1998 DODGE RAM 1500 rear axle

Condition Possible Causes Correction
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 lift under axle and secure lift to the
axle.
(3) Remove wheels and tires assemblies.
(4) Remove all brake components.
(5) Mark propeller shaft and companion flange for
installation alignment reference.
(6) Remove propeller shaft.
(7) Remove shock absorbers from axle (Fig. 1).
(8) Remove U-bolts from axle (Fig. 2).(9) Remove axle from the vehicle.
Fig. 1 SHOCK ABSORBER
1 - NUT
2 - AXLE
3 - SHOCK ABSORBER
Fig. 2 REAR SPRING
1 - LEAF SPRING
2 - PLATE
3 - NUTS
4 - FRONT NUT & BOLT
5 - SPRING CLAMP BOLTS
6 - SHACKLES
DRREAR AXLE - 10 1/2 AA 3 - 115
REAR AXLE - 10 1/2 AA (Continued)

INSTALLATION
(1) Raise axle with lift and align to the leaf spring
centering bolts.
(2) Install axle U-bolts and tighten to 149 N´m
(110 ft. lbs.).
(3) Install shock absorbers to axle and tighten to
specification.
(4) Install all brake components.
(5) Align propeller shaft and pinion companion
flange reference marks and tighten companion flange
bolts to 115 N´m (85 ft. lbs.).
(6) Install the wheels and tires.
(7) Fill differential to specifications.
(8) Remove lift from axle and lower the vehicle.
ADJUSTMENTS
Ring and pinion gears are supplied as matched
sets. Compensation for pinion depth variance is
achieved with a select shim. The shim is located
between the rear pinion bearing and the pinion gear
head.
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. 3).
(1) Assemble Pinion Height Block 6739, Pinion
Block 8899 and rear pinion bearing onto Screw 6741
(Fig. 3).
(2) Insert assembled height gauge components,
rear bearing and screw into the housing through pin-
ion bearing cups (Fig. 4).
(3) Install front pinion bearing and Cone-nut 6740
onto the screw. Tighten cone-nut until Torque To
Rotate the screw is 1.7-2.26 N´m (15-20 in. lbs.) (Fig.
3).
(4) Place Arbor Disc 6732 on Arbor D-115-3 in posi-
tion in the housing side bearing cradles (Fig. 5).
(5) Install differential bearing caps on arbor discs
and snug the bearing cap bolts. Then cross tighten
cap bolts to 165 N´m (122 ft. lbs.).
NOTE: Arbor should rotate freely in the arbor discs.
(6) Assemble Dial Indicator C-3339 into Scooter
Block D-115-2 and secure set screw.
(7) Position Scooter Block/Dial Indicator flush on
the pinion height block. Hold scooter block and zero
the dial indicator.
(8) Slowly slide the scooter block across the pinion
height block over to the arbor (Fig. 6). Move the
scooter block till dial indicator crests the arbor, then
record the highest reading.
(9) Select a shim equal to the dial indicator read-
ing.(10) Install the select shim between the rear pin-
ion bearing and the pinion gear head.
Fig. 3 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. 4 PINION HEIGHT BLOCK
1 - PINION BLOCK
2 - PINION HEIGHT BLOCK
3 - 116 REAR AXLE - 10 1/2 AADR
REAR AXLE - 10 1/2 AA (Continued)

DIFFERENTIAL CASE BEARING PRELOAD AND
GEAR BACKLASH
Backlash is adjusted by moving the adjusters in
and out or both. By moving the adjusters the case/
ring gear will move closer or further away from the
pinion. In most cases this adjustment can be used to
achieve the correct gear tooth pattern and set the
case bearing preload.
(1) Remove adjuster lock bolts and adjuster locks
(Fig. 7).
(2) Loosen the differential bearing caps.
(3) Slide differential case toward the pinion gear
until the gears make contact/zero backlash. If zerobacklash cannot be obtained, turn the pinion side
adjuster until zero backlash is obtained.
(4) Holding the differential case toward the pinion
gear, turn bearing adjusters with Spanner Wrench
8883 (Fig. 8) until they make contact with the differ-
ential bearings/cups.
(5) Back off the ring gear side adjuster 4 holes, to
obtain initial ring gear backlash.
Fig. 5 GAUGE TOOLS IN HOUSING
1 - ARBOR DISC
2 - PINION BLOCK
3 - ARBOR
4 - PINION HEIGHT BLOCK
Fig. 6 PINION GEAR DEPTH MEASUREMENT
1 - ARBOR
2 - SCOOTER BLOCK
3 - DIAL INDICATOR
Fig. 7 ADJUSTER LOCK BOLT
1 - DIFFERENTIAL CASE
2 - ADJUSTER LOCK
3 - ADJUSTER LOCK BOLT
4 - BEARING CAP BOLT
Fig. 8 ADJUSTER SPANNER WRENCH
1 - WRENCH
2 - DIFFERENTIAL
DRREAR AXLE - 10 1/2 AA 3 - 117
REAR AXLE - 10 1/2 AA (Continued)

