AXLE SHAFTS
REMOVAL
(1) Place the transmission in Neutral.
(2) Raise and support vehicle.
(3) Remove right wheel and tire and assembly.
(4) Remove right half shaft from vehicle.
(5) Remove snap ring from axle shaft.
(6) Assemble Remover 8420A onto the shaft (Fig.
25). Thread slid hammer into remover and remove
shaft.
(7) Slide axle shaft out of the axle tube.
NOTE: Use care to prevent damage to axle shaft
bearing and seal, which will remain in axle shaft
tube.
INSTALLATION
(1) Lubricate bearing bore and seal lip with gear
lubricant. Insert axle shaft through seal, bearing
(Fig. 26) and engage it into side gear splines.
NOTE: Use care to prevent shaft splines from dam-
aging axle shaft seal.
(2) Push on the axle shaft until the axle shaft
snap-ring passes through the side gear.
(3) Install right half shaft.
(4) Install right wheel and tire assembly.
(5) Check differential fluid level.
(6) Lower vehicle.
AXLE SHAFT SEALS
REMOVAL
(1) Remove half shaft.
(2) Remove axle shaft for right side seal removal.
(3) Remove shaft seal with Remover 7794-A and a
slide hammer (Fig. 27).
Fig. 25 AXLE SHAFT PULLER
1 - SNAP RING GROVE
2 - SLID HAMMER THREADS
3 - REMOVER BLOCKS
4 - REMOVER COLLAR
Fig. 26 AXLE SHAFT SEAL
1 - BEARING
2 - SEAL
Fig. 27 SHAFT SEAL REMOVER
1 - SHAFT SEAL
2 - REMOVER
KJFRONT AXLE - 186FIA 3 - 37
INSTALLATION
(1) Apply a light coat of lubricant on the lip of the
shaft seal.
(2) Installnewshaft seal with Installer 8806 and
Handle C-4171 (Fig. 28).
(3) Install right axle shaft if removed.
(4) Install half shaft.
AXLE BEARINGS
REMOVAL
(1) Remove half shaft.
(2) Remove axle shaft for right side seal removal.
(3) Remove shaft seal with Remover 7794-A and a
slide hammer.
(4) Remove shaft bearing with Remover 7794-A
and a slide hammer (Fig. 29).
INSTALLATION
(1) Installnewshaft bearing with Installer 8805
and Handle C-4171.
(2) Apply a light coat of lubricant on the lip of the
shaft seal.
(3) Installnewshaft seal with an appropriate
installer.
(4) Install right axle shaft if removed.
(5) Install half shaft.
PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assemblies.
(3) Remove brake calipers and rotors, refer to 5
Brakes for procedures.
(4) Mark propeller shaft and pinion companion
flange for installation reference.
(5) Remove propeller shaft from the pinion com-
panion flange.
(6) Rotate pinion gear a minimum of ten times and
verify the pinion rotates smoothly.
(7) Record the torque to rotate the pinion gear
(Fig. 30) with a inch pound torque wrench.
Fig. 28 SEAL INSTALLER
1 - SEAL BORE
2 - INSTALLER
Fig. 29 SHAFT BEARING REMOVER
1 - SHAFT BEARING
2 - REMOVER
Fig. 30 PINION ROTATING TORQUE
1 - PINION COMPANION FLANGE
2 - TORQUE WRENCH
3 - 38 FRONT AXLE - 186FIAKJ
AXLE SHAFT SEALS (Continued)
(4) Rotate pinion a minimum of ten time and ver-
ify pinion rotates smoothly. Rotate the pinion shaft
with an inch pound torque wrench. Rotating torque
should be equal to the reading recorded during
removal plus 0.56 N´m (5 in. lbs.) (Fig. 35).
(5) If the rotating torque is low, use Spanner
Wrench 6958 to hold the pinion companion flange
and tighten the pinion shaft nut in 6.8 N´m (5 ft.
lbs.) increments until proper rotating torque is
achieved.
CAUTION: If maximum tightening torque is reached
prior to reaching the required rotating torque, the
collapsible spacer may have been damaged.
Replace the collapsible spacer.
(6) Install propeller shaft with installation refer-
ence marks aligned.
(7) Fill differential with gear lubricant.
(8) Install brake rotors and calipers.
(9) Install wheel and tire assemblies.
(10) Lower the vehicle.
DIFFERENTIAL
REMOVAL
(1) Remove axle from the vehicle.
(2) Remove differential housing cover (Fig. 36).
(3) Push right axle shaft out of side gear (Fig. 37)
and remove the shaft.
(4) Mark differential bearing caps for installation
reference.
