ZJ PROPELLER SHAFTS 16 - 1 PROPELLER SHAFTS CONTENTS page pageGENERAL INFORMATION . . . . . . . . . . . . . . . . . . 1 TORQUE SPECIFICATIONS . . . . . . . . . . . . . . . . 15PROPELLER SHAFT REPLACEMENT . . . . . . . . . . 8 UNIVERSAL JOINT REPLACEMENT . . . . . . . . . 10SERVICE DIAGNOSIS/PROCEDURES . . . . . . . . . 4 GENERAL INFORMATIONPROPELLER SHAFTS phasing. This design produces the smoothest running The function of a prop shaft is to transmit power condition. An out of phase shaft can cause a vibra-from one point to another in a smooth action. The tion.shaft is designed to send torque through an angle Before undercoating a vehicle, the propellerfrom the transmission (transfer case on 4WD vehi- shaft and the U-joints should be covered. Thiscles) to the axle (Fig. 1). will prevent the undercoating from causing an The propeller shaft must operate through con- unbalanced condition and vibration.stantly changing relative angles between the trans-mission and axle. It must also be capable of changing CAUTION: Use exact replacement hardware for at-length while transmitting torque. The axle rides sus- taching the propeller shafts. This will ensure safepended by springs in a floating motion. This means operation. The specified torque must always be ap-the propeller shaft must be able to change angles plied when tightening the fasteners.when going over various roads. This is accomplishedthrough universal joints, which permit the propeller 4WD FRONT PROPELLER SHAFTSshaft to operate at different angles. The slip joints (or The 4WD vehicles use 3 types of front propelleryokes) permit contraction or expansion. shaft. Type 1 and Type 2 have a single cardan joint Tubular propeller shafts are balanced by the man- at the axle end and a double cardan joint at theufacturer with weights spot welded to the tube. transfer case end. The difference between Type 1 and The propeller shaft is designed and built with the 2 is the slip yoke. Type 1 uses a dustcap and seal toyoke lugs in line with each other which is called protect the slip yoke from dirt (Fig. 2). Type 2 uses a rubber boot to protect the slip yoke (Fig. 3). Fig. 1 Front & Rear Propeller Shafts 4WD
16 - 2 PROPELLER SHAFTS ZJ 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. Fig. 4 Type 3 Front Propeller Shaft damaged constant velocity joint or boot (Fig. 7) the propeller shaft must be replaced. Fig. 2 Type 1 Front Propeller Shaft Fig. 5 Single Cardan U-Joint (Typical) LUBRICATION The slip yoke on the Type 1 front shaft is equipped with a lubrication fitting. Use a multi-purpose NLGI Grade 2 EP lubricant, refer to Group 0, Lubrication Fig. 3 Type 2 Front Propeller Shaft and Maintenance for additional information. The fac-UNIVERSAL JOINTS tory installed U-joints are lubricated for the life of the vehicle and do not need re-lubrication. All Three different types of universal joints are used U-joints should be inspected for leakage and damage(Fig. 5,6 & 7). These joints are not repairable if worn each time the vehicle is serviced. If seal leakage oror damaged they must be replaced. If a vehicle has a damage exists, the U-joint should be replaced.
