 34 25 -
Differential Cover Bolts 41 30 -
Bearing Cap Bolts 108 80 -
Ring Gear Bolts 176 130 -
Pinion Nut 292-678 215-496 -
Axle Nut 237 175 -
Shift Motor Bolts 11 8 96
SPECIAL TOOLS
FRONT AXLE
REMOVER - C-452
SPREADER - W-129-B
INSTALLER, BEARING - C-3095-A
WRENCH, FLANGE - C-3281
BR/BEFRONT AXLE - 248FBI 3 - 27
FRONT AXLE - 248FBI (Continued)
Page 83 of 2255
PILOTS, STUDS - C-3288-B
DIAL INDICATOR, SET - C-3339
INSTALLER, FLANGE - C-3718
HANDLE, DRIVE - C-4171
INSTALLER, BEARING - C-4190
INSTALLER, CUP - C-111
INSTALLER, CUP - C-146
REMOVER, CUP - D-158
REMOVER, CUP - D-162
PULLER/PRESS - C-293-PA
3 - 28 FRONT AXLE - 248FBIBR/BE
FRONT AXLE - 248FBI (Continued)
Page 84 of 2255

AXLE SHAFTS
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assembly.
(3) Remove brake caliper, rotor and ABS wheel
speed sensor if equipped. Refer to 5 Brakes for pro-
cedures.
(4) Remove the cotter pin and axle hub nut.
(5) Remove hub bearing bolts (Fig. 21) and remove
hub bearing from the steering knuckle.
(6) Remove brake dust shield from knuckle.
(7) 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.
BLOCK, ADAPTER ± C-239-37
BLOCK, ADAPTER ± C-239-62
HOLDER, YOKE - 6719A
PINION DEPTH, SET ± 6730
Fig. 21 HUB AND KNUCKLE
1 - KNUCKLE
2 - HUB BEARING
BR/BEFRONT AXLE - 248FBI 3 - 29
FRONT AXLE - 248FBI (Continued)
Page 85 of 2255

AXLE SHAFTS -
INTERMEDIATE
REMOVAL
(1) Remove vacuum shift motor housing.
(2) Remove outer axle shaft.
(3) Remove 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) Assemble intermediate axle shaft bushing tools
(Fig. 22).
(6) Remove intermediate axle shaft bushing.
INSTALLATION - INTERMEDIATE AXLE
(1) Position the bushing on installation tool and
seat the bushing (Fig. 23) in the housing bore.
(2) Clean the inside perimeter of the axle shaft
tube with fine crocus cloth.
(3) Apply a light film of oil to the inside lip of the
new axle shaft seal.
(4) Install the inner axle seal (Fig. 24).
(5) Install the shift collar in the axle housing.
(6) Lubricate splined end of the intermediate axle
shaft with multi-purpose lubricant.
(7) Insert the intermediate axle shaft into the dif-
ferential side gear.CAUTION: Apply all-purpose lubricant to the axle
shaft splines to prevent damage to the seal during
axle shaft installation.
(8) Insert axle shaft into the tube and engage the
splined end of the shaft with the shift collar.
(9) Install the vacuum shift motor housing.
Fig. 22 INTERMEDIATE SHAFT BUSHING
1 - BUSHING
2 - SHIFT MOTOR HOUSING OPENING
3 - AXLE TUBE
4 - LOCATION FOR OPEN-END WRENCH
5 - SPECIAL TOOL 5041-2
6 - NUT
7 - SPECIAL TOOL 8417
8 - SPECIAL TOOL 8415
Fig. 23 BUSHING INSTALLATION
1 - SHIFT MOTOR HOUSING OPENING
2 - SPECIAL TOOL 5417
3 - SPECIAL TOOL 5041-2
4 - SPECIAL TOOL 8416
5 - BUSHING
Fig. 24 SEAL INSTALLATION
1 - SHIFT MOTOR HOUSING OPENING
2 - SEAL
3 - AXLE TUBE
4 - LOCATION FOR OPEN-END WRENCH
5 - SPECIAL TOOL 5041-2
6 - SPECIAL TOOL 8417
7 - SPECIAL TOOL 8411
3 - 30 FRONT AXLE - 248FBIBR/BE
Page 86 of 2255

AXLE SHAFT SEALS
REMOVAL
(1) Remove hub bearings and axle shafts.
(2) Remove axle shaft seal from the differential
housing with a long drift or punch.Be careful not
to damage housing.
(3) Clean the inside perimeter of the differential
housing with fine crocus cloth.
INSTALLATION
(1) Apply a light film of oil to the inside lip of the
new axle shaft seal.
(2) Install the inner axle seal (Fig. 25).
(3) Install axles and hub bearings.
AXLE VACUUM MOTOR
DESCRIPTION
The disconnect axle control system consists of:
²Shift motor.
²Indicator switch.
²Vacuum switch.
²Vacuum harness (Fig. 26).
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. When
this 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. 25 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. 26 VACUUM CONTROL SYSTEM
1 - CHECK VALVE
2 - CONTROL SWITCH ON TRANSFER CASE
3 - AIR VENT FILTER
4 - AXLE SHIFT MOTOR
5 - INDICATOR SWITCH
BR/BEFRONT AXLE - 248FBI 3 - 31
Page 87 of 2255
DIAGNOSIS AND TESTING - VACUUM MOTOR
AXLE VACUUM SHIFT MOTOR
3 - 32 FRONT AXLE - 248FBIBR/BE
AXLE VACUUM MOTOR (Continued)
Page 88 of 2255
AXLE VACUUM SHIFT MOTOR (CONT'D)
BR/BEFRONT AXLE - 248FBI 3 - 33
AXLE VACUUM MOTOR (Continued)