2001 DODGE RAM engine

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. 37).
(7) Remove the differential bearing caps.
(8) Position Spreader W-129-B with the tool dowel
pins seated in the locating holes (Fig. 38).
(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. 38) 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. 38).
CAUTION: Do not spread over 0.50 mm (0.020 in). If
the housing is over-spread it could be distorted or
damaged.
(12) Remove the dial indicator.(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. 39).
(14) Remove the case from housing.
(15) Remove and tag bearing cups to indicate their
original location.
DISASSEMBLY
(1) Remove roll-pin holding mate shaft in housing.
(2) Remove pinion gear mate shaft (Fig. 40).
Fig. 36 Tightening Pinion Shaft Nut
1 - PINION FLANGE
2 - HOLDING TOOL 6719
3 - AXLE HOUSING
Fig. 37 Bearing Cap Reference
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
Fig. 38 Spread Differential Housing
1 - HOUSING SPREADER W-129B
2 - DIAL INDICATOR C-3339
3 - DIFFERENTIAL
4 - AXLE HOUSING
5 - GUIDE PIN C-3288±B
3 - 68 FRONT AXLE - 248FBIBR/BE
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

When road testing, first warm-up the axle fluid by
driving the vehicle at least 5 miles and then acceler-
ate the vehicle to the speed range where the noise is
the greatest. Shift out-of-gear and coast through the
peak-noise range. If the noise stops or changes
greatly:
²Check for insufficient lubricant.
²Incorrect ring gear backlash.
²Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehi-
cle turns. A worn pinion shaft can also cause a snap-
ping 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 a:
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 rearend vibra-
tion. Do not overlook engine accessories, brackets
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/BEREAR AXLE - 9 1/4 3 - 81
REAR AXLE - 9 1/4 (Continued)

CAUTION: Never loosen pinion nut to decrease pin-
ion bearing rotating torque and never exceed spec-
ified preload torque. If rotating torque is exceeded,
a new collapsible spacer must be installed.(10) If the rotating torque is low, use Holder 6719
to hold the companion flange (Fig. 23) and tighten
the pinion nut in 6.8 N´m (5 ft. lbs.) increments until
proper rotating torque is achieved.
NOTE: The bearing rotating torque should be con-
stant during a complete revolution of the pinion. If
the rotating torque varies, this indicates a binding
condition.
(11) The seal replacement is unacceptable if the
final pinion nut torque is less than 285 N´m (210 ft.
lbs.).
(12) Install the propeller shaft with the installa-
tion reference marks aligned.
(13) Tighten the companion flange bolts to 108
N´m (80 ft. lbs.).
(14) Install the brake drums.
(15) Install wheel and tire assemblies and lower
the vehicle.
(16) Check the differential housing lubricant level.
DIFFERENTIAL
REMOVAL
(1) Raise and support the 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 the axle shafts.
(6) Remove RWAL/ABS sensor from housing.
NOTE: Side play resulting from bearing races being
loose on case hubs requires replacement of the dif-
ferential case.
(7) Mark the differential housing and differential
bearing caps for installation reference (Fig. 25).
(8) Remove bearing threaded adjuster lock from
each bearing cap. Loosen the bolts, but do not
remove the bearing caps.
(9) Loosen the threaded adjusters with Wrench
C-4164 (Fig. 26).
(10) Hold the differential case while removing
bearing caps and adjusters.
(11) Remove the differential case.
NOTE: Each differential bearing cup and threaded
adjuster must be kept with their respective bearing.
Fig. 23 Pinion Nut
1 - DIFFERENTIAL HOUSING
2 - COMPANION FLANGE HOLDER
3 - TORQUE WRENCH
Fig. 24 Pinion Rotation Torque
1 - COMPANION FLANGE
2 - INCH POUND TORQUE WRENCH
3 - 96 REAR AXLE-91/4BR/BE
PINION SEAL (Continued)

(2) Raise one rear wheel until it is completely off
the ground.
(3) Engine off, transmission in neutral, and park-
ing brake off.
(4) Remove wheel and bolt Special Tool 6790 or
equivalent tool to studs.
(5) Use torque wrench on special tool to rotate
wheel and read rotating torque (Fig. 31).
(6) If rotating torque is less than 22 N´m (30 ft.
lbs.) or more than 271 N´m (200 ft. lbs.) on either
wheel the unit should be serviced.
DISASSEMBLY
(1) Clamp side gear Holding Fixture 6965 in a vise
and position the differential case on the Holding Fix-
ture (Fig. 32).
(2) Remove ring gear if the ring gear is to be
replaced. The Trac-lokydifferential can be serviced
with the ring gear installed.
(3) Remove pinion shaft roll pin.
(4) Remove pinion shaft with a drift and hammer
(Fig. 33).
(5) Install and lubricate Step Plate C-6960-3 (Fig.
34).
(6) Assemble Threaded Adapter C-6960-1 into top
side gear. Thread Forcing Screw C-6960-4 into
adapter until it becomes centered in adapter plate.
Fig. 31 Trac-lokYTest -Typical
1 - SPECIAL TOOL 6790 WITH BOLT IN CENTER HOLE
2 - TORQUE WRENCH
Fig. 32 Differential Case Holding Fixture
1 - HOLDING FIXTURE
2 - VISE
3 - DIFFERENTIAL
Fig. 33 Pinion Shaft
1 - PINION MATE SHAFT
2 - SIDE GEAR
3 - DRIFT
4 - PINION MATE GEAR
BR/BEREAR AXLE - 9 1/4 3 - 99
DIFFERENTIAL - TRAC-LOK (Continued)

