lock DODGE RAM 2001 Service Owner's Manual

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
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. 8).(1) Assemble Pinion Height Block 6739, Pinion
Block 8542 and rear pinion bearing onto Screw 6741
(Fig. 8).
(2) Insert assembled height gauge components,
rear bearing, and screw into the housing through
pinion bearing cups (Fig. 9).
(3) Install front pinion bearing and Cone-Nut 6740
hand tight (Fig. 8).
(4) Place Arbor Disc 8541 on Arbor D-115-3 in posi-
tion in the housing side bearing cradles (Fig. 10).
Install differential bearing caps on arbor discs and
tighten cap bolts to 41 N´m (30 ft. lbs.).
NOTE: Arbor Discs 8541 has different step diame-
ters to fit other axles. Choose proper step for axle
being serviced.
Fig. 8 Pinion 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. 9 Pinion Height Block
1 - PINION BLOCK
2 - PINION HEIGHT BLOCK
BR/BEREAR AXLE - 9 1/4 3 - 85
REAR AXLE - 9 1/4 (Continued)

(5) Assemble Dial Indicator C-3339 into Scooter
Block D-115-2 and secure set screw.
(6) Place Scooter Block/Dial Indicator in position
in axle housing so dial probe and scooter block are
flush against the rearward surface of the pinion
height block (Fig. 8). Hold scooter block in place and
zero the dial indicator. Tighten dial indicator face
lock screw.
(7) Slowly slide the dial indicator probe over the
edge of the pinion height block.
(8) 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. 11). When the dial probe contacts the arbor bar,
the dial pointer will turn clockwise. 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.
(9) Select a shim equal to the dial indicator read-
ing plus the drive pinion gear depth variance number
marked on the shaft of the pinion. For example, if
the depth variance is ±2, add +0.002 in. to the dial
indicator reading.
DIFFERENTIAL BEARING PRELOAD AND GEAR
BACKLASH
The following must be considered when adjusting
bearing preload and gear backlash:
²The maximum ring gear backlash variation is
0.003 inch (0.076 mm).
²Mark the gears so the same teeth are meshed
during all backlash measurements.²Maintain the torque while adjusting the bearing
preload and ring gear backlash.
²Excessive adjuster torque will introduce a high
bearing load and cause premature bearing failure.
Insufficient adjuster torque can result in excessive
differential case free-play and ring gear noise.
²Insufficient adjuster torque will not support the
ring gear correctly and can cause excessive differen-
tial case free-play and ring gear noise.
NOTE: The differential bearing cups will not always
immediately follow the threaded adjusters as they
are moved during adjustment. To ensure accurate
bearing cup responses to the adjustments:
²Maintain the gear teeth engaged (meshed) as
marked.
²The bearings must be seated by rapidly rotating
the drive pinion gear a half turn back and forth.
²Do this five to ten times each time the threaded
adjusters are adjusted.
(1) Use Wrench C-4164 to adjust each threaded
adjuster inward until the differential bearing free-
play is eliminated (Fig. 12). Allow some ring gear
backlash (approximately 0.25 mm / 0.01 inch)
between the ring and pinion gear. Seat the bearing
cups with the procedure described above.
(2) Install dial indicator and position the plunger
against the drive side of a ring gear tooth (Fig. 13).
Measure the backlash at 4 positions (90 degrees
apart) around the ring gear. Locate and mark the
area of minimum backlash.
(3) Rotate the ring gear to the position of the least
backlash. Mark the gear so that all future backlash
Fig. 10 Pinion Depth Tools
1 - ARBOR DISC
2 - PINION BLOCK
3 - ARBOR
4 - PINION HEIGHT BLOCKFig. 11 Pinion Gear Depth Measurement
1 - ARBOR
2 - SCOOTER BLOCK
3 - DIAL INDICATOR
3 - 86 REAR AXLE-91/4BR/BE
REAR AXLE - 9 1/4 (Continued)

