1995 JEEP YJ torque

(11) Check bearing rotating torque with an inch
pound torque wrench (Fig. 54).If torque to rotate is
within specification, remove old nut and install new
nut. The torque necessary to rotate the pinion gear
should be;
²Original Bearings: 1 to 3 Nzm (10 to 20 in. lbs.).
²New Bearings: 2 to 5 Nzm (15 to 35 in. lbs.).
(12) If rotating torque is high, add shims to de-
crease torque. If rotating torque is low, remove shims
to increase torque.DIFFERENTIAL SHIM PACK MEASUREMENT AND
ADJUSTMENT
(1) Place Master Differential Bearing D-134
(D-348) on the case hubs.
(2) Install a pilot stud at the left side of housing.
Attach Dial Indicator to housing. Load the indicator
plunger against the back of the ring gear (Fig. 55).
Ensure ring and pinion gear teeth are tightly
meshed. Zero the indicator.
Fig. 51 Pinion Seal Installation
Fig. 52 Pinion Yoke Installation
Fig. 53 Tightening Pinion Nut
Fig. 54 Check Pinion Gear Torque
JFRONT SUSPENSION AND AXLE 2 - 43

(3) Spread the housing enough to install the case
in the housing. Measure the distance with the dial
indicator (Fig. 58).
(4) Remove the dial indicator.
(5) Install case in the housing. Tap the differential
case to ensure the bearings are fully seated (Fig. 59).
Remove the spreader.
(6) Install the bearing caps at their original loca-
tions (Fig. 60). Tighten the bearing cap bolts to 61
Nzm (45 ft. lbs.) torque.
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. 61).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, transfer shims from
one side of carrier to the other side. Adjust the back-
lash accordingly (Fig. 62).DO NOT INCREASE
THE TOTAL SHIM PACK THICKNESS, EXCES-
SIVE BEARING PRELOAD AND DAMAGE WILL
OCCUR.
If the mesh and backlash steps have been followed,
good gear teeth contact patterns should exist.
The ring gear teeth contact patterns will show if
the pinion gear depth is correct. It will also show if
the ring gear backlash has been adjusted correctly.
The backlash must be maintained within the speci-
fied limits until the correct tooth contact patterns are
obtained.
(2) Apply a thin coat of hydrated ferric oxide (yel-
low oxide of iron) to the drive and coast side of the
ring gear teeth.
Fig. 58 Spread Differential Housing
Fig. 59 Differential Installation
Fig. 60 Differential Bearing Cap Reference Letters
Fig. 61 Ring Gear Backlash Measurement
JFRONT SUSPENSION AND AXLE 2 - 45

(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 to load gears. This will produce a distinct con-
tact patterns on both the drive side and coast side of
the ring gear teeth.(4) Note patterns in compound. Refer to (Fig. 63)
for interpretation of contact patterns and adjust ac-
cordingly.
FINAL ASSEMBLY
(1) Install the axle shafts. Refer to Axle Shaft In-
stallation in this Group.
(2) Scrape the residual sealant from the housing
and cover mating surfaces. Clean the mating surfaces
with mineral spirits. Apply a bead of MOPARtSili-
cone Rubber Sealant on the housing cover (Fig. 64).
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.
(3) Install the cover on the differential with the at-
taching bolts. Install the identification tag. Tighten
the cover bolts with 41 Nzm (30 ft. lbs.) torque.
CAUTION: Overfilling the differential can result in
lubricant foaming and overheating.
(4) Refill the differential housing with the specified
quantity of MOPARtHypoid Gear Lubricant.
(5) Install the fill hole plug and tighten to 34 Nzm
(25 ft. lbs.) torque.
Fig. 62 Backlash Shim Adjustment
2 - 46 FRONT SUSPENSION AND AXLEJ