REAR AXLE - 248RBI
TABLE OF CONTENTS
page page
REAR AXLE - 248RBI
DESCRIPTION..........................109
OPERATION............................109
DIAGNOSIS AND TESTING.................111
AXLE...............................111
REMOVAL.............................113
INSTALLATION..........................114
ADJUSTMENTS.........................114
SPECIFICATIONS........................122
SPECIAL TOOLS........................122
AXLE SHAFTS
REMOVAL.............................125
INSTALLATION..........................125
AXLE BEARINGS
REMOVAL.............................125
INSTALLATION..........................125
PINION SEAL
REMOVAL.............................125INSTALLATION..........................125
DIFFERENTIAL
REMOVAL.............................127
DISASSEMBLY..........................128
ASSEMBLY............................128
INSTALLATION..........................129
DIFFERENTIAL - TRAC-LOK
DIAGNOSIS AND TESTING................130
TRAC-LOK...........................130
DISASSEMBLY..........................130
ASSEMBLY............................132
DIFFERENTIAL CASE BEARINGS
REMOVAL.............................134
INSTALLATION..........................134
PINION GEAR/RING GEAR/TONE RING
REMOVAL.............................135
INSTALLATION..........................137
REAR AXLE - 248RBI
DESCRIPTION
The Rear Beam-design Iron (RBI) axle housings
consist of an iron center casting (differential housing)
with axle shaft tubes extending from either side. The
tubes are pressed in to form a one-piece axle housing.
The integral type housing, hypoid gear design has
the centerline of the pinion set below the centerline
of the ring gear.
The axles are equipped with full-floating axle
shafts, meaning that loads are supported by the axle
housing tubes. The full-float axle shafts are retained
by bolts attached to the hub. The hub rides on two
bearings at the outboard end of the axle tube. The
axle shafts can be removed without disturbing or
removing the wheel bearings. The wheel bearings are
opposed tapered roller bearings and are contained in
the hub assembly.
The removable, stamped steel cover provides a
means for inspection and service without removing
the complete axle from the vehicle. A small, stamped
metal axle gear ratio identification tag is attached to
the housing cover via one of the cover bolts. This tag
also identifies the number of ring and pinion teeth.
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 mustbe 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 for the standard differentials
and the Trac-lokydifferential are a one-piece design.
The differential pinion mate shaft is retained with a
roll pin. Differential bearing preload and ring gear
backlash are adjusted by the use of shims located
between the differential bearing cones and case. Pin-
ion bearing preload is set and maintained by the use
of a solid shims.
OPERATION
STANDARD DIFFERENTIAL
The axle receives power from the transmission/
transfer case through the rear propeller shaft. The
rear propeller shaft is connected to the pinion gear
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 pinion mate and side gears. The side
gears are splined to the axle shafts.
During straight-ahead driving, the differential pin-
ion gears do not rotate on the pinion mate shaft. This
occurs because input torque applied to the gears is
divided and distributed equally between the two side
BR/BEREAR AXLE - 248RBI 3 - 109

of traction, the wheel with the least traction may
spin.
DIAGNOSIS AND TESTING - AXLE
GEAR NOISE
Axle gear noise can be caused by insufficient lubri-
cant, incorrect backlash, incorrect pinion depth, tooth
contact, worn/damaged gears, or the carrier housing
not having the proper offset and squareness.
Gear noise usually happens at a specific speed
range. The noise can also occur during a specific type
of driving condition. These conditions are accelera-
tion, deceleration, coast, or constant load.
When road testing, first warm-up the axle fluid by
driving the vehicle at least 5 miles and then acceler-
ate the vehicle to the speed range where the noise is
the greatest. Shift out-of-gear and coast through the
peak-noise range. If the noise stops or changes
greatly:
²Check for insufficient lubricant.
²Incorrect ring gear backlash.
²Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehi-
cle turns. A worn pinion shaft can also cause a snap-
ping 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 a:
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 rearend vibra-
tion. Do not overlook engine accessories, brackets
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/BEREAR AXLE - 248RBI 3 - 111
REAR AXLE - 248RBI (Continued)

(11) Install the brake drums.
(12) Add gear lubricant to the differential housing,
if necessary. Refer to the Lubricant Specifications for
gear lubricant requirements.
(13) Install wheel and tire assemblies and lower
the vehicle.
DIFFERENTIAL
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the lubricant fill hole plug from the
differential 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 axle shafts.
(6) Note the orientation of the installation refer-
ence letters stamped on the bearing caps and hous-
ing machined sealing surface (Fig. 26).
(7) Remove the differential bearing caps.
(8) Position Spreader W-129-B with the tool dowel
pins seated in the locating holes (Fig. 27).
(9) Install the hold down clamps and tighten the
tool turnbuckle finger-tight.
(10) Install a Pilot Stud C-3288-B at the left side
of the differential housing. Attach dial indicator tohousing pilot stud. Load the indicator plunger
against the opposite side of the housing (Fig. 27) and
zero the indicator.
(11) Spread the housing enough to remove the case
from the housing. Measure the distance with the dial
indicator (Fig. 27).
CAUTION: Do not spread over 0.50 mm (0.020 in). If
the housing is over-spread, it could be distorted or
damaged.
Fig. 25 Check Pinion Rotation Torque
1 - PINION YOKE
2 - INCH POUND TORQUE WRENCH
Fig. 26 Bearing Cap Identification
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
Fig. 27 Spread Differential Housing
1 - SPREADER
2 - DIAL INDICATOR
3 - DIFFERENTIAL
4 - DIFFERENTIAL HOUSING
5 - PILOT STUD
BR/BEREAR AXLE - 248RBI 3 - 127
PINION SEAL (Continued)