95ZJ_16.PDF

PROPELLER SHAFTS

CONTENTS

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GENERAL INFORMATION . . . . . . . . . . . . . . . . . . 1PROPELLER SHAFT REPLACEMENT . . . . . . . . . . 8SERVICE DIAGNOSIS/PROCEDURES . . . . . . . . . 4

TORQUE SPECIFICATIONS . . . . . . . . . . . . . . . . 15UNIVERSAL JOINT REPLACEMENT . . . . . . . . . 10

GENERAL INFORMATION

PROPELLER SHAFTSThe function of a prop shaft is to transmit power

from one point to another in a smooth action. Theshaft is designed to send torque through an anglefrom the transmission (transfer case on 4WD vehi-cles) to the axle (Fig. 1).

The propeller shaft must operate through con-stantly changing relative angles between the trans-mission and axle. It must also be capable of changinglength while transmitting torque. The axle rides sus-pended by springs in a floating motion. This meansthe propeller shaft must be able to change angleswhen going over various roads. This is accomplishedthrough universal joints, which permit the propellershaft to operate at different angles. The slip joints (oryokes) permit contraction or expansion.

Tubular propeller shafts are balanced by the man-ufacturer with weights spot welded to the tube.

The propeller shaft is designed and built with theyoke lugs in line with each other which is called

phasing. This design produces the smoothest runningcondition. An out of phase shaft can cause a vibra-tion.

Before undercoating a vehicle, the propellershaft and the U-joints should be covered. Thiswill prevent the undercoating from causing anunbalanced condition and vibration.

CAUTION: Use exact replacement hardware for at-taching the propeller shafts. This will ensure safeoperation. The specified torque must always be ap-plied when tightening the fasteners.

4WD FRONT PROPELLER SHAFTSThe 4WD vehicles use 3 types of front propeller

shaft. Type 1 and Type 2 have a single cardan jointat the axle end and a double cardan joint at thetransfer case end. The difference between Type 1 and2 is the slip yoke. Type 1 uses a dustcap and seal toprotect the slip yoke from dirt (Fig. 2). Type 2 uses arubber boot to protect the slip yoke (Fig. 3).

Fig. 1 Front & Rear Propeller Shafts 4WD

ZJ PROPELLER SHAFTS 16 - 1

The third propeller shaft used Type 3 has no slipyoke. This shaft uses a double cardan joint at thetransfer case end and a constant velocity joint (CV)at the front axle end (Fig. 4). The CV joint contractsand extends which eliminates the need for a slipyoke. The CV joint has a splined shaft which allowsthe overall shaft length to be adjusted for optimumjoint travel. This spline shaft is locked in place witha nut. Never attempt to adjust the shaft length.The overall shaft length is preset during manu-facturing.

UNIVERSAL JOINTSThree different types of universal joints are used

(Fig. 5,6 & 7). These joints are not repairable if wornor damaged they must be replaced. If a vehicle has a

damaged constant velocity joint or boot (Fig. 7) thepropeller shaft must be replaced.

LUBRICATIONThe slip yoke on the Type 1 front shaft is equipped

with a lubrication fitting. Use a multi-purpose NLGIGrade 2 EP lubricant, refer to Group 0, Lubricationand Maintenance for additional information. The fac-tory installed U-joints are lubricated for the life ofthe vehicle and do not need re-lubrication. AllU-joints should be inspected for leakage and damageeach time the vehicle is serviced. If seal leakage ordamage exists, the U-joint should be replaced.

Fig. 2 Type 1 Front Propeller Shaft



Fig. 5 Single Cardan U-Joint (Typical)

16 - 2 PROPELLER SHAFTS ZJ

Fig. 7 Constant Velocity Joint

Fig. 6 Double Cardan U-Joint


SERVICE DIAGNOSIS/PROCEDURES

INDEX

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Runout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Unbalance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Universal Joint Angle Measurement . . . . . . . . . . . . . 5Vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

VIBRATIONTires that are out-of-round or wheels that are un-

balanced will cause a low frequency vibration. Referto Group 22, Tires And Wheels for additional infor-mation.

Brake drums that are unbalanced will cause aharsh, low frequency vibration. Refer to Group 5,Brakes for additional information.

Driveline vibration can also result from loose ordamaged engine mounts. Refer to Group 21, Trans-missions for additional information.

Propeller shaft vibration will increase as the vehi-cle speed is increased. A vibration that occurs withina specific speed range is not caused by propellershaft unbalance. Defective universal joints or an in-correct propeller shaft angle are usually the cause.

