differential DODGE RAM 2002 Service User Guide

(7) Using a dead-blow hammer, seat the differen-
tial dummy bearings to each side of the housing (Fig.
11) and (Fig. 12).
(8) Thread Pilot Stud C-3288-B into rear cover bolt
hole below ring gear (Fig. 13).
(9) Attach the Dial Indicator C-3339 to pilot stud.
Position the dial indicator plunger on a flat surface
between the ring gear bolt heads (Fig. 13).
(10) Push and hold differential case to pinion gear
side of the housing and zero dial indicator (Fig. 14).
Fig. 11 SEAT PINION GEAR SIDE DUMMY BEARING
1 - DEAD-BLOW HAMMER
2 - DIFFERENTIAL HOUSING
3 - DIFFERENTIAL CASE
Fig. 12 SEAT RING GEAR SIDE DUMMY BEARING
1 - DIFFERENTIAL HOUSING
2 - DEAD-BLOW HAMMER
3 - DIFFERENTIAL CASE
Fig. 13 DIFFERENTIAL SIDE PLAY
1 - DIFFERENTIAL CASE
2 - DIFFERENTIAL HOUSING
3 - PILOT STUD
4 - DIAL INDICATOR
Fig. 14 DIAL INDICATOR LOCATION
1 - DIFFERENTIAL CASE TO PINION GEAR SIDE
2 - PILOT STUD
3 - DIAL INDICATOR ARM
4 - DIAL INDICATOR FACE
BR/BEFRONT AXLE - 248FBI 3 - 23
FRONT AXLE - 248FBI (Continued)

(11) Push and hold differential case to ring gear
side of the housing and record the dial indicator
reading (Fig. 15).
(12) Add 0.38 mm (0.015 in.) to the zero end play
total. This total represents the thickness of shims
needed to preload the new bearings when the differ-
ential is installed.
(13) Rotate dial indicator out of the way on the
pilot stud.
(14) Remove differential case and dummy bearings
from the housing.
(15) Install the pinion gear in the housing. Install
the pinion yoke and establish the correct pinion
rotating torque.
(16) Install differential case and dummy bearings
D-343 in the housing (without shims), install bearing
caps and tighten bolts snug.
(17) Seat ring gear side dummy bearing (Fig. 12).
(18) Position dial indicator plunger on a flat sur-
face between the ring gear bolt heads (Fig. 13).
(19) Push and hold differential case toward pinion
gear and zero the dial indicator (Fig. 16).
(20) Push and hold differential case to ring gear
side of the housing and record dial indicator reading
(Fig. 17). This is the shim thickness needed on the
ring gear side of the differential case for proper back-
lash.
(21) Subtract the backlash shim thickness from
the total preload shim thickness. The remainder is
the shim thickness required on the pinion side of the
housing.
(22) Rotate dial indicator out of the way on pilot
stud.
(23) Remove differential case and dummy bearings
from the housing.(24) Install selected side bearing shims onto the
differential case hubs.
(25) Install side bearings on differential case hubs
with Install C-4487-1 and Handle C-4171.
(26) Install bearing cups on differential.
(27) Install Spreader W-129-B and some items
from Adapter Set 6987 on the housing and spread
open enough to receive differential case.
Fig. 15 DIFFERENTIAL CASE RING GEAR SIDE
1 - DIAL INDICATOR
2 - DIFFERENTIAL CASE TO RING GEAR SIDE
3 - DIFFERENTIAL HOUSING
Fig. 16 DIFFERENTIAL CASE PINION GEAR SIDE
1 - DIAL INDICATOR FACE
2 - DIFFERENTIAL CASE TO PINION GEAR SIDE
3 - PINION GEAR
4 - DIFFERENTIAL HOUSING
5 - DIFFERENTIAL CASE
Fig. 17 DIFFERENTIAL CASE RING GEAR SIDE
1 - DIAL INDICATOR
2 - DIFFERENTIAL CASE TO RING GEAR SIDE
3 - PINION GEAR
4 - DIFFERENTIAL HOUSING
5 - DIFFERENTIAL CASE
3 - 24 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)

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)

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)

