2002 JEEP LIBERTY Workshop Manual

Fig. 16 Gear Tooth Contact Patterns
3 - 96 REAR AXLE-81/4KJ
REAR AXLE - 8 1/4 (Continued)

SIDE GEAR CLEARANCE
NOTE: When measuring side gear clearance, check
each gear independently. If it necessary to replace a
side gear, replace both gears as a matched set.
(1) Install the axle shafts, C-locks and pinion mate
shaft.
(2) Measure each side gear clearance. Insert a
matched pair of feeler gauge blades between the gear
and differential housing on opposite sides of the hub
(Fig. 17).
(3) If side gear clearances is no more than 0.005
inch. Determine if the axle shaft is contacting the
pinion mate shaft.Do not remove the feeler
gauges, inspect the axle shaft with the feeler
gauge inserted behind the side gear.If the end ofthe axle shaft is not contacting the pinion mate
shaft, the side gear clearance is acceptable.
(4) If clearance is more than 0.005 inch (axle shaft
not contacting mate shaft), record the side gear clear-
ance. Remove the thrust washer and measure its
thickness with a micrometer. Add the washer thick-
ness to the recorded side gear clearance. The sum of
gear clearance and washer thickness will determine
required thickness of replacement thrust washer
(Fig. 18).
In some cases, the end of the axle shaft will move
and contact the mate shaft when the feeler gauge is
inserted. The C-lock is preventing the side gear from
sliding on the axle shaft.
(5) If there is no side gear clearance, remove the
C-lock from the axle shaft. Use a micrometer to mea-
sure the thrust washer thickness. Record the thick-
ness and re-install the thrust washer. Assemble the
differential case without the C-lock installed and re-
measure the side gear clearance.
(6) Compare both clearance measurements. If the
difference is less than 0.012 inch (0.305 mm), add
clearance recorded when the C-lock was installed to
thrust washer thickness measured. The sum will
determine the required thickness of the replacement
thrust washer.
(7) If clearance is 0.012 inch (0.305 mm) or
greater, both side gears must be replaced (matched
set) and the clearance measurements repeated.
(8) If clearance (above) continues to be 0.012 inch
(0.305 mm) or greater, the case must be replaced.
Fig. 17 Side Gear Clearance
1 - FEELER GAUGE BLADES
2 - SIDE GEAR
Fig. 18 Side Gear Calculations
KJREAR AXLE - 8 1/4 3 - 97
REAR AXLE - 8 1/4 (Continued)

SPECIFICATIONS
REAR AXLE
AXLE SPECIFICATIONS
DESCRIPTION SPECIFICATION
Axle Ratio 3.07, 3.55, 4.10
Differential Case Flange Runout 0.076 mm (0.003 in.)
Differential Case Clearance 0.12 mm (0.005 in.)
Ring Gear Diameter 209.5 mm (8.25 in.)
Ring Gear Backlash 0.12-0.20 mm (0.005-0.008 in.)
Ring Gear Runout 0.12 mm (0.005 in.)
Pinion Bearing Preload - Original Bearings 1-2 N´m (10-20 in. lbs.)
Pinion Bearing Preload - New Bearings 1-3.4 N´m (10-30 in. lbs.)
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Differential Cover Bolts 41 30 -
Bearing Cap Bolts 136 100 -
Ring Gear Bolts 95 70 -
Pinion Nut Minimum 285 210 -
Pinion Mate Shaft Screw 16.25 12 -
SPECIAL TOOLS
8 1/4 AXLE
PULLER 6790
REMOVER 6310
INSTALLER C-4198
HANDLE C-4171
3 - 98 REAR AXLE-81/4KJ
REAR AXLE - 8 1/4 (Continued)

INSTALLER C-4076-B
HANDLE C-4735-1
HOLDER 6719
PULLER C-452
INSTALLER C-3718
ADJUSTMENT WRENCH C-4164
PULLER/PRESS C-293±PA
ADAPTERS C-293-48
ADAPTER PLUG SP-3289
ADAPTERS C-293-47
INSTALLER C-4340
KJREAR AXLE - 8 1/4 3 - 99
REAR AXLE - 8 1/4 (Continued)

FIXTURE 8138
INSTALLER C-4345
REMOVER C-4307
INSTALLER C-4308
INSTALLER D-130
INSTALLER 6448
TRAC-LOKŸ TOOLS 8140
TRAC-LOKŸ TOOLS 6960
PINION BLOCK 8540
ARBOR DISCS 8541
PINION GAUGE SET
3 - 100 REAR AXLE-81/4KJ
REAR AXLE - 8 1/4 (Continued)