AXLE SPECIFICATIONS
MODEL 30 FRONT AXLE
Axle Type........................................................Hypoid
Lubricant................SAE Thermally Stable 80W-90
Lube Capacity
YJ .....................................................1.65 L (3.76 pts.)
XJ .....................................................1.48 L (3.13 pts.)
Axle Ratio...................................3.07 3.55 3.73 4.10
DifferentialSide Gear Clearance .0.12-0.20mm (0.005-0.008 in.)
Ring Gear
Diameter .....................................18.09 cm (7.125 in.)
Backlash.........................0-0.15 mm (0.005-0.008 in.)
Pinion Std. Depth...................92.1 mm (3.625 in.)
Pinion Bearing Preload
Original Bearing ..................1-2 Nzm (10-20 in. lbs.)
New Bearing ......................1.5-4 Nzm (15-35 in. lbs.)
TORQUE SPECIFICATIONS
XJ FRONT SUSPENSION COMPONENTS
DESCRIPTION ................................................TORQUE
Shock Absorber
Upper Nut ......................................11 Nzm (8 ft. lbs.)
Lower Nut ....................................23 Nzm (17 ft. lbs.)
Suspension Arm Upper
Front Nut .....................................74 Nzm (55 ft. lbs.)
Rear Nut ......................................89 Nzm (66 ft. lbs.)
Suspension Arm Lower
Front and Rear Nut ..................115 Nzm (85 ft. lbs.)
Stabilizer Bar
Clamp Bolt ...................................54 Nzm (40 ft. lbs.)
Link Upper Nut ..........................36 Nzm (27 ft. lbs.)
Link Lower Nut ..........................95 Nzm (70 ft. lbs.)
Track Bar
Ball Stud Nut ..............................81 Nzm (60 ft. lbs.)
Axle Bracket Bolt ......................100 Nzm (74 ft. lbs.)
Track Bar Bracket
Bolts............................................125 Nzm (92 ft. lbs.)
Nut ..............................................100 Nzm (74 ft. lbs.)
Support Bolts ...............................42 Nzm (31 ft. lbs.)
YJ FRONT SUSPENSION COMPONENTS
DESCRIPTION ................................................TORQUE
Shock Absorber
Upper Nut ......................................13 Nzm (9 ft. lbs.)Lower Nut ....................................61 Nzm (45 ft. lbs.)
Stabilizer Bar
Clamp Bolt ...................................41 Nzm (30 ft. lbs.)
Link Nut ......................................61 Nzm (45 ft. lbs.)
Track Bar
Frame Bracket Nut.................142 Nzm (105 ft. lbs.)
Axle Bracket Nut ......................100 Nzm (74 ft. lbs.)
Spring
U-Bolt Nut .................................122 Nzm (90 ft. lbs.)
Front Shackle Bolt ..................135 Nzm (100 ft. lbs.)
Rear Pivot Bolt........................142 Nzm (105 ft. lbs.)
MODEL 30 AXLE
DESCRIPTION ................................................TORQUE
Fill Hole Plug...........................34 Nzm (25 ft. lbs.)
Diff. Cover Bolt........................41 Nzm (30 ft. lbs.)
Bearing Cap Bolt.....................61 Nzm (45 ft. lbs.)
Ring Gear Bolt.............95-122 Nzm (70-90 ft. lbs.)
Shift Motor Bolt.........................11 Nzm (8 ft. lbs.)
Axle Nut.................................237 Nzm (175 ft. lbs.)
Wheel Brg. Bolt......................102 Nzm (75 ft. lbs.)
Lower Ball Stud.....................108 Nzm (80 ft. lbs.)
Upper Ball Stud.....................101 Nzm (75 ft. lbs.)
ABS Sensor Bolt......................11 Nzm (96 in. lbs.)
JFRONT SUSPENSION AND AXLE 2 - 49

