torque DODGE RAM 2001 Service Service Manual

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)

ASSEMBLY
(1) Install differential side gears and thrust wash-
ers.
(2) Install differential pinion and thrust washers.
(3) Install the pinion shaft.
(4) Align the hole in the pinion shaft with the hole
in the differential case and install the pinion shaft
lock screw.
(5) Lubricate all differential components with
hypoid gear lubricant.
INSTALLATION
(1) Apply a coating of hypoid gear lubricant to the
differential bearings, bearing cups, and threaded
adjusters. A dab of grease can be used to keep the
adjusters in position. Carefully position the assem-
bled differential case in the housing.
(2) Observe the reference marks and install the
differential bearing caps at their original locations
(Fig. 29).
(3) Install bearing cap bolts and tighten the upper
bolts to 14 N´m (10 ft. lbs.). Tighten the lower bolts
finger-tight until the bolt head is seated.
(4) Perform the differential bearing preload and
adjustment procedure.
NOTE: Be sure that all bearing cap bolts are tight-
ened to their final torque of 136 N´m (100 ft.lbs.)
before proceeding.
(5) Install the axle shafts.
(6) Apply a bead of Mopar Silicone Rubber Sealant
or equivalent to the housing cover (Fig. 30).Install the housing cover within 5 minutes
after applying the sealant.
(7) Install the cover and any identification tag.
Tighten the cover bolts to 41 N´m (30 ft. lbs.) torque.
(8) Fill differential with lubricant to bottom of the
fill plug hole. Refer to the Lubricant Specifications
for the quantity and type.
(9) Install the fill hole plug and lower the vehicle.
(10) Trac-lokydifferential equipped vehicles
should be road tested by making 10 to 12 slow figure-
eight turns. This maneuver will pump the lubricant
through the clutch discs to eliminate a possible chat-
ter noise complaint.
DIFFERENTIAL - TRAC-LOK
DIAGNOSIS AND TESTING - TRAC-LOKY
The most common problem is a chatter noise when
turning corners. Before removing a Trac-lokyunit
for repair, drain, flush and refill the axle with the
specified lubricant. A container of Mopar Trac-loky
Lubricant (friction modifier) should be added after
repair service or during a lubricant change.
After changing the lubricant, drive the vehicle and
make 10 to 12 slow, figure-eight turns. This maneu-
ver will pump lubricant through the clutches. This
will correct the condition in most instances. If the
chatter persists, clutch damage could have occurred.
DIFFERENTIAL TEST
The differential can be tested without removing the
differential case by measuring rotating torque. Make
sure brakes are not dragging during this measure-
ment.
(1) Place blocks in front and rear of both front
wheels.
Fig. 29 Bearing Caps & Bolts
1 - REFERENCE MARKS
2 - REFERENCE MARKS
3 - ADJUSTER LOCK
4 - BEARING CAP
Fig. 30 Differential Cover
1 - SEALANT
2 - DIFFERENTIAL COVER
3 - 98 REAR AXLE-91/4BR/BE
DIFFERENTIAL (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)

(7) Position a small screw driver in slot of
Threaded Adapter Disc C-6960-3 (Fig. 35) to prevent
adapter from turning.
(8) Install Forcing Screw C-6960-4 and tighten
screw to 122 N´m (90 ft. lbs.) maximum to compress
Belleville springs in clutch packs (Fig. 36).
(9) With a feeler gauge remove thrust washers
from behind the differential pinion gears (Fig. 37).
(10) Insert Turning Bar C-6960-2 into the pinion
shaft hole in the case (Fig. 38).
(11) Loosen the Forcing Screw in small increments
until the clutch pack tension is relieved and the dif-
ferential case can be turned using Turning Bar.
(12) Rotate differential case until the pinion gears
can be removed.
(13) Remove pinion gears from differential case.
(14) Remove Forcing Screw, Step Plate and
Threaded Adapter.
(15) Remove top side gear, clutch pack retainer
and clutch pack. Keep plates in correct order during
removal (Fig. 39).
(16) Remove differential case from the Holding
Fixture. Remove side gear, clutch pack retainer and
clutch pack. Keep plates in correct order during
removal.
Fig. 34 Step Plate
1 - LOWER SIDE GEAR
2 - DIFFERENTIAL CASE
3 - STEP PLATEFig. 35 Threaded Adapter Disc
1 - SOCKET
2 - SLOT IN ADAPTER
3 - SCREWDRIVER
4 - DISC
5 - FORCING SCREW
6 - THREADED ADAPTER DISC
Fig. 36 Compress Belleville Spring
1 - TORQUE WRENCH
2 - TOOL ASSEMBLED
3 - DIFFERENTIAL CASE
3 - 100 REAR AXLE-91/4BR/BE
DIFFERENTIAL - TRAC-LOK (Continued)