UNBALANCEIf propeller shaft unbalance is suspected, it can be

verified with the following procedure.Removing and re-indexing the propeller shaft

180° may eliminate some vibrations.

• Clean all the foreign material from the propellershaft and the universal joints (mud, undercoating,etc.).• Inspect the propeller shaft for missing balanceweights, broken welds, and bent areas.If the propel-ler shaft is bent, it must be replaced.• Ensure the universal joints are not worn, are prop-erly installed, and are correctly aligned with theshaft.• Check the universal joint clamp screws torque.

(1) Raise the vehicle.(2) Remove the wheel and tires. Install the wheel

lug nuts to retain the brake drums.(3) Mark and number the prop shaft tube six

inches from the yoke end at four positions 90° apart.(4) Run and accelerate the vehicle until vibration

occurs. Note the intensity and speed the vibration oc-curred. Stop the engine.

(5) Install a screw clamp at Position 1 (Fig. 1).(6) Start the engine and re-check for vibration. If

there is little or no change in vibration, move theclamp to one of the other three positions. Repeat thevibration test.

DRIVELINE VIBRATION


(7) If there is no change in vibration, the vibrationmay not be caused by prop shaft unbalance.

(8) If the vibration decreased, install a secondclamp (Fig. 2). Repeat the vibration test.

(9) If the clamps cause an additional unbalancedcondition. Separate the clamp screws (1/4 inch aboveand 1/4 inch below the mark). Repeat the vibrationtest (Fig. 3).

(10) Increase distance between the clamp screwsand repeat the test until the amount of vibration isat the lowest level. Bend the slack end of the clampsso the screws will not loosen.

(11) Install the wheel and tires. Lower the vehicle.(12) If the amount of vibration remains unaccept-

able, perform the procedures at the front end of thepropeller shaft.

RUNOUT(1) Remove dirt, rust, paint, and undercoating

from the propeller shaft surface. Areas where the dialindicator will contact the shaft must be clean.

(2) The dial indicator must be installed perpendic-ular to the shaft surface.

(3) Measure runout at the center and ends awayfrom welds.

(4) Refer to Runout Specifications chart.(5) Replace the propeller shaft if the runout ex-

ceeds the limit.

UNIVERSAL JOINT ANGLE MEASUREMENT

INFORMATIONWhen two shafts intersect at a common universal

joint, the angle is called the operating angle. Thelarger the operating angle, the larger the amount ofacceleration and deceleration of the joint. For everyrevolution there are two accelerations and decelera-tion of the universal joint. This speeding up andslowing down of the joint must be cancelled to pro-duce a smooth power flow. This is done through phas-ing and proper universal joint working angles.

A propeller shaft is properly phased when the yokeends are on the same plane or in line. A twisted shaftwill throw the yokes out of phase and cause a notice-able vibration.

When taking universal joint angle measurementsor checking phasing with two piece shafts, considereach shaft separately. On 4WD vehicles, the frontshaft input (pinion shaft) angle has priority over thecaster angle.

Fig. 1 Clamp Screw At Position 1

Fig. 2 Two Clamp Screws At The Same Position

Fig. 3 Clamp Screws Separated

RUNOUT SPECIFICATIONS


Ideally the driveline system should have:• Angles that are equal or opposite within 1 de-gree of each other• Have a 3 degree maximum operating angle• Have at least a 1/2 degree continuous operat-ing (propeller shaft) angle

Engine speed (R.P.M.) is the main factor in deter-mining maximum allowable operating angles. As aguide to maximum normal operating angles refer tothe chart listed (Fig. 4).

INSPECTIONBefore measuring universal joint angles, the

following must be done.• Inflate all tires to correct pressure.• Check angles in the same loaded or unloadedcondition as when the vibration occurred. Propshaft angles will change according to theamount of load in the vehicle. Always check an-gles in loaded and unloaded conditions.• Check the condition of all suspension springs andverify all fasteners are torqued to specifications.• Check the condition of the engine and transmis-sion mounts. Verify all fasteners are torqued to spec-ifications.

MEASUREMENTTo accurately check driveline alignment, raise and

support the vehicle at the axles as level as possible.Allow the wheels and propeller shaft to turn. Removesnap rings from universal joint so Inclinometer 7663(J-23498A) base sits flat on cap.

(1) Rotate the shaft until transmission/transfercase output yoke bearing is facing downward.

