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
(7) Remove pinion flange with Pinion Flange
Puller 8992 (Fig. 24).
(8) Remove pinion shaft seal with a pry tool or
slide hammer mounted screw.
INSTALLATION
(1) Installnewpinion seal with Installer 8896
(Fig. 25).
(2) Apply a light coat of teflon sealant to the pin-
ion flange splines.
(3) Lightly tap the pinion flange onto the pinion
until a few threads are showing.
(4) Install flange washer andnewpinion nut.(5) Hold pinion flange with Flange Wrench 8979
(Fig. 26) and tighten pinion nut until pinion end play
is taken up.
(6) Rotate pinion several times to seat bearings.
(7) Measure pinion rotating torque with an inch
pound torque wrench and compare it to recorded
measurement. Tighten pinion nut in small incre-
ments, until pinion rotating torque is 0.40-0.57 N´m
(3-5 in. lbs.) greater than recorded measurement.
(8) Rotate pinion several times then verify pinion
rotating torque again.
(9) Install axle shafts.
(10) Install propeller shaft with reference marks
aligned.
(11) Check differential fluid level.
Fig. 23 FLANGE WRENCH
1 - PINION FLANGE
2 - FLANGE WRENCH
Fig. 24 PINION FLANGE PULLER
1 - PINION FLANGE
2 - PULLER
Fig. 25 PINION SEAL INSTALLER
1 - HANDLE
2 - INSTALLER
Fig. 26 FLANGE WRENCH
1 - FLANGE WRENCH
2 - PINION FLANGE
3 - 154 REAR AXLE - 11 1/2 AADR
PINION SEAL (Continued)
(3) Rotate one pinion gear with thrust washer
(Fig. 30) to the differential window and remove the
gear.
(4) Rotate the other pinion gear with thrust
washer (Fig. 31) to the differential window and
remove the gear.
(5) Remove differential side gears and thrust
washers (Fig. 32).
ASSEMBLY
NOTE: If the same gears and thrust washers are
being used, install them into their orignial locations.
(1) Lubricate all differential components with axle
lubricant.
(2) Install differential side gears and thrust wash-
ers (Fig. 33).
Fig. 30 FIRST PINION GEAR
1 - DIFFERENTIAL WINDOW
2 - PINION GEAR
3 - THRUST WASHER
Fig. 31 SECOND PINION GEAR
1 - DIFFERENTIAL WINDOW
2 - THRUST WASHER
3 - PINION GEAR
Fig. 32 SIDE GEARS
1 - SIDE GEAR
2 - SIDE GEAR
3 - PINION GEARS
Fig. 33 SIDE GEAR
1 - DIFFERENTIAL WINDOW
2 - SIDE GEAR
3 - 156 REAR AXLE - 11 1/2 AADR
DIFFERENTIAL (Continued)
(3) Install first pinion gear into the differential
window and side gears. Rotate the pinion gear to the
back of the case (Fig. 34).
(4) Install the other pinion gear and thrust
washer. Rotate the gears to align hole in the pinion
gears with hole in the differential case.
(5) Slide pinion shaft into the case and through
the pinion gears. Tap the shaft to seat the pinion
shaft snap-ring into the case (Fig. 35).
(6) Install ring gear.
INSTALLATION
(1) Clean the housing cavity with a flushing oil,
light engine oil or lint free cloth.
CAUTION: Do not use water, steam, kerosene or
gasoline for cleaning.
(2) Lubricate differential case bearing.
(3) Install differential case with bearings cups into
the housing.
NOTE: A light coat of grease on the cups will hold
them in place during installation.
(4) Install bearing caps and bolts (Fig. 36). Tighten
the bearing cap bolts finger-tight.
NOTE: Do not torque bearing cap and bolts at this
time.
Fig. 34 PINION GEAR
1 - DIFFERENTIAL WINDOW
2 - SIDE GEARS
3 - PINION GEAR
Fig. 35 PINION SHAFT INSTALLATION
1 - SNAP RING
2 - SIDE GEAR
3 - PINION GEAR
4 - PINION SHAFT
Fig. 36 CASE BEARING CAP
1 - DIFFERENTIAL HOUSING
2 - BEARING CAP
3 - ADJUSTER
DRREAR AXLE - 11 1/2 AA 3 - 157
DIFFERENTIAL (Continued)
(5) Slide differential case toward the pinion gear
until the gears make contact/zero backlash. If zero
backlash cannot be obtained, turn the pinion side
adjuster until zero backlash is obtained.
(6) Holding the differential case toward the pinion
gear, turn bearing adjusters with Spanner Wrench
8883 until they make contact with the differential
bearings/cups.
(7) Back off the ring gear side adjuster 4 holes, to
obtain initial ring gear backlash.
(8) Install ring gear side adjuster lock and bolt. Do
not tighten adjuster lock bolt at this time.
(9) Tighten pinion gear side adjuster firmly
against the differential case bearing cup.
(10) Rotate the pinion several times to seat the dif-
ferential bearings.
(11) Loosen pinion gear side adjuster until it is no
longer in contact with the bearing cup.
(12) Tighten pinion gear side adjuster until it just
makes contact with the bearing cup.
(13) Tighten pinion gear side adjuster an addi-
tional:
²New Bearings6 Adjuster Holes
²Original Bearings4 Adjuster Holes
(14) Install pinion gear side adjuster lock and bolt.
Do not tighten adjuster lock bolt at this time.