AXLE SHAFTS
REMOVAL
(1) Place the transmission in NEUTRAL and raise
and support vehicle.
(2) Remove wheel and tire assembly.
(3) Remove brake drum.
(4) Remove the housing cover and drain lubricant.
(5) Rotate differential case to access the pinion
shaft lock screw. Remove lock screw and pinion shaft
from differential case (Fig. 19).
(6) Push axle shaft inward then remove axle shaft
C-lock (Fig. 20).(7) Remove axle shaft being carefull not to damage
shaft bearing and seal.
(8) Inspect axle shaft seal for leakage or damage.
(9) Inspect axle shaft bearing contact surface for
signs of brinelling, galling and pitting.
INSTALLATION
(1) Lubricate bearing bore and seal lip with gear
lubricant. Insert axle shaft through seal, bearing and
engage it into side gear splines.
NOTE: Use care to prevent shaft splines from dam-
aging axle shaft seal lip.
(2) Insert C-lock in end of axle shaft. Push axle
shaft outward to seat C-lock in side gear.
(3) Insert pinion shaft into differential case and
through thrust washers and differential pinions.
(4) Align hole in shaft with hole in the differential
case and install lock screw with Loctiteton the
threads. Tighten lock screw to 11 N´m (8 ft. lbs.).
(5) Install cover and fill with gear lubricant to the
bottom of the fill plug hole.
(6) Install brake drum.
(7) Install wheel and tire assemblies.
(8) Remove support and lower vehicle.
AXLE SHAFT SEALS
REMOVAL
(1) Raise and support vehicle.
(2) Remove axle shaft.
(3) Remove axle shaft seal from the axle tube with
a small pry bar (Fig. 21).
Fig. 19 Pinion Shaft Lock Screw
1 - LOCK SCREW
2 - PINION SHAFT
Fig. 20 Axle Shaft C-Lock
1 - C-LOCK
2 - AXLE SHAFT
3 - SIDE GEARFig. 21 Axle Seal
1 - AXLE TUBE
2 - AXLE SEAL
3-PRYBAR
KJREAR AXLE - 8 1/4 3 - 101

INSTALLATION
(1) Wipe the axle tube bore clean. Remove any old
sealer or burrs from the tube.
(2) Install anewaxle seal with Installer C-4076-B
and Handle C-4735-1. When the tool contacts the
axle tube, the seal is installed to the correct depth.
(3) Coat the lip of the seal with axle lubricant for
protection prior to installing the axle shaft.
(4) Install the axle shaft.
(5) Check and fill gear lubricant.
(6) Install wheel and tire assembly.
(7) Remove support and lower vehicle.
AXLE BEARINGS
REMOVAL
(1) Raise and support vehicle.
(2) Remove axle shaft.
(3) Remove axle shaft seal from the axle tube with
a small pry bar (Fig. 22).
NOTE: The seal and bearing can be removed at the
same time with the bearing removal tool.
(4) Remove axle shaft bearing with Bearing
Removal Tool Set 6310 and Adapter Foot 6310-9 (Fig.
23).
INSTALLATION
(1) Wipe the axle tube bore clean. Remove any old
sealer or burrs from the tube.
(2) Install axle shaft bearing with Installer C-4198
and Handle C-4171.NOTE: Install bearing with part number against the
installer.
(3) Install anewaxle seal with Installer C-4198
and Handle C-4171. When the tool contacts the axle
tube, the seal is installed to the correct depth.
(4) Coat the lip of the seal with axle lubricant for
protection prior to installing the axle shaft.
(5) Install the axle shaft.
(6) Check and fill gear lubricant.
(7) Install wheel and tire assembly.
(8) Remove support and lower vehicle.
PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Mark the universal joint, pinion yoke and pin-
ion shaft for installation reference.
(3) Remove propeller shaft from pinion yoke.
(4) Remove the wheel and tire assemblies.
(5) Remove the brake drums.
(6) Rotate the pinion yoke three or four times.
Fig. 22 Axle Seal
1 - AXLE TUBE
2 - AXLE SEAL
3-PRYBAR
Fig. 23 Axle Shaft Bearing
1 - NUT
2 - GUIDE PLATE
3 - GUIDE
4 - THREADED ROD
5 - ADAPTER
6 - FOOT
7 - AXLE TUBE
3 - 102 REAR AXLE-81/4KJ
AXLE SHAFT SEALS (Continued)

(7) Measure rotating torque of the pinion gear
with an inch pound torque wrench and record the
reading for installation reference.
(8) Hold the pinion yoke with Holder 6719 and
remove the pinion nut and washer.
(9) Remove yoke with Remover C-452 (Fig. 24).
(10) Remove pinion seal with a pry tool or screw
mounted to a slide-hammer mounted.
INSTALLATION
(1) Apply a light coating of gear lubricant on the
lip of pinion seal.
NOTE: The outer perimeter of the seal is pre-coated
with a special sealant. An additional application of
sealant is not required.
(2) Install thenewpinion seal (Fig. 25) with
Installer C-4076-A and Handle C-4735.
(3) Install pinion yoke on the shaft with the refer-
ence marks aligned.
(4) Seat yoke on pinion shaft with Installer C-3718
and Holder 6719A.
(5) Remove the tools and install the pinion yoke
washer. The convex side of the washer must face out-
ward.
(6) Using yoke Holder 6719A tighten shaft nut to
285 N´m (210 ft. lbs.) (Fig. 26). Rotate the pinion sev-
eral revolutions to ensure the bearing rollers are
seated.
(7) Rotate the pinion using an inch pound torque
wrench. Rotating torque should be equal to the read-
ing recorded during removal, plus an additional 0.56
N´m (5 in. lbs.) (Fig. 27).CAUTION: Never loosen pinion nut to decrease pin-
ion rotating torque and never exceed specified pre-
load torque. If preload torque is exceeded a new
collapsible spacer must be installed.
(8) If the rotating torque is low, use Holder 6719A
(Fig. 26) and tighten the pinion nut in 6.8 N´m (5 ft.
Fig. 24 Pinion Yoke
1 - PINION YOKE
2 - REMOVER
Fig. 25 Pinion Seal Installer
1 - HANDLE
2 - DIFFERENTIAL HOUSING
3 - INSTALLER
Fig. 26 Tightening Pinion Nut
1 - DIFFERENTIAL HOUSING
2 - YOKE HOLDER
3 - TORQUE WRENCH
KJREAR AXLE - 8 1/4 3 - 103
PINION SEAL (Continued)