JEEP YJ 1995 Service And Repair Manual

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 gear 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
²Worn, out-of-balance wheels
²Loose wheel lug nuts
²Worn U-joint
²Loose spring U-bolts
²Loose/broken springs
²Damaged axle shaft bearings
²Loose pinion gear nut
²Excessive pinion yoke run out
²Bent axle shaft
Check for loose or damaged front-end components
or engine/transmission mounts. These components
can contribute to what appears to be a rear-end vi-
bration. Do not overlook engine accessories, brackets
and drive belts.
All driveline components should be examined be-
fore starting any repair.
Refer to Group 22, Wheels and Tires for additional
information.
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
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\ase clearance
The source of a snap or a clunk noise can be deter-
mined with the assistance of a helper. Raise the ve-
hicle 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.
REAR AXLE ALIGNMENT
MEASUREMENT
The following procedure can be used to determine
if abnormal rear tire tread wear is the result of a
bent or deformed rear axle shaft.
(1) Raise both rear wheels off the surface with a
frame contact hoist.
(2) Attach a one-inch long piece of masking tape at
the center of each tire tread for use as reference marks.
(3) Rotate the rear wheels until both reference
marks face the front of the vehicle. Measure the dis-
tance between the outside edges of the two pieces of
tape. Record this measurement as the front of tire
(FTR) measurement.
(4) Rotate the rear wheels until both reference
marks face the rear of the vehicle. Measure the dis-
tance between the outside edges of the two pieces of
tape. Record this measurement as the rear of tire
(RTR) measurement.
(5) Subtract the (RTR) measurement from the
(FTR) measurement to obtain the amount of wheel
toe. The acceptable rear wheel toe-in position is 1/16
inch (1.6 mm) to 3/16 inch (4.8 mm) toe-out.
(6) Rotate the rear wheels until the reference
marks are facing downward. Measure the distance
between the outside edges of the two pieces of tape.
Record this measurement as the bottom of tire (BTR)
measurement.
(7) Average the (FTR) and the (RTR) distance mea-
surements. Subtract the (BTR) measurement from
this average distance to obtain the camber. The ac-
ceptable amount of camber is 1/16 inch to 3/32 inch
(1.6 to 2.4 mm).
(FTR + RTR) DIVIDED BY 2 (TWO) MINUS
BTR EQUALS CAMBER
If the (BTR) distance measurement is less
than the average FTR and RTR distance mea-
surement, the camber will be positive(+).If
the (BTR) distance measurement is greater
than the average FTR and RTR distance, the
camber will be negative(-).
If the toe position or camber is not acceptable, a bent
or deformed rear axle shaft is most likely the cause.
LIMITED SLIP DIFFERENTIAL
Under normal traction conditions, engine torque is di-
vided evenly. With low-traction surfaces, engine torque
is transferred to the wheel with the most tire traction.
When diagnosing a limited-slip differential the wheel
with the least traction can continue spinning.
The most common problem is a chatter noise when
turning corners. Check for incorrect or contaminated
lubricant. Replace the gear lubricant if necessary.
²With Trac-LokŸ differentials add a container of
MOPAR Trac-Lok Lubricant.
This will correct the condition in most instances. If
the chatter persists, clutch damage could have oc-
curred.
After changing the lubricant, drive the vehicle and
make 10 to 12 slow, figure-eight turns. This maneu-
ver will pump lubricant through the clutches.
3 - 10 REAR SUSPENSION AND AXLESJ