measurements will be taken with the same gear
teeth meshed.
(4) Loosen the right-side, tighten the left-side
threaded adjuster. Obtain backlash of 0.003 to 0.004
inch (0.076 to 0.102 mm) with each adjuster tight-
ened to 14 N´m (10 ft. lbs.). Seat the bearing cups
with the procedure described above.
(5) Tighten the differential bearing cap bolts 136
N´m (100 ft. lbs.).
(6) Tighten the right-side threaded adjuster to 102
N´m (75 ft. lbs.). Seat the bearing cups with the pro-
cedure described above. Continue to tighten theright-side adjuster and seat bearing cups until the
torque remains constant at 102 N´m (75 ft. lbs.)
(7) Measure the ring gear backlash. The range of
backlash is 0.13 to 0.203 mm (0.005 to 0.008 inch).
(8) Continue increasing the torque at the right-
side threaded adjuster until the specified backlash is
obtained.
NOTE: The left-side threaded adjuster torque
should have approximately 102 N´m (75 ft. lbs.). If
the torque is considerably less, the complete
adjustment procedure must be repeated.
(9) Tighten the left-side threaded adjuster until
102 N´m (75 ft. lbs.) torque is indicated. Seat the
bearing rollers with the procedure described above.
Do this until the torque remains constant.
(10) Install the threaded adjuster locks and
tighten the lock screws to 10 N´m (90 in. lbs.).
After the proper backlash is achieved, perform the
Gear Contact procedure.GEAR CONTACT PATTERN
The ring gear and pinion teeth contact patterns
will show if the pinion depth is correct in the hous-
ing. 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 a 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.
14)and adjust pinion depth and gear backlash as nec-
essary.
SIDE GEAR CLEARANCE
When measuring side gear clearance, check each
gear independently. If it necessary to replace a side
gear, replace both gears as a matched set.
(1) Install the axle shafts and C-locks and pinion
shaft.
(2) Measure each side gear clearance. Insert a
matched pair of feeler gauge blades between the gear
Fig. 12 Threaded Adjuster Tool
1 - AXLE TUBE
2 - BACKING PLATE
3 - THREAD ADJUSTER WRENCH
Fig. 13 Ring Gear Backlash
1 - DIAL INDICATOR
2 - RING GEAR
3 - EXCITER RING
BR/BEREAR AXLE - 9 1/4 3 - 87
REAR AXLE - 9 1/4 (Continued)

and differential housing on opposite sides of the hub
(Fig. 15) .
(3) If side gear clearances is no more than 0.005
inch. Determine if the axle shaft is contacting the
pinion shaft.Do not remove the feeler gauges,
inspect the axle shaft with the feeler gauge
inserted behind the side gear.If the end of the
axle shaft is not contacting the pinion shaft, the side
gear clearance is acceptable.
(4) If clearance is more than 0.005 inch (axle shaft
not contacting pinion shaft), record the side gear
clearance. Remove the thrust washer and measureits thickness with a micrometer. Add the washer
thickness to the recorded side gear clearance. The
sum of gear clearance and washer thickness will
determine required thickness of replacement thrust
washer (Fig. 16). In some cases, the end of the axle
shaft will move and contact the pinion shaft when
the feeler gauge is inserted. The C-lock is preventing
the side gear from sliding on the axle shaft.
(5) If there is no side gear clearance, remove the
C-lock from the axle shaft. Use a micrometer to mea-
sure the thrust washer thickness. Record the thick-
ness and re-install the thrust washer. Assemble the
differential case without the C-lock installed and re-
measure the side gear clearance.
(6) Compare both clearance measurements. If the
difference is less than 0.012 inch (0.305 mm), add
clearance recorded when the C-lock was installed to
thrust washer thickness measured. The sum will
determine the required thickness of the replacement
thrust washer.
(7) If clearance is 0.012 inch (0.305 mm) or
greater, both side gears must be replaced (matched
set) and the clearance measurements repeated.
(8) If clearance (above) continues to be 0.012 inch
(0.305 mm) or greater, the case must be replaced.
Fig. 15 Side Gear Clearance
1 - FEELER GAUGE
2 - SIDE GEAR
Fig. 16 Side Gear Calculations
BR/BEREAR AXLE - 9 1/4 3 - 89
REAR AXLE - 9 1/4 (Continued)

