2001 DODGE RAM bolt pattern

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)

(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)

(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: Do not spread over 0.50 mm (0.020 in). If
the housing is over-spread, it could be distorted 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. 43).
(6) Remove the spreader.
(7) Install bearing caps in their original locations
(Fig. 44) and tighten bearing cap bolts to 109 N´m
(80 ft. lbs.).
(8) Install axle shafts.
(9) Install the hub bearings.
(10) Apply a bead of Mopar Silicone Rubber Seal-
ant or equivalent to the housing cover (Fig. 45).
Install the housing cover within 5 minutes
after applying the sealant.(11) Install the cover and any identification tag.
Tighten the cover bolts in a criss-cross pattern to 47
N´m (35 ft. lbs.).
(12) Refill the differential with Mopar Hypoid
Gear Lubricant or equivalent to bottom of the fill
plug hole. Refer to the Lubricant Specifications for
correct quantity and type.
(13) Install the fill hole plug and tighten to 34 N´m
(25 ft. lbs.).
(14) Remove support and lower vehicle.
Fig. 42 Pinion Mate Shaft Roll-Pin
1 - PUNCH
2 - PINION MATE SHAFT
3 - MATE SHAFT LOCKPIN
Fig. 43 Differential Case
1 - RAWHIDE HAMMER
Fig. 44 Bearing Cap Reference
1 - REFERENCE LETTERS
2 - REFERENCE LETTERS
3 - 70 FRONT AXLE - 248FBIBR/BE
DIFFERENTIAL (Continued)

(11) Install yoke washer and anewnut on the
pinion gear. Tighten the nut to 291 N´m (215 ft. lbs.)
minimum.Do not over±tighten.Maximum torque
is 380 N´m (280 ft. lbs.).
CAUTION: Never loosen pinion gear nut to decrease
pinion gear bearing preload torque and never
exceed specified preload torque. If preload torque
is exceeded a new collapsible spacer must be
installed.
(12) Use Yoke Holder 6719A to hold the yoke (Fig.
61) and tighten the nut in 6.8 N´m (5 ft. lbs.) until
the rotating torque is achieved. Measure the preload
torque frequently to avoid over-tightening the nut.
(13) Check bearing preload torque with an inch
pound torque wrench (Fig. 62). The torque necessary
to rotate the pinion gear should be:
²Original Bearings: 1 to 2 N´m (10 to 20 in. lbs.).
²New Bearings: 1.7 to 4 N´m (15 to 35 in. lbs.).
(14) Invert differential case in a vise and start two
ring gear bolts. This will provide case-to-ring gear
bolt hole alignment.
(15) Installnewring gear bolts and alternately
tighten to 176 N´m (130 ft. lbs.). (Fig. 63).
CAUTION: Do not reuse the bolts that held the ring
gear to the differential case. The bolts can fracture
causing extensive damage.
(16) Install differential in axle housing and verify
gear mesh and contact pattern. Refer to Adjustments
(Gear Contact Pattern).
(17) Install differential cover and fill with lubri-
cant.(18) Install propeller shaft with reference marks
aligned.
(19) Remove support and lower vehicle.
Fig. 61 Tightening Pinion Nut
1 - PINION FLANGE
2 - YOKE HOLDING
3 - DIFFERENTIAL HOUSING
Fig. 62 Pinion Rotating Torque
1 - PINION YOKE
2 - TORQUE WRENCH
Fig. 63 Ring Gear Bolt
1 - TORQUE WRENCH
2 - RING GEAR BOLT
3 - RING GEAR
4 - CASE
3 - 76 FRONT AXLE - 248FBIBR/BE
PINION GEAR/RING GEAR (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 the 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 the propeller shaft and companion
flange for installation alignment reference.
(11) Remove propeller shaft.
(12) Disconnect shock absorbers from axle.
(13) Remove the spring clamps and spring brack-
ets. Refer to 2 Suspension for procedures.
(14) Separate the axle from the vehicle.
BR/BEREAR AXLE - 9 1/4 3 - 83
REAR AXLE - 9 1/4 (Continued)

INSTALLATION
(1) Raise the axle with lifting device and align to
the leaf spring centering bolts.
(2) Install the spring clamps and spring brackets.
Refer to 2 Suspension for procedures.
(3) Install shock absorbers and tighten nuts to 82
N´m (60 ft. lbs.).
(4) Install the RWAL sensor to the differential
housing, if necessary. Refer to 5 Brakes for proce-
dures.
(5) Connect the parking brake cables and cable
brackets.
(6) Install the brake drums. Refer to 5 Brakes for
procedures.
(7) Connect the brake hose to the axle junction
block. Refer to 5 Brakes for procedures.
(8) Install axle vent hose.
(9) Align propeller shaft and pinion companion
flange reference marks. Install the companion flange
bolts. Tighten to 108 N´m (80 ft. lbs.).
(10) Install the wheels and tires.
(11) Add gear lubricant, if necessary. Refer to
Specifications for lubricant requirements.
(12) Remove lifting device from axle and lower the
vehicle.
ADJUSTMENTS
Ring gear and pinion are supplied as matched sets
only. The identifying numbers for the ring gear and
pinion are painted onto the pinion gear head (Fig. 6)
and the side of the ring gear. A plus (+) number,
minus (±) number or zero (0) along with the gear set
sequence number (01 to 99) is on each gear. This first
number is the amount (in thousandths of an inch)
the depth varies from the standard depth setting of a
pinion marked with a (0). The next two numbers are
the sequence number of the gear set. The standard
depth provides the best teeth contact pattern. Refer
to Backlash and Contact Pattern for additional infor-
mation.
Compensation for pinion depth variance is
achieved with select shims. The shims are placed
behind the rear pinion bearing. (Fig. 7).
If a new gear set is being installed, note the depth
variance painted onto both the original and replace-
ment pinion. Add or subtract the thickness of the
original depth shims to compensate for the difference
in the depth variances. Refer to the Depth Variance
chart.
Note where Old and New Pinion Marking columns
intersect. Intersecting figure represents plus or
minus the amount needed.Note the painted number on the shaft of the drive
pinion (±1, ±2, 0, +1, +2, etc.). The numbers repre-
sent 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 number
is positive, subtract that value from the thickness of
the depth shim. If the number is 0 no change is nec-
essary.
Fig. 6 Pinion ID Number
1 - PRODUCTION NUMBER
2 - PINION GEAR DEPTH VARIANCE
3 - GEAR MATCHING NUMBER
Fig. 7 Adjustment Shim Locations
1 - AXLE HOUSING
2 - COLLAPSIBLE SPACER
3 - PINION BEARING
4 - PINION DEPTH SHIM
5 - DRIVE PINION GEAR
6 - BEARING CUP
3 - 84 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)

(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)