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

REMOVAL
(1) Disconnect the vacuum and wiring connector
from the shift housing.
(2) Remove indicator switch.
(3) Remove shift motor housing cover, gasket and
shield from the housing (Fig. 27).
DISASSEMBLY
(1) Remove E-clips from the shift motor housing
and shaft. Remove shift motor and shift fork from
the housing (Fig. 28).
(2) Remove O-ring seal from the shift motor shaft.
(3) Clean and inspect all components. Replaced
any component that is excessively worn or damaged.
ASSEMBLY
(1) Install a new O-ring seal on the shift motor
shaft.
(2) Insert shift motor shaft through the hole in the
housing and shift fork. The shift fork offset should be
toward the differential.
(3) Install E-clips on the shift motor shaft and
housing.
INSTALLATION
(1) Install shift motor housing gasket.
(2) Guide the shift fork onto the shift collar groove,
while install the shift motor housing cover.
(3) Install shift motor housing shield and tighten
the bolts to 11 N´m (96 in. lbs.).(4) Add 148 ml (5 ounces) of API grade GL 5
hypoid gear lubricant to the shift motor housing. Add
lubricant through indicator switch mounting hole.
(5) Install indicator switch, electrical connector
and vacuum harness.
SINGLE CARDAN UNIVERSAL
JOINTS
REMOVAL
Single cardan U-joint components are not service-
able. If defective they must be replaced as a unit.
CAUTION: Clamp only the narrow forged portion of
the yoke in the vise. To avoid distorting the yoke,
do not over tighten the vise jaws.
(1) Remove axle shaft.
(2) Remove the bearing cap retaining snap rings
(Fig. 29).
NOTE: Saturate the bearing caps with penetrating
oil prior to removal.
(3) Locate a socket with an inside diameter is
larger than the bearing cap. Place the socket (receiv-
er) against the yoke and around the perimeter of the
bearing cap to be removed.
(4) Locate a socket with an outside diameter is
smaller than the bearing cap. Place the socket (driv-
er) against the opposite bearing cap.
Fig. 27 SHIFT MOTOR HOUSING
1 - INDICATOR LAMP SWITCH
2 - DISCONNECT HOUSING
3 - VACUUM SHIFT MOTOR
4 - AXLE SHAFT
5 - SEAL
6 - SHIFT COLLAR
7 - SHIFT FORK
8 - BEARING
9 - INTERMEDIATE AXLE SHAFT
Fig. 28 SHIFT MOTOR COMPONENTS
1 - INDICATOR SWITCH
2 - E-CLIP
3 - O-RING
4 - SHIFT MOTOR
5 - SHIFT FORK
6 - VACUUM PORTS
7 - DISCONNECT HOUSING AND GASKET
3 - 34 FRONT AXLE - 248FBIBR/BE
AXLE VACUUM MOTOR (Continued)

DIFFERENTIAL
REMOVAL
(1) Raise and support vehicle.
(2) Remove lubricant fill hole plug from the differ-
ential housing cover.
(3) Remove differential housing cover and drain
the lubricant from the housing.
(4) Clean the housing cavity with a flushing oil,
light engine oil or lint free cloth.Do not use water,
steam, kerosene or gasoline for cleaning.
(5) Remove hub bearings and axle shafts.
(6) Note the installation reference letters stamped
on the bearing caps and housing machined sealing
surface (Fig. 36).
(7) Remove the differential bearing caps.
(8) Position Spreader W-129-B with the tool dowel
pins seated in the locating holes (Fig. 37).
(9) Install the hold down clamps and tighten the
spreader turnbuckle finger-tight.
(10) Install Pilot Stud C-3288-B to 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 (Fig. 37) and zero the
dial indicator.
(11) Spread the housing enough to remove the case
from the housing. Measure the distance with the dial
indicator (Fig. 37).
CAUTION: Never spread the housing over 0.50 mm
(0.020 in). If the housing is over-spread it could be
distorted or damaged.
(12) Remove the dial indicator.
Fig. 35 PINION SHAFT NUT
1 - PINION FLANGE
2 - YOKE HOLDER
3 - DIFFERENTIAL HOUSING
Fig. 36 Bearing Cap Reference
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
Fig. 37 SPREAD DIFFERENTIAL HOUSING
1 - SPREADER
2 - DIAL INDICATOR
3 - DIFFERENTIAL
4 - DIFFERENTIAL HOUSING
5 - PILOT STUD
BR/BEFRONT AXLE - 248FBI 3 - 37
PINION SEAL (Continued)

(13) Pry the differential case loose from the hous-
ing. To prevent damage, pivot on housing with the
end of the pry bar against spreader (Fig. 38).
(14) Remove the case from housing.
(15) Remove and tag bearing cups to indicate their
location.
DISASSEMBLY
(1) Remove roll-pin holding mate shaft in housing.
(2) Remove pinion gear mate shaft (Fig. 39).
(3) Rotate differential side gears and remove pin-
ion mate gears and thrust washers (Fig. 40).
(4) Remove differential side gears and thrust
washers.
ASSEMBLY
(1) Install differential side gears and thrust wash-
ers.
(2) Install pinion mate gears and thrust washers.
(3) Install pinion gear mate shaft.
(4) Align hole in the pinion gear mate shaft with
hole in the differential case.
(5) Install and seat pinion mate shaft roll-pin in
the differential case and mate shaft with a punch
and hammer (Fig. 41). Peen the edge of the roll-pin
hole in the differential case slightly in two places
180É apart.
(6) Lubricate all differential components with
hypoid gear lubricant.
Fig. 38 DIFFERENTIAL REMOVAL
1 - DIFFERENTIAL
2-PRYBAR
Fig. 39 PINION MATE SHAFT
1 - PINION MATE GEAR
2 - PINION MATE SHAFT
3 - SIDE GEAR
4 - DRIFT
Fig. 40 Pinion Mate/Side Gear
1 - THRUST WASHER
2 - SIDE GEAR
3 - PINION MATE GEAR
3 - 38 FRONT AXLE - 248FBIBR/BE
DIFFERENTIAL (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)