
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

²Smooth appearance with no broken/dented sur-
faces on the bearing rollers or the roller contact sur-
faces
²Bearing cups must not be distorted or cracked
²Machined surfaces should be smooth and without
any raised edges
²Raised metal on shoulders of cup bores should be
removed with a hand stone
²Wear and damage to pinion gear mate shaft, pin-
ion gears, side gears and thrust washers. Replace as
a matched set only.
²Ring and pinion gear for worn and chipped teeth
²Ring gear for damaged bolt threads. Replaced as a
matched set only.
²Pinion yoke for cracks, worn splines, pitted areas,
and a rough/corroded seal contact surface. Repair or
replace as necessary.
²Preload shims for damage and distortion. Install
new shims if necessary.
DIFFERENTIAL ASSEMBLY
(1) Install the following components in the differ-
ential case.
²Differential side gears and thrust washers
²Pinion gears and thrust washers
²Pinion gear mate shaft (align holes in shaft and
case)
(2) Lubricate all differential components with hy-
poid gear lubricant.
PINION GEAR DEPTH INFORMATION
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. 22). Aplus (+) 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 centerline of the
ring gear to the back face of the pinion is 96.8 mm
(3.813 inches) for Model 35 axles (Fig. 23). The standard
depth provides the best teeth contact pattern.
THE BUTTON END ON THE PINION GEAR HEAD
IS NO LONGER A MACHINED-TO-SPECIFICATIONS
SURFACE. DO NOT USE THIS SURFACE FOR PIN-
ION DEPTH SET-UP OR CHECKING (Fig. 23).
Compensation for pinion depth variance is achieved
with select shims. In production the shims are placed
between the pinion gear and the inner pinion bearing
cone. For service the shims are placed under the in-
ner pinion bearing cup (Fig. 24).
If a new gear set is being installed, note the
depth variance etched into both the original
and replacement pinion gear. Add or subtract
the thickness of the original depth shims to
compensate for the difference in the depth vari-
ances. Refer to the Depth Variance charts.
Fig. 21 Inner Bearing Removal
Fig. 22 Pinion Gear ID Numbers
Fig. 23 Pinion Gear Head
JREAR SUSPENSION AND AXLES 3 - 21

BACKLASH AND CONTACT PATTERN ANALYSIS
(1) Rotate assembly several revolutions to seat
bearings. Measure backlash at three equally spaced
locations around the perimeter of the ring gear with
a dial indicator (Fig. 43).
The ring gear backlash must be within 0.12 -
0.20 mm (0.005 - 0.008 inch). It cannot vary
more than 0.05 mm (0.002 inch) between the
points checked.
If backlash must be adjusted, spacers are available
in various thicknesses. Adjust the backlash accord-
ingly (Fig. 44).DO NOT INCREASE THE TOTAL
SHIM PACK THICKNESS, EXCESSIVE BEAR-
ING PRELOAD AND DAMAGE WILL OCCUR.
The ring gear teeth contact patterns will show if
the pinion gear depth shim(s) have the correct thick-ness. It will also show if the ring gear backlash has
been adjusted correctly. The backlash must be main-
tained within the specified limits until the correct
tooth contact patterns are obtained.
(2) Apply a thin coat of hydrated ferric oxide, or
equivalent, to the drive and coast side of the ring
gear teeth.
(3) Rotate the ring gear one complete revolution in
both directions while a load is being applied. Insert a
pry bar between the differential housing and the case
flange. This will produce distinct contact patterns on
both the drive side and coast side of the ring gear
teeth.
(4) Note patterns in compound. Refer to (Fig. 45)
for interpretation of contact patterns and adjust ac-
cordingly.
Fig. 41 Differential Installation
Fig. 42 Differential Bearing Cap Reference Letters
Fig. 43 Ring Gear Backlash Measurement
Fig. 44 Backlash Shim Adjustment
JREAR SUSPENSION AND AXLES 3 - 27

8 1/4 AXLE
INDEX
page page
Axle Shaft, Seal and Bearing Service.......... 32
Differential Service........................ 34
Drive Axle Assembly ReplacementÐXJ Vehicles . . 31
Information.............................. 30Lubricant Change......................... 31
Lubricant Specifications..................... 31
Pinion Seal Replacement................... 33
INFORMATION
The housing consists of an iron differential housing
with axle shaft tubes extending from either side. The
tubes are welded to the housing to form a one-piece
axle.
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 used to relieve internal pres-
sure caused by lubricant vaporization and internal
expansion.
The axle shafts are retained by C-clips in the dif-
ferential side gears.
The removable cover provides a means for servicing
the differential without removing the axle.The axles have the gear ratio listed on a tag. The
tag is attached to the housing cover.
The differential case is a one-piece design. The dif-
ferential pinion mate shaft is retained with a
threaded roll pin. Preload and backlash is adjusted
by the use of threaded adjusters. Pinion bearing pre-
load is set and maintained by the use of a collapsible
spacer.
PINION GEAR DEPTH MEASUREMENT WITH
GAUGE SET 6575 is used when;
²The axle/differential housing is being replaced
²The original pinion depth shim pack is lost or mis-
placed
²Replacing the differential case
²Replacing pinion and differential bearings
Fig. 1 Axle DifferentialÐ8 1/4
3 - 30 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

