Condition Possible Causes Correction
Gear Teeth Broke 1. Overloading. 1. Replace gears. Examine other
gears and bearings for possible
damage.
2. Erratic clutch operation. 2. Replace gears and examine the
remaining parts for damage. Avoid
erratic clutch operation.
3. Ice-spotted pavement. 3. Replace gears and examine
remaining parts for damage.
4. Improper adjustments. 4. Replace gears and examine
remaining parts for damage. Ensure
ring gear backlash is correct.
Axle Noise 1. Insufficient lubricant. 1. Fill differential with the correct
fluid type and quantity.
2. Improper ring gear and pinion
adjustment.2. Check ring gear and pinion
contact pattern.
3. Unmatched ring gear and pinion. 3. Replace gears with a matched
ring gear and pinion.
4. Worn teeth on ring gear and/or
pinion.4. Replace ring gear and pinion.
5. Loose pinion bearings. 5. Adjust pinion bearing pre-load.
6. Loose differential bearings. 6. Adjust differential bearing
pre-load.
7. Mis-aligned or sprung ring gear. 7. Measure ring gear run-out.
Replace components as necessary.
8. Loose differential bearing cap
bolts.8. Inspect differential components
and replace as necessary. Ensure
that the bearing caps are torqued
tot he proper specification.
9. Housing not machined properly. 9. Replace housing.
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheels and tires.
(3) Remove brake calipers and rotors. Refer to 5
Brakes for procedures.
(4) Remove ABS wheel speed sensors, if equipped.
Refer to 5 Brakes for procedures.
(5) Disconnect axle vent hose.
(6) Disconnect vacuum hose and electrical connec-
tor at disconnect housing.
(7) Remove front propeller shaft.
(8) Disconnect stabilizer bar links at the axle
brackets.
(9) Disconnect shock absorbers from axle brackets.
(10) Disconnect track bar from the axle bracket.
(11) Disconnect tie rod and drag link from the
steering knuckles.
(12) Position suitable lifting device under the axle
assembly.(13) Secure axle to lifting device.
(14) Mark suspension alignment cams for installa-
tion reference.
(15) Disconnect 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.
3 - 18 FRONT AXLE - 248FBIBR/BE
FRONT AXLE - 248FBI (Continued)
(2) Secure axle to lifting device.
(3) Position the axle under the vehicle.
(4) Install springs, retainer clip and bolts.
(5) Raise axle and align it with the spring pads.
(6) Position 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 track bar to the axle bracket and
install the bolt. Do not tighten at this time.
(8) Install shock absorber and tighten bolts to 121
N´m (89 ft. lbs.).
(9) Install stabilizer bar link to the axle bracket.
Tighten the nut to 37 N´m (27 ft. lbs.).
(10) Install drag link and tie rod to the steering
knuckles and tighten the nuts to 88 N´m (65 ft. lbs.).
(11) Install ABS wheel speed sensors, if equipped.
Refer to 5 Brakes for procedures.
(12) Install rotors and brake calipers, refer to 5
Brakes for 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 for lubricant
requirements.
(17) Install wheel and tire assemblies.
(18) Remove supports and lower the vehicle.
(19) Tighten upper suspension arm nuts at axle to
121 N´m (89 ft. lbs.). Tighten upper suspension arm
nuts at frame to 84 N´m (62 ft. lbs.).
(20) Tighten lower suspension arm nuts at axle to
84 N´m (62 ft. lbs.). Tighten the lower suspension
arm nuts at frame to 119 N´m (88 ft. lbs.).
(21) Tighten track bar bolt at the axle bracket to
176 N´m (130 ft. lbs.).
(22) Check 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. 3). 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 center 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 Backlash and Contact Pattern
in this section for additional information.
Compensation for pinion depth variance is
achieved with a select shim/slinger. The shims are
placed between the rear pinion bearing and the pin-
ion gear head (Fig. 4).
Fig. 3 PINION GEAR ID NUMBERS
1 - PRODUCTION NUMBERS
2 - PINION GEAR DEPTH VARIANCE
3 - GEAR MATCHING NUMBER
Fig. 4 SHIM LOCATIONS
1 - PINION GEAR DEPTH SHIM/SLINGER
2 - DIFFERENTIAL BEARING SHIM
BR/BEFRONT AXLE - 248FBI 3 - 19
FRONT AXLE - 248FBI (Continued)
DIFFERENTIAL SIDE BEARING PRELOAD AND
GEAR BACKLASH
Differential side bearing preload and gear backlash
is achieved by selective shims positioned behind the
differential side bearing cones. The proper shim
thickness can be determined using slip-fit Dummy
Bearings D-343 in place of the differential side bear-
ings and a Dial Indicator C-3339. Before proceeding
with the differential bearing preload and gear back-
lash measurements, measure the pinion gear depth
and prepare the pinion 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 side
play is measured, the pinion is installed, and the
gear backlash shim thickness is measured. The over-
all shim thickness is the total of the dial indicator
reading and the preload 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 dif-
ferential (Fig. 9). Differential shim measurements
are performed with spreader W-129-B removed.