(5) Loosen the bearing cap bolts.
Fig. 35 PINION ROTATING TORQUE
1 - PINION COMPANION FLANGE
2 - TORQUE WRENCHFig. 36 DIFFERENTIAL COVER
1 - COVER
2 - VENT TUBE
Fig. 37 RIGHT SHAFT IN SIDE GEAR
1 - AXLE SHAFT
2 - SCREWDRIVER
3 - SIDE GEAR
3 - 40 FRONT AXLE - 186FIAKJ
PINION SEAL (Continued)
The Trac-lokŸ design provides the differential
action needed for turning corners and for driving
straight ahead during periods of unequal traction.
When one wheel looses traction, the clutch packs
transfer additional torque to the wheel having the
most traction. Trac-lokŸ differentials resist wheel
spin on bumpy roads and provide more pulling power
when one wheel looses traction. Pulling power is pro-
vided continuously until both wheels loose traction. If
both wheels slip due to unequal traction, Trac-lokŸ
operation is normal. In extreme cases of differences
of traction, the wheel with the least traction may
spin.
DIAGNOSIS AND TESTING - AXLE
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:
²Check for insufficient lubricant.
²Incorrect ring gear backlash.
²Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehi-
cle turns. A worn pinion shaft can also cause a snap-
ping 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 bearings have 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.
Worn or damaged differential bearings usually pro-
duce a low pitch noise. Differential bearing noise is
similar to pinion bearing noise. The pitch of differen-tial bearing noise is also constant and varies only
with vehicle speed.
Axle shaft bearings produce 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 a worn
U-joint or by worn side±gear thrust washers. A worn
pinion shaft bore will also cause low speed knock.
VIBRATION
Vibration at the rear of the vehicle is usually
caused by a:
²Damaged drive shaft.
²Missing drive shaft balance weight(s).
²Worn or out-of-balance wheels.
²Loose wheel lug nuts.
²Worn U-joint(s).
²Loose/broken springs.
²Damaged axle shaft bearing(s).
²Loose pinion gear nut.
²Excessive pinion yoke run out.
²Bent axle shaft(s).
Check for loose or damaged front-end components
or engine/transmission mounts. These components
can contribute to what appears to be a rearend vibra-
tion. Do not overlook engine accessories, brackets
and drive belts.
NOTE: All driveline components should be exam-
ined before starting any repair.
DRIVELINE SNAP
A snap or clunk noise when the vehicle is shifted
into gear (or the clutch engaged), can be caused by:
²High engine idle speed.
²Transmission shift operation.
²Loose engine/transmission/transfer case mounts.
²Worn U-joints.
²Loose spring mounts.
²Loose pinion gear nut and yoke.
²Excessive ring gear backlash.
²Excessive side gear to case clearance.
The source of a snap or a clunk noise can be deter-
mined with the assistance of a helper. Raise the vehi-
cle on a hoist with the wheels free to rotate. Instruct
the helper to shift the transmission into gear. Listen
for the noise, a mechanics stethoscope is helpful in
isolating the source of a noise.
KJREAR AXLE - 198RBI 3 - 51
REAR AXLE - 198RBI (Continued)
DIAGNOSTIC CHART
Condition Possible Causes Correction
Wheel Noise 1. Wheel loose. 1. Tighten loose nuts.
2. Faulty, brinelled wheel bearing. 2. Replace bearing.
Axle Shaft Noise 1. Misaligned axle tube. 1. Inspect axle tube alignment.
Correct as necessary.
2. Bent or sprung axle shaft. 2. Inspect and correct as necessary.
Axle Shaft Broke 1. Misaligned axle tube. 1. Replace the broken shaft after
correcting tube mis-alignment.
2 Vehicle overloaded. 2. Replace broken shaft and avoid
excessive weight on vehicle.
3. Erratic clutch operation. 3. Replace broken shaft and avoid
or correct erratic clutch operation.
4. Grabbing clutch. 4. Replace broken shaft and inspect
and repair clutch as necessary.
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.
3 - 52 REAR AXLE - 198RBIKJ
REAR AXLE - 198RBI (Continued)
(10) Install axle vent hose.
(11) Install propeller shaft with reference marks.
(12) Install the wheels and tires.
(13) Add gear lubricant to specifications, if neces-
sary.
(14) Remove lifting device from axle and lower the
vehicle.
(15) Tighten the lower control arm bolts to torque
specification.
ADJUSTMENTS
ADJUSTMENT
Ring and pinion gears are supplied as matched
sets only. The identifying numbers for the ring and
pinion gear are etched into the face of each gear (Fig.
