Jeep Cherokee XJ 1995-1999 Rear Suspension and Axles

REAR SUSPENSION AND AXLES

CONTENTS

page page

8 1/4 AXLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30AXLE NOISE/VIBRATION DIAGNOSIS . . . . . . . . . 9AXLE SPECIFICATIONS . . . . . . . . . . . . . . . . . . . 51GENERAL INFORMATION . . . . . . . . . . . . . . . . . . 1MODEL 35 AXLE . . . . . . . . . . . . . . . . . . . . . . . . 13

TORQUE SPECIFICATIONS . . . . . . . . . . . . . . . . 51TRAC-LOK DIFFERENTIAL . . . . . . . . . . . . . . . . . 45XJ SUSPENSION . . . . . . . . . . . . . . . . . . . . . . . . . 3YJ SUSPENSION . . . . . . . . . . . . . . . . . . . . . . . . . 6

GENERAL INFORMATION

SUSPENSION COMPONENTSThe Jeep rear suspension is comprised of;

Drive axle Leaf springs Dual-action shock absorbers Track bar (YJ vehicles) Stabilizer bar (XJ vehicles) Jounce bumpers

The rear suspension design uses semi-ellipticmulti-leaf springs and a solid drive axle. The forwardend of the springs are mounted to the frame railhangers through rubber bushings. The bushings iso-late road noise as the springs move. The rearwardend of the springs are attached to the frame by theuse of shackles. Again the spring and shackles userubber bushings to isolate road noise. The shacklesallow the springs to change their length as the vehi-cle moves over various road conditions. The springand axle travel is limited through the use of bumpersmounted on frame.

All suspension components that use bushingsshould be tightened with the vehicle at normal rideheight. 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 thatholds the spring leafs in position. The bolt is alsoused 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 thejounce and rebound as the vehicle travels over vari-ous road conditions. The top of shock absorbers arebolted to the frame bracket. The bottom of the shocksare bolted to the axle bracket.

The stabilizer bar on the XJ is used to minimizevehicle rear sway during turns. The bar helps the ve-hicle maintain a flat attitude to the road surface. Thebar extends across the underside of the chassis andconnects to the frame rails. The links are connected

to 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 rearaxle side-to-side movement. The track bar is attachedto the frame rail bracket and axle bracket and is iso-lated with bushings.

The jounce bumpers are used to limit the jounceand rebound travel of the suspension.

AXLESThe 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 castiron center section. Two steel axle shaft tubes arepressed into the differential housing and welded.

It is not necessary to remove the axle from the ve-hicle for service. A removable differential cover isprovided for routine vehicle service. If the differentialhousing is damaged, the complete axle assembly canbe removed.

For complete drive axle assembly removal and in-stallation refer to Drive Axle Assembly Replacementin this Group.

IDENTIFICATIONModel 35 axle has the assembly part number and

gear ratio listed on a tag. The tag is attached to the leftside of the housing cover (Fig. 1). Build date identifica-tion codes on axles are stamped on the axle shaft tubecover side. The Model 35 axle has a flat housing covergasket 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). Thehousing cover gasket has a rolled gasket flange atthe outer edge (Fig. 2). The Model 35 axle has shaft tubes that are 2.625inch (66.67 mm) in diameter. The 8 1/4 axle has axle shaft tubes that are 3.0-inch (76.2 mm) in diameter.

J REAR SUSPENSION AND AXLES 3 - 1

STANDARD DIFFERENTIAL OPERATIONThe 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 axleshaft. The pinion gears are mounted on a pinionmate shaft and are free to rotate on the shaft. Thepinion gear is fitted in a bore in the differential caseand is positioned at a right angle to the axle shafts.

In operation, power flow occurs as follows: The pinion gear rotates the ring gear

The ring gear (bolted to the differential case) ro-tates the case The differential pinion gears (mounted on the pin-ion mate shaft in the case) rotate the side gears The side gears (splined to the axle shafts) rotatethe shafts

During straight-ahead driving, the differential pin-ion gears do not rotate on the pinion mate shaft. Thisoccurs because input torque applied to the gears isdivided and distributed equally between the two sidegears. As a result, the pinion gears revolve with thepinion mate shaft but do not rotate around it (Fig. 3).

When turning corners, the outside wheel must travela greater distance than the inside wheel in order tocomplete a turn. The difference must be compensatedfor, to prevent the tires from scuffing and skiddingthrough 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 piniongears 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 theoutside wheel to rotate at a faster speed.

Fig. 4 Differential OperationOn Turns

Fig. 1 Model 35 Differential Cover

Fig. 2 8 1/4 Differential Cover

Fig. 3 Differential OperationStraight-Ahead Driving

3 - 2 REAR SUSPENSION AND AXLES J

XJ SUSPENSION

INDEX

page page

Leaf Spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Leaf Spring Eye Bushing Replacement . . . . . . . . . . 5Shock Absorber . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Spring and Shock Diagnosis . . . . . . . . . . . . . . . . . . 3Stabilizer Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

SPRING AND SHOCK DIAGNOSISA noise from the shock absorber or spring bushings

can be produced if movement between the rubberbushings and the metal occurs. This noise can usu-ally be stopped by tightening the nuts. If the noisepersists, 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 absorbermust be replaced. To test a shock absorber, hold it inan upright position and force the piston into and outof 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 notrequire any type of lubrication. Do not attempt tostop 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 forbroken and shifted components.

CAUTION: Suspension components with rubberbushings should be tightened with the vehicle atnormal height. It is important to have the springssupporting the weight of the vehicle when the fas-teners are torqued. If springs are not at their normalride position, vehicle ride comfort could be affectedand premature bushing wear may occur. Rubberbushings must never be lubricated.

SPRING AND SHOCK ABSORBER DIAGNOSIS


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 andupper 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 fromaxle (Fig. 1).

(7) Remove nut and bolt attaching spring front eyeto 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). Donot tighten at this time.

(2) Position the rear eye in the shackle bracket.Loosely install the attaching bolt and nut (Fig. 1). Donot 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 springbracket.

(5) Connect the shock absorber to the axle bracketor 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 AbsorberXJ Vehicles


LEAF SPRING EYE BUSHING REPLACEMENT(1) Assemble tools shown (Fig. 2). Tighten the nut

located at the socket wrench end of the threaded roduntil the bushing is forced out.

(2) Assemble and align the bushing installationtools.

(3) Align the bushing with the spring eye. Tightenthe nut located at the socket wrench end of thethreaded rod. Tighten until the bushing is forced intothe spring eye.

The bushing must be centered in the springeye. The ends of the bushing must be flush orslightly recessed within the end surfaces of thespring eye.

STABILIZER BAR

REMOVAL(1) Raise and support the vehicle.(2) Disconnect stabilizer bar links from spring

brackets (Fig. 3).(3) Disconnect the stabilizer bar brackets from the

frame rails. Remove the stabilizer bar and links.

INSTALLATION(1) Position the stabilizer bar links at the spring

brackets (Fig. 3). Install the attaching bolts and nutsand tighten to 74 Nzm (55 ft. lbs.) torque.

(2) Attach the stabilizer bar to the frame railbrackets with the bolts. Tighten to 54 Nzm (40 ft.lbs.).

(3) Remove the supports and lower the vehicle.

Fig. 2 Spring Eye Bushing Removal

Fig. 3 Stabilizer BarXJ Vehicles


YJ SUSPENSION

INDEX

page page

Leaf Spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Leaf Spring Eye Bushing Replacement . . . . . . . . . . 7Shock Absorber . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Spring and Shock Diagnosis . . . . . . . . . . . . . . . . . . 6Track Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

SPRING AND SHOCK DIAGNOSISA noise from the shock absorber or spring bushings

can be produced if movement between the rubberbushings and the metal occurs. This noise can usu-ally be stopped by tightening the nuts. If the noisepersists, 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 absorbermust be replaced. To test a shock absorber, hold it inan upright position and force the piston into and outof 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 notrequire 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 forbroken and shifted components.