REAR SUSPENSION AND AXLES
CONTENTS
page page
8 1/4 AXLE............................ 30
AXLE NOISE/VIBRATION DIAGNOSIS......... 9
AXLE SPECIFICATIONS................... 51
GENERAL INFORMATION.................. 1
MODEL 35 AXLE........................ 13TORQUE SPECIFICATIONS................ 51
TRAC-LOK DIFFERENTIAL................. 45
XJ SUSPENSION......................... 3
YJ SUSPENSION......................... 6
GENERAL INFORMATION
SUSPENSION COMPONENTS
The Jeep rear suspension is comprised of;
²Drive axle
²Leaf springs
²Dual-action shock absorbers
²Track bar (YJ vehicles)
²Stabilizer bar (XJ vehicles)
²Jounce bumpers
The rear suspension design uses semi-elliptic
multi-leaf springs and a solid drive axle. The forward
end of the springs are mounted to the frame rail
hangers through rubber bushings. The bushings iso-
late road noise as the springs move. The rearward
end of the springs are attached to the frame by the
use of shackles. Again the spring and shackles use
rubber bushings to isolate road noise. The shackles
allow the springs to change their length as the vehi-
cle moves over various road conditions. The spring
and axle travel is limited through the use of bumpers
mounted on frame.
All suspension components that use bushings
should be tightened with the vehicle at normal ride
height. If the springs are not at normal ride position,
vehicle ride comfort could be affected. Rubber bush-
ings must never be lubricated.
The springs are attached to the axle pads with U-
bolts and plates. The springs use a center bolt that
holds the spring leafs in position. The bolt is also
used to locate the spring assembly to the axle pad.
Ride control is accomplished through the use of du-
al-action shock absorbers. The shocks dampen the
jounce and rebound as the vehicle travels over vari-
ous road conditions. The top of shock absorbers are
bolted to the frame bracket. The bottom of the shocks
are bolted to the axle bracket.
The stabilizer bar on the XJ is used to minimize
vehicle rear sway during turns. The bar helps the ve-
hicle maintain a flat attitude to the road surface. The
bar extends across the underside of the chassis and
connects to the frame rails. The links are connectedto the axle brackets. All mounting points of the sta-
bilizer bar are isolated by bushings.
The track bar on the YJ is used to minimize rear
axle side-to-side movement. The track bar is attached
to the frame rail bracket and axle bracket and is iso-
lated with bushings.
The jounce bumpers are used to limit the jounce
and rebound travel of the suspension.
AXLES
The Model 35 axle is standard for XJ and YJ vehi-
cles. The 8 1/4 axle is available in XJ vehicles with-
out ABS brakes.
The Model 35 and 8 1/4 axle housings has a cast
iron center section. Two steel axle shaft tubes are
pressed into the differential housing and welded.
It is not necessary to remove the axle from the ve-
hicle for service. A removable differential cover is
provided for routine vehicle service. If the differential
housing is damaged, the complete axle assembly can
be removed.
For complete drive axle assembly removal and in-
stallation refer to Drive Axle Assembly Replacement
in this Group.
IDENTIFICATION
Model 35 axle has the assembly part number and
gear ratio listed on a tag. The tag is attached to the left
side of the housing cover (Fig. 1). Build date identifica-
tion codes on axles are stamped on the axle shaft tube
cover side. The Model 35 axle has a flat housing cover
gasket flange at the outer edge (Fig. 1).
The 8 1/4 axle has the build date code and gear ra-
tio tags attached to the housing cover (Fig. 2). The
housing cover gasket has a rolled gasket flange at
the outer edge (Fig. 2).
²The Model 35 axle has shaft tubes that are 2.625
inch (66.67 mm) in diameter.
²The 8 1/4 axle has axle shaft tubes that are 3.0-
inch (76.2 mm) in diameter.
JREAR SUSPENSION AND AXLES 3 - 1

STANDARD DIFFERENTIAL OPERATION
The differential gear system divides the torque be-
tween the axle shafts. It allows the axle shafts to ro-
tate at different speeds when turning corners.
Each differential side gear is splined to an axle
shaft. The pinion gears are mounted on a pinion
mate shaft and are free to rotate on the shaft. The
pinion gear is fitted in a bore in the differential case
and is positioned at a right angle to the axle shafts.
In operation, power flow occurs as follows:
²The pinion gear rotates the ring gear²The ring gear (bolted to the differential case) ro-
tates the case
²The differential pinion gears (mounted on the pin-
ion mate shaft in the case) rotate the side gears
²The side gears (splined to the axle shafts) rotate
the shafts
During straight-ahead driving, the differential pin-
ion gears do not rotate on the pinion mate shaft. This
occurs because input torque applied to the gears is
divided and distributed equally between the two side
gears. As a result, the pinion gears revolve with the
pinion mate shaft but do not rotate around it (Fig. 3).
When turning corners, the outside wheel must travel
a greater distance than the inside wheel in order to
complete a turn. The difference must be compensated
for, to prevent the tires from scuffing and skidding
through turns. To accomplish this, the differential al-
lows the axle shafts to turn at unequal speeds (Fig. 4).
In this instance, the input torque applied to the pinion
gears is not divided equally. The pinion gears now ro-
tate around the pinion mate shaft in opposite directions.
This allows the side gear and axle shaft attached to the
outside wheel to rotate at a faster speed.
Fig. 4 Differential OperationÐOn Turns
Fig. 1 Model 35 Differential Cover
Fig. 2 8 1/4 Differential Cover
Fig. 3 Differential OperationÐStraight-Ahead Driving
3 - 2 REAR SUSPENSION AND AXLESJ