SHIM SELECTION
NOTE: It is difficult to salvage the differential side
bearings during the removal procedure. Install
replacement bearings if necessary.
(1) Remove differential side bearings from differ-
ential case.(2) Remove factory installed shims from differen-
tial case.
(3) Install ring gear on differential case and
tighten bolts to specification.
(4) Install dummy side bearings D-343 on differen-
tial case.
(5) Install differential case in the housing.
(6) Install the marked bearing caps in their correct
positions and snug the bolts (Fig. 10).
Fig. 8 PINION GEAR DEPTH MEASUREMENT
1 - ARBOR
2 - SCOOTER BLOCK
3 - DIAL INDICATOR
Fig. 9 SHIM LOCATIONS
1 - PINION GEAR DEPTH SHIM/SLINGER
2 - DIFFERENTIAL BEARING SHIM
Fig. 10 BEARING CAP BOLTS
1 - BEARING CAP
2 - DIFFERENTIAL HOUSING
3 - DIFFERENTIAL CASE
3 - 22 FRONT AXLE - 248FBIBR/BE
FRONT AXLE - 248FBI (Continued)
CAUTION: Never spread housing over 0.50 mm
(0.020 in.). The housing can be damaged if over-
spread.
(28) Install differential case into the housing.
(29) Remove spreader from the housing.
(30) Rotate differential case several times to seat
the side bearings.
(31) Position indicator plunger against a ring gear
tooth (Fig. 18).
(32) Push and hold ring gear upward while not
allowing the pinion gear to rotate.
(33) Zero dial indicator face to pointer.
(34) Push and hold ring gear downward while not
allowing the pinion gear to rotate. Dial indicator
reading should be between 0.12 mm (0.005 in.) and
0.20 mm (0.008 in.). If backlash is not within specifi-
cations transfer the necessary amount of shim thick-
ness from one side of the housing to the other (Fig.
19).
(35) Verify differential case and ring gear runout
by measuring ring to pinion gear backlash at eight
locations around the ring gear. Readings should not
vary more than 0.05 mm (0.002 in.). If readings vary
more than specified, the ring gear or the differential
case is defective.
After the proper backlash is achieved, perform
Gear Contact Pattern Analysis procedure.
GEAR CONTACT PATTERN
The ring and pinion gear contact patterns will
show if the pinion depth is correct. It will also show
if the ring gear backlash has been adjusted correctly.
The backlash can be adjusted within specifications to
achieve desired tooth contact patterns.
(1) Apply a thin coat of hydrated ferric oxide or
equivalent to the drive and coast side of the ring gear
teeth.
(2) Wrap, twist and hold a shop towel around the
pinion yoke to increase the turning resistance of the
pinion. This will provide a more distinct contact pat-
tern.
(3) With a boxed end wrench on the ring gear bolt,
rotate the differential case one complete revolution in
both directions while a load is being applied from
shop towel.
The areas on the ring gear teeth with the greatest
degree of contact against the pinion teeth will squee-
gee the compound to the areas with the least amount
of contact. Note and compare patterns on the ring
gear teeth to Gear Tooth Contact Patterns chart (Fig.
20)and adjust pinion depth and gear backlash as nec-
essary.
Fig. 18 RING GEAR BACKLASH
1 - DIAL INDICATOR
Fig. 19 BACKLASH SHIM
BR/BEFRONT AXLE - 248FBI 3 - 25
FRONT AXLE - 248FBI (Continued)
INSTALLATION
NOTE: If replacement differential bearings or differ-
ential case are being installed, differential side
bearing shim requirements may change. Refer to
Adjustments (Differential Bearing Preload and Gear
Backlash) procedures to determine proper shim
selection.
(1) Position Spreader W-129-B with the tool dowel
pins seated in the locating holes. Install the hold
down clamps and tighten the tool turnbuckle finger-
tight.
(2) Install a Pilot Stud C-3288-B at the left side of
the differential housing and attach dial indicator to
the pilot stud. Load the indicator plunger against the
opposite side of the housing and zero the dial indica-
tor.
(3) Spread the housing enough to install the case
in the housing. Measure the distance with the dial
indicator.