SPRING AND SHOCK ABSORBER DIAGNOSIS


SHOCK ABSORBER

REMOVAL(1) Remove the upper attaching nut and washer

from the frame bracket stud (Fig. 1).(2) Remove the lower attaching nut, washers and

bolt from the axle bracket. Remove the shock ab-sorber (Fig. 1).

INSTALLATION(1) Position the shock upper eye on the frame

bracket stud. Install the washer and nut (Fig. 1).(2) Position the shock lower eye in the axle shaft

tube bracket. Install the lower attaching bolt, wash-ers and nut (Fig. 1).

(3) Tighten the upper and lower shock bolts to 61Nzm (45 ft. lbs.) torque.

LEAF SPRING

REMOVAL(1) Raise the vehicle at the frame.(2) Use a hydraulic jack to relieve the axle weight.(3) Remove the wheel and tire.(4) Remove the nuts, the U-bolts and spring

bracket from the axle (Fig. 1).(5) Remove the nut and bolt that attaches the

spring rear eye to the shackle (Fig. 1).(6) Remove the nut and bolt from the spring front

eye (Fig. 1).(7) Remove the spring from the vehicle.

INSTALLATION(1) Position the spring front eye in the bracket.

Loosely install the attaching bolt and nut (Fig. 1). Donot tighten at this time.

(2) Position the rear eye in the shackle bracket.Loosely install the attaching bolt and nut (Fig. 1). Donot tighten at this time.

(3) Align the rear spring center bolt with the locat-ing hole in the rear axle spring pad.

(4) Lower the rear axle until it is completely sup-ported by the spring.

Ensure that the spring center bolt is seated inthe axle spring pad locating hole. Realign thecenter bolt with the locating hole, if necessary.

(5) Position the axle. Install the spring bracket, U-bolts and nuts (Fig. 1). Tighten the U-bolt nuts to122 Nzm (90 ft. lbs.) torque.

(6) Remove the hydraulic jack.(7) Remove the support stands and lower the vehi-

cle.(8) Tighten the spring shackle plate bolts and front

spring eye bolt to 135 Nzm (100 ft. lbs.) torque.

LEAF SPRING EYE BUSHING REPLACEMENT(1) Assemble tools shown (Fig. 2). Tighten the nut

located at the socket wrench end of the threaded roduntil the bushing is forced out.

(2) Assemble and align the bushing installationtools.

(3) Align the bushing with the spring eye andtighten the nut located at the socket wrench end ofthe threaded rod. Tighten until the bushing is forcedinto the spring eye.

Fig. 1 Spring & Shock AbsorberYJ Vehicles


The bushing must be centered in the springeye. The ends of the bushing must be flush orslightly recessed within the end surfaces of thespring eye.

TRACK BAR

REMOVAL(1) Raise the vehicle. Position a hydraulic jack un-

der the axle and raise the axle to relieve the springsof axle weight.

(2) Remove the fasteners that attach the track barto the frame bracket and axle bracket (Fig. 3).

(3) Remove the track bar from the vehicle.

INSTALLATION(1) Position the ends of the track bar in the frame

and axle brackets (Fig. 3).(2) Install and tighten the track bar attaching nuts

to 168 Nzm (125 ft. lbs.) torque.(3) Remove the supports and lower the vehicle.

Fig. 2 Spring Eye Bushing Removal

Fig. 3 Track BarYJ Vehicles


AXLE NOISE/VIBRATION DIAGNOSIS

INDEX

page page

Driveline Snap . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Gear and Bearing Noise . . . . . . . . . . . . . . . . . . . . . 9General Information . . . . . . . . . . . . . . . . . . . . . . . . 9Limited Slip Differential . . . . . . . . . . . . . . . . . . . . . 10

Low Speed Knock . . . . . . . . . . . . . . . . . . . . . . . . . 10Rear Axle Alignment . . . . . . . . . . . . . . . . . . . . . . . 10Vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

GENERAL INFORMATIONAxle bearing problem conditions are usually caused

by: Insufficient or incorrect lubricant Foreign matter/water contamination Incorrect bearing preload torque adjustment Incorrect backlash (to tight)

When serviced, the bearings must be cleaned thor-oughly. They should be dried with lint-free shop tow-els. Never dry bearings with compressed air.This will overheat them and brinell the bearingsurfaces. This will result in noisy operation af-ter repair.

Axle gear problem conditions are usually the result of: Insufficient lubrication Incorrect or contaminated lubricant Overloading (excessive engine torque) or exceedingvehicle weight capacity Incorrect clearance or backlash adjustment

Insufficient lubrication is usually the result of ahousing cover leak. It can also be from worn axleshaft or pinion gear seals. Check for cracks or porousareas in the housing or tubes.

Using the wrong lubricant will cause overheatingand gear failure. Gear tooth cracking and bearingspalling are indicators of this.

Axle component breakage is most often the result of: Severe overloading Insufficient lubricant Incorrect lubricant Improperly tightened components

Overloading occurs when towing heavier than rec-ommended loads. Component breakage can occurwhen the wheels are spun excessively. Incorrect lu-bricant quantity contributes to breakage. Loose dif-ferential components can also cause breakage.

Incorrect bearing preload or gear backlash will notresult in component breakage. Mis-adjustment willproduce enough noise to cause service repair before afailure occurs. If a mis-adjustment condition is notcorrected, component failure can result.

Excessive bearing preload may not be noisy. Thiscondition will cause high temperature which can re-sult in bearing failure.

GEAR AND BEARING NOISE

GEAR NOISEAxle gear noise can be caused by insufficient lubri-

cant. Incorrect backlash, tooth contact, or worn/dam-aged gears can cause noise.

Gear noise usually happens at a specific speedrange. The range is 30 to 40 mph, or above 50 mph.The noise can also occur during a specific type ofdriving condition. These conditions are acceleration,deceleration, coast, or constant load.

When road testing, accelerate the vehicle to thespeed range where the noise is the greatest. Shiftout-of-gear and coast through the peak-noise range.If the noise stops or changes greatly, check for insuf-ficient lubricant. Incorrect ring gear backlash, orgear damage can cause noise changes.

Differential side and pinion gears can be checkedby turning the vehicle. They usually do not causenoise in straight-ahead driving. These gears areloaded during vehicle turns. If noise does occur dur-ing vehicle turns, the side or pinion gears could beworn or damaged. A worn pinion gear mate shaft canalso cause a snapping or a knocking noise.

BEARING NOISEThe axle shaft, differential and pinion gear bear-

ings can all produce noise when worn or damaged.Bearing noise can be either a whining, or a growlingsound.

Pinion gear bearings have a constant-pitch noise.This noise changes only with vehicle speed. Pinionbearing noise will be higher because it rotates at afaster rate. Drive the vehicle and load the differen-tial. If bearing noise occurs the pinion rear bearing isthe source of the noise. If the bearing noise is heardduring a coast, front bearing is the source.

Worn, damaged differential bearings usually pro-duce a low pitch noise. Differential bearing noise issimilar to pinion bearing. The pitch of differentialbearing noise is also constant and varies only withvehicle speed.

Axle shaft bearings produce noise and vibrationwhen worn or damaged. The noise generally changeswhen the bearings are loaded. Road test the vehicle.Turn the vehicle sharply to the left and to the right.


This will load the bearings and change the noiselevel. Where axle bearing damage is slight, the noiseis usually not noticeable at speeds above 30 mph.

LOW SPEED KNOCKLow speed knock is generally caused by a worn

U-joint or by worn side-gear thrust washers. A wornpinion gear shaft bore will also cause low speed knock.

VIBRATIONVibration at the rear of the vehicle is usually

caused by a: Damaged drive shaft Missing drive shaft balance weight Worn, out-of-balance wheels Loose wheel lug nuts Worn U-joint Loose spring U-bolts Loose/broken springs Damaged axle shaft bearings Loose pinion gear nut Excessive pinion yoke run out Bent axle shaft

Check for loose or damaged front-end componentsor engine/transmission mounts. These componentscan contribute to what appears to be a rear-end vi-bration. Do not overlook engine accessories, bracketsand drive belts.

