2002 JEEP LIBERTY Workshop Manual

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)

(5) Assemble Dial Indicator C-3339 into Scooter
Block D-115-2 and secure set screw.
(6) Position Scooter Block/Dial Indicator flush on
the pinion height block. Hold scooter block and zero
the dial indicator.
(7) Slowly slide the scooter block across the pinion
height block over to the arbor (Fig. 14). Move the
scooter block till the dial indicator probe crests the
arbor bar and record the highest reading. If the dial
indicator can not achieve the zero reading, the rear
bearing cup or the pinion depth gauge set is not
installed correctly.
(8) Select a shim equal to the dial indicator read-
ing plus the drive pinion gear depth variance number
etched in the face of the pinion gear (Fig. 9) using
the opposite sign on the variance number. For exam-
ple, if the depth variance is ±2, add +0.002 in. to the
dial indicator reading.
(9) Remove the pinion depth gauge components
from the housing
DIFFERENTIAL BEARING PRELOAD
Differential side bearing preload and gear backlash
is achieved by selective shims inserted between the
bearing cup and the housing. The proper shim thick-
ness can be determined using slip-fit Dummy Bear-
ings D-348 in place of the differential side bearings
and a Dial Indicator C-3339. Before proceeding with
the differential bearing preload and gear backlash
measurements, measure the pinion gear depth and
prepare the pinion gear for installation. Establishing
proper pinion gear depth is essential to establishing
gear backlash and tooth contact patterns. After the
overall shim thickness to take up differential sideplay is measured, the pinion gear is installed and the
gear backlash shim thickness is measured. The over-
all shim thickness is the total of the dial indicator
reading, starting point shim thickness and the pre-
load specification added together. The gear backlash
measurement determines the thickness of the shim
used on the ring gear side of the differential case.
Subtract the gear backlash shim thickness from the
total overall shim thickness and select that amount
for the pinion gear side of the differential (Fig. 15).
Fig. 13 GAUGE TOOLS IN HOUSING
1 - ARBOR DISC
2 - PINION BLOCK
3 - ARBOR
4 - PINION HEIGHT BLOCKFig. 14 Pinion Gear Depth Measurement
1 - ARBOR
2 - SCOOTER BLOCK
3 - DIAL INDICATOR
Fig. 15 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 - 57
REAR AXLE - 198RBI (Continued)

PRELOAD SHIM SELECTION
NOTE: It is difficult to salvage the differential side
bearings during the removal procedure. Install
replacement bearings if necessary.
(1) Remove side bearings from differential case.
(2) Install ring gear, if necessary, on differential
case and tighten bolts to specification.
(3) Install Dummy Bearings D-348 on differential
case.
(4) Install differential case in the housing.
(5) Insert Dummy Shims 8107 (0.118 in. / 3.0 mm)
starting point shims between the dummy bearing
and the housing (Fig. 16).
(6) Install bearing caps in their correct positions
and snug the bolts.
(7) Use a dead-blow hammer to seat the differen-
tial dummy bearings to each side of the housing (Fig.
17) and (Fig. 18).
Fig. 16 DUMMY SHIMS
1 - DUMMY SHIM
2 - DIFFERENTIAL HOUSING
3 - DIFFERENTIAL CASE
4 - DUMMY BEARINGS
Fig. 17 SEAT DUMMY BEARING PINION GEAR SIDE
Fig. 18 SEAT DUMMY BEARING RING GEAR SIDE
1 - DIFFERENTIAL HOUSING
2 - DEAD-BLOW HAMMER
3 - DIFFERENTIAL CASE
3 - 58 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)

(24) Rotate dial indicator out of the way on pilot
stud.
(25) Remove differential case and dummy bearings
from the housing.
(26) Install new side bearing cones and cups on
differential case.
(27) Install spreader W-129-B and some compo-
nents of Adapter Set 6987 on differential housing and
spread axle opening enough to receive differential
case.
(28) Place side bearing shims into the housing
against the axle tubes.
(29) Install differential case in the housing.
(30) Rotate the differential case several times to
seat the side bearings.
(31) Position the indicator plunger against a ring
gear tooth (Fig. 22).
(32) Push and hold ring gear upward while not
allowing the pinion gear to rotate.
(33) Zero dial indicator face to pointer.
(34) Push and hold ring gear downward while not
allowing the pinion gear to rotate. Dial indicator
reading should be between 0.13-0.20 mm (0.005-0.008
in.). If backlash is not within specifications transfer
the necessary amount of shim thickness from one
side of the differential housing to the other (Fig. 23).
(35) Verify differential case and ring gear runout
by measuring ring to pinion gear backlash at eight
locations around the ring gear. Readings should not
vary more than 0.05 mm (0.002 in.). If readings varymore than specified, the ring gear or the differential
case is defective.
After the proper backlash is achieved, perform the
Gear Contact Pattern Analysis procedure.
GEAR CONTACT PATTERN
The ring gear and pinion teeth contact patterns
will show if the pinion depth is correct in the hous-
ing. It will also show if the ring gear backlash has
been adjusted correctly. The backlash can be adjusted
within specifications to achieve desired tooth contact
patterns.
(1) Apply a thin coat of hydrated ferric oxide or
equivalent to the drive and coast side of the ring gear
teeth.
(2) Wrap, twist, and hold a shop towel around the
pinion yoke to increase the turning resistance of the
pinion. This will provide a more distinct contact pat-
tern.
(3) With a boxed end wrench on a ring gear bolt,
rotate the differential case one complete revolution in
both directions while a load is being applied from
shop towel.
The areas on the ring gear teeth with the greatest
degree of contact against the pinion teeth will
squeeze the compound to the areas with the least
amount of contact. Note and compare patterns on the
ring gear teeth to Gear Tooth Contact Patterns chart
(Fig. 24) and adjust pinion depth and gear backlash
as necessary.
Fig. 22 RING GEAR BACKLASH
1 - DIAL INDICATOR
Fig. 23 BACKLASH SHIM
3 - 60 REAR AXLE - 198RBIKJ
REAR AXLE - 198RBI (Continued)

Fig. 24 GEAR TOOTH CONTACT PATTERNS
KJREAR AXLE - 198RBI 3 - 61
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)

SPECIAL TOOLS
REAR AXLE
PULLER C-293-PA
ADAPTER 8352
ADAPTER C-293-39
PLUG SP-3289
PULLER C-452
WRENCH C-3281
SPANNER WRENCH 6958
HANDLE C-4171
INSTALLER C-3716-A
INSTALLER D-130
KJREAR AXLE - 198RBI 3 - 63
REAR AXLE - 198RBI (Continued)