1995 JEEP YJ wheel torque

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

LUBRICANT SPECIFICATIONS
Multi-purpose, hypoid gear lubricant should be
used in the 8 1/4 inch axle. The lubricant should
have MIL-L-2105C and API GL 5 quality specifica-
tions. MOPARtHypoid Gear Lubricant conforms to
both of these specifications.
²The factory installed lubricant for the 8 1/4 inch
rear axle is SAE 80W 90 gear lubricant.
²The factory installed lubricant quantity is 6762
fluid oz.
CAUTION: Overfilling the differential can result in
lubricant foaming and overheating.
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.
DRIVE AXLE ASSEMBLY REPLACEMENTÐXJ
VEHICLES
REMOVAL
(1) Raise the vehicle. Position support stands un-
der 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.
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. Use solvent to clean the mating surfaces.
(6) Apply a bead of MOPARtSilicone Rubber Seal-
ant to the housing cover (Fig. 2). Allow the sealant to
cure for a few minutes.
Install the housing cover within 5 minutes after
applying the sealant. If not installed the sealant
must be removed and another bead applied.
(7) Install the cover and any identification tag.
Tighten the cover bolts in a criss-cross pattern to 47
Nzm (35 ft. lbs.) torque.
(8) Refill the differential with Mopar Hypoid Gear
Lubricant 13 mm (1/2 in.) below the fill plug hole.
With Trac-Lok differentials, add a container of Mopar
Hypoid Gear Lubricant Additive.
CAUTION: Overfilling the differential can result in
lubricant foaming and overheating.
(9) Install the fill hole plug and lower the vehicle.
JREAR SUSPENSION AND AXLES 3 - 31

BEARING AND SEAL 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) If the original bearing is not reusable, install a
new bearing. Place the axle shaft bearing on the pilot
of Bearing Installer C-4198 and Handle C-4171.
CAUTION: DO NOT use the new axle shaft seal to
position or seat the bearing in the axle shaft bore.
(3) Insert the bearing into the tube. Ensure that
the bearing is not cocked and is seated firmly against
the tube shoulder.
(4) Install the new axle shaft seal (Fig. 6) with In-
staller C-4198 and Handle C-4171. The flat side of
the installation tool must face the seal.
(5) When the tool contacts the end of the tube
(face), the seal will be at the correct position and
depth.
AXLE SHAFT INSTALLATION
(1) Lubricate the bearing bore and seal lip. Insert
the axle shaft and engage the splines with the side
gear. Use care to prevent the shaft splines from dam-
aging the axle shaft seal lip.
(2) Insert the C-clip lock in the recessed groove(Fig. 4). Push the axle shaft outward to seat the C-
clip lock.
(3) Insert the pinion gear mate shaft in the case.
Install through the thrust washers and pinion gears.
Align the hole in the shaft with the lock screw hole.
Install the lock screw with Loctiteton the threads.
Tighten the screw to 11 Nzm (8 ft. lbs.) torque (Fig.
3).
(4) Clean the cover and apply a bead of sealant.
Refer to the Drain and Refill in this section.
(5) Install the brake drum and wheel and tire.
(6) Raise or lower the hoist until the vehicle is
level.
(7) Remove the fill hole plug. Fill the differential
housing with lubricant. Refer to the Specifications
chart for the type and the quantity. Install the fill
hole plug.
(8) Lower the vehicle and test the brakes and axle
for correct operation.
PINION SEAL REPLACEMENT
CAUTION: The following procedures must be used
so the correct pinion bearing preload torque is re-
tained. If this procedure is not followed completely,
it may result in premature failure of the rear axle.
REMOVAL
(1) Raise and support the vehicle.
(2) Mark the U-joint, pinion yoke, and pinion shaft
for reference.
(3) Disconnect the drive shaft from the pinion
yoke. Secure the drive shaft in an upright position to
prevent damage to the rear U-joint.
(4) Remove the rear wheels and brake drums to
prevent any drag. The drag can cause a possible false
bearing preload torque measurement.