(6) Install ring gear side adjuster lock and bolt. Do
not tighten adjuster lock bolt at this time.
(7) Tighten pinion gear side adjuster firmly
against the differential case bearing cup.
(8) Rotate the pinion several times to seat the def-
erential bearings.
(9) Loosen pinion gear side adjuster until it is no
longer in contact with the bearing cup, then tighten
it until it makes contact.
(10) Tighten pinion gear side adjuster an addi-
tional:
²New Bearings:6 Adjuster Holes
²Original Bearings:4 Adjuster Holes
(11) Install pinion gear side adjuster lock and bolt.
Do not tighten adjuster lock bolt at this time.
(12) Tighten bearing cap bolts to 115 N´m (85 ft.
lbs.).
(13) Tighten adjuster lock bolts to 33 N´m (24 ft.
lbs.).
(14) Measure ring gear backlash with a Dial Indi-
cator C-3339 and Dial Indicator Stud L-4438 at eight
points around the drive side of the ring gear (Fig. 9).
The backlash should be 0.08-0.25 mm (0.003-0.010
in) with a preferred backlash of 0.13-0.18 mm (0.005-
0.007 in).
NOTE: Backlash measurement should not vary
more than 0.05 mm (0.002 in) between measuring
points. If measurement does vary inspect the gears
for burrs, the differential case flange and ring gear
mounting.GEAR TOOTH CONTACT PATTERN
Gear tooth contact pattern is used to verify the cor-
rect running position of the ring and pinion gears.
This will produce low noise and long gear life. Gears
which are not positioned properly may be noisy and
have shorten gear life.
(1) Wipe clean each tooth of the ring gear.
(2) Apply gear marking compound to all of the ring
gear teeth.
(3) Verify bearing cap bolts are torque specifica-
tion.
(4) Apply parking brakes lightly to create at 14
N´m (10 ft. lbs.) pinion rotating torque.
(5) Rotate the pinion/pinion yoke 4 full revolutions
in each directions.
(6) Read gear tooth contact pattern:
²Gear contact pattern correct (Fig. 10). Backlash
and pinion depth is correct.
²Ring gear too far away from pinion gear (Fig.
11). Decrease the backlash, by moving the ring closer
to the pinion gear using the adjusters.
²Ring gear too close to pinion gear (Fig. 12).
Increase the backlash, by moving the ring away from
the pinion gear using the adjusters.
Fig. 9 RING GEAR BACKLASH
1 - DIAL INDICATOR
2 - RING GEAR
Fig. 10 CORRECT CONTACT PATTERN
Fig. 11 INCORRECT BACKLASH
1 - COAST SIDE TOE
2 - DRIVE SIDE HEEL
3 - 118 REAR AXLE - 10 1/2 AADR
REAR AXLE - 10 1/2 AA (Continued)

²Ring gear too far away from pinion gear (Fig.
13). Decrease the backlash, by moving the ring closer
to the pinion gear using the adjusters.
²Ring gear too close to pinion gear (Fig. 14).
Increase the backlash, by moving the ring away from
the pinion gear using the adjusters.
²Pinion gear is set too low (Fig. 15). Increase the
pinion gear height, by increasing the pinion depth
shim thickness.
²Pinion gear is set too high (Fig. 16). Decrease
the pinion depth, by decreasing the pinion depth
shim thickness.
Fig. 12 INCORRECT BACKLASH
1 - DRIVE SIDE TOE
2 - COAST SIDE HEEL
Fig. 13 INCORRECT BACKLASH
1 - DRIVE SIDE HEEL
2 - COAST SIDE HEEL
Fig. 14 INCORRECT BACKLASH
1 - DRIVE SIDE TOE
2 - COAST SIDE TOE
Fig. 15 LOW PINION HEIGHT
Fig. 16 HIGH PINION HEIGHT
DRREAR AXLE - 10 1/2 AA 3 - 119
REAR AXLE - 10 1/2 AA (Continued)

SPECIFICATIONS
AXLE SPECIFICATIONS
DESCRIPTION SPECIFICATION
Axle Ratio 3.73, 4.10
Ring Gear Diameter 266 mm (10.5 in.)
Ring Gear Backlash 0.13-0.18 mm (0.005-0.007 in.)
Pinion Bearing Preload - New Bearings 1.69-2.82 N´m (15-25 in. lbs.)
Pinion Bearing Preload - Original Bearings 1-2 N´m (10-20 in. lbs.)
Pinion Bearing Preload + Diff Case Bearing Preload -
New Bearings3.4-5.6 N´m (30-50 in. lbs.)
Pinion Bearing Preload + Diff Case Bearing Preload -
Original Bearings2.8-5.1 N´m (25-45 in. lbs.)
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Fill Hole Plug 32 24 -
Differential Cover Bolts 40 30 -
Bearing Cap Bolts 165 122 -
Ring Gear Bolts 237 175 -
Axle Flange Bolts 129 95 -
Adjuster Lock Bolt 25 18 -
SPECIAL TOOLS
PULLER C-293-PA
DIAL INDICATOR SET C-3339
HANDLE C-4171
3 - 120 REAR AXLE - 10 1/2 AADR
REAR AXLE - 10 1/2 AA (Continued)

DIAL INDICATOR STUD L-4438
BEARING INSTALLER MD-998805
SPLITTER 1130
PINION DEPTH GAUGE 6730
ARBOR DISCS 6732
ADAPTERS 8879
ADJUSTER WRENCH 8883
DRREAR AXLE - 10 1/2 AA 3 - 121
REAR AXLE - 10 1/2 AA (Continued)

PLUG 8888
SEAL INSTALLER 8896
GAUGE BLOCK 8899
SOCKET 8954
BEARING INSTALLER 8956
CUP INSTALLER 8959
3 - 122 REAR AXLE - 10 1/2 AADR
REAR AXLE - 10 1/2 AA (Continued)