SERVICE DIAGNOSIS
JREAR SUSPENSION AND AXLES 3 - 11

SERVICE DIAGNOSIS (CONT'D)
3 - 12 REAR SUSPENSION AND AXLESJ

MODEL 35 AXLE
INDEX
page page
Axle Shaft............................... 16
Axle Shaft Seal and Bearing................. 17
Backlash and Contact Pattern Analysis......... 27
Cleaning/Inspection........................ 20
Differential Assembly....................... 21
Differential Disassembly.................... 18
Differential Measurement and Installation........ 25
Differential Removal....................... 18
Drive Axle Assembly ReplacementÐXJ Vehicles . . 14Drive Axle Assembly ReplacementÐYJ Vehicles . . 14
Final Assembly........................... 29
General Information....................... 13
Lubricant Change......................... 13
Lubricant Specifications..................... 13
Pinion Gear Depth Information............... 21
Pinion Measurement and Assembly............ 22
Pinion Removal/Disassembly................. 19
Pinion Shaft Seal Replacement............... 15
GENERAL INFORMATION
The Model 35 housing has an iron center casting
(differential housing) with axle shaft tubes extending
from either side. The tubes are pressed into and
welded to the differential housing to form a one-piece
axle housing.
The integral type housing, hypoid gear design has
the centerline of the pinion set below the centerline
of the ring gear.
The axle has a vent hose to relieve internal pres-
sure caused by lubricant vaporization and internal
expansion.
The axles are equipped with semi-floating axle
shafts, meaning that loads are supported by the axle
shaft and bearings. The axle shafts are retained by
C-clips in the differential side gears.
The cover provides a means for servicing the differ-
ential without removing the axle.
Axles may be equipped with drum or disc brakes.
The axles that are equipped with ABS brake have a
tone ring pressed on the axle shaft. Use care when
removing axle shafts as NOT to damage the tone
wheel or the sensor.
The Model 35 axle has the assembly part number
and gear ratio listed on a tag. The tag is attached to
the housing cover. Build date identification codes are
stamped on the axle shaft tube cover side.
The differential case is a one-piece design. The dif-
ferential pinion mate shaft is retained with a
threaded roll pin. Differential bearing preload and
ring gear backlash is adjusted by the use of spacer
shims. Pinion bearing preload is set and maintained
by the use of a collapsible spacer.
For complete drive axle assembly removal
and installation refer to Drive Axle Assembly
Replacement in this Group.
LUBRICANT SPECIFICATIONS
Multi-purpose, hypoid gear lubricant should be
used for Model 35 axle. The lubricant should haveMIL-L-2105C and API GL 5 quality specifications.
MOPAR Hypoid Gear Lubricant conforms to both of
these specifications.
²Lubricant for Model 35 axle is a thermally stable
SAE 80W-90 gear lubricant.
²Lubricant for Model 35 axle with Trailer Tow is
SAE 75W-140 SYNTHETIC gear lubricant.
²Trac-Lok differentials add 4 oz. of friction modifier.
²Lubricant quantity is 1.66 L (3.50 pts.).
Refer to Group 0, Lubrication and Maintenance for
additional information.
CAUTION: If axle is submerged in water, lubricant
must be replaced immediately to avoid possible
premature axle failure.
LUBRICANT CHANGE
The gear lubricant will drain quicker if the vehicle
has been recently driven.
(1) Raise and support the vehicle.
(2) Remove the lubricant fill hole plug from the dif-
ferential housing cover.
(3) Remove the differential housing cover and
drain the lubricant from the housing.
(4) Clean the housing cavity with a flushing oil,
light engine oil or lint free cloth.Do not use water,
steam, kerosene or gasoline for cleaning.
(5) Remove the sealant from the housing and cover
surfaces.
(6) Apply a bead of MOPARtSilicone Rubber Seal-
ant to the housing cover (Fig. 1).Allow the sealant
to cure for a few minutes.
Install the housing cover within 5 minutes af-
ter applying the sealant. If not installed the
sealant must be removed and another bead ap-
plied.
(7) Install the cover and any identification tag.
Tighten the cover bolts to 41 Nzm (30 ft. lbs.) torque.
(8) Refill differential with Mopar Hypoid Gear Lu-
bricant to bottom of the fill plug hole.
JREAR SUSPENSION AND AXLES 3 - 13