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.
(23) Measure pinion bearing preload torque by ro-
tating pinion shaft with a Newton-meter or an inch-
pound torque wrench. The correct bearing preload
torque is 1 to 2 Nzm (10 to 20 in. lbs.). This torque
value is with replacement bearings and pinion nut
tightened with a minimum of 285 Nzm (210 ft. lbs.)
torque (Fig. 27).
When using original pinion rear bearing and
a replacement front bearing. The correct pre-
load torque is 1 Nzm (10 in. lbs.) in addition to
the torque measured and recorded during dis-
assembly.
The bearing preload torque should be con-
stant during a complete revolution of the pin-
ion gear shaft. If preload torque varies during
rotation of the shaft, there is an internal bind-
ing that must be corrected before final assem-
bly.
(24) If the specified torque is not obtained, tighten
the nut in small increments until the preload torque
is obtained.
The differential will be unacceptable for use
if the final nut torque is less than 285 Nzm (210
ft. lbs.) torque. If the preload torque is not
within the specified range this is also unaccept-
able.
DIFFERENTIAL CASE INSTALLATION
(1) Apply a coating of hypoid gear lubricant to the
differential bearings, bearing cups and threaded ad-
justers. A dab of grease can be used to keep the ad-
justers in position. Carefully position the assembled
differential case in the housing.(2) Observe the reference marks and install the
differential bearing caps at their original locations
(Fig. 28).
(3) Install the bearing cap bolts (Fig. 28). Tighten
the upper bolts to 14 Nzm (10 ft. lbs.) torque. Tighten
the lower bolts finger-tight until the bolt head is
lightly seated.
DIFFERENTIAL BEARING PRELOAD AND RING
GEAR BACKLASH ADJUSTMENT
The following limitations must be considered when
adjusting the differential:
²The maximum ring gear backlash variation is
0.003 inch (0.076 mm).
²Mark the gears so the same teeth are meshed dur-
ing all backlash measurements.
²Maintain the specified threaded-adjuster torque
while adjusting.
²Excessive adjuster torque will introduce a high
bearing load and cause premature bearing failure.
Insufficient adjuster torque can result in excessive
differential case free-play and ring gear noise.
²Insufficient adjuster torque will not support the
ring gear correctly and can cause excessive differen-
tial case free-play and ring gear noise.
The differential bearing cups will not always
immediately follow the threaded adjusters as
they are moved during adjustment. Ensure ac-
curate bearing cup responses to the adjust-
ments. Maintain the gear teeth engaged
(meshed) as marked. The bearings must be
seated by rapidly rotating the pinion gear a
half turn back and forth. Do this five to ten
times each time the threaded adjusters are ad-
justed.
(1) Use Wrench C-4164 to adjust each threaded ad-
juster inward (Fig. 29) until the differential bearing
free-play is eliminated. Allow some ring gear back-
lash (approximately 0.01 inch/0.25 mm) between the
Fig. 27 Bearing Preload Torque Measurement
Fig. 28 Bearing Caps & Bolts
JREAR SUSPENSION AND AXLES 3 - 41

ring and pinion gear. Seat the bearing cups with the
procedure described above.
(2) Install Dial Indicator (Fig. 30). Position the
plunger against the drive side of a ring gear tooth.
Measure the backlash at 4 positions (90 degrees
apart) around the ring gear. Locate and mark the
area of minimum backlash.
(3) Rotate the ring gear to the position of the least
backlash. Mark the gear so that all future backlash
measurements will be taken with the same gear
teeth meshed.
(4) Loosen the right-side, tighten the left-side
threaded adjuster. Obtain backlash of 0.003 to 0.004
inch (0.076 to 0.102 mm) with each adjuster tight-
ened to 14 Nzm (10 ft. lbs.) torque. Seat the bearing
cups with the procedure described above.(5) Tighten the differential bearing cap bolts to 136
Nzm (100 ft. lbs.) torque.
(6) Use Wrench C-4164 to tighten the right-side
threaded adjuster to 95 Nzm (70 ft. lbs.) torque. Seat
the bearing cups with the procedure described above.
Continue to tighten the right-side adjuster and seat
bearing cups until the torque remains constant at 95
Nzm (70 ft. lbs.)
(7) Measure the ring gear backlash. The range of
backlash is 0.005 to 0.008 inch (0.127 to 0.203 mm).
Continue increasing the torque at the right-side
threaded adjuster until the specified backlash is ob-
tained.
The left-side threaded adjuster torque should
have approximately 95 Nzm (70 ft. lbs.) torque.
If the torque is considerably less, the complete
adjustment procedure must be repeated.
(8) Tighten the left-side threaded adjuster until 95
Nzm (70 ft. lbs.) torque is indicated. Seat the bearing
rollers with the procedure described above. Do this
until the torque remains constant.
(9) Install the threaded adjuster locks . Ensure the
lock finger is engaged with the adjuster hole. Tighten
the lock screws to 10 Nzm (90 in. lbs.) torque.
SIDE GEAR CLEARANCE MEASUREMENT AND
ADJUSTMENT
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 and C-clip locks and pin-
ion mate shaft. If necessary, refer to the installation
located within this group.
(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. 31).
(3) If side gear clearances is no more than 0.005
inch. Determine if the shaft is contacting the pinion
Fig. 29 Threaded Adjuster Tool
Fig. 30 Ring Gear Backlash Measurement
Fig. 31 Side Gear Clearance Measurement
3 - 42 REAR SUSPENSION AND AXLESJ