All driveline components should be examined be-fore starting any repair.

Refer to Group 22, Wheels and Tires for additionalinformation.

DRIVELINE SNAPA snap or clunk noise when the vehicle is shifted

into gear (or the clutch engaged), can be caused by: High engine idle speed Loose engine/transmission/transfer case mounts Worn U-joints Loose spring mounts Loose pinion gear nut and yoke Excessive ring gear backlash Excessive 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 intogear. Listen for the noise, a mechanics stethoscope ishelpful in isolating the source of a noise.

REAR AXLE ALIGNMENT

MEASUREMENTThe following procedure can be used to determine

if abnormal rear tire tread wear is the result of abent or deformed rear axle shaft.

(1) Raise both rear wheels off the surface with aframe contact hoist.

(2) Attach a one-inch long piece of masking tape atthe center of each tire tread for use as reference marks.

(3) Rotate the rear wheels until both referencemarks face the front of the vehicle. Measure the dis-tance between the outside edges of the two pieces oftape. Record this measurement as the front of tire(FTR) measurement.

(4) Rotate the rear wheels until both referencemarks face the rear of the vehicle. Measure the dis-tance between the outside edges of the two pieces oftape. Record this measurement as the rear of tire(RTR) measurement.

(5) Subtract the (RTR) measurement from the(FTR) measurement to obtain the amount of wheeltoe. The acceptable rear wheel toe-in position is 1/16inch (1.6 mm) to 3/16 inch (4.8 mm) toe-out.

(6) Rotate the rear wheels until the referencemarks are facing downward. Measure the distancebetween 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 fromthis 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) MINUSBTR EQUALS CAMBER

If the (BTR) distance measurement is lessthan the average FTR and RTR distance mea-surement, the camber will be positive ( + ). Ifthe (BTR) distance measurement is greaterthan the average FTR and RTR distance, thecamber will be negative ( - ).

If the toe position or camber is not acceptable, a bentor deformed rear axle shaft is most likely the cause.

LIMITED SLIP DIFFERENTIALUnder normal traction conditions, engine torque is di-

vided evenly. With low-traction surfaces, engine torqueis transferred to the wheel with the most tire traction.When diagnosing a limited-slip differential the wheelwith the least traction can continue spinning.

The most common problem is a chatter noise whenturning corners. Check for incorrect or contaminatedlubricant. Replace the gear lubricant if necessary. With Trac-Lok differentials add a container ofMOPAR Trac-Lok Lubricant.

This will correct the condition in most instances. Ifthe chatter persists, clutch damage could have oc-curred.

After changing the lubricant, drive the vehicle andmake 10 to 12 slow, figure-eight turns. This maneu-ver will pump lubricant through the clutches.


SERVICE DIAGNOSIS


SERVICE DIAGNOSIS (CONTD)


MODEL 35 AXLE

INDEX

page page

Axle Shaft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Axle Shaft Seal and Bearing . . . . . . . . . . . . . . . . . 17Backlash and Contact Pattern Analysis . . . . . . . . . 27Cleaning/Inspection . . . . . . . . . . . . . . . . . . . . . . . . 20Differential Assembly . . . . . . . . . . . . . . . . . . . . . . . 21Differential Disassembly . . . . . . . . . . . . . . . . . . . . 18Differential Measurement and Installation . . . . . . . . 25Differential Removal . . . . . . . . . . . . . . . . . . . . . . . 18Drive Axle Assembly ReplacementXJ Vehicles . . 14

Drive Axle Assembly ReplacementYJ Vehicles . . 14Final Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 29General Information . . . . . . . . . . . . . . . . . . . . . . . 13Lubricant Change . . . . . . . . . . . . . . . . . . . . . . . . . 13Lubricant Specifications . . . . . . . . . . . . . . . . . . . . . 13Pinion Gear Depth Information . . . . . . . . . . . . . . . 21Pinion Measurement and Assembly . . . . . . . . . . . . 22Pinion Removal/Disassembly . . . . . . . . . . . . . . . . . 19Pinion Shaft Seal Replacement . . . . . . . . . . . . . . . 15

GENERAL INFORMATIONThe Model 35 housing has an iron center casting

(differential housing) with axle shaft tubes extendingfrom either side. The tubes are pressed into andwelded to the differential housing to form a one-pieceaxle housing.

The integral type housing, hypoid gear design hasthe centerline of the pinion set below the centerlineof the ring gear.

The axle has a vent hose to relieve internal pres-sure caused by lubricant vaporization and internalexpansion.

The axles are equipped with semi-floating axleshafts, meaning that loads are supported by the axleshaft and bearings. The axle shafts are retained byC-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 atone ring pressed on the axle shaft. Use care whenremoving axle shafts as NOT to damage the tonewheel or the sensor.

The Model 35 axle has the assembly part numberand gear ratio listed on a tag. The tag is attached tothe housing cover. Build date identification codes arestamped on the axle shaft tube cover side.

The differential case is a one-piece design. The dif-ferential pinion mate shaft is retained with athreaded roll pin. Differential bearing preload andring gear backlash is adjusted by the use of spacershims. Pinion bearing preload is set and maintainedby the use of a collapsible spacer.

For complete drive axle assembly removaland installation refer to Drive Axle AssemblyReplacement in this Group.

LUBRICANT SPECIFICATIONSMulti-purpose, hypoid gear lubricant should be

used for Model 35 axle. The lubricant should have

MIL-L-2105C and API GL 5 quality specifications.MOPAR Hypoid Gear Lubricant conforms to both ofthese specifications. Lubricant for Model 35 axle is a thermally stableSAE 80W-90 gear lubricant. Lubricant for Model 35 axle with Trailer Tow isSAE 75W-140 SYNTHETIC gear lubricant. Trac-Lok differentials add 4 oz. of friction modifier. Lubricant quantity is 1.66 L (3.50 pts.).

Refer to Group 0, Lubrication and Maintenance foradditional information.

CAUTION: If axle is submerged in water, lubricantmust be replaced immediately to avoid possiblepremature axle failure.

LUBRICANT CHANGEThe 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 coversurfaces.

(6) Apply a bead of MOPARt Silicone Rubber Seal-ant to the housing cover (Fig. 1). Allow the sealantto cure for a few minutes.

Install the housing cover within 5 minutes af-ter applying the sealant. If not installed thesealant 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.


CAUTION: Overfilling the differential can result inlubricant 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-eightturns. This maneuver will pump the lubricantthrough the clutch discs to eliminate a possible chat-ter noise complaint.

DRIVE AXLE ASSEMBLY REPLACEMENTXJVEHICLES

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 shaftfrom 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 connectionsat the axle.

(9) Support the axle with a hydraulic jack underthe differential.

(10) Remove the spring U-bolts from the platebrackets.

(11) Lower the jack enough to remove the axle.

INSTALLATION


(1) Support the axle on a hydraulic jack under thedifferential. Position the axle under the vehicle.

(2) Raise the axle and align the spring center boltswith the locating holes in the axle pads and platebrackets.

(3) Install the spring U-bolts through the platebrackets and tighten to 70 Nzm (52 ft. lbs.) torque.

(4) Install ABS wiring connections (if equipped) atthe axle.

(5) Connect the brake hose at the axle junctionblock.

(6) Install the shock absorbers to the axle bracketsand 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-jointclamp 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 REPLACEMENTYJVEHICLES

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



equalizer or backing plate.(6) Disconnect the shock absorbers from the plate

brackets.

Fig. 1 Typical Housing Cover With Sealant


(7) Disconnect the brake hose at the axle junctionblock. 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 relievethe axle weight from the springs.


(11) Loosen BUT DO NOT REMOVE the bolts thatattach 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 lowerthe springs to the surface.


INSTALLATION



(2) Raise the springs and install the spring shacklebolts. Do not tighten at this time.

(3) Lower the axle and align the spring centerbolts with the locating holes in the axle pads andplate brackets.