Always make measurements from front torear.

(2) Place Inclinometer on yoke bearing (A) parallelto the shaft (Fig. 5). Center bubble in sight glass andrecord measurement.

This measurement will give you the transmissionor OUTPUT YOKE ANGLE (A).

(3) Rotate propeller shaft 90 degrees. Place Incli-nometer on yoke bearing parallel to the shaft (Fig. 6).Center bubble in sight glass and record measure-ment.

This measurement will give you the PROPELLERSHAFT ANGLE (C).

(4) Subtract smaller figure from larger (C minus A)to obtain transmission OUTPUT OPERATING AN-GLE.

(5) Rotate propeller shaft 90 degrees and place In-clinometer on pinion yoke bearing parallel to theshaft (Fig. 7). Center bubble in sight glass and recordmeasurement.

This measurement will give you the pinion shaft orINPUT YOKE ANGLE (B).

(6) Subtract smaller figure from larger (C minusB) to obtain axle INPUT OPERATING ANGLE.

Fig. 4 Maximum Angles and R.P.M.

Fig. 5 Front (Output) Angle Measurement (A)

Fig. 6 Propeller Shaft Angle Measurement (C)


Refer to rules given below and the example in (Fig.8) for additional information.• Good cancellation of u-joint operating angles (within1°)• Operating angles less than 3°• At least 1/2 of one degree continuous operating(propeller shaft) angle

ADJUSTMENT WITH CAMSAdjust the angle by rotating cams on the upper suspen-

sion arms (Fig. 9). On 4WD vehicles, the front shaft input(pinion shaft) angle has priority over the caster angle.

A cam service kit is available to adjust the rearpropeller shaft angle. The cam kit is installed in theupper suspension arms at the axle.

Fig. 7 Rear (Input) Angle Measurement (B)

Fig. 8 Universal Joint Angle Example

Fig. 9 Angle Adjustment With Cams


PROPELLER SHAFT REPLACEMENT

PRECAUTIONSUse exact replacement hardware for attaching the

propeller shafts. This will ensure safe operation. Thespecified torque must always be applied when tight-ening the fasteners.

It is important to mark the propeller shaft yokeand axle or transmission yoke before removal (Fig.1). This will assure correct phasing and eliminatepossible vibration.

CAUTION: Do not allow the propeller shaft to dropor hang from either universal joint during removal.Attach it to the vehicle underside with wire to pre-vent damage to the universal joints.

CAUTION: It is important to protect the machinedexternal surface of the slip yoke from damage. Ifdamaged, the transmission extension seal could bedamaged and leak.

FRONT TYPE 1 AND TYPE 2

REMOVAL(1) Shift the transmission and transfer case (if ap-

plicable) to Neutral position. Raise the vehicle. Re-move skid plates (if equipped) from frame, refer toGroup 13, Frames.

(2) Scribe alignment marks on the yokes at thetransfer case and axle pinion. Place marks at thepinion shaft and at each end of the propeller shaft.These marks will be used for installation reference(Fig. 2).

(3) Remove U-joint bolts and straps from pinionyoke.

(4) Remove bolts from transfer case yoke and re-move the propeller shaft.

INSTALLATION(1) Position the propeller shaft with the yoke refer-

ence marks aligned. Install the propeller shaft (Fig.2).

(2) Install U-joint straps and bolts to pinion yokeand tighten to 19 Nzm (14 ft. lbs.) torque.Replace U-joint straps and bolts must be installed.

(3) Install transfer case yoke bolts and tighten to27 Nzm (20 ft. lbs.) torque.

FRONT TYPE 3


plicable) to Neutral position. Raise the vehicle. Re-move skid plates (if equipped) from frame, refer toGroup 13, Frames.

(2) Scribe alignment marks on the yoke at thetransfer case and the axle flange. Place marks at thepinion shaft and at each end of the propeller shaft.These marks will be used for installation reference.

(3) Remove 6 bolts at the pinion yoke.(4) Remove bolts from transfer case yoke and push

the shaft into the CV joint and remove the shaft.

INSTALLATION(1) Position the propeller shaft with the yoke refer-

ence marks aligned. Install the propeller shaft.(2) Install bolts to pinion flange and tighten to 41

Nzm (30 ft. lbs.) torque.(3) Install transfer case yoke bolts and tighten to

27 Nzm (20 ft. lbs.) torque.

Fig. 1 Reference Marks on Yokes

Fig. 2 Front Propeller Shaft


CAUTION: If this shaft is replaced the new shaftlength must be measured and adjusted before thevehicle is driven.

