1998 DODGE RAM 1500 Rear differential

DIFFERENTIAL CASE
BEARINGS
REMOVAL
(1) Remove differential case from the housing.
(2) Install Plug 8888 into the end of the case.
(3) Remove differental case bearings with Bearing
Splitter 1130 and Bridge 938 (Fig. 47).
INSTALLATION
(1) Install differenial case bearings with Installer
8956 and Handle C-4171 (Fig. 48).
(2) Install differentail case into housing.
PINION GEAR/RING GEAR/
TONE RING
REMOVAL
NOTE: The ring and pinion gears are service in a
matched set. Never replace the ring gear/pinion
gear without replacing the other matching gear.
(1) Mark pinion flange and propeller shaft for
installation alignment.
(2) Disconnect propeller shaft from pinion flange
and remove propeller shaft.
(3) Remove differential from axle housing.
Fig. 47 DIFFERENTIAL CASE BEARING
1 - BRIDGE
2 - SPLITTER
3 - BEARING
4 - PLUG
Fig. 48 DIFFERENTIAL CASE BEARINGS
1 - HANDLE
2 - DIFFERENTIAL CASE
3 - BEARING
4 - INSTALLER
3 - 134 REAR AXLE - 10 1/2 AADR

(4) Place differential on Plug 8888 and drive
exciter ring off the differential case with a hammer
and punch (Fig. 49).
NOTE: Do not remove the exciter ring if it is not
being replaced.
(5) Place differential case in a vise with soft metal
jaw protectors
(6) Remove bolts holding ring gear to differential
case.
(7) Drive ring gear from differential case with a
soft hammer (Fig. 50).
(8) Hold pinion flange with Flange Wrench 8979
(Fig. 51) and remove pinion flnage nut and washer.
Fig. 49 EXCITER RING
1 - DIFFERENTIAL CASE
2 - RING GEAR
3 - PUNCH
4 - EXCITER RING
Fig. 50 RING GEAR
1 - DIFFERENTIAL CASE
2 - RING GEAR
3 - HAMMER
Fig. 51 FLANGE WRENCH
1 - PINION FLANGE
2 - FLANGE WRENCH
DRREAR AXLE - 10 1/2 AA 3 - 135
PINION GEAR/RING GEAR/TONE RING (Continued)

(5) Installnewcollapsible spacer (Fig. 59).
(6) Lubricate pinion and bearings.
(7) Install pinion into the housing and place front
pinion bearing onto the pinion shaft. Draw the pinion
shaft into the front bearing with Installer 8981 (Fig.
60).(8) Installnewpinion seal (Fig. 61) with Installer
8896 and Handle C-4171.
(9) Apply a light coat of teflon sealant to the pin-
ion flange splines.
(10) Hold the pinion and lightly tap the pinion
flange onto the pinion, until a few threads are show-
ing.
(11) Install pinion flange washer andnewpinion
nut.
(12) Hold pinion flange with Flange Wrench 8979
(Fig. 62) and tighten pinion nut until pinion end play
is taken up.
Fig. 59 COLLAPSIBLE SPACER
1 - COLAPSIBLE SPACER
2 - PINION GEAR
3 - REAR PINION BEARING
Fig. 60 PINION GEAR INSTALLER
1 - INSTALLER
2 - DIFFERENTIAL HOUSING
Fig. 61 PINION SEAL INSTALLER
1 - HANDLE
2 - INSTALLER
Fig. 62 FLANGE WRENCH
1 - FLANGE WRENCH
2 - PINION FLANGE
3 - 138 REAR AXLE - 10 1/2 AADR
PINION GEAR/RING GEAR/TONE RING (Continued)

(13) Rotate pinion several times to seat bearings.
(14) Measure pinion rotating torque with an inch
pound torque wrench (Fig. 63). Tighten pinion nut in
small increments until pinion rotating torque is:
²New Pinion Bearings:1.7-2.8 N´m (15-25 in.
lbs.)
²Original Pinion Bearings:1.1-2.2 N´m (10-20
in. lbs.)
(15) Rotate pinion several times then verify pinion
rotating torque again.
(16) Position the ring gear on differential case and
start twonewring gear bolts.
(17) Install the rest of thenewring gear bolts and
tighten them alternately to seat the ring gear.
(18) Torque ring gear bolts to 237 N´m (175 ft.
lbs.).
(19) If exciter ring was removed, position differen-
tial assembly on differential Plug 8888 (Fig. 64) and
place exciter ring on the differential case.
(20) Install the exciter ring on the differential case
evenly with a hammer and brass punch (Fig. 65).
Drive the ring down until it is seated against the
ring gear.
CAUTION: Do not damage exciter ring teeth during
installation.
(21) Install differential into the housing.
(22) Verify ring gear backlash and gear contact
pattern.
(23) Measure final rotating torque with an inch
pound torque wrench. The final pinion rotating
torque plus differential case bearing preload is:
²New Bearings:3.4-5.6 N´m (30-50 in. lbs.)²Original Bearings:2.8-5.1 N´m (25-45 in. lbs.)
(24) Install axle shafts.
(25) Install the propeller shaft with the reference
marks aligned.
(26) Install differential cover with gasket and
tighten bolts to 40 N´m (30 ft. lbs.).
(27) Fill differential with fluid and tighten fill plug
to 32 N´m (24 ft. lbs.).
Fig. 63 PINION ROTATING TORQUE
1 - PINION FLANGE
2 - TORQUE WRENCH
Fig. 64 EXCITER RING
1 - EXCITER RING
2 - RING GEAR
3 - DIFFERENTIAL PLUG
4 - DIFFERENTIAL CASE
Fig. 65 EXCITER RING INSTALLATION
1 - EXCITER RING
2 - PUNSH
3 - RING GEAR
DRREAR AXLE - 10 1/2 AA 3 - 139
PINION GEAR/RING GEAR/TONE RING (Continued)