CAUTION: Overfilling the differential can result in
lubricant foaming and overheating.
Trac-Lok Differentials; A container of Trac-Lok lu-
bricant (friction modifier) should be added after re-
pair service or a lubricant change.
(9) Install the fill hole plug and lower the vehicle.
LIMITED SLIP DIFFERENTIAL vehicles should
be road tested by making 10 to 12 slow figure-eight
turns. This maneuver will pump the lubricant
through the clutch discs to eliminate a possible chat-
ter noise complaint.
DRIVE AXLE ASSEMBLY REPLACEMENTÐXJ
VEHICLES
REMOVAL
(1) Raise the vehicle and position support stands
under the frame rails slightly in front the springs.
(2) Remove the rear wheels.
(3) Mark the drive shaft yoke and axle pinion yoke
for alignment reference. Disconnect the drive shaft
from the axle.
(4) Disconnect the axle vent hose.
(5) Disconnect the parking brake cables at the
equalizer or backing plate.
(6) Disconnect the shock absorbers from the axle
brackets.
(7) Disconnect the brake hose at the axle junction
block.Do not disconnect the wheel cylinder tub-
ing fittings.
(8) If equipped, disconnect ABS wiring connections
at the axle.(9) Support the axle with a hydraulic jack under
the differential.
(10) Remove the spring U-bolts from the plate
brackets.
(11) Lower the jack enough to remove the axle.
INSTALLATION
CAUTION: Suspension components with rubber
bushings should be tightened with the vehicle at
normal height. It is important to have the springs
supporting the weight of the vehicle when the fas-
teners are torqued. If springs are not at their normal
ride position, vehicle ride comfort could be affected
and premature bushing wear may occur. Rubber
bushings must never be lubricated.
(1) Support the axle on a hydraulic jack under the
differential. Position the axle under the vehicle.
(2) Raise the axle and align the spring center bolts
with the locating holes in the axle pads and plate
brackets.
(3) Install the spring U-bolts through the plate
brackets and tighten to 70 Nzm (52 ft. lbs.) torque.
(4) Install ABS wiring connections (if equipped) at
the axle.
(5) Connect the brake hose at the axle junction
block.
(6) Install the shock absorbers to the axle brackets
and tighten to 62 Nzm (46 ft. lbs.) torque.
(7) Connect the parking brake cables at the equal-
izer or backing plate.
(8) Connect the vent hose to the tube fitting.
(9) Align the reference marks and connect the
drive shaft to the axle yoke. Tighten the U-joint
clamp bolts to 19 Nzm (14 ft. lbs.) torque.
(10) Check differential lubricant and add if neces-
sary.
(11) Install the wheel and tire.
(12) Bleed the brakes.
(13) Remove the supports and lower the vehicle.
DRIVE AXLE ASSEMBLY REPLACEMENTÐYJ
VEHICLES
REMOVAL
(1) Raise the vehicle and position support stands
under the frame rails slightly in front the springs.
(2) Remove the rear wheels.
(3) Mark the drive shaft yoke and axle pinion yoke
for alignment reference. Disconnect the drive shaft
from the axle.
(4) Disconnect the axle vent hose.
(5) Disconnect the parking brake cables at the
equalizer or backing plate.
(6) Disconnect the shock absorbers from the plate
brackets.
Fig. 1 Typical Housing Cover With Sealant
3 - 14 REAR SUSPENSION AND AXLESJ

(7) Disconnect the brake hose at the axle junction
block.Do not disconnect the wheel cylinder tub-
ing fittings.
(8) Disconnect the track bar at the axle bracket.
(9) Support the axle with a hydraulic jack under
the differential. Raise the axle just enough to relieve
the axle weight from the springs.
(10) Remove the spring U-bolts from the plate
brackets.
(11) Loosen BUT DO NOT REMOVE the bolts that
attach the spring front pivot at the frame rail brack-
ets. This will allow the springs to pivot without bind-
ing on the bushings.
(12) Disconnect shackle from the springs and lower
the springs to the surface.
(13) Lower the jack enough to remove the axle.
INSTALLATION
CAUTION: Suspension components with rubber
bushings should be tightened with the vehicle at
normal height. It is important to have the springs
supporting the weight of the vehicle when the fas-
teners are torqued. If springs are not at their normal
ride position, vehicle ride comfort could be affected
and premature bushing wear may occur. Rubber
bushings must never be lubricated.
(1) Support the axle on a hydraulic jack under the
differential. Position the axle under the vehicle.
(2) Raise the springs and install the spring shackle
bolts.Do not tighten at this time.
(3) Lower the axle and align the spring center
bolts with the locating holes in the axle pads and
plate brackets.
(4) Install the spring U-bolts through the plate
brackets and tighten to 122 Nzm (90 ft. lbs.) torque.
(5) Connect the track bar to the axle bracket and
install the bolt. Do not tighten at this time.
It is important that the springs support the
weight of the vehicle when the track bar is con-
nected. If the springs are not at their usual po-
sition, vehicle ride comfort could be affected.
(6) Connect the brake hose at the axle junction
block.
(7) Install the shock absorbers to the axle brackets
and tighten to 61 Nzm (45 ft. lbs.) torque.
(8) Connect the parking brake cables at the equal-
izer or backing plate.
(9) Connect the vent hose to the tube fitting.
(10) Align the reference marks and connect the
drive shaft to the axle yoke. Tighten the U-joint
clamp bolts to 19 Nzm (14 ft. lbs.) torque.
(11) Check differential lubricant and add if neces-
sary.
(12) Install the wheel and tire.
(13) Bleed the brakes.
(14) Remove the supports and lower the vehicle.(15) Tighten the spring front pivot bolt/nut to 142
Nzm (105 ft. lbs.) torque. Tighten the spring shackle
bolt/nut to 135 Nzm (100 ft. lbs.) torque.
(16) Tighten the track bar bolt at the axle bracket
to 142 Nzm (105 ft. lbs.) torque.
PINION SHAFT SEAL REPLACEMENT
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assemblies.
(3) Mark the drive shaft yoke and pinion yoke for
installation alignment reference.
(4) Remove the drive shaft from the yoke.
(5) Rotate the pinion gear three or four times.
Make sure brakes are not dragging during this
procedure.
(6) Measure the amount of torque (in Newton-
meters or inch-pounds) necessary to rotate the pinion
gear with a torque wrench. Note the torque for in-
stallation reference.It must be known to properly
adjust the pinion gear bearing preload torque
after seal installation.
(7) Remove the pinion yoke nut and washer. Use
Remover C-452 and Wrench C-3281 to remove the
pinion yoke (Fig. 2).
(8) Mark the positions of the yoke and pinion gear
for installation alignment reference.
(9) Use Remover 7794A and slide hammer to re-
move the pinion gear seal (Fig. 3).
INSTALLATION
(1) Apply a light coating of gear lubricant on the
lip of pinion seal. Install seal with Installer D-163
and Handle C-4171 (Fig. 4).
(2) Align the installation reference marks and in-
stall yoke on the pinion gear with Installer W-162-D.
(3) Install a new nut on the pinion gear.Tighten
the nut only enough to remove the shaft end
play.
Fig. 2 Pinion Yoke Removal
JREAR SUSPENSION AND AXLES 3 - 15