(5) Connect the track bar to the axle bracket andinstall the bolt. Do not tighten at this time.

It is important that the springs support theweight 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.








(15) Tighten the spring front pivot bolt/nut to 142Nzm (105 ft. lbs.) torque. Tighten the spring shacklebolt/nut to 135 Nzm (100 ft. lbs.) torque.

(16) Tighten the track bar bolt at the axle bracketto 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 thisprocedure.

(6) Measure the amount of torque (in Newton-meters or inch-pounds) necessary to rotate the piniongear with a torque wrench. Note the torque for in-stallation reference. It must be known to properlyadjust the pinion gear bearing preload torqueafter seal installation.

(7) Remove the pinion yoke nut and washer. UseRemover C-452 and Wrench C-3281 to remove thepinion yoke (Fig. 2).

(8) Mark the positions of the yoke and pinion gearfor 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-163and 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. Tightenthe nut only enough to remove the shaft endplay.

Fig. 2 Pinion Yoke Removal


CAUTION: Exercise care during the bearing preloadtorque adjustment. Do not over-tighten, or loosenand then re-tighten the nut. Do not exceed the bear-ing preload torque. The collapsible preload spaceron the shaft will have to be replaced. The bearingpreload torque will be re-adjusted afterward.

(4) Install a socket and inch-pound torque wrenchon the pinion nut.

(5) Rotate the shaft with the torque wrench andnote the torque.

The required preload torque is equal to theamount recorded during removal plus an addi-tional 0.56 Nzm (5 in. lbs.).

(6) Use Flange Wrench C-3281 to retain the yokeand shaft (Fig. 5). Tighten the shaft nut in verysmall increments.

(7) Continue tightening the shaft nut in small in-crements until the correct bearing preload torque isattained.

(8) Align the installation reference marks and at-tach the drive shaft to the yoke.

(9) Add API grade GL 5 hypoid gear lubricant tothe 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 pinionmate gear shaft lock screw is accessible. Remove thelock screw and the pinion mate gear shaft from thecase (Fig. 6).

(7) Force the axle shaft in toward the center of thevehicle. Remove the axle shaft C-clip lock from theaxle shaft (Fig. 7).

(8) Remove the axle shaft. Use care to preventdamage to the axle shaft bearing and seal, which willremain 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


(10) Inspect the roller bearing contact surface onthe axle shaft for signs of brinelling, spalling and pit-ting.

(11) If any of these conditions exist, the axle shaftand 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 axleshaft. Push the axle shaft outward to seat the C-cliplock in the side gear.

(3) Insert the mate shaft into the case and throughthe thrust washers and pinion gears. Align the holein shaft with the hole in the differential case and in-stall the lock screw with Loctitet on the threads.Tighten the screw to 19 Nzm (14 ft. lbs.) torque.

(4) Install the cover and add fluid. Refer to theDrain 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.Ar960-02).

(5) Inspect the axle shaft tube bore for roughnessand burrs. Remove as necessary.

CAUTION: Inspect the housing bore for burrs. Re-move them if they exist.

INSTALLATIONDo 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 thebearing 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 installationprocedure.

Fig. 6 Mate Shaft Lock Screw

Fig. 7 Axle Shaft C-Clip Lock

Fig. 8 Axle Shaft Bearing Removal Tool


DIFFERENTIAL REMOVALTo service the differential the axle shafts must be

removed. Refer to the removal procedures in thisGroup.

(1) Note the installation reference letters stampedon the bearing caps and housing machined sealingsurface (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 theholddown 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 pilotstud. Load the indicator plunger against the oppositeside of the housing (Fig. 11) and zero the indicator.

CAUTION: Do not spread over 0.38 mm (0.015 in). Ifthe housing is over-separated, it could be distortedor damaged.

(5) Separate the housing enough to remove thecase from the housing. Measure the distance with thedial 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 ofthe pry bar against spreader (Fig. 12).

(8) Remove the case from housing. Mark or tagbearing cups and outboard shim/spacer (selectedthickness) 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


Place adapter rings so they do not damagethe bearing cage.

(2) Clamp the differential case in a vise equippedwith soft jaws. Remove and discard the ring gearbolts. Tap the ring gear with a rawhide or plasticmallet and remove (Fig. 14).

(3) Rotate the differential side gears and removethe pinion mate gears and thrust washers (Fig. 15).

(4) Remove the differential side gears and thrustwashers.

(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 thepinion yoke (Fig. 16).

(2) Remove the pinion gear from housing (Fig. 17).Catch the pinion with your hand to prevent it fromfalling 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


(7) Remove the collapsible preload spacer (Fig. 20).(8) Remove the inner bearing from the pinion with

Puller C-293-PA and Adapter C-293-39 (Fig. 21).Place adapter rings so they do not damage

the bearing cage.(9) Remove the depth shims from the pinion gear

shaft. Record the thickness of the depth shims.

CLEANING/INSPECTIONWash differential components with cleaning solvent

and dry with compressed air. Do not steam cleanthe differential components.

Wash bearings with solvent and towel dry, or drywith compressed air. DO NOT spin bearings withcompressed air Cup and bearing must be re-placed as a matched sets only.

Clean axle shaft tubes and oil channels in housing.Inspect for;

Fig. 17 Remove Pinion Gear

Fig. 18 Front Bearing Cup Removal

Fig. 19 Rear Bearing Cup Removal

Fig. 20 Collapsible Spacer


Smooth appearance with no broken/dented sur-faces on the bearing rollers or the roller contact sur-faces Bearing cups must not be distorted or cracked Machined surfaces should be smooth and withoutany raised edges Raised metal on shoulders of cup bores should beremoved with a hand stone Wear and damage to pinion gear mate shaft, pin-ion gears, side gears and thrust washers. Replace asa matched set only. Ring and pinion gear for worn and chipped teeth Ring gear for damaged bolt threads. Replaced as amatched set only. Pinion yoke for cracks, worn splines, pitted areas,and a rough/corroded seal contact surface. Repair orreplace as necessary. Preload shims for damage and distortion. Installnew shims if necessary.

DIFFERENTIAL ASSEMBLY(1) Install the following components in the differ-

ential case. Differential side gears and thrust washers Pinion gears and thrust washers Pinion gear mate shaft (align holes in shaft andcase)

(2) Lubricate all differential components with hy-poid gear lubricant.

PINION GEAR DEPTH INFORMATIONRing and pinion gears are supplied as matched sets

only. The identifying numbers for the ring and piniongear are etched into the face of each gear (Fig. 22). A

plus (+) number, minus (-) number or zero (0) is etchedinto the face of the pinion gear. This number is theamount (in thousandths of an inch) the depth variesfrom the standard depth setting of a pinion etched witha (0). The standard setting from the centerline of thering gear to the back face of the pinion is 96.8 mm(3.813 inches) for Model 35 axles (Fig. 23). The standarddepth provides the best teeth contact pattern.

THE BUTTON END ON THE PINION GEAR HEADIS NO LONGER A MACHINED-TO-SPECIFICATIONSSURFACE. DO NOT USE THIS SURFACE FOR PIN-ION DEPTH SET-UP OR CHECKING (Fig. 23).

Compensation for pinion depth variance is achievedwith select shims. In production the shims are placedbetween the pinion gear and the inner pinion bearingcone. For service the shims are placed under the in-ner pinion bearing cup (Fig. 24).

If a new gear set is being installed, note thedepth variance etched into both the originaland replacement pinion gear. Add or subtractthe thickness of the original depth shims tocompensate 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


Note where Old and New Pinion Marking columnsintersect. Intersecting figure represents plus or mi-nus amount needed.

For example, if old pinion is plus (+) 1 and the newpinion is minus (-) 3, intersecting figure is (+)0.004inch (0.10mm). Add this amount to the original shim.Or if the old pinion is (-) 3 and the new pinion is (-)2, intersecting figure is (-)0.001 inch (0.025mm). Sub-tract this amount from original shim. Refer to thePinion Gear Depth Variance Chart.

