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)
Condition Possible Causes Correction
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.
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.
KJREAR AXLE - 198RBI 3 - 53
REAR AXLE - 198RBI (Continued)
REMOVAL
(1) Raise and support the vehicle.
(2) Position a lift/jack under the axle and secure
axle to device.
(3) Remove wheels and tires.
(4) Mark propeller shaft and pinion yoke for
installation reference.
(5) Remove propeller shaft and suspend under the
vehicle.
(6) Remove brake drums, parking brake cables and
speed sensor from the axle.
(7) Disconnect the brake hose at the body junction
block.
(8) Remove brakes and backing plates.
(9) Remove vent hose from the axle shaft tube.
(10) Remove the stabilizer bar (Fig. 5).
(11) Remove upper control arm ball joint pinch
bolt from bracket (Fig. 6).
(12) Remove shock absorbers from axle brackets
(Fig. 7).
(13) Loosen all lower control arms mounting bolts
(Fig. 8).
(14) Lower axle enough to remove coil springs and
spring insulators.
(15) Remove lower control arm bolts from the axle
brackets.
(16) Lower and remove the axle.
INSTALLATION
CAUTION: The weight of the vehicle must be sup-
ported by the springs before the lower control arms
are tightened. This must be done to maintain vehi-
cle ride height and prevent premature bushing fail-
ure.(1) Raise the axle under the vehicle.
(2) Install lower control arms onto the axle brack-
ets and loosely install the mounting bolts.
(3) Install coil spring isolators and spring.
(4) Raise axle up until springs are seated.
(5) Install upper control arm ball joint into axle
bracket and tighten pinch bolt to torque specification.
(6) Install shock absorbers and tighten nuts to
torque specification.
(7) Install stabilizer bar and tighten nuts to torque
specification.
(8) Install brake backing plates, parking brake
cables, brake drums and speed sensor.
(9) Install brake hose to the body junction block
and bleed the brakes.
Fig. 5 STABILIZER BAR MOUNTS
1 - STABILIZER BAR MOUNTING BOLTS
2 - LOWER SUSPENSION ARM
Fig. 6 BALL JOINT PINCH BOLT
1 - UPPER BALL JOINT
2 - PINCH BOLT
Fig. 7 SHOCK ABSORBER
1 - UPPER MOUNTING BOLT
2 - LOWER MOUNTING BOLT
3 - 54 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)
PINION GEAR DEPTH VARIANCE
Original Pinion
Gear Depth
VarianceReplacement Pinion Gear Depth Variance
24232221 0 +1 +2 +3 +4
+4+0.008 +0.007 +0.006 +0.005 +0.004 +0.003 +0.002 +0.001 0
+3+0.007 +0.006 +0.005 +0.004 +0.003 +0.002 +0.001 020.001
+2+0.006 +0.005 +0.004 +0.003 +0.002 +0.001 020.00120.002
+1+0.005 +0.004 +0.003 +0.002 +0.001 020.00120.00220.003
0+0.004 +0.003 +0.002 +0.001 020.00120.00220.00320.004
21+0.003 +0.002 +0.001 020.00120.00220.00320.00420.005
22+0.002 +0.001 020.00120.00220.00320.00420.00520.006
23+0.001 020.00120.00220.00320.00420.00520.00620.007
24020.00120.00220.00320.00420.00520.00620.00720.008
PINION DEPTH MEASUREMENT
Measurements are taken with pinion cups and pin-
ion bearings installed in the housing. Take measure-
ments with a Pinion Gauge Set, Pinion Block 6735,
Arbor Discs 6732 and Dial Indicator C-3339 (Fig. 11).
(1) Assemble Pinion Height Block 6739, PinionBlock 6735 and rear pinion bearing onto Screw 6741
(Fig. 11).
(2) Insert assembled height gauge components,
rear bearing and screw into the housing through pin-
ion bearing cups (Fig. 12).
(3) Install front pinion bearing and Cone 6740
hand tight.
(4) Place Arbor Disc 6732 on Arbor D-115-3 in posi-
tion in the housing side bearing cradles (Fig. 13).
Install differential bearing caps on Arbor Discs and
tighten cap bolts. Refer to the Torque Specifications.
NOTE: Arbor Discs 6732 have different step diame-
ters to fit other axle sizes. Pick correct size step for
axle being serviced.
Fig. 11 PINION DEPTH TOOLS
1 - DIAL INDICATOR
2 - ARBOR
3 - PINION HEIGHT BLOCK
4 - CONE
5 - SCREW
6 - PINION BLOCK
7 - SCOOTER BLOCK
8 - ARBOR DISC
Fig. 12 PINION HEIGHT BLOCK
1 - PINION BLOCK
2 - PINION HEIGHT BLOCK
3 - 56 REAR AXLE - 198RBIKJ
REAR AXLE - 198RBI (Continued)
(8) Thread Pilot Stud C-3288-B into rear cover bolt
hole below ring gear (Fig. 19).
(9) Attach Dial Indicator C-3339 to the pilot stud
and position indicator plunger on a flat surface of the
ring gear bolt head (Fig. 19).
(10) Push the differential case firmly to the pinion
gear side of the housing (Fig. 20) and zero dial indi-
cator.
(11) Push differential case firmly to the ring gear
side and record dial indicator reading (Fig. 21).
(12) Add the dial indicator reading to the starting
point shim thickness to determine total shim thick-
ness to achieve zero differential end play.
