2001 DODGE RAM differential

Note where Old and New Pinion Marking columns
intersect. Intersecting figure represents plus or
minus the amount needed.
Note the etched number on the face of the pinion
gear head (±1, ±2, 0, +1, +2, etc.). The numbers rep-
resent thousands of an inch deviation from the stan-
dard. If the number is negative, add that value to the
required thickness of the depth shims. If the numberis positive, subtract that value from the thickness of
the depth shim. If the number is 0 no change is nec-
essary.
PINION GEAR DEPTH VARIANCE
Original Pinion
Gear Depth
VarianceReplacement Pinion Gear Depth Variance
þ4 þ3 þ2 þ1 0 +1 +2 +3 +4
+4+0.008 +0.007 +0.006 +0.005 +0.004 +0.003 +0.002 +0.001 0
+3+0.007 +0.006 +0.005 +0.004 +0.003 +0.002 +0.001 0 þ0.001
+2+0.006 +0.005 +0.004 +0.003 +0.002 +0.001 0 þ0.001 þ0.002
+1+0.005 +0.004 +0.003 +0.002 +0.001 0 þ0.001 þ0.002 þ0.003
0+0.004 +0.003 +0.002 +0.001 0 þ0.001 þ0.002 þ0.003 þ0.004
þ1+0.003 +0.002 +0.001 0 þ0.001 þ0.002 þ0.003 þ0.004 þ0.005
þ2+0.002 +0.001 0 þ0.001 þ0.002 þ0.003 þ0.004 þ0.005 þ0.006
þ3+0.001 0 þ0.001 þ0.002 þ0.003 þ0.004 þ0.005 þ0.006 þ0.007
þ40 þ0.001 þ0.002 þ0.003 þ0.004 þ0.005 þ0.006 þ0.007 þ0.008
PINION DEPTH MEASUREMENT AND ADJUSTMENT
Measurements are taken with pinion bearing cups
and pinion bearings installed in the housing. Take
measurements with Pinion Gauge Set and Dial Indi-
cator C-3339 (Fig. 6).
(1) Assemble Pinion Height Block 6739, Pinion
Block 6736 and rear pinion bearing onto Screw 6741
(Fig. 6).(2) Insert assembled height gauge components,
rear bearing and screw into the housing through pin-
ion bearing cups (Fig. 7).
(3) Install front pinion bearing and Cone-nut 6740
hand tight (Fig. 6).
(4) Place Arbor Disc 6732 on Arbor D-115-3 in posi-
tion in the housing side bearing cradles (Fig. 8).
Fig. 5 Adjustment Shim Loactions
1 - PINION GEAR DEPTH SHIM/OIL BAFFLE
2 - DIFFERENTIAL BEARING SHIM
Fig. 4 Pinion Gear ID Numbers
1 - PRODUCTION NUMBERS
2 - PINION GEAR DEPTH VARIANCE
3 - GEAR MATCHING NUMBER
BR/BEFRONT AXLE - 248FBI 3 - 51
FRONT AXLE - 248FBI (Continued)

NOTE: Arbor Discs 6732 has different step diame-
ters to fit other axles. Choose proper step for axle
being serviced.(5) Install differential bearing caps on arbor discs
and snug the bearing cap bolts. Then cross tighten
cap bolts to 108 N´m (80 ft. lbs.).
(6) Assemble Dial Indicator C-3339 into Scooter
Block D-115-2 and secure set screw.
(7) Place Scooter Block/Dial Indicator in position
in the housing so dial probe and scooter block are
flush against the rearward surface of the pinion
height block (Fig. 6). Hold scooter block in place and
zero the dial indicator face to the pointer. Tighten
dial indicator face lock screw.
(8) With scooter block still in position against the
pinion height block, slowly slide the dial indicator
probe over the edge of the pinion height block.
(9) Slide the dial indicator probe across the gap
between the pinion height block and the arbor bar
with the scooter block against the pinion height block
(Fig. 9). When the dial probe contacts the arbor bar,
the dial pointer will turn clockwise. Bring dial
pointer back to zero against the arbor bar, do not
turn dial face. Continue moving the dial probe to the
crest of the arbor bar and record the highest reading.
If the dial indicator can not achieve the zero reading,
the rear bearing cup or the pinion depth gauge set is
not installed correctly.
(10) Select a shim/oil baffle equal to the dial indi-
cator reading plus the pinion depth variance number
etched in the face of the pinion (Fig. 4). For example,
if the depth variance is ±2, add +0.002 in. to the dial
indicator reading.
Fig. 6 Pinion Gear Depth Gauge Tools
1 - DIAL INDICATOR
2 - ARBOR
3 - PINION HEIGHT BLOCK
4 - CONE
5 - SCREW
6 - PINION BLOCK
7 - SCOOTER BLOCK
8 - ARBOR DISC
Fig. 7 Pinion Height Block
1 - PINION BLOCK
2 - PINION HEIGHT BLOCK
Fig. 8 Gauge Tools In Housing
1 - ARBOR DISC
2 - PINION BLOCK
3 - ARBOR
4 - PINION HEIGHT BLOCK
3 - 52 FRONT AXLE - 248FBIBR/BE
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. 10). 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. 11).
Fig. 9 Pinion Gear Depth Measurement
1 - ARBOR
2 - SCOOTER BLOCK
3 - DIAL INDICATOR
Fig. 10 Adjustment Shim Loactions
1 - PINION GEAR DEPTH SHIM/OIL BAFFLE
2 - DIFFERENTIAL BEARING SHIM
Fig. 11 Bearing Cap Bolts
1 - BEARING CAP
2 - DIFFERENTIAL HOUSING
3 - DIFFERENTIAL CASE
BR/BEFRONT AXLE - 248FBI 3 - 53
FRONT AXLE - 248FBI (Continued)