(5) Use a Newton-meter or an inch-pound torque
wrench to measure the pinion bearing preload. Ro-
tate the pinion shaft several times with the torque
wrench. Note the indicated torque as the wrench is
moved through several revolutions.
This measurement is very important because
the bearing preload torque must be carefully
re-adjusted after the new seal is installed.
(6) Retain the yoke with Wrench C-3281. Remove
the pinion shaft nut and Belleville washer.
(7) Make reference marks and remove the yoke
with a puller.
(8) Lower the rear of the vehicle to prevent lubri-
cant leakage.
(9) Remove the pinion shaft seal with Puller
C-748. Clean the seal contact surface in the housing
bore.
Fig. 5 Axle Shaft Bearing Removal
Fig. 6 Axle Shaft Seal Installation
JREAR SUSPENSION AND AXLES 3 - 33

INSTALLATION
(1) Examine the splines on the pinion shaft for
burrs or wear.
(2) Remove any burrs and clean the shaft.
(3) Inspect the pinion yoke for cracks, worn splines
and a worn seal contact surface. Repair or replace
the yoke as necessary.
The outer perimeter of the seal is pre-coated
with a special sealant. An additional applica-
tion of sealant is not required.
(4) Install the replacement pinion shaft seal (Fig.
7) with Seal Installer C-4076-A and Handle C-4735-1.
The seal is correctly installed when the seal
flange contacts the face of the differential hous-
ing flange.
(5) Position the pinion yoke on the end of the shaft
with the reference marks aligned.
(6) Seat the yoke on the pinion shaft with Installer
C-3718 and Wrench C-3281.
(7) Remove the tools. Install the Belleville washer.
The convex side of the washer must face outward.
(8) Retain the pinion yoke with Wrench C-3281.
Tighten the shaft nut to 285 Nzm (210 ft. lbs.) torque
(Fig. 8). Rotate the pinion shaft several complete rev-
olutions to ensure that the bearing rollers are seated.
Use a Newton-meter or an inch-pound torque
wrench to measure the pinion gear bearing pre-
load torque.
CAUTION: Never loosen pinion gear nut to decrease
pinion gear bearing preload torque and never ex-
ceed specified preload torque. If preload torque is
exceeded a new collapsible spacer must be in-
stalled. The torque sequence will have to be re-
peated.
(9) Continue tightening and measuring the bearing
preload torque until it is the same as the original.The bearing preload torque should never be
greater than 1 Nzm (10 in. lbs.) more than the
recorded value.
The bearing preload torque should be con-
stant during a complete revolution of the pin-
ion gear. If the preload torque varies, this
indicates a binding condition. This condition
must be corrected before the installation of the
drive shaft.
(10) If the specified torque is not obtained, tighten
the nut in small increments until the preload torque
is obtained.
(11) Seal replacement is unacceptable if final nut
torque is less than 285 Nzm (210 ft. lbs.) torque.
(12) Install the drive shaft with the installation
reference marks aligned. Tighten the U-joint yoke
clamp screws to 19 Nzm (14 ft. lbs. or 170 in. lbs.)
torque.
(13) Install the brake drums, wheels and tires.
(14) Adjust the hoist so that the vehicle is in a
level position. Check the differential housing lubri-
cant level. If necessary, add MOPARtHypoid Gear
Lubricant.
DIFFERENTIAL SERVICE
SERVICE INFORMATION
It is not necessary to remove the complete axle to
service the differential.
CAUTION: When differential service is necessary,
both rear wheels must be raised off the surface.
They must be free to rotate.
Fig. 7 Pinion Shaft Seal Installation
Fig. 8 Tightening Pinion Shaft Nut
3 - 34 REAR SUSPENSION AND AXLESJ

TRAC-LOK DIFFERENTIAL
OPERATION
In a conventional differential, the torque applied to
the ring gear is transmitted to the axle shafts through
the differential gears. During normal operation, the
torque transmitted to each wheel is equal at all times.