SPECIFICATIONS
REAR AXLE-91/4
AXLE SPECIFICATIONS
DESCRIPTION SPECIFICATION
Axle Ratio 3.21, 3.55, 3.92
Differential Case Flange Runout 0.076 mm (0.003 in.)
Differential Case Clearance 0.12 mm (0.005 in.)
Ring Gear Diameter 235 mm (9.25 in.)
Ring Gear Backlash 0.13-0.20 mm (0.005-0.008 in.)
Ring Gear Runout 0.12 mm (0.005 in.)
Pinion Bearing Preload - Original Bearings 1-2 N´m (10-20 in. lbs.)
Pinion Bearing Preload - New Bearings 1.7-4 N´m (15-35 in. lbs.)
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Differential Cover Bolts 41 30 -
Bearing Cap Bolts 136 100 -
Ring Gear Bolts 157 115 -
Pinion Nut Minimum 285 210 -
Adjuster Lock Screw 11 8 96
Backing Plate Nuts 54 40 -
SPECIAL TOOLS
REAR AXLE-91/4
Puller 6790
Holder Yoke 6719A
Remover, Bearing 6310
Installer C-4198
3 - 90 REAR AXLE-91/4BR/BE
REAR AXLE - 9 1/4 (Continued)

AXLE SHAFTS
REMOVAL
(1) Place the transmission in NEUTRAL and raise
and support vehicle.
(2) Remove wheel and tire assembly.
(3) Remove brake drum (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/DRUM - REMOVAL) ..
(4) Clean all foreign material from housing cover
area.
(5) Remove the housing cover and drain lubricant.
(6) Rotate differential case to access the pinion
shaft lock screw. Remove lock screw and pinion shaft
from differential case (Fig. 17).
(7) Push axle shaft inward then remove axle shaft
C-lock (Fig. 18).
(8) Remove axle shaft being carefull not to damage
shaft bearing and seal.
(9) Inspect axle shaft seal for leakage or damage.
(10) Inspect axle shaft bearing contact surface for
signs of brinelling, galling and pitting.
INSTALLATION
(1) Lubricate bearing bore and seal lip with gear
lubricant. Insert axle shaft through seal, bearing and
engage it into side gear splines.
NOTE: Use care to prevent shaft splines from dam-
aging axle shaft seal lip.
(2) Insert C-lock in end of axle shaft. Push axle
shaft outward to seat C-lock in side gear.
(3) Insert pinion shaft into differential case and
through thrust washers and differential pinions.
(4) Align hole in shaft with hole in the differential
case and install lock screw with Loctiteton the
threads. Tighten lock screw to 11 N´m (8 ft. lbs.).
Trac-lok Tools 8139
Height Block 8542
Arbor Discs 8541
Fig. 17 Pinion Shaft Lock Screw
1 - LOCK SCREW
2 - PINION MATE SHAFT
Fig. 18 Axle Shaft C-Lock
1 - C-LOCK
2 - AXLE SHAFT
3 - SIDE GEAR
BR/BEREAR AXLE - 9 1/4 3 - 93
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)

DISASSEMBLY
(1) Remove pinion shaft lock screw (Fig. 27).
(2) Remove pinion shaft.
(3) Rotate differential side gears and remove the
differential pinions and thrust washers (Fig. 28).(4) Remove the differential side gears and thrust
washers.
Fig. 25 Reference Mark
1 - REFERENCE MARKS
2 - REFERENCE MARK
3 - BEARING CAPS
Fig. 26 Threaded Adjuster
1 - AXLE TUBE
2 - BACKING PLATE
3 - TOOL C-4164
Fig. 27 Pinion Shaft Lock Screw
1 - LOCK SCREW
2 - PINION SHAFT
Fig. 28 Differential
1 - THRUST WASHER
2 - SIDE GEAR
3 - DIFFERENTIAL PINIONS
BR/BEREAR AXLE - 9 1/4 3 - 97
DIFFERENTIAL (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)

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