TYPE 3 SHAFT MEASUREMENTThis measurement is taken with the shaft installed

and the vehicle at curb height.(1) Place vehicle on floor or drive-on hoist at curb

height.(2) Take a measure from the CV joint cup to the

end of the CV boot (Fig. 3).

(3) Adjust by loosening the lock nut and movingthe one end of the shaft in or out of the other end.

(4) When the shaft is adjusted to the correct length(Fig. 3) 138.2 mm (5.44 in.) ±4.5 mm tighten thelock-nut (Fig. 4) to 115 Nzm (85 ft. lbs.).

CAUTION: This is a one time adjustment and mustnot be readjusted.

REAR


plicable) to Neutral position. Raise the vehicle.(2) Scribe alignment marks at the pinion yoke and

at each end of the propeller shaft.

(3) Remove U-joint bolts and straps from pinionyoke.

(4) Slide the slip yoke off transmission/transfercase output shaft. Remove the propeller shaft (Fig.5).

INSTALLATION(1) Slide the slip yoke on the transmission/transfer

case output shaft. Align the installation referencemarks at the pinion yoke. Install the propeller shaft.

(2) Install U-joint straps and bolts and tighten to19 Nzm (14 ft. lbs.) torque.Replacement U-jointstraps and bolts must be installed.

Fig. 3 Measurement

Fig. 4 Lock-nut

Fig. 5 Rear Propeller Shaft

ZJ PROPELLER SHAFTS 16 - 91995 Grand CherokeePublication No. 81-370-5147TSB 26-02-95 April, 1995

UNIVERSAL JOINT REPLACEMENT

PRECAUTIONSIt is very important to put reference marks on the

yokes before removal or component service (Fig. 1).This will assure correct phasing and eliminate possi-ble vibration.

CONSTANT VELOCITY JOINTThe most common failure of CV-joints is torn or

ripped boots and subsequent lubricant loss or con-tamination. Look for lubricant around the exterior ofboot. Check for a punctured or torn boot or retainingclamp loose.

The constant velocity joint found on the Type 3front propeller shaft is not serviceable. If the joint isworn or damaged the shaft must be replaced. Referto Type 3 front propeller shaft for procedure.

SINGLE CARDAN

REMOVAL/DISASSEMBLYSingle cardan universal joints are not serviceable.

If worn or leaking, they must be replaced as a unit.(1) Remove the propeller shaft. Refer to Propeller

Shaft Replacement in this Group.(2) Paint or score alignment marks on the yokes

and propeller shaft for installation reference.(3) Using a soft drift, tap the outside of the bear-

ing assembly to loosen snap ring.(4) Remove snap rings from both sides of yoke (Fig.

2).(5) Set the yoke in an arbor press or vise with a

large socket beneath it. Position the yoke with the

lube fitting pointing up (if equipped). Place a smallersocket on the upper bearing assembly and press itthrough to release the lower bearing assembly (Fig.3).

(6) If the bearing assembly will not pull out byhand after pressing, tap the base of the lug near it todislodge.

Fig. 1 Reference Marks on Yokes

Fig. 2 Remove Snap Ring

Fig. 3 Press Out Bearing


(7) To remove the opposite bearing, turn the yokeover and straighten the cross in the open hole. Thencarefully press the end of the cross until the remain-ing bearing can be removed (Fig. 4).

CAUTION: If the cross or bearing assembly arecocked when being pressed, the bearing assemblywill score the walls of the yoke bore and ruin theyoke.

CLEANING AND INSPECTION(1) Clean all the universal joint yoke bores with

cleaning solvent and a wire brush.(2) Inspect the yokes for distortion, cracks and

worn bearing assembly bores.

ASSEMBLY/INSTALLATION(1) Apply extreme pressure (EP) N.L.G.I. Grade 1

or 2 grease to aid in installation.(2) Position the cross in the yoke with its lube fit-

ting (if equipped) pointing up (Fig. 5).(3) Place a bearing assembly over the trunnion and

align it with the cross hole (Fig. 6). Keep the needlebearings upright in the bearing assembly. A needleroller lying at the bottom will prevent proper assem-bly.

(4) Press the bearing assembly into the cross holeenough to install a snap ring. Install a snap ring.