(15) Tighten bearing cap bolts to 281 N´m (207 ft.
lbs.).
(16) Tighten adjuster lock bolts to 25 N´m (18 ft.
lbs.) (Fig. 37).
(17) Measure ring gear backlash and check gear
tooth contact pattern. Refer to Adjustments for pro-
cedure.
(18) Install axle shaft gasket and install axle
shafts.
(19) Install differential housing gasket and cover.
Tighten cover bolts to 40 N´m (30 ft. lbs.).
(20) Fill axle with lubricant, refer to Lubrication &
Maintenance for capacity and lubricant type.
(21) Install fill plug and tighten to 32 N´m (24 ft.
lbs.).
DIFFERENTIAL TRAC-RITE
DESCRIPTION
The Trac-RiteŸ differential is a helical gear differ-
ential. The differential has two side gears, six pinion
gears and six pinion brake shoes.
NOTE: The differential is seviced as an assembly
only if damaged, but can be disassembled for
cleaning. The assembly should be cleaned every
time a bearing is changed due to damage.
OPERATION
When one wheel begins to spin the pinion gears on
that side are forced toward the pinion brake shoes.
The pinion brake shoes then cause frictional drag on
the opposite pinion gears and the side gear. These
friction forces transfer the power to the opposite
wheel. Once the frictional forces are overcome, differ-
entiation will occur. The torque will be continually
biased by the frictional forces to the high traction
wheel.
DISASSEMBLY
(1) Remove differential ring gear bolts.
(2) Remove differential case cover locating screws
(Fig. 38).
(3) Remove differential case cover.
(4) Remove side gear and thrust washer (Fig. 39).
NOTE: Mark all component locations.
Fig. 37 ADJUSTER LOCK BOLT
1 - DIFFERENTIAL CASE
2 - ADJUSTER LOCK
3 - ADJUSTER LOCK BOLT
4 - BEARING CAP BOLT
3 - 158 REAR AXLE - 11 1/2 AADR
DIFFERENTIAL (Continued)
(5) Remove three pinion brake shoes (Fig. 40).
(6) Remove six pinion gears (Fig. 41).(7) Remove remaining side gear thrust washer and
spacer.
(8) Remove remaining three pinion brake shoes.
Fig. 38 LOCATION SCREWS
1 - DIFFERENTIAL COVER
2 - LOCATION SCREWS
Fig. 39 SIDE GEAR AND THRUST WASHER
1 - SIDE GEAR
2 - THRUST WASHER
Fig. 40 PINION BRAKE SHOES
1 - BRAKE SHOES
2 - PINION GEARS
Fig. 41 PINION GEARS
1 - PINION GEARS
2 - SIDE GEAR
DRREAR AXLE - 11 1/2 AA 3 - 159
DIFFERENTIAL TRAC-RITE (Continued)
CLEANING
Clean the differential case and gears with light oil
or a lint free cloth.
NOTE: Never use water, steam, kerosene or gaso-
line for cleaning.
INSPECTION
NOTE: Minor corrosion, nicks or scratches can be
smoothed with 400 grit emery cloth and polished
out with crocus cloth.
(1) Inspect pinion gears teeth for chips and cracks
(Fig. 42).
(2) Inspect pinion gears shafts and brake shoes for
scratches, flat-spots or worn (Fig. 42).
(3) Inspect side gears teeth for chips and cracks
(Fig. 43).
(4) Inspect pinion and side gear bores for scratches
(Fig. 44).
NOTE: If any damage is found the differential must
be replaced as an assembly. Individual components
can not be replaced separately.
Fig. 42 PINION GEAR AND BRAKE SHOE
1 - BRAKE SHOES
2 - PINION GEAR
3 - PINION SHAFT
Fig. 43 SIDE GEARS
1 - THRUST WASHERS
2 - SPACER
3 - SIDE GEARS
Fig. 44 PINION/SIDE GEAR BORE
1 - PINION BORES
2 - SIDE GEAR BORE
3 - 160 REAR AXLE - 11 1/2 AADR
DIFFERENTIAL TRAC-RITE (Continued)
ASSEMBLY
NOTE: Install all component in their original loca-
tions.
(1) Lubricate all gears and differential bores with
differential lubricant.
(2) Install one set of pinion brake shoes into the
case bores.
NOTE: Brake shoes can be installed upside down,
but if install wrong pinion gear will not fit.
(3) Install side gear thrust washer, side gear and
spacer (Fig. 45).
(4) Install one set of pinion gears into the bores
next to the brake shoes, with the pinion shaft facing
up.
(5) Install other side gear and thrust washer.
(6) Install other set of pinion gears into the brake
shoes in the case.(7) Install other set of brake shoes onto the pinion
gears shafts (Fig. 46).
(8) Install differential cover and location screws.
(9) Installnewring gear bolts and tighten to 237
N´m (175 ft. lbs.).
DIFFERENTIAL CASE
BEARINGS
REMOVAL
(1) Remove differential case from the housing.
(2) Install Plug 8964 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
8965 and Handle C-4171 (Fig. 48).
(2) Install differentail case into housing.
Fig. 45 SIDE GEAR AND SPACER
1 - SPACER
2 - SIDE SPACER
Fig. 46 PINION BRAKE SHOES
1 - BRAKE SHOES
2 - PINION GEARS
DRREAR AXLE - 11 1/2 AA 3 - 161
DIFFERENTIAL TRAC-RITE (Continued)