(7) Using a dead-blow hammer, seat the differen-
tial dummy bearings to each side of the housing (Fig.
12) and (Fig. 13).
(8) Thread Pilot Stud C-3288-B into rear cover bolt
hole below ring gear (Fig. 14).
(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. 14).
(10) Push and hold differential case to pinion gear
side of the housing and zero dial indicator (Fig. 15).(11) Push and hold differential case to ring gear
side of the housing and record the dial indicator
reading (Fig. 16).
(12) Add 0.38 mm (0.015 in.) to the zero end play
total. This total represents the thickness of shims
Fig. 12 Seat Pinion Gear Side Dummy Bearing
1 - DEAD-BLOW HAMMER
2 - DIFFERENTIAL HOUSING
3 - DIFFERENTIAL CASE
Fig. 13 Seat Ring Gear Side Differential Dummy
Bearing
1 - DIFFERENTIAL HOUSING
2 - DEAD-BLOW HAMMER
3 - DIFFERENTIAL CASE
Fig. 14 Differential Side Play Measurement
1 - DIFFERENTIAL CASE
2 - DIFFERENTIAL HOUSING
3 - PILOT STUD
4 - DIAL INDICATOR
Fig. 15 Dial Indicator Location
1 - DIFFERENTIAL CASE TO PINION GEAR SIDE
2 - PILOT STUD
3 - DIAL INDICATOR ARM
4 - DIAL INDICATOR FACE
3 - 54 FRONT AXLE - 248FBIBR/BE
FRONT AXLE - 248FBI (Continued)

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. 13).
(18) Position the dial indicator plunger on a flat
surface between the ring gear bolt heads (Fig. 14).
(19) Push and hold differential case toward pinion
gear and zero the dial indicator (Fig. 17).
(20) Push and hold differential case to ring gear
side of the housing and record dial indicator reading
(Fig. 18).
(21) This is the shim thickness needed on the ring
gear side of the differential case for proper backlash.
(22) 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.
(23) Rotate dial indicator out of the way on pilot
stud.
(24) Remove differential case and dummy bearings
from the housing.
(25) Install the selected side bearing shims onto
the differential case hubs.
(26) Install side bearings on differential case hubs
with Install C-4487-1 and Handle C-4171.
(27) Install bearing cups on differential.(28) Install Spreader W-129-B and some items
from Adapter Set 6987 on the housing and spread
open enough to receive differential case.
CAUTION: Do not spread housing over 0.50 mm
(0.020 in.). The housing can be damaged if over-
spread.
(29) Install differential case into the housing.
(30) Remove spreader from the housing.
Fig. 16 Differential Case To Ring Gear Side
1 - DIAL INDICATOR
2 - DIFFERENTIAL CASE TO RING GEAR SIDE
3 - DIFFERENTIAL HOUSING
Fig. 17 Differential Case To Pinion Gear Side
1 - DIAL INDICATOR FACE
2 - DIFFERENTIAL CASE TO PINION GEAR SIDE
3 - PINION GEAR
4 - DIFFERENTIAL HOUSING
5 - DIFFERENTIAL CASE
Fig. 18 Differential Case To Ring Gear Side
1 - DIAL INDICATOR
2 - DIFFERENTIAL CASE TO RING GEAR SIDE
3 - PINION GEAR
4 - DIFFERENTIAL HOUSING
5 - DIFFERENTIAL CASE
BR/BEFRONT AXLE - 248FBI 3 - 55
FRONT AXLE - 248FBI (Continued)

(31) Rotate the differential case several times to
seat the side bearings.
(32) Position the indicator plunger against a ring
gear tooth (Fig. 19).
(33) Push and hold ring gear upward while not
allowing the pinion gear to rotate.
(34) Zero dial indicator face to pointer.
(35) 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.
20).
(36) 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.
21)and adjust pinion depth and gear backlash as nec-
essary.
Fig. 19 Ring Gear Backlash Measurement
1 - DIAL INDICATOR
Fig. 20 Backlash Shim
3 - 56 FRONT AXLE - 248FBIBR/BE
FRONT AXLE - 248FBI (Continued)

SPECIFICATIONS
FRONT AXLE - 248FBI
AXLE SPECIFICATIONS
DESCRIPTION SPECIFICATION
Axle Ratio 3.55, 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 1.7-4 N´m (15-35 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
3 - 58 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)