PINION MEASUREMENT AND ASSEMBLY

PINION GEAR DEPTH MEASUREMENTPinion gear depth measurement is necessary

when; Axle housing or differential case is replaced Pinion select shim pack is unknown Ring and pinion gears are replaced

Measurements are taken with pinion cups and pin-ion bearings installed in housing. Take measure-ments with Pinion Gauge Set 6774, Pinion Block6735 and Dial Indicator C-3339 (Fig. 25).

Fig. 24 Shim Locations

PINION GEAR DEPTH VARIANCE

Fig. 25 Pinion Gear Depth Gauge Tools


(1) Assemble Pinion Gauge Set, Pinion Block andpinion bearings. Install assembly into differentialpinion gear bore and hand tighten cone (Fig. 26).

(2) Place Arbor Disc 6732 on Arbor D-115-3 and po-sition in the bearing cradles (Fig. 27). Install differ-ential bearing caps on Arbor Discs and tighten capssnug only.

Arbor Discs have different steps to fit otheraxle sizes. Pick correct size step for axle beingserviced.

(3) Firmly place Scooter Block and Dial Indicatoron pinion height block tool and zero the dial indicatorpointer.

(4) Slide the Scooter Block across the arbor whileobserving indicator (Fig. 28). Record the longesttravel distance, whether inward (-) or outward (+),indicated by the pointer.

The plunger travel distance indicated, plus orminus the variance etched in the gear is the re-quired thickness for the depth shims.

(5) Measure the thickness of each depth shim witha micrometer and combine the shims necessary for

total required shim pack thickness. Include oilslinger or baffle thickness with the total shimpack thickness.

(6) Remove the measurement tools from the differ-ential housing.

PINION GEAR ASSEMBLY/INSTALLATIONIn production depth select shims are placed be-

tween the inner pinion bearing cone and pinion gear.For service the select shims are placed under the in-ner bearing cup.

(1) Place the depth shims (and baffle if equipped)in the pinion gear rear bearing bore. Install the bear-ing cup with Installer D-146 and Driver HandleC-4171 (Fig. 29). Ensure cup is correctly seated.

Fig. 26 Pinion Height Block

Fig. 27 Gauge Tools In Housing

Fig. 28 Pinion Gear Depth Measurement

Fig. 29 Pinion Rear Bearing Cup Installation


(2) Install the pinion front bearing cup with In-staller D-130 and Handle C-4171 (Fig. 30).

(3) Install pinion front bearing, oil slinger. Apply alight coating of gear lubricant on the lip of pinionseal. Install seal with Installer D-163 and HandleC-4171 (Fig. 31).

(4) Install the rear bearing (and slinger if used) onthe pinion gear with Installer W-262 (Fig. 32).

(5) Install a new collapsible preload spacer on pin-ion shaft and install pinion gear in housing (Fig. 33).

(6) Install yoke with Installer W-162-D andWrench C-3281 (Fig. 34).

(7) Install the yoke washer and a new nut on thepinion gear. Tighten the nut to 271 Nzm (200 ft.lbs.)minimum. Do not over-tighten. Maximum torque is475 Nzm (350 ft. lbs.).

CAUTION: Never loosen pinion gear nut to decreasepinion gear bearing preload torque and never exceedspecified preload torque. If preload torque is exceededa new collapsible spacer must be installed. The torquesequence will have to be repeated.

(8) Use Flange Wrench C-3281 to retain the yoke(Fig. 35). Slowly tighten the nut in small incrementsuntil the rotating torque is achieved. Measure the pre-load torque frequently to avoid over-tightening the nut.

(9) Check bearing preload torque with an inch

Fig. 30 Pinion Front Bearing Cup Installation

Fig. 31 Pinion Seal Installation

Fig. 32 Shaft Rear Bearing Installation

Fig. 33 Collapsible Preload Spacer


pound torque wrench (Fig. 36). The torque necessaryto rotate the pinion gear should be; Original Bearings 1 to 3 Nzm (10 to 20 in. lbs.). New Bearings 2 to 5 Nzm (15 to 35 in. lbs.).

DIFFERENTIAL MEASUREMENT AND INSTALLATION

DIFFERENTIAL SHIM PACK MEASUREMENT(1) Install the bearings on the hub with Installer

C-3716A and Driver Handle C-4171.

(2) Match each bearing cup with bearing (original).Install the cups on the bearings.

Note:It is recommended whenever bearings are re-moved that they be replaced.

(3) Install the differential case in the housing.(4) Install the outboard shim/spacer (selected thick-

ness) on each side between bearing cup and housing(Fig. 37). Use 0.142 in. (3.6 mm) as a starting point,shim/spacers are available in various thicknesses.

(5) Install the marked bearing caps in their correctpositions. Install and snug the bolts.

Fig. 34 Pinion Yoke Installation

Fig. 35 Tightening Pinion Nut

Fig. 36 Check Pinion Gear Torque

Fig. 37 Differential Bearing Shim Installation


(6) Attach a dial indicator to the housing. Positionthe indicator plunger so that it contacts the ring gearmating surface (Fig. 38).

(7) Pry the differential case to one side and zerothe dial indicator pointer.

(8) Pry the differential case to the opposite sideand record indicator reading. Reading is additionalshim thickness needed for zero end play. For exam-ple, if reading was 0.008 inch (0.20 mm), an addi-tional 0.004-inch (0.10-mm) thick shim will beneeded at each side zero end play.

(9) Install zero end-play shims on each side ofcase.

The differential bearings must be preloadedto compensate for heat and load during opera-tion.

(10) Add an additional 0.004-inch (0.1-mm) to eachoutboard shim/spacer for bearing preload.

RING GEAR INSTALLATION(1) Invert the differential case and start two ring

gear bolts. This will provide case-to-ring gear bolthole alignment.

(2) Install new ring gear bolts and alternatelytighten to 95-122 Nzm (70-90 ft. lbs.) torque (Fig. 39).

DIFFERENTIAL INSTALLATION(1) Position Spreader W-129-B with the tool dowel

pins seated in the locating holes (Fig. 40). Install theholddown clamps and tighten the tool turnbuckle fin-ger-tight.

(2) Install a pilot stud at the left side of the differ-ential housing. Attach Dial Indicator to housing pilotstud. Load the indicator plunger against the oppositeside of the housing (Fig. 40) and zero the indicator.

CAUTION: Do not spread over 0.38 mm (0.015 in). Ifthe housing is over-separated, it could be distortedor damaged.

(3) Separate the housing enough to install the casein the housing. Measure the distance with the dialindicator (Fig. 40).

(4) Remove the dial indicator.(5) Install differential and outboard shim/spacer

(selected thickness) in housing.(6) Install case in the housing. Tap the differential

case to ensure the bearings are fully seated (Fig. 41).Remove the spreader.

(7) Install the bearing caps at their original loca-tions (Fig. 42). Tighten the bearing cap bolts to 77Nzm (57 ft. lbs.) torque.

Fig. 38 Shim Measurement

Fig. 39 Ring Gear Bolt Installation

Fig. 40 Spread Differential Housing


BACKLASH AND CONTACT PATTERN ANALYSIS(1) Rotate assembly several revolutions to seat

bearings. Measure backlash at three equally spacedlocations around the perimeter of the ring gear witha dial indicator (Fig. 43).

The ring gear backlash must be within 0.12 -0.20 mm (0.005 - 0.008 inch). It cannot varymore than 0.05 mm (0.002 inch) between thepoints checked.

If backlash must be adjusted, spacers are availablein various thicknesses. Adjust the backlash accord-ingly (Fig. 44). DO NOT INCREASE THE TOTALSHIM PACK THICKNESS, EXCESSIVE BEAR-ING PRELOAD AND DAMAGE WILL OCCUR.

The ring gear teeth contact patterns will show ifthe pinion gear depth shim(s) have the correct thick-

ness. It will also show if the ring gear backlash hasbeen adjusted correctly. The backlash must be main-tained within the specified limits until the correcttooth contact patterns are obtained.