16 - 4 PROPELLER SHAFTS ZJ SERVICE DIAGNOSIS/PROCEDURES INDEX page pageRunout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Universal Joint Angle Measurement . . . . . . . . . . . . . 5Unbalance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4VIBRATION • Clean all the foreign material from the propeller Tires that are out-of-round or wheels that are un- shaft and the universal joints (mud, undercoating,balanced will cause a low frequency vibration. Refer etc.).to Group 22, Tires And Wheels for additional infor- • Inspect the propeller shaft for missing balancemation. weights, broken welds, and bent areas.If the propel- Brake drums that are unbalanced will cause a ler shaft is bent, it must be replaced.harsh, low frequency vibration. Refer to Group 5, • Ensure the universal joints are not worn, are prop-Brakes for additional information. erly installed, and are correctly aligned with the Driveline vibration can also result from loose or shaft.damaged engine mounts. Refer to Group 21, Trans- • Check the universal joint clamp screws torque.missions for additional information. (1) Raise the vehicle. Propeller shaft vibration will increase as the vehi- (2) Remove the wheel and tires. Install the wheelcle speed is increased. A vibration that occurs within lug nuts to retain the brake drums.a specific speed range is not caused by propeller (3) Mark and number the prop shaft tube sixshaft unbalance. Defective universal joints or an in- inches from the yoke end at four positions 90° apart.correct propeller shaft angle are usually the cause. (4) Run and accelerate the vehicle until vibration occurs. Note the intensity and speed the vibration oc-UNBALANCE curred. Stop the engine. If propeller shaft unbalance is suspected, it can be (5) Install a screw clamp at Position 1 (Fig. 1).verified with the following procedure. (6) Start the engine and re-check for vibration. If Removing and re-indexing the propeller shaft there is little or no change in vibration, move the180° may eliminate some vibrations. clamp to one of the other three positions. Repeat the vibration test. DRIVELINE VIBRATION
ZJ PROPELLER SHAFTS 16 - 5 Fig. 1 Clamp Screw At Position 1 Fig. 3 Clamp Screws Separated (7) If there is no change in vibration, the vibration (3) Measure runout at the center and ends awaymay not be caused by prop shaft unbalance. from welds. (8) If the vibration decreased, install a second (4) Refer to Runout Specifications chart.clamp (Fig. 2). Repeat the vibration test. (5) Replace the propeller shaft if the runout ex- ceeds the limit. RUNOUT SPECIFICATIONS UNIVERSAL JOINT ANGLE MEASUREMENT Fig. 2 Two Clamp Screws At The Same Position (9) If the clamps cause an additional unbalanced INFORMATIONcondition. Separate the clamp screws (1/4 inch above When two shafts intersect at a common universaland 1/4 inch below the mark). Repeat the vibration joint, the angle is called the operating angle. Thetest (Fig. 3). larger the operating angle, the larger the amount of (10) Increase distance between the clamp screws acceleration and deceleration of the joint. For everyand repeat the test until the amount of vibration is revolution there are two accelerations and decelera-at the lowest level. Bend the slack end of the clamps tion of the universal joint. This speeding up andso the screws will not loosen. slowing down of the joint must be cancelled to pro- (11) Install the wheel and tires. Lower the vehicle. duce a smooth power flow. This is done through phas- (12) If the amount of vibration remains unaccept- ing and proper universal joint working angles.able, perform the procedures at the front end of the A propeller shaft is properly phased when the yokepropeller shaft. ends are on the same plane or in line. A twisted shaft will throw the yokes out of phase and cause a notice-RUNOUT able vibration. (1) Remove dirt, rust, paint, and undercoating When taking universal joint angle measurementsfrom the propeller shaft surface. Areas where the dial or checking phasing with two piece shafts, considerindicator will contact the shaft must be clean. each shaft separately. On 4WD vehicles, the front (2) The dial indicator must be installed perpendic- shaft input (pinion shaft) angle has priority over theular to the shaft surface. caster angle.
16 - 6 PROPELLER SHAFTS ZJ 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). Fig. 5 Front (Output) Angle Measurement (A) This measurement will give you the PROPELLER Fig. 4 Maximum Angles and R.P.M. SHAFT ANGLE (C).INSPECTION Before measuring universal joint angles, thefollowing 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.MEASUREMENT To accurately check driveline alignment, raise andsupport 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. Fig. 6 Propeller Shaft Angle Measurement (C) (1) Rotate the shaft until transmission/transfer (4) Subtract smaller figure from larger (C minus A)case output yoke bearing is facing downward. to obtain transmission OUTPUT OPERATING AN- Always make measurements from front torear. GLE. (2) Place Inclinometer on yoke bearing (A) parallel (5) Rotate propeller shaft 90 degrees and place In-to the shaft (Fig. 5). Center bubble in sight glass and clinometer on pinion yoke bearing parallel to therecord measurement. shaft (Fig. 7). Center bubble in sight glass and record This measurement will give you the transmission measurement.or OUTPUT YOKE ANGLE (A). This measurement will give you the pinion shaft or (3) Rotate propeller shaft 90 degrees. Place Incli- INPUT YOKE ANGLE (B).nometer on yoke bearing parallel to the shaft (Fig. 6). (6) Subtract smaller figure from larger (C minusCenter bubble in sight glass and record measure- B) to obtain axle INPUT OPERATING ANGLE.ment.