(9) Install anewcollapsible preload spacer on pin-
ion shaft and install the pinion into the housing (Fig.
56).
(10) Install companion flange with Installer
C-3718 and Holder 6719.
(11) Install bolts into two of the threaded holes in
the companion flange 180É apart.
(12) Position Holder 6719 against the companion
flange and install a bolt and washer into one of the
remaining threaded holes. Tighten the bolts so the
Holder 6719 is held to the flange.
(13) Install the companion flange washer and a
new nut on the pinion and tighten the pinion nut
until there is zero bearing end-play.
(14) Tighten the nut to 285 N´m (210 ft. lbs.) (Fig.
57).CAUTION: Never loosen pinion nut to decrease pin-
ion bearing rotating torque and never exceed spec-
ified preload torque. If preload torque or rotating
torque is exceeded a new collapsible spacer must
be installed.
(15) Slowly tighten the nut in 6.8 N´m (5 ft. lbs.)
increments until the desired rotating torque is
achieved. Measure the rotating torque frequently to
avoid over crushing the collapsible spacer (Fig. 58).
(16) Check bearing rotating torque with an inch
pound torque wrench (Fig. 58). The torque necessary
to rotate the pinion should be:
²Original Bearings: 1 to 3 N´m (10 to 20 in. lbs.).
²New Bearings: 2 to 5 N´m (15 to 35 in. lbs.).
(17) Position exciter ring on differential case.
(18) Using a brass drift, slowly and evenly tap the
exciter ring into position.
Fig. 56 Collapsible Preload Spacer
1 - COLLAPSIBLE SPACER
2 - SHOULDER
3 - PINION GEAR
4 - DEPTH SHIM
5 - REAR BEARINGFig. 57 Pinion Nut
1 - DIFFERENTIAL HOUSING
2 - HOLDER
3 - TORQUE WRENCH
BR/BEREAR AXLE - 9 1/4 3 - 107
PINION GEAR/RING GEAR/TONE RING (Continued)

(19) Position ring gear on the differential case and
start two ring gear bolts. This will provide case-to-
ring gear bolt hole alignment.
(20) Invert the differential case in the vise.
(21) Installnewring gear bolts and alternately
tighten to 156 N´m (115 ft. lbs.) (Fig. 59).
CAUTION: Do not reuse the bolts that held the ring
gear to the differential case. The bolts can fracture
causing extensive damage.
(22) Install differential in axle housing and verify
gear mesh and contact pattern.(23) Install axle shafts.
(24) Install wheel and tire assemblies.
(25) Install differential cover and fill with gear
lubricant.
(26) Install propeller shaft wtih reference marks
aligned.
(27) Remove support and lower vehicle.
Fig. 58 Pinion
1 - COMPANION FLANGE
2 - TORQUE WRENCHFig. 59 Ring Gear Bolts
1 - TORQUE WRENCH
2 - RING GEAR BOLTS
3 - RING GEAR
4 - DIFFERENTIAL CASE
3 - 108 REAR AXLE-91/4BR/BE
PINION GEAR/RING GEAR/TONE RING (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

gears. As a result, the pinion gears revolve with the
pinion mate shaft but do not rotate around it (Fig. 1).
When turning corners, the outside wheel must
travel a greater distance than the inside wheel to
complete a turn. The difference must be compensated
for to prevent the tires from scuffing and skidding
through turns. To accomplish this, the differential
allows the axle shafts to turn at unequal speeds (Fig.
2). In this instance, the input torque applied to the
pinion gears is not divided equally. The pinion gears
now rotate around the pinion mate shaft in opposite
directions. This allows the side gear and axle shaft
attached to the outside wheel to rotate at a faster
speed.TRAC-LOKYDIFFERENTIAL
The Trac-lokyclutches are engaged by two concur-
rent forces. The first being the preload force exerted
through Belleville spring washers within the clutch
packs. The second is the separating forces generated
by the side gears as torque is applied through the
ring gear (Fig. 3).
The Trac-lokydesign provides the differential
action needed for turning corners and for driving
straight ahead during periods of unequal traction.
When one wheel looses traction, the clutch packs
transfer additional torque to the wheel having the
most traction. Trac-lokydifferentials resist wheel
spin on bumpy roads and provide more pulling power
when one wheel looses traction. Pulling power is pro-
vided continuously until both wheels loose traction. If
both wheels slip due to unequal traction, Trac-loky
operation is normal. In extreme cases of differences
Fig. 1 Differential Operation - Straight Ahead Driving
1 - IN STRAIGHT AHEAD DRIVING EACH WHEEL ROTATES AT
100% OF CASE SPEED
2 - PINION GEAR
3 - SIDE GEAR
4 - PINION GEARS ROTATE WITH CASE
Fig. 2 Differential Operation - On Turns
1 - PINION GEARS ROTATE ON PINION SHAFT
Fig. 3 Trac-lokYLimited Slip Differential
1 - CASE
2 - RING GEAR
3 - DRIVE PINION
4 - PINION GEAR
5 - MATE SHAFT
6 - CLUTCH PACK
7 - SIDE GEAR
8 - CLUTCH PACK
3 - 110 REAR AXLE - 248RBIBR/BE
REAR AXLE - 248RBI (Continued)

Condition Possible Causes Correction
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.
REMOVAL
(1) Raise and support the vehicle.
(2) Position a suitable lifting device under the
axle.
(3) Secure axle to device.
(4) Remove the wheels and tires.
(5) Secure brake drums to the axle shaft.
(6) Remove RWAL sensor from the differential
housing, if necessary. Refer to 5 Brakes for proce-
dures.
(7) Disconnect the brake hose at the axle junction
block. Do not disconnect the brake hydraulic lines at
the wheel cylinders. Refer to 5 Brakes for procedures.(8) Disconnect the parking brake cables and cable
brackets.
(9) Disconnect the vent hose from the axle shaft
tube.
(10) Mark propeller shaft and yoke for installation
alignment reference.
(11) Remove propeller shaft.
(12) Disconnect shock absorbers from axle.
(13) Remove spring clamps and spring brackets.
Refer to 2 Suspension for procedures.
(14) Separate axle from the vehicle.
BR/BEREAR AXLE - 248RBI 3 - 113
REAR AXLE - 248RBI (Continued)

(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. 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).
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
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
3 - 118 REAR AXLE - 248RBIBR/BE
REAR AXLE - 248RBI (Continued)