(13) Add 0.2 mm (0.008 in.) to the zero end play
total. This new total represents the thickness of
shims to compress or preload the new bearings when
the differential is installed.
(14) Rotate dial indicator out of the way.
(15) Remove differential case, dummy bearings
and starting point shims from the housing.
(16) Install pinion gear in the housing. Install the
yoke and establish the correct pinion rotating torque.
(17) Install differential case and dummy bearings
in the housing (without shims) and tighten retaining
cap bolts.
(18) Position the dial indicator plunger on a flat
surface between the ring gear bolt heads (Fig. 19).(19) Push and hold differential case toward pinion
gear.
(20) Zero dial indicator face to pointer.
(21) Push and hold differential case to ring gear
side of the housing and record dial indicator reading.
(22) Subtract 0.05 mm (0.002 in.) from the dial
indicator reading to compensate for backlash between
ring and pinion gears. This total is the thickness of
shim required to achieve proper backlash.
(23) Subtract the backlash shim thickness from
the total preload shim thickness. The remainder is
the shim thickness required on the pinion side of the
housing.
Fig. 19 DIFFERENTIAL SIDE PLAY
1 - DIFFERENTIAL CASE
2 - DIFFERENTIAL HOUSING
3 - PILOT STUD
4 - DIAL INDICATOR
Fig. 20 ZERO DIAL INDICATOR
1 - FORCE CASE TO PINION SIDE
2 - PILOT STUD
3 - DIAL INDICATOR EXTENSION
4 - DIAL INDICATOR
Fig. 21 RECORD DIAL INDICATOR
1 - DIAL INDICATOR
2 - FORCE CASE TO RING GEAR SIDE
3 - DIFFERENTIAL HOUSING
KJREAR AXLE - 198RBI 3 - 59
REAR AXLE - 198RBI (Continued)
DIFFERENTIAL BEARING PRELOAD CHECK
The final check on the differential assembly before
installing the axles is torque to rotate pinion and dif-
ferential combined. This will verify the correct differ-
ential bearing preload.Torque to rotate the differential and pinion is the
torque to rotate the pinion plus:
Gear Ratio 3.73.......0.45-0.76 N´m (4-7 in. lbs.)
Gear Ratio 4.10......0.41-0.69 N´m (3.6-6 in. lbs.)
SPECIFICATIONS - REAR AXLE
SPECIFICATIONS
DESCRIPTION SPECIFICATION
Axle Ratio 3.73 4.10
Ring Gear Diameter 198 mm (7.795 in.)
Ring Gear Backlash 0.13-0.20 mm (0.005-0.008 in.)
Pinion Gear Standard Depth 96.85 mm (3.813 in.)
Pinion Bearing Preload - New Bearings 1.69-2.82 N´m (15-25 in. lbs.)
Differential Side Gear Clearance 0-0.15 mm (0-0.006 in.)
Differential Bearing Preload 0.20 mm (0.008 in.)
Differential Bearing Preload Added To Pinion Torque To Rotate
3.73 Gear Ratio 0.45-0.76 N´m (4-7 in. lbs.)
4.10 Gear Ratio 0.41-0.69 N´m (3.6-6 in. lbs.)
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Ring Gear Bolts 129-142 95-105 -
Differential Bearing Cap
Bolts64-91 47-67 -
Differential Cover Bolts 38-45 28-33 -
Pinion Nut (Minimum) 271 200 -
Cross Shaft Lock Screw 11-22 8-16 -
3 - 62 REAR AXLE - 198RBIKJ
REAR AXLE - 198RBI (Continued)
PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assemblies.
(3) Remove rear brake rotors drums.
(4) Mark propeller shaft and pinion yoke for
installation reference.
(5) Remove the propeller shaft from the yoke.
(6) Rotate pinion gear three or four times and ver-
ify that pinion rotates smoothly.
(7) Measure and record torque to rotate the pinion
gear with an inch pound dial-type torque wrench.
(8) With a short piece of pipe and Spanner Wrench
6958 remove the pinion nut and washer (Fig. 31).
(9) Remove pinion companion flange with Remover
C-452 and Flange Wrench C-3281. (Fig. 32)
(10) Remove pinion seal with Remover 7794-A and
a slide hammer (Fig. 33).
INSTALLATION
(1) Apply a light coating of gear lubricant on the
lip of pinion seal. Install seal with an appropriate
seal installer (Fig. 34).
(2) Install yoke on the pinion gear with Installer
C-3718 and Spanner Wrench 6958 (Fig. 35).(3) Install anewnut on the pinion gear.Tighten
the nut only enough to remove the shaft end
play.
CAUTION: Do not exceed the minimum torque 271
N´m (200 ft. lbs.) when installing the pinion yoke
retaining nut at this point. Damage to collapsible
spacer or bearings may result.
(4) Rotate the pinion a minimum of ten times and
verify pinion rotates smoothly.
(5) Measure and recore pinion torque to rotate
with an inch pound torque wrench. Torque to rotate
should be equal to the reading recorded during
removal, plus 0.56 N´m (5 in. lbs.) (Fig. 36).
Fig. 31 YOKE SPANNER WRENCH
1 - PINION YOKE
2 - WRENCH
3 - PIPE
Fig. 32 PINION YOKE REMOVER
1 - WRENCH
2 - YOKE
3 - REMOVER
Fig. 33 PINION SEAL REMOVER
1 - REMOVER
2 - SLIDE HAMMER
3 - PINION SEAL
3 - 68 REAR AXLE - 198RBIKJ