ZJ PROPELLER SHAFTS 16 - 7 Fig. 7 Rear (Input) Angle Measurement (B) Refer to rules given below and the example in (Fig. Fig. 9 Angle Adjustment With Cams8) for additional information. ADJUSTMENT WITH CAMS• Good cancellation of u-joint operating angles (within Adjust the angle by rotating cams on the upper suspen-1°) sion arms (Fig. 9). On 4WD vehicles, the front shaft input• Operating angles less than 3° (pinion shaft) angle has priority over the caster angle.• At least 1/2 of one degree continuous operating A cam service kit is available to adjust the rear propeller shaft angle. The cam kit is installed in the(propeller shaft) angle upper suspension arms at the axle. Fig. 8 Universal Joint Angle Example
16 - 8 PROPELLER SHAFTS ZJ PROPELLER SHAFT REPLACEMENTPRECAUTIONS Use exact replacement hardware for attaching thepropeller 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. Fig. 2 Front Propeller Shaft INSTALLATION (1) Position the propeller shaft with the yoke refer- Fig. 1 Reference Marks on Yokes ence marks aligned. Install the propeller shaft (Fig. 2).CAUTION: Do not allow the propeller shaft to drop (2) Install U-joint straps and bolts to pinion yokeor hang from either universal joint during removal. and tighten to 19 N⅐m (14 ft. lbs.) torque.Replace U-Attach it to the vehicle underside with wire to pre- joint straps and bolts must be installed.vent damage to the universal joints. (3) Install transfer case yoke bolts and tighten to 27 N⅐m (20 ft. lbs.) torque.CAUTION: It is important to protect the machinedexternal surface of the slip yoke from damage. If FRONT TYPE 3damaged, the transmission extension seal could be REMOVALdamaged and leak. (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 toFRONT TYPE 1 AND TYPE 2 Group 13, Frames.REMOVAL (2) Scribe alignment marks on the yoke at the transfer case and the axle flange. Place marks at the (1) Shift the transmission and transfer case (if ap- pinion shaft and at each end of the propeller shaft.plicable) to Neutral position. Raise the vehicle. Re- These marks will be used for installation reference.move skid plates (if equipped) from frame, refer to (3) Remove 6 bolts at the pinion yoke.Group 13, Frames. (4) Remove bolts from transfer case yoke and push (2) Scribe alignment marks on the yokes at the the shaft into the CV joint and remove the shaft.transfer case and axle pinion. Place marks at thepinion shaft and at each end of the propeller shaft. INSTALLATIONThese marks will be used for installation reference (1) Position the propeller shaft with the yoke refer-(Fig. 2). ence marks aligned. Install the propeller shaft. (3) Remove U-joint bolts and straps from pinion (2) Install bolts to pinion flange and tighten to 41yoke. N⅐m (30 ft. lbs.) torque. (4) Remove bolts from transfer case yoke and re- (3) Install transfer case yoke bolts and tighten tomove the propeller shaft. 27 N⅐m (20 ft. lbs.) torque.
ZJ PROPELLER SHAFTS 16 - 9 1995 Grand Cherokee Publication No. 81-370-5147 TSB 26-02-95 April, 1995CAUTION: If this shaft is replaced the new shaftlength must be measured and adjusted before thevehicle is driven.TYPE 3 SHAFT MEASUREMENT This measurement is taken with the shaft installedand the vehicle at curb height. (1) Place vehicle on floor or drive-on hoist at curbheight. (2) Take a measure from the CV joint cup to theend of the CV boot (Fig. 3). Fig. 4 Lock-nut (3) Remove U-joint bolts and straps from pinion yoke. (4) Slide the slip yoke off transmission/transfer case output shaft. Remove the propeller shaft (Fig. 5). Fig. 3 Measurement (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 N⅐m (85 ft. lbs.).CAUTION: This is a one time adjustment and mustnot be readjusted. Fig. 5 Rear Propeller ShaftREAR INSTALLATIONREMOVAL (1) Slide the slip yoke on the transmission/transfer (1) Shift the transmission and transfer case (if ap- case output shaft. Align the installation referenceplicable) to Neutral position. Raise the vehicle. marks at the pinion yoke. Install the propeller shaft. (2) Scribe alignment marks at the pinion yoke and (2) Install U-joint straps and bolts and tighten toat each end of the propeller shaft. 19 N⅐m (14 ft. lbs.) torque.Replacement U-joint straps and bolts must be installed.