CAUTION: Exercise care during the bearing preload
torque adjustment. Do not over-tighten, or loosen
and then re-tighten the nut. Do not exceed the bear-
ing preload torque. The collapsible preload spacer
on the shaft will have to be replaced. The bearing
preload torque will be re-adjusted afterward.
(4) Install a socket and inch-pound torque wrench
on the pinion nut.
(5) Rotate the shaft with the torque wrench and
note the torque.
The required preload torque is equal to the
amount recorded during removal plus an addi-
tional 0.56 Nzm (5 in. lbs.).
(6) Use Flange Wrench C-3281 to retain the yoke
and shaft (Fig. 5). Tighten the shaft nut in very
small increments.(7) Continue tightening the shaft nut in small in-
crements until the correct bearing preload torque is
attained.
(8) Align the installation reference marks and at-
tach the drive shaft to the yoke.
(9) Add API grade GL 5 hypoid gear lubricant to
the differential housing, if necessary.
(10) Install wheel and tire assemblies.
(10) Lower the vehicle.
AXLE SHAFT
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the wheel and tire.
(3) Remove the brake drum.
(4) Clean all the foreign material from housing
cover area.
(5) Loosen the housing cover bolts. Drain the lubri-
cant from the housing and the axle shaft tubes. Re-
move the housing cover.
(6) Rotate the differential case so that the pinion
mate gear shaft lock screw is accessible. Remove the
lock screw and the pinion mate gear shaft from the
case (Fig. 6).
(7) Force the axle shaft in toward the center of the
vehicle. Remove the axle shaft C-clip lock from the
axle shaft (Fig. 7).
(8) Remove the axle shaft. Use care to prevent
damage to the axle shaft bearing and seal, which will
remain in the axle shaft tube.
(9) Inspect axle shaft seal for leakage or damage.
Fig. 3 Seal Removal
Fig. 4 Pinion Seal Installation
Fig. 5 Tightening Pinion Shaft Nut
3 - 16 REAR SUSPENSION AND AXLESJ