9). A plus (+) number, minus (±) number or zero (0) is
etched into the face of the pinion gear. This number
is the amount (in thousandths of an inch) the depth
varies from the standard depth setting of a pinion
etched with a (0). The standard setting from the cen-
ter line of the ring gear to the back face of the pinion
is 96.850 mm (3.813 in.). The standard depth pro-
vides the best teeth contact pattern. Refer to Back-
lash and Contact Pattern Analysis Paragraph in this
section for additional information.
Compensation for pinion depth variance is
achieved with select shims. The shims are placed
under the inner pinion bearing cone (Fig. 10).
If a new gear set is being installed, note the depth
variance etched into both the original and replace-
ment pinion gear. Add or subtract the thickness of
the original depth shims to compensate for the differ-
ence in the depth variances. Refer to the Depth Vari-
ance charts.Note where Old and New Pinion Marking columns
intersect. Intersecting figure represents plus or
minus amount needed.
Note the etched number on the face of the drive
pinion gear (±1, ±2, 0, +1, +2, etc.). The numbers rep-
resent thousands of an inch deviation from the stan-
dard. If the number is negative, add that value to the
required thickness of the depth shim(s). If the num-
ber is positive, subtract that value from the thickness
of the depth shim(s). If the number is 0 no change is
necessary. Refer to the Pinion Gear Depth Variance
Chart.
Fig. 8 LOWER SUSPENSION ARM
1 - AXLE BRACKET BOLT
2 - LOWER CONTROL ARM
3 - BODY BRACKET BOLTFig. 9 PINION GEAR ID NUMBERS
1 - PRODUCTION NUMBERS
2 - PINION GEAR DEPTH VARIANCE
3 - GEAR MATCHING NUMBER
Fig. 10 Shim Locations
1 - PINION GEAR DEPTH SHIM
2 - DIFFERENTIAL BEARING SHIM
3 - RING GEAR
4 - DIFFERENTIAL BEARING SHIM
5 - COLLAPSIBLE SPACER
KJREAR AXLE - 198RBI 3 - 55
REAR AXLE - 198RBI (Continued)
AXLE SHAFTS
REMOVAL
(1) Place transmission in neutral and raise and
support vehicle.
(2) Remove wheel and tire assembly.
(3) Remove brake drum.
(4) Remove axle retainer plate nuts from the rear
of the axle flange.
(5) Pull axle shaft from the axle with Slide Ham-
mer 7420 and Adapter 6790. Mount the adapter to
the axle with lug nuts.
NOTE: It is normal that the axle bearing race is
loose in the axle tube.
INSTALLATION
(1) Insall axle into the axle tube with the flat area
of the retainer plate upward.
(2) Insert retaining plate studs into the brake
backing plate and axle tube flange.
(3) Install retainer nuts and tighten to 47-75 N´m
(35-55 ft. lbs.).
(4) Install the brake drum.
(5) Install wheel and tire.
(6) Check and fill the differential with gear lubri-
cant.
(7) Lower vehicle.
PILOT STUDS C-3288-B
PULLER 6790
DIAL INDICATOR C-3339
INSTALLER C-3718
KJREAR AXLE - 198RBI 3 - 65
REAR AXLE - 198RBI (Continued)
INSTALLATION
NOTE: Verify axle shaft retaining plate is flat with a
straight edge. If the plate is warped replace the
plate.
(1) Install retaining plate on the axle shaft (Fig.
28).
(2) Apply a coat of multi-purpose grease on sealing
surface of axle seal.
(3) Install seal on the axle shaft with cavity away
from retaining plate (Fig. 28).
(4) Lubricate bearing with MopartWheel Bearing
Grease or equivalent. Wipe excess grease from the
bearing.
(5) Install bearing on the axle shaft with Installer
7913 and a press (Fig. 29).
(6) Press retaining ring onto axle shaft with
Installer 7913 and a press (Fig. 30).
(7) Install axle in vehicle.
Fig. 29 BEARING ON AXLE
1 - PRESS RAM
2 - INSTALLER - 7913
3 - AXLE BEARING
4 - SEAL
5 - RETAINING PLATE
6 - AXLE
Fig. 30 BEARING RETAINING RING ON AXLE
1 - PRESS
2 - AXLE
3 - AXLE BEARING
4 - INSTALLER
5 - SOFT METAL RETAINING RING
Fig. 28 AXLE BEARING AND SEAL COMPONENTS
1 - RETAINING RING
2 - SEAL
3 - AXLE
4 - RETAINING PLATE
5 - AXLE BEARING
KJREAR AXLE - 198RBI 3 - 67
AXLE BEARING/SEAL (Continued)