(2) Apply a thin coat of hydrated ferric oxide, orequivalent, to the drive and coast side of the ringgear teeth.

(3) Rotate the ring gear one complete revolution inboth directions while a load is being applied. Insert apry bar between the differential housing and the caseflange. This will produce distinct contact patterns onboth the drive side and coast side of the ring gearteeth.

(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


Fig. 45 Gear Tooth Contact Patterns


FINAL ASSEMBLY(1) Install the axle shafts. Refer to Axle Shaft In-

stallation within this group.(2) Scrape the residual sealant from the housing

and cover mating surfaces. Clean the mating surfaceswith mineral spirits. Apply a bead of MOPARt Sili-cone Rubber Sealant on the housing cover (Fig. 46).Allow the sealant to cure for a few minutes.

Install the housing cover within 5 minutes af-ter applying the sealant. If not installed thesealant must be removed and another bead ap-plied.

(3) Install the cover on the differential with the at-taching bolts. Install the identification tag. Tightenthe cover bolts to 41 Nzm (30 ft. lbs.) torque.


(4) Refill the differential housing with the specifiedquantity of MOPARt Hypoid Gear Lubricant.

(5) Install the fill hole plug and tighten to 34 Nzm(25 ft. lbs.) torque. Axles equipped with rubber fillplug install plug into cover.



8 1/4 AXLE

INDEX

page page

Axle Shaft, Seal and Bearing Service . . . . . . . . . . 32Differential Service . . . . . . . . . . . . . . . . . . . . . . . . 34Drive Axle Assembly ReplacementXJ Vehicles . . 31Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Lubricant Change . . . . . . . . . . . . . . . . . . . . . . . . . 31Lubricant Specifications . . . . . . . . . . . . . . . . . . . . . 31Pinion Seal Replacement . . . . . . . . . . . . . . . . . . . 33

INFORMATIONThe housing consists of an iron differential housing

with axle shaft tubes extending from either side. Thetubes are welded to the housing to form a one-pieceaxle.

The integral type housing, hypoid gear design hasthe centerline of the pinion set below the centerlineof the ring gear.

The axle has a vent used to relieve internal pres-sure caused by lubricant vaporization and internalexpansion.

The axle shafts are retained by C-clips in the dif-ferential side gears.

The removable cover provides a means for servicingthe differential without removing the axle.

The axles have the gear ratio listed on a tag. Thetag is attached to the housing cover.

The differential case is a one-piece design. The dif-ferential pinion mate shaft is retained with athreaded roll pin. Preload and backlash is adjustedby the use of threaded adjusters. Pinion bearing pre-load is set and maintained by the use of a collapsiblespacer.

PINION GEAR DEPTH MEASUREMENT WITHGAUGE SET 6575 is used when; The axle/differential housing is being replaced The original pinion depth shim pack is lost or mis-placed Replacing the differential case Replacing pinion and differential bearings

Fig. 1 Axle Differential8 1/4


LUBRICANT SPECIFICATIONSMulti-purpose, hypoid gear lubricant should be

used in the 8 1/4 inch axle. The lubricant shouldhave MIL-L-2105C and API GL 5 quality specifica-tions. MOPARt Hypoid Gear Lubricant conforms toboth of these specifications. The factory installed lubricant for the 8 1/4 inchrear axle is SAE 80W 90 gear lubricant. The factory installed lubricant quantity is 6762fluid oz.


Refer to Group 0, Lubrication and Maintenance foradditional information.

CAUTION: If axle is submerged in water, lubricantmust be replaced immediately to avoid possiblepremature axle failure.

DRIVE AXLE ASSEMBLY REPLACEMENTXJVEHICLES

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



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 connectionsat the axle.

(9) Support the axle with a hydraulic jack underthe differential.



INSTALLATION



(2) Raise the axle and align the spring center boltswith the locating holes in the axle pads and platebrackets.


(4) Install ABS wiring connections (if equipped) atthe axle.








LUBRICANT CHANGEThe 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 coversurfaces. Use solvent to clean the mating surfaces.

(6) Apply a bead of MOPARt Silicone Rubber Seal-ant to the housing cover (Fig. 2). Allow the sealant tocure for a few minutes.

Install the housing cover within 5 minutes afterapplying the sealant. If not installed the sealantmust be removed and another bead applied.

(7) Install the cover and any identification tag.Tighten the cover bolts in a criss-cross pattern to 47Nzm (35 ft. lbs.) torque.

(8) Refill the differential with Mopar Hypoid GearLubricant 13 mm (1/2 in.) below the fill plug hole.With Trac-Lok differentials, add a container of MoparHypoid Gear Lubricant Additive.


(9) Install the fill hole plug and lower the vehicle.


AXLE SHAFT, SEAL AND BEARING SERVICE

CAUTION: When rear axle service is necessary,both rear wheels must be raised off the surface sothat they are free to rotate. Be cautious when thetires are being rotated by the engine or by othermeans.

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 and drain the

lubricant from the housing. Remove the housingcover.

(6) Rotate the differential case so that the pinionmate gear shaft lock screw is accessible. Remove thelock screw and the pinion mate gear shaft from thecase (Fig. 3).

(7) Push the axle shaft in toward the center of thevehicle. Remove the axle shaft C-clip lock from theaxle shaft (Fig. 4).

(8) Remove the axle shaft. Use care to preventdamage to the axle shaft bearing, which will remainin the axle shaft tube.

(9) Inspect the axle shaft bearing contact surfacearea for indications of brinelling, spalling, and pit-ting.

If any of these conditions exist, the axle shaftand bearing should be replaced. Normal bear-

ing contact on the shaft will be a dull gray andit could appear to be lightly dented.

(10) If any of these conditions exist, the axle shaftand bearing must be replaced.

The normal appearance (from roller bearingcontact) will be a dull gray surface area thatcould appear slightly dented.

AXLE SHAFT SEAL AND BEARING REMOVAL(1) Remove the axle shaft seal with a small pry

bar.(2) Remove the bearing if it appears damaged or

the axle shaft shows any of the conditions describedabove.

(3) Remove the bearing with Remover C-4167 (Fig.5). Attach Slide Hammer 7420 and Adapter 7420-8 tothe end of the removal tool.

(4) Inspect the axle shaft seal surface and tubebore for roughness and burrs. Polish each axleshaft with No. 600 crocus cloth. This can re-move slight surface damage. Do not reduce thediameter of the axle shaft seal contact surface.When polishing, the crocus cloth should bemoved around the circumference of the shaft(not in-line with the shaft).


Fig. 3 Pinion Mate Shaft Lock Screw

Fig. 4 Axle Shaft C-Clip Lock


BEARING AND SEAL INSTALLATIONDo 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 pilotof Bearing Installer C-4198 and Handle C-4171.

CAUTION: DO NOT use the new axle shaft seal toposition or seat the bearing in the axle shaft bore.

(3) Insert the bearing into the tube. Ensure thatthe bearing is not cocked and is seated firmly againstthe tube shoulder.

(4) Install the new axle shaft seal (Fig. 6) with In-staller C-4198 and Handle C-4171. The flat side ofthe 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 anddepth.

AXLE SHAFT INSTALLATION(1) Lubricate the bearing bore and seal lip. Insert

the axle shaft and engage the splines with the sidegear. 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 Loctitet on 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 Specificationschart for the type and the quantity. Install the fillhole plug.

(8) Lower the vehicle and test the brakes and axlefor correct operation.

PINION SEAL REPLACEMENT

CAUTION: The following procedures must be usedso 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 toprevent damage to the rear U-joint.

(4) Remove the rear wheels and brake drums toprevent any drag. The drag can cause a possible falsebearing preload torque measurement.

(5) Use a Newton-meter or an inch-pound torquewrench to measure the pinion bearing preload. Ro-tate the pinion shaft several times with the torquewrench. Note the indicated torque as the wrench ismoved through several revolutions.

This measurement is very important becausethe bearing preload torque must be carefullyre-adjusted after the new seal is installed.

(6) Retain the yoke with Wrench C-3281. Removethe pinion shaft nut and Belleville washer.