REAR AXLE - 11 1/2 AA
TABLE OF CONTENTS
page page
REAR AXLE - 11 1/2 AA
DIAGNOSIS AND TESTING...............140
REMOVAL............................143
INSTALLATION........................144
ADJUSTMENTS.......................144
SPECIFICATIONS......................148
SPECIAL TOOLS.......................148
AXLE SHAFTS
REMOVAL............................152
INSTALLATION........................152
AXLE BEARINGS
REMOVAL............................152
INSTALLATION........................153
PINION SEAL
REMOVAL............................153
INSTALLATION........................154
DIFFERENTIAL
REMOVAL............................155DISASSEMBLY........................155
ASSEMBLY...........................156
INSTALLATION........................157
DIFFERENTIAL TRAC-RITE
DESCRIPTION........................158
OPERATION..........................158
DISASSEMBLY........................158
CLEANING...........................160
INSPECTION.........................160
ASSEMBLY...........................161
DIFFERENTIAL CASE BEARINGS
REMOVAL............................161
INSTALLATION........................161
PINION GEAR/RING GEAR/TONE RING
REMOVAL............................162
INSTALLATION........................164
REAR AXLE - 11 1/2 AA
DIAGNOSIS AND TESTING
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 check for:
²Insufficient lubricant.
²Incorrect ring gear backlash.
²Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. The side gears are loaded dur-
ing turns. They usually do not cause noise during
straight-ahead driving when the gears are unloaded.
A worn pinion shaft can also cause a snapping 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 bearingshave 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.
Differential bearingsusually produce a low pitch
noise. Differential bearing noise is similar to pinion
bearing noise. The pitch of differential bearing noise
is also constant and varies only with vehicle speed.
Axle shaft bearingsproduce 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:
²Worn U-joint(s).
²Worn side gear thrust washers.
²Worn pinion shaft bore.
3 - 140 REAR AXLE - 11 1/2 AADR

Condition Possible Causes Correction
Differential Cracked 1. Improper adjustment of the
differential bearings.1. Replace case and inspect gears
and bearings for further damage. Set
differential bearing pre-load properly.
2. Excessive ring gear backlash. 2. Replace case and inspect gears
and bearings for further damage. Set
ring gear backlash properly.
3. Vehicle overloaded. 3. Replace case and inspect gears
and bearings for further damage.
Avoid excessive vehicle weight.
4. Erratic clutch operation. 4. Replace case and inspect gears
and bearings for further damage.
Avoid erratic use of clutch.
Differential Gears Scored 1. Insufficient lubrication. 1. Replace scored gears. Fill
differential with the correct fluid type
and quantity.
2. Improper grade of lubricant. 2. Replace scored gears. Fill
differential with the correct fluid type
and quantity.
3. Excessive spinning of one
wheel/tire.3. Replace scored gears. Inspect all
gears, pinion bores, and shaft for
damage. Service as necessary.
Loss Of Lubricant 1. Lubricant level too high. 1. Drain lubricant to the correct level.
2. Worn axle shaft seals. 2. Replace seals.
3. Cracked differential housing. 3. Repair as necessary.
4. Worn pinion seal. 4. Replace seal.
5. Worn/scored yoke. 5. Replace yoke and seal.
6. Axle cover not properly sealed. 6. Remove, clean, and re-seal cover.
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.
3 - 142 REAR AXLE - 11 1/2 AADR
REAR AXLE - 11 1/2 AA (Continued)

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 lifting device 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 - 11 1/2 AA 3 - 143
REAR AXLE - 11 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, located between the rear
pinion bearing and 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 8897 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 Discs 8289 on Arbor D-115-3 in
position 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 281 N´m (207 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 - 144 REAR AXLE - 11 1/2 AADR
REAR AXLE - 11 1/2 AA (Continued)