CAUTION: Never spread the housing over 0.50 mm
(0.020 in). If housing is over-spread, it could be dis-
torted or damaged.
(4) Remove the dial indicator.(5) Install differential into the housing. Tap the
differential case with a rawhide/rubber hammer to
ensure the bearings are seated in housing (Fig. 42).
(6) Remove the spreader.
(7) Install bearing caps in their original locations
(Fig. 43) and tighten bearing cap bolts in a criss-
cross pattern to 109 N´m (80 ft. lbs.).
(8) Install axle shafts.
(9) Install the hub bearings.
Fig. 41 Pinion Mate Shaft Roll-Pin
1 - PUNCH
2 - PINION MATE SHAFT
3 - MATE SHAFT LOCKPIN
Fig. 42 DIFFERENTIAL CASE
1 - RAWHIDE HAMMER
Fig. 43 Bearing Cap Reference
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
BR/BEFRONT AXLE - 248FBI 3 - 39
DIFFERENTIAL (Continued)
(10) Apply a bead of red Mopar Silicone Rubber
Sealant or equivalent to the housing cover (Fig. 44).
CAUTION: If housing cover is not installed within 3
to 5 minutes, the cover must be cleaned and new
RTV applied or adhesion quality will be compro-
mised.
(11) Install the cover and tighten bolts in a criss-
cross pattern to 47 N´m (35 ft. lbs.).
(12) Fill the differential with Mopar Hypoid Gear
Lubricant or equivalent to bottom of the fill plug
hole.
(13) Install fill hole plug and tighten to 34 N´m (25
ft. lbs.).
(14) Remove support and lower vehicle.DIFFERENTIAL CASE
BEARINGS
REMOVAL
(1) Remove differential case from axle housing.
(2) Remove bearings from the differential case
with Puller/Press C-293-PA, Adapters C-293-62 and
Step Plate C-4487-1 (Fig. 45).
Fig. 44 DIFFERENTIAL COVER - TYPICAL
1 - SEALANT SURFACE
2 - SEALANT
3 - SEALANT THICKNESS
Fig. 45 Differential Bearing Removal
1 - PULLER
2 - ADAPTERS
3 - STEP PLATE
4 - BEARING
5 - DIFFERENTIAL CASE
3 - 40 FRONT AXLE - 248FBIBR/BE
DIFFERENTIAL (Continued)
(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)
Condition Possible Causes Correction
Loss Of Lubricant 1. Lubricant level too high. 1. Drain lubricant to the correct
level.
2. Worn axle shaft seals. 2. Replace seals.
3. Cracked differential housing. 3. Repair as necessary.
4. Worn pinion seal. 4. Replace seal.
5. Worn/scored yoke. 5. Replace yoke and seal.
6. Axle cover not properly sealed. 6. Remove, clean, and re-seal
cover.
Axle Overheating 1. Lubricant level low. 1. Fill differential to correct level.
2. Improper grade of lubricant. 2. Fill differential with the correct
fluid type and quantity.
3. Bearing pre-loads too high. 3. Re-adjust bearing pre-loads.
4. Insufficient ring gear backlash. 4. Re-adjust ring gear backlash.
Gear Teeth Broke 1. Overloading. 1. Replace gears. Examine other
gears and bearings for possible
damage.
2. Erratic clutch operation. 2. Replace gears and examine the
remaining parts for damage. Avoid
erratic clutch operation.
3. Ice-spotted pavement. 3. Replace gears and examine
remaining parts for damage.
4. Improper adjustments. 4. Replace gears and examine
remaining parts for damage. Ensure
ring gear backlash is correct.
Axle Noise 1. Insufficient lubricant. 1. Fill differential with the correct
fluid type and quantity.
2. Improper ring gear and pinion
adjustment.2. Check ring gear and pinion
contact pattern. Adjust backlash or
pinion depth.
3. Unmatched ring gear and pinion. 3. Replace gears with a matched
ring gear and pinion.
4. Worn teeth on ring gear and/or
pinion.4. Replace ring gear and pinion.
5. Loose pinion bearings. 5. Adjust pinion bearing pre-load.
6. Loose differential bearings. 6. Adjust differential bearing
pre-load.
7. Mis-aligned or sprung ring gear. 7. Measure ring gear run-out.
Replace components as necessary.
8. Loose differential bearing cap
bolts.8. Inspect differential components
and replace as necessary. Ensure
that the bearing caps are torqued
tot he proper specification.
9. Housing not machined properly. 9. Replace housing.
3 - 50 REAR AXLE - 248RBIBR/BE
REAR AXLE - 248RBI (Continued)