(7) Make reference marks and remove the yokewith a puller.

(8) Lower the rear of the vehicle to prevent lubri-cant leakage.

(9) Remove the pinion shaft seal with PullerC-748. Clean the seal contact surface in the housingbore.

Fig. 5 Axle Shaft Bearing Removal

Fig. 6 Axle Shaft Seal Installation


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 replacethe yoke as necessary.

The outer perimeter of the seal is pre-coatedwith 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 sealflange contacts the face of the differential hous-ing flange.

(5) Position the pinion yoke on the end of the shaftwith the reference marks aligned.

(6) Seat the yoke on the pinion shaft with InstallerC-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 torquewrench to measure the pinion gear bearing pre-load torque.

CAUTION: Never loosen pinion gear nut to decreasepinion gear bearing preload torque and never ex-ceed specified preload torque. If preload torque isexceeded a new collapsible spacer must be in-stalled. The torque sequence will have to be re-peated.

(9) Continue tightening and measuring the bearingpreload torque until it is the same as the original.

The bearing preload torque should never begreater than 1 Nzm (10 in. lbs.) more than therecorded value.

The bearing preload torque should be con-stant during a complete revolution of the pin-ion gear. If the preload torque varies, thisindicates a binding condition. This conditionmust be corrected before the installation of thedrive shaft.

(10) If the specified torque is not obtained, tightenthe nut in small increments until the preload torqueis obtained.

(11) Seal replacement is unacceptable if final nuttorque is less than 285 Nzm (210 ft. lbs.) torque.

(12) Install the drive shaft with the installationreference marks aligned. Tighten the U-joint yokeclamp 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 MOPARt Hypoid GearLubricant.

DIFFERENTIAL SERVICE

SERVICE INFORMATIONIt 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


CAUTION: Do not subject the bearings, cups, boresor journals to heat from a torch or other abuse. Per-manent damage could result. Special tools areavailable and recommended when servicing axle.

DIFFERENTIAL CASE REMOVAL(1) Remove the axle shafts, refer to Axle Shaft Re-

moval.Side play and runout checks taken during

disassembly will be very useful in reassembly.(2) Check differential side play. Position a screw-

driver or pinch bar between left side of axle housingand case flange (Fig. 9). Use a prying motion to de-termine if any side play exists. There should be noside play.

Side play resulting from bearing races beingloose on case hubs require replacement of thedifferential case. Otherwise, use threaded ad-juster to remove the side play before measuringthe ring gear runout.

(3) Eliminate any side play in the differential case.Attach Dial Indicator to Pilot stud C-3288-B. Placethe indicator plunger at a right angle (90) to thering gear (Fig. 10). The plunger should exert a slightforce against the gear face.

(4) Measure runout by turning the ring gear sev-eral complete revolutions. Observe the dial indicatorpointer. Mark the ring gear and the differential caseat the areas of maximum runout. The ring gearrunout should not exceed 0.13 mm (0.005 inch). If therunout exceeds 0.13 mm (0.005 inch), a damaged dif-ferential case could be the cause.

Marking the differential case will be very use-ful later during differential case runout mea-surement.

(5) Mark the differential housing and differentialbearing caps for installation reference (Fig. 11).

(6) Remove the bearing threaded adjuster lockfrom each bearing cap. Loosen the bolts, but do notremove the bearing caps.

(7) Loosen the threaded adjusters with WrenchC-4164 (Fig. 12).

(8) Hold the differential case in place. Remove thebearing caps, adjusters and differential case (Fig. 13).

Each differential bearing cup and threadedadjuster must be kept with their respectivebearing.

PINION GEAR SHAFT REMOVAL(1) Remove the pinion gear nut and washer. Use

Puller C-452 and Wrench C-3281 to remove the pin-ion gear yoke.

Fig. 9 Differential Case Side Play Test

Fig. 10 Ring Gear Runout Measurement

Fig. 11 Housing & Caps Marked For InstallationReference


(2) Use Puller C-748 to remove pinion seal and dis-card seal.

(3) Force pinion gear shaft out the front bearingand remove bearing. This will damage the frontbearing rollers and bearing cup. The frontbearing and cup must be replaced. Discard col-lapsible spacer.

(4) Remove the front and rear bearing cups. Front bearing cup use Remover C-4345 and Han-dle C-4171 Rear bearing cup use Remover C-4307 and HandleC-4171

(5) Remove the rear bearing from the pinion shaftwith Puller C-293-PA (J-29721) and Adapter C-293-42(Fig. 14). Remove and record the pinion depth shims.

RING GEAR

Do not remove the ring gear from case unlessthe runout must be measured.

(1) Clamp the case with the ring gear bolts facingupward. Use a vise equipped with soft jaws (brass).

(2) Remove and discard left-hand threaded ringgear bolts. Use a hammer and a brass drift to forcering gear loose from the case pilots. Remove the ringgear.

CASE FLANGE RUNOUT MEASUREMENT(1) If the ring gear runout exceeded 0.13 mm

(0.005 inch), case flange runout should be measured.Install the case with bearing cups and threaded ad-justers close to their original position.

(2) Install the bearing caps and bolts. Tighten thebolts lightly. Use Wrench C-4164 (Fig. 12) to threadboth adjusters inward. Remove all side play.

(3) Attach Dial Indicator to measure the flangerunout. The plunger should contact the ring squarelybetween the outer edge and gear attaching bolt holes(Fig. 15).

(4) Rotate the differential case several times. Ob-serve the dial indicator pointer. Mark the area ofmaximum flange runout. The differential case flangerunout must not exceed 0.08 mm (0.003 inch). Ifrunout exceeds this amount replace differential case.

To reduce excessive ring gear runout, posi-tion gear runout mark 180 degrees oppositeflange runout mark.

(5) Remove differential bearing cap bolts. Removedifferential case from differential housing.

Fig. 12 Threaded Adjuster Tool

Fig. 13 Differential Bearing Cap Removed

Fig. 14 Inner Bearing Removal


DIFFERENTIAL CASE DISASSEMBLY(1) Rotate side gears until pinion gears are located

at the differential case opening. Remove gears.(2) Remove side gears and thrust washers.(3) Remove differential bearings from the case

hubs with Puller C-293-PA, Adapter C-293-48 andPlug SP-3289 (Fig. 16).

CLEANING/INSPECTION(1) Clean all differential components in cleaning

solvent. Allow the bearings to either air dry or drythem with a lint-free cloth. Dry the other componentswith compressed air.

(2) Examine each component for wear or damage.(3) Replace shims, bearings and cups as a set only.

Replace bearings and cups if either is galled, worn,cracked, or damaged.

(4) Inspect the differential side and pinion gears.Replace any gear that is worn, cracked or chipped.

(5) Inspect differential case and replace case ifcracked or damaged.

Polish each axle shaft sealing surface withNo. 600 crocus cloth. This can remove slightsurface damage. Do not reduce the diameter ofthe axle shaft seal contact surface. When pol-ishing, the crocus cloth should be movedaround the circumference of the shaft (not in-line with the shaft).

When replacing a drive pinion gear bearing,always replace the bearing and cup as amatched set.

(6) Inspect the axle shaft C-clip locks for cracks orexcessive wear. Replace them if necessary.

(7) Test each threaded adjuster to determine if itrotates freely.

(8) If an adjuster binds, repair the damagedthreads or replace the adjuster.

DIFFERENTIAL CASE ASSEMBLY(1) Lubricate all the differential case components

with gear lubricant.(2) Place the thrust washers on the differential

side gears. Position the gears in the differential casecounterbores.

If replacement side gears or thrust washersare used, refer to Differential Side Gear Clear-ance Measurement And Adjustment (Fig. 17).

(3) Position the thrust washers on the differentialpinion gears. Mesh the pinion gears with the sidegears.Ensure that the pinion gears are exactly180 degrees opposite each other.

(4) Rotate the side gears to align the pinion gearsand thrust washers. Align these components with themate shaft bores in the case.