However, if one wheel spins, the opposite wheel will
generate only as much torque as the spinning wheel.
In the Trac-Lok differential, part of the ring gear
torque is transmitted through clutch packs. The clutch
packs contain multiple disc. The clutch will have radial
grooves on the plates, and concentric grooves on the
discs or bonded fiber material which is smooth.
In operation, the Trac-Lok clutches are engaged by
two concurrent forces. The first being preload force ex-
erted through Belleville spring washers. The second is
from separating forces generated by the side gears (Fig.
1).
The Trac-Lok design provides the normal differential
action needed for turning corners. It also provides for
the transmission of equal torque to both wheels when
driving straight ahead. When one wheel loses traction,
the clutch packs transfer torque to the wheel having the
most traction. Trac-lok differentials resist wheel spin on
bumpy roads. It also provides more pulling power when
one wheel loses traction. Pulling power is continuous
until both wheels lose traction. If both wheels slip due
to unequal traction, Trac-Lok operation is normal. In ex-
treme cases of differences of traction, the wheel with
the least traction may spin. This occurs after the Trac-
Lok has transferred as much torque as possible to the
non-spinning wheel.
NOISE DIAGNOSIS
If chatter occurs when turning corners, the most
probable cause is incorrect or contaminated lubri-
cant. Before removing the Trac-Lok unit for repair,
drain, flush and refill the axle with the specified lu-
bricant. Refer to Lubricant change in this Group.
A container of Trac-Lok Lubricant (friction modi-
fier) should be added after.
Vehicles with a limited slip differential should be
road tested by making 10 to 12 slow figure-eight
turns. This maneuver will pump the lubricant
through the clutch discs.
Refer to Group 0, Lubrication and Maintenance for
additional information.
DIFFERENTIAL TEST
WARNING: WHEN SERVICING VEHICLES WITH A
LIMITED SLIP DIFFERENTIAL DO NOT USE THE EN-
GINE TO TURN THE AXLE AND WHEELS. BOTH
REAR WHEELS MUST BE RAISED AND THE VEHI-
CLE SUPPORTED. A LIMITED SLIP AXLE CAN EX-
ERT ENOUGH FORCE (IF ONE WHEEL IS IN
CONTACT WITH THE SURFACE) TO CAUSE THE
VEHICLE TO MOVE.
The differential can be tested without removing the
differential case by measuring rotating torque. Make
sure brakes are not dragging during this measure-
ment.
(1) Engine off, transmission in neutral, and park-
ing brake off.
(2) Place blocks in front and rear of both front
wheels.
(3) Jack up one rear wheel until it is completely off
the ground.
(4) Remove wheel and bolt special tool to studs.
Fig. 1 Limited Slip Differential OperationÐBoth
Wheels Driving
JREAR SUSPENSION AND AXLES 3 - 45

(5) Use torque wrench on Special Tool 6790 to ro-
tate wheel and read rotating torque (Fig. 2).
(6) If rotating torque is less than 22 Nzm (30 ft.
lbs.) or more than 271 Nzm (200 ft. lbs.) on either
wheel the unit should be service.
DIFFERENTIAL OVERHAUL
The Trac-Lok differential components are illus-
trated in (Fig. 3). Refer to this illustration during re-
pair service.
DISASSEMBLY
Service to the Trac-Lok differential requires the
use of Tool Set C-4487 (J-23781). Refer to Model 35
Axle section in this Group for Differential Removal
and Installation.
(1) Clamp one axle shaft in a vise equipped with
soft jaws (Fig. 4).
Fig. 3 Trac-Lok Differential Components
Fig. 2 Trac-Loc Test
Fig. 4 Axle Shaft As Holding Fixture
3 - 46 REAR SUSPENSION AND AXLESJ

pedal. The proper course of action is to bleed the sys-
tem, or replace thin drums and suspect quality brake
lines and hoses.
HARD PEDAL OR HIGH PEDAL EFFORT
A hard pedal or high pedal effort may be due to lin-
ing that is water soaked, contaminated, glazed, or
badly worn. The power booster or check valve could
also be faulty. Test the booster and valve as described
in this section.