(5) Repeat steps 3 and 4 to install the oppositebearing assembly. If the joint is stiff, strike the yokewith a soft hammer to seat the needle bearings. In-stall a snap ring.

(6) Add grease to lube fitting (if equipped).(7) Install the propeller shaft. Refer to Propeller

Shaft Replacement in this Group.

Fig. 4 Press Out Remaining Bearing

Fig. 5 Install Cross In Yoke

Fig. 6 Install Bearing On Trunnion


DOUBLE CARDAN

REMOVAL/DISASSEMBLYCardan universal joints are not serviceable. If worn

or leaking, they must be replaced as a unit.(1) Remove the propeller shaft. Refer to Propeller

Shaft Replacement in this Group.(2) Paint or score alignment marks on the yokes

and propeller shaft for installation reference.(3) Remove all the bearing assembly snap rings

(Fig. 7).

(4) Press the bearing assembly partially from theoutboard side of the center yoke, enough to grasp byvise jaws (Fig. 8). Be sure to remove any lube fittingsthat may interfere with removal.

(5) Grasp the protruding bearing by vise jaws. Tapthe tube yoke with a mallet and drift to dislodgefrom the yoke (Fig. 9).

(6) Flip assembly and repeat steps 4 and 5 for re-moving the opposite side bearing. This will allow re-moval of the cross centering kit assembly and spring(Fig. 10).

(7) Press the remaining bearing assemblies out theother cross as described above to complete the disas-sembly.

Fig. 7 Remove Snap Rings

Fig. 8 Press Out Bearing

Fig. 9 Remove Bearing From Yoke

Fig. 10 Remove Centering Kit


CLEANING AND INSPECTION(1) Clean all the U-joint yoke bores with cleaning

solvent and a wire brush.(2) Inspect the yokes for distortion, cracks and

worn bearing assembly bores.

ASSEMBLY/INSTALLATIONDuring installation, ensure that the spiders

and yokes are aligned to the reference marks.(1) Fit a cross into the tube yoke (Fig. 11).

(2) Place a bearing assembly in a tube yoke holeand over a trunnion. Keep the needle bearings up-right in the bearing assembly (Fig. 12). A needleroller lying at the bottom will prevent proper assem-bly. Be sure to remove any lube fittings that may in-terfere with removal.

(3) Press the bearing assembly in place and installa snap ring (Fig. 13).

(4) Flip the tube yoke and bearing assembly instal-lation on the opposite trunnion. Install a snap ring(Fig. 14).

Fig. 11 Install Cross In Yoke

Fig. 12 Install Bearing Assembly

Fig. 13 Press In Bearing Assembly



(5) Fit the center yoke on the remaining two trun-nions and press bearing assemblies in place, bothsides (Fig. 15). Install a snap ring.

(6) Install the centering kit assembly inside thecenter yoke making sure the spring is in place (Fig.16). Align the lube fitting on the centering kit withthe lube fitting on the installed cross.

(7) Place two bearing assemblies on the remainingcross (opposite sides). Fit the open trunnions into thecenter yoke holes and the bearing assemblies into thecentering kit (Fig. 17). Align the lube fitting on thecross with the other two lube fittings.

(8) Press the remaining two bearing assembliesinto place and install snap rings (Fig. 18).

Fig. 15 Install Center Yoke

Fig. 16 Install Centering Kit

Fig. 17 Install Remaining Cross



(9) Tap the snap rings to allow them to seat intothe grooves (Fig. 19).

(10) Check for proper assembly. Flex the CV jointbeyond center, it should snap over-center in both di-rections when correctly assembled (Fig. 20).

(11) Add grease to all three lube fittings.(12) Install the propeller shaft. Refer to Propeller

Shaft Replacement in this Group.

TORQUE SPECIFICATIONS

PROPELLER SHAFTS AND U-JOINTS

DESCRIPTION................................................TORQUEFront ShaftTransfer Case Yoke Bolts ...........27 Nzm (20 ft. lbs.)Axle Yoke Bolts ...........................19 Nzm (14 ft. lbs.)Type 3 Front Shaft

Transfer Case Yoke Bolts ...........27 Nzm (20 ft. lbs.)Pinion Flange Bolts ....................41 Nzm (30 ft. lbs.)Lock Nut ....................................115 Nzm (85 ft. lbs.)Rear ShaftAxle Yoke Bolts ...........................19 Nzm (14 ft. lbs.)

Fig. 19 Seat Snap Rings In GrooveFig. 20 Check Assembly


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