(5) If ring gear was removed, clean all contact sur-faces. Use an Arkansas stone or fine file to removeany sharp areas from the chamfered inside diameter.

Fig. 15 Case Flange Runout Measurement

Fig. 16 Differential Bearing Removal

Fig. 17 Side Gear Calculations


(6) If removed, heat ring gear with a heat lamp orby immersing in a hot fluid. The temperature shouldnot exceed 149C (300F). Do not use a torch toheat the ring gear.

(7) Position heated rear gear on case. Use twoequally spaced Pilot Studs C-3288-B to align the gearwith the flange holes (Fig. 18).

(8) Install replacement ring gear bolts (with lefthand threads). Alternately and evenly tighten eachbolt to 95 Nzm (70 ft. lbs.) torque.

CAUTION: When installing a differential bearing,never apply force to the bearing cage because bear-ing damage will result.

(9) Install a differential bearing on each hub withInstaller C-4340 and Handle C-4171 (Fig. 19).

PINION DEPTH MEASUREMENT ANDADJUSTMENT WITH GAUGE SET 6575

(1) Use pinion gear adjustment gauge set 6575(Fig. 20) and continue the assembly:

(2) Install front (outer) bearing cup use InstallerD-130 and Handle C-4171.

(3) Install rear (inner) bearing cup use InstallerC-4308 and Handle C-4171.

Assemble tools as described; Position Spacer (SP-6030) over Shaft (SP-5385) Position pinion rear bearing on shaft Position tools (with bearing) in the housing Install Sleeve (SP-5382) Install pinion front bearing Install Spacer (SP-6022) Install Sleeve (SP-3194-B), Washer (SP-534) andNut (SP-3193)

(4) Prevent compression sleeve tool from turningwith Wrench C-3281.

Tighten the nut to seat the pinion bearings in thehousing (Fig. 21). Allow the sleeve to turn severaltimes during the tightening to prevent brinelling thebearing cups or bearings.

Depth shim(s) are positioned between the pin-ion gear rear bearing and pinion gear. The re-quired thickness of the depth shim(s) isdetermined according to the following informa-tion.

(5) Loosen the compression nut tool. Lubricate thepinion gear front and rear bearings with gear lubri-cant. Re-tighten the compression nut tool to 1 to 3Nzm (15 to 25 in. lbs.) torque. Rotate the pinion gearseveral complete revolutions to align the bearing roll-ers.

(6) Install Gauge Block SP-5383 at the end of SP-5385. Install Cap Screw (SP-536) and tighten.

(7) Position Arbor (SP-6029) in the differentialhousing (Fig. 22).

Fig. 18 Case-To-Ring Gear Alignment

Fig. 19 Differential Bearing Installation

Fig. 20 Axle Adjustment Tools8 1/4


(8) Center the tool. Place a piece of 0.002 inchshim stock at each end of the arbor tool. Install thebearing caps on the arbor tool. Tighten the cap boltsto 14 Nzm (10 ft. lbs.) torque.

(9) Trial fit depth shim(s) between the arbor tooland gauge block tool (Fig. 22). The depth shim(s)fit must be snug but not tight (drag friction of afeeler gauge blade).

Depth shims are available in 0.001-inch incre-ments from 0.020 inch to 0.038 inch.

(10) Note the etched number on the face of the pin-ion gear. The numbers represent thousands-of-an-inch deviation from the standard. If the number is -(negative), add that value to the required thicknessof the depth shim(s). If the number is + (positive),

subtract that value from the thickness of the depthshim(s). If the number is 0, no change is necessary.

(11) Remove tools from differential housing.(12) Position depth shim(s) on the pinion gear. In-

stall rear bearing with Installer C-4040 (Fig. 23). Besure the contact surfaces are clean and without for-eign particles.

(13) Lubricate pinion gear front and rear bearingswith gear lubricant.

(14) Install pinion gear into the housing. Installnew collapsible spacer at the end of the pinion gear.Install pinion gear front bearing.

(15) Install pinion yoke with Remover/InstallerC-3718 and Wrench C-3281 (Fig. 24).

Fig. 22 Depth Shim(s) Selection

PINION GEAR DEPTH VARIANCE

Fig. 21 Seating Pinion Bearings


It is necessary to use the tools (above) to cor-rectly seat the front bearing on the drive pin-ion gear shaft (Fig. 24).

CAUTION: Use care to prevent collapsing preloadcollapsible spacer during installation of the yokeand seating the front bearing.

(16) Remove yoke and tools from the pinion gear.(17) Install the pinion seal with Seal Installer

C-4076-A and Handle C-4735-1 (Fig. 25).The outer perimeter of the seal is pre-coated

with a special sealant. An additional applica-tion of sealant is not required.

(18) Install pinion yoke with Remover/InstallerC-3718 and Wrench C-3281.

(19) Remove the tools. Install the Bellevillewasher. The convex side of the washer must face out-ward. Install the pinion nut.

(20) Retain pinion yoke with Wrench C-3281. Ini-tially tighten the pinion gear shaft nut enough to re-move the bearing end play. While tightening, rotatethe pinion shaft to ensure the bearing rollers are cor-rectly seated.

(21) Tighten the pinion nut (Fig. 26) to 285 Nzm(210 ft. lbs.) torque (minimum).

(22) Remove the tools from the shaft. Rotate thepinion several revolutions to seat the bearing rollers.

Fig. 23 Shaft Rear Bearing Installation

Fig. 24 Pinion Yoke Installation

Fig. 25 Pinion Gear Seal Installation

Fig. 26 Tightening Pinion Gear Nut


CAUTION: Never loosen pinion gear nut to decreasepinion gear bearing preload torque and never ex-ceed specified preload torque. If preload torque isexceeded 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 preloadtorque is 1 to 2 Nzm (10 to 20 in. lbs.). This torquevalue is with replacement bearings and pinion nuttightened with a minimum of 285 Nzm (210 ft. lbs.)torque (Fig. 27).

When using original pinion rear bearing anda replacement front bearing. The correct pre-load torque is 1 Nzm (10 in. lbs.) in addition tothe 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 duringrotation 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, tightenthe nut in small increments until the preload torqueis obtained.

The differential will be unacceptable for useif the final nut torque is less than 285 Nzm (210ft. lbs.) torque. If the preload torque is notwithin 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 assembleddifferential case in the housing.

(2) Observe the reference marks and install thedifferential bearing caps at their original locations(Fig. 28).

(3) Install the bearing cap bolts (Fig. 28). Tightenthe upper bolts to 14 Nzm (10 ft. lbs.) torque. Tightenthe lower bolts finger-tight until the bolt head islightly seated.

DIFFERENTIAL BEARING PRELOAD AND RINGGEAR BACKLASH ADJUSTMENT

The following limitations must be considered whenadjusting the differential: The maximum ring gear backlash variation is0.003 inch (0.076 mm). Mark the gears so the same teeth are meshed dur-ing all backlash measurements. Maintain the specified threaded-adjuster torquewhile adjusting. Excessive adjuster torque will introduce a highbearing load and cause premature bearing failure.Insufficient adjuster torque can result in excessivedifferential case free-play and ring gear noise. Insufficient adjuster torque will not support thering gear correctly and can cause excessive differen-tial case free-play and ring gear noise.

The differential bearing cups will not alwaysimmediately follow the threaded adjusters asthey 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 beseated by rapidly rotating the pinion gear ahalf turn back and forth. Do this five to tentimes 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 bearingfree-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


ring and pinion gear. Seat the bearing cups with theprocedure described above.

(2) Install Dial Indicator (Fig. 30). Position theplunger against the drive side of a ring gear tooth.Measure the backlash at 4 positions (90 degreesapart) around the ring gear. Locate and mark thearea of minimum backlash.

(3) Rotate the ring gear to the position of the leastbacklash. Mark the gear so that all future backlashmeasurements will be taken with the same gearteeth meshed.

(4) Loosen the right-side,

Documents

Jeep Cherokee XJ 1995-1999 Rear Suspension and Axles