BRAKE DRAG
Brake drag occurs when the lining is in constant
contact with the rotor or drum. Drag can occur at one
wheel, all wheels, fronts only, or rears only. It is a
product of incomplete brakeshoe release. Drag can be
minor or severe enough to overheat the linings, ro-
tors and drums. A drag condition also worsens as
temperature of the brake parts increases.
Brake drag also has a direct effect on fuel economy.
If undetected, minor brake drag can be misdiagnosed
as an engine or transmission/torque converter prob-
lem.
Minor drag will usually cause slight surface char-
ring of the lining. It can also generate hard spots in
rotors and drums from the overheat/cool down pro-
cess. In most cases, the rotors, drums, wheels and
tires are quite warm to the touch after the vehicle is
stopped.
Severe drag can char the brake lining all the way
through. It can also distort and score rotors and
drums to the point of replacement. The wheels, tires
and brake components will be extremely hot. In se-
vere cases, the lining may generate smoke as it chars
from overheating.
An additional cause of drag involves the use of in-
correct length caliper mounting bolts. Bolts that are
too long can cause a partial apply condition. The cor-
rect caliper bolts have a shank length of 67 mm
(2.637 in.), plus or minus 0.6 mm (0.0236 in.). Refer
to the Disc Brake service section for more detail on
caliper bolt dimensions and identification.
Some common causes of brake drag are:
²loose or damaged wheel bearing
²seized or sticking caliper or wheel cylinder piston
²caliper binding on bolts or slide surfaces
²wrong length caliper mounting bolts (too long)
²loose caliper mounting bracket
²distorted rotor, brake drum, or shoes
²brakeshoes binding on worn/damaged support
plates
²severely rusted/corroded components
²misassembled components.
If brake drag occurs at all wheels, the problem may
be related to a blocked master cylinder compensatorport or faulty power booster (binds-does not release).
The condition will worsen as brake temperature in-
creases.
The brakelight switch can also be a cause of drag.
An improperly mounted or adjusted brakelight
switch can prevent full brake pedal return. The re-
sult will be the same as if the master cylinder com-
pensator ports are blocked. The brakes would be
partially applied causing drag.
BRAKE FADE
Brake fade is a product of overheating caused by
brake drag. However, overheating and subsequent
fade can also be caused by riding the brake pedal,
making repeated high deceleration stops in a short
time span, or constant braking on steep roads. Refer
to the Brake Drag information in this section for
causes.
PEDAL PULSATION (NON-ABS BRAKES ONLY)
Pedal pulsation is caused by parts that are loose,
or beyond tolerance limits. This type of pulsation is
constant and will occur every time the brakes are ap-
plied.
Disc brake rotors with excessive lateral runout or
thickness variation, or out of round brake drums are
the primary causes of pulsation.
On vehicles with ABS brakes, remember that pedal
pulsation is normal during antilock mode brake
stops. If pulsation occurs during light to moderate
brake stops, a standard brake part is either loose, or
worn beyond tolerance.
BRAKE PULL
A front pull condition could be the result of:
²contaminated lining in one caliper
²seized caliper piston
²binding caliper
²wrong caliper mounting bolts (too long)
²loose caliper
²loose or corroded mounting bolts
²improper brakeshoes
²damaged rotor
²incorrect wheel bearing adjustment (at one wheel)
A worn, damaged wheel bearing or suspension com-
ponent are further causes of pull. A damaged front
tire (bruised, ply separation) can also cause pull.
Wrong caliper bolts (too long) will cause a partial ap-
ply condition and pull if only one caliper is involved.
A common and frequently misdiagnosed pull condi-
tion is where direction of pull changes after a few
stops. The cause is a combination of brake drag fol-
lowed by fade at the dragging brake unit.