(10) Inspect the roller bearing contact surface on
the axle shaft for signs of brinelling, spalling and pit-
ting.
(11) If any of these conditions exist, the axle shaft
and bearing or seal must be replaced.
INSTALLATION
(1) Lubricate the bearing bore and seal lip with
gear lubricant. Insert the axle shaft through the seal,
bearing, and engage it with the side gear splines.
Use care to prevent the shaft splines from dam-
aging the axle shaft seal lip.
(2) Insert the C-clip lock in the end of the axle
shaft. Push the axle shaft outward to seat the C-clip
lock in the side gear.
(3) Insert the mate shaft into the case and through
the thrust washers and pinion gears. Align the hole
in shaft with the hole in the differential case and in-
stall the lock screw with Loctiteton the threads.
Tighten the screw to 19 Nzm (14 ft. lbs.) torque.
(4) Install the cover and add fluid. Refer to the
Drain and Refill in this section.
AXLE SHAFT SEAL AND BEARING
REMOVAL
(1) Remove the axle shaft. Refer to the Removal
procedures in this Group.
(2) Remove the axle shaft seal from the end of the
axle shaft tube with a small pry bar.
(3) Remove the bearing if it appears damaged.
The seal and bearing can be removed at the same
time with the bearing removal tool.
(4) Remove the axle shaft bearing from the tube
(Fig. 8) with Bearing Removal Tool Set 6310 (T.Ar
960-02).
(5) Inspect the axle shaft tube bore for roughness
and burrs. Remove as necessary.
CAUTION: Inspect the housing bore for burrs. Re-
move them if they exist.
INSTALLATION
Do not install the original axle shaft seal. Al-
ways install a new seal.
(1) Wipe the bore in the axle shaft tube clean.
(2) Install axle shaft bearing with Installer 6436
and Handle C-4171. Ensure part number on the
bearing must go against the Installer.
(3) Install the new axle shaft seal (Fig. 9) with In-
staller 6437 and Handle C-4171.
(4) Install the Axle Shaft. Refer to the installation
procedure.
Fig. 6 Mate Shaft Lock Screw
Fig. 7 Axle Shaft C-Clip Lock
Fig. 8 Axle Shaft Bearing Removal Tool
JREAR SUSPENSION AND AXLES 3 - 17

DIFFERENTIAL REMOVAL
To service the differential the axle shafts must be
removed. Refer to the removal procedures in this
Group.
(1) Note the installation reference letters stamped
on the bearing caps and housing machined sealing
surface (Fig. 10).
(2) Remove the differential bearing caps.
(3) Position Spreader W-129-B with the tool dowel
pins seated in the locating holes (Fig. 11). Install the
holddown clamps and tighten the tool turnbuckle fin-
ger-tight.
(4) Install a pilot stud at the left side of the differ-
ential housing. Attach Dial Indicator to housing pilot
stud. Load the indicator plunger against the opposite
side of the housing (Fig. 11) and zero the indicator.
CAUTION: Do not spread over 0.38 mm (0.015 in). If
the housing is over-separated, it could be distorted
or damaged.(5) Separate the housing enough to remove the
case from the housing. Measure the distance with the
dial indicator (Fig. 11).
(6) Remove the dial indicator.
(7) Pry the differential case loose from the housing.
To prevent damage, pivot on housing with the end of
the pry bar against spreader (Fig. 12).
(8) Remove the case from housing. Mark or tag
bearing cups and outboard shim/spacer (selected
thickness) indicating which side they were removed.
Remove spreader from housing.
DIFFERENTIAL DISASSEMBLY
(1) Remove the bearings from the differential case
with Press C-293-PA, Plug SP3289, Adapter C-293-18
(Fig. 13).
Fig. 9 Axle Shaft Seal Installation
Fig. 10 Bearing Cap Identification
Fig. 11 Spread Differential Housing
Fig. 12 Differential Removal
3 - 18 REAR SUSPENSION AND AXLESJ

Place adapter rings so they do not damage
the bearing cage.
(2) Clamp the differential case in a vise equipped
with soft jaws. Remove and discard the ring gear
bolts. Tap the ring gear with a rawhide or plastic
mallet and remove (Fig. 14).
(3) Rotate the differential side gears and remove
the pinion mate gears and thrust washers (Fig. 15).
(4) Remove the differential side gears and thrust
washers.(5) Remove the case from the vise.
PINION REMOVAL/DISASSEMBLY
(1) Remove the pinion yoke nut and washer. Use
Remover C-452 and Wrench C-3281 to remove the
pinion yoke (Fig. 16).
(2) Remove the pinion gear from housing (Fig. 17).
Catch the pinion with your hand to prevent it from
falling and being damaged.
(3) Remove the pinion gear seal with a slide ham-
mer or pry out with bar.
(4) Remove oil slinger, front bearing.
(5) Remove the front pinion bearing cup and seal
with Remover D-147 and Handle C-4171 (Fig. 18).
(6) Remove the rear bearing cup from housing (Fig.
19). Use Remover D-148 and Handle C-4171.
Fig. 13 Differential Bearing Removal
Fig. 14 Ring Gear Removal
Fig. 15 Pinion Mate Gear Removal
Fig. 16 Pinion Yoke Removal
JREAR SUSPENSION AND AXLES 3 - 19