XJ SUSPENSION
INDEX
page page
Leaf Spring............................... 4
Leaf Spring Eye Bushing Replacement.......... 5
Shock Absorber........................... 4Spring and Shock Diagnosis.................. 3
Stabilizer Bar............................. 5
SPRING AND SHOCK DIAGNOSIS
A noise from the shock absorber or spring bushings
can be produced if movement between the rubber
bushings and the metal occurs. This noise can usu-
ally be stopped by tightening the nuts. If the noise
persists, inspect for damaged and worn bushings. Re-
pair as necessary.
The shock absorbers are not refillable or adjust-
able. If a malfunction occurs, the shock absorber
must be replaced. To test a shock absorber, hold it in
an upright position and force the piston into and out
of the cylinder four or five times. The action through-
out each stroke should be smooth and even.
The spring eye and shock absorber bushings do not
require any type of lubrication.Do not attempt to
stop spring bushing noise by lubricating them.Grease and mineral oil-base lubricants will de-
teriorate the bushing rubber.
If the vehicle is used for severe, off-road operation,
the springs should be examined regularly. Check for
broken and shifted components.
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.
SPRING AND SHOCK ABSORBER DIAGNOSIS
JREAR SUSPENSION AND AXLES 3 - 3

SHOCK ABSORBER
REMOVAL
(1) Remove the shock absorber upper bolts from the
frame bracket (Fig. 1).
(2) Remove the lower attaching nut and washer
from the bracket stud. Remove the shock absorber.
INSTALLATION
(1) Install the shock absorber lower eye on the
spring bracket stud. Install the shock absorber and
upper bolts on the frame bracket (Fig. 1).
(2) Tighten the lower nut to 62 Nzm (46 ft. lbs.)
torque.
(3) Tighten the upper bolts to 23 Nzm (17 ft. lbs.)
torque.
LEAF SPRING
REMOVAL
(1) Raise vehicle at frame.
(2) Remove the wheel and tire assemblies.
(3) Support axle with hydraulic jack to relieve axle
weight.
(4) Disconnect the shock absorber from the axle
bracket or the spring bracket (Fig. 1).
(5) Disconnect the stabilizer bar link from the
spring bracket stud.(6) Remove nuts, U-bolts and spring bracket from
axle (Fig. 1).
(7) Remove nut and bolt attaching spring front eye
to shackle (Fig. 1).
(8) Remove nut and bolt from spring rear eye (Fig.
1).
(9) Remove spring from vehicle.
INSTALLATION
(1) Position the spring front eye in the bracket.
Loosely install the attaching bolt and nut (Fig. 1). Do
not tighten at this time.
(2) Position the rear eye in the shackle bracket.
Loosely install the attaching bolt and nut (Fig. 1). Do
not tighten at this time.
(3) Position the axle. Install the spring bracket,
U-bolts and nuts (Fig. 1). Tighten the nuts to 70 Nzm
(52 ft. lbs.) torque.
(4) Connect the stabilizer bar link to the spring
bracket.
(5) Connect the shock absorber to the axle bracket
or spring bracket.
(6) Remove the hydraulic jack.
(7) Lower the vehicle.
(8) Tighten the spring front eye attaching bolts to
148 Nzm (109 ft. lbs.) torque.
(9) Tighten the spring rear eye attaching bolts to
108 Nzm (80 ft. lbs.) torque.
Fig. 1 Spring & Shock AbsorberÐXJ Vehicles
3 - 4 REAR SUSPENSION AND AXLESJ