As the dragging brake overheats, efficiency is so re-
duced that fade occurs. If the opposite brake unit is
still functioning normally, its braking effect is magni-
5 - 6 SERVICE BRAKE DIAGNOSISJ

air gap should be 0.40 to 1.3 mm (0.0157 to 0.051
in.). If gap is incorrect, the sensor is either loose, or
damaged.
A rear sensor air gap adjustment is only needed
when reinstalling an original sensor. Replacement
sensors have an air gap spacer attached to the sensor
pickup face. The spacer establishes correct air gap
when pressed against the tone ring during installa-
tion. As the tone ring rotates, it peels the spacer off
the sensor to create the required air gap. Rear sensor
air gap is 0.92-1.45 mm (0.036-0.057 in.).
Sensor air gap measurement, or adjustment proce-
dures are provided in this section. Refer to the front,
or rear sensor removal and installation procedures as
required.
FRONT WHEEL SENSOR REMOVAL
(1) Raise vehicle and turn wheel outward for easier
access to sensor.
(2) Remove sensor wire from mounting brackets.
(3) Clean sensor and surrounding area with shop
towel before removal.
(4) Remove bolt attaching sensor to steering
knuckle and remove sensor.
(5) remove sensor wire from brackets on body and
steering knuckle.
(6) Unseat sensor wire grommet in wheel house
panel.
(7) In engine compartment, disconnect sensor wire
connector at harness plug. Then remove sensor and
wire.
FRONT WHEEL SENSOR INSTALLATION
(1) Iforiginalsensor will be installed, wipe all
traces of old spacer material off sensor pickup face.
Use a dry shop towel for this purpose.
(2) Apply Mopar Lock N' Seal or Loctite 242 to bolt
that secures sensor in steering knuckle. Use new
sensor bolt if original bolt is worn or damaged.
(3) Position sensor on steering knuckle. Seat sen-
sor locating tab in hole in knuckle and install sensor
attaching bolt finger tight.
(4) Tighten sensor attaching bolt to 14 Nzm (11 ft.
lbs.) torque.
(5) If original sensor has been installed, check sen-
sor air gap. Air gap should be 0.40 to 1.3 mm (0.0157
to 0.051 in.). If gap is incorrect, sensor is either loose,
or damaged.
(6) Secure sensor wire to steering knuckle and
body brackets.
(7) Route sensor wire forward and behind shock
absorber. Then attach sensor wire to spring seat
bracket with grommets on sensor wire.
(8) Route sensor wire to outer sill bracket. Remove
all twists or kinks from wire.
(9) Attach sensor wire to sill bracket with grom-
met. Be sure wire is free of twists and kinks.(10) Verify sensor wire routing. Wire should loop
forward and above sill bracket. Loose end of wire
should be below sill bracket and towards brake hose.
(11) Seat sensor wire grommet in body panel and
clip wire to brake line at grommet location.
(12) Connect sensor wire to harness in engine com-
partment.
REAR WHEEL SENSOR REMOVAL
(1) On XJ models, raise and fold rear seat forward
for access to rear sensor connectors (Fig. 9).
(2) Disconnect sensors at rear harness connectors.
(3) Push sensor grommets and sensor wires
through floorpan.
(4) Raise vehicle.
(5) Disconnect sensor wires at rear axle connectors.
(6) Remove wheel and tire assembly.
(7) Remove brake drum.
(8) Remove clips securing sensor wires to brake-
lines, rear axle and, brake hose.
(9) Unseat sensor wire support plate grommet.
(10) Remove bolt attaching sensor to bracket and
remove sensor.
REAR WHEEL SENSOR INSTALLATION AND
ADJUSTMENT
(1) Iforiginal sensoris being installed, remove
any remaining pieces of cardboard spacer from sen-
sor pickup face. Use dry shop towel only to remove
old spacer material.
(2) Insert sensor wire through support plate hole.
Then seat sensor grommet in support plate.
(3) Apply Mopar Lock N' Seal or Loctite 242 to
Fig. 9 Acceleration Switch And Rear Sensor
Connections (XJ)
5 - 38 ABS OPERATION AND SERVICEJ