16 - 10 PROPELLER SHAFTS ZJ UNIVERSAL JOINT REPLACEMENTPRECAUTIONS It is very important to put reference marks on theyokes before removal or component service (Fig. 1).This will assure correct phasing and eliminate possi-ble vibration. Fig. 2 Remove Snap Ring lube fitting pointing up (if equipped). Place a smaller socket on the upper bearing assembly and press it Fig. 1 Reference Marks on Yokes through to release the lower bearing assembly (Fig.CONSTANT VELOCITY JOINT 3). The most common failure of CV-joints is torn orripped 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 CARDANREMOVAL/DISASSEMBLY Single cardan universal joints are not serviceable.If worn or leaking, they must be replaced as a unit. (1) Remove the propeller shaft. Refer to PropellerShaft Replacement in this Group. (2) Paint or score alignment marks on the yokesand 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. Fig. 3 Press Out Bearing2). (6) If the bearing assembly will not pull out by (5) Set the yoke in an arbor press or vise with a hand after pressing, tap the base of the lug near it tolarge socket beneath it. Position the yoke with the dislodge.
ZJ PROPELLER SHAFTS 16 - 11 (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. Fig. 5 Install Cross In Yoke Fig. 4 Press Out Remaining BearingCLEANING AND INSPECTION (1) Clean all the universal joint yoke bores withcleaning solvent and a wire brush. (2) Inspect the yokes for distortion, cracks andworn bearing assembly bores.ASSEMBLY/INSTALLATION (1) Apply extreme pressure (EP) N.L.G.I. Grade 1or 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 Fig. 6 Install Bearing On Trunnionalign 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 PropellerShaft Replacement in this Group.
16 - 12 PROPELLER SHAFTS ZJDOUBLE CARDAN (5) Grasp the protruding bearing by vise jaws. Tap the tube yoke with a mallet and drift to dislodgeREMOVAL/DISASSEMBLY from the yoke (Fig. 9). Cardan universal joints are not serviceable. If wornor leaking, they must be replaced as a unit. (1) Remove the propeller shaft. Refer to PropellerShaft Replacement in this Group. (2) Paint or score alignment marks on the yokesand propeller shaft for installation reference. (3) Remove all the bearing assembly snap rings(Fig. 7). Fig. 9 Remove Bearing From Yoke (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). Fig. 7 Remove Snap Rings (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. Fig. 10 Remove Centering Kit (7) Press the remaining bearing assemblies out the other cross as described above to complete the disas- sembly. Fig. 8 Press Out Bearing
ZJ PROPELLER SHAFTS 16 - 13CLEANING AND INSPECTION (3) Press the bearing assembly in place and install (1) Clean all the U-joint yoke bores with cleaning a snap ring (Fig. 13).solvent and a wire brush. (2) Inspect the yokes for distortion, cracks andworn bearing assembly bores.ASSEMBLY/INSTALLATION During installation, ensure that the spidersand yokes are aligned to the reference marks. (1) Fit a cross into the tube yoke (Fig. 11). Fig. 13 Press In Bearing Assembly (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 (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. Fig. 14 Press In Bearing Assembly Fig. 12 Install Bearing Assembly
16 - 14 PROPELLER SHAFTS ZJ (5) Fit the center yoke on the remaining two trun- (7) Place two bearing assemblies on the remainingnions and press bearing assemblies in place, both cross (opposite sides). Fit the open trunnions into thesides (Fig. 15). Install a snap ring. center yoke holes and the bearing assemblies into the centering kit (Fig. 17). Align the lube fitting on the cross with the other two lube fittings. Fig. 15 Install Center Yoke (6) Install the centering kit assembly inside the Fig. 17 Install Remaining Crosscenter yoke making sure the spring is in place (Fig.16). Align the lube fitting on the centering kit with (8) Press the remaining two bearing assembliesthe lube fitting on the installed cross. into place and install snap rings (Fig. 18). Fig. 16 Install Centering Kit Fig. 18 Press In Bearing Assembly
ZJ PROPELLER SHAFTS 16 - 15 Fig. 20 Check Assembly Fig. 19 Seat Snap Rings In Groove (11) Add grease to all three lube fittings. (9) Tap the snap rings to allow them to seat into (12) Install the propeller shaft. Refer to Propellerthe grooves (Fig. 19). Shaft Replacement in this Group. (10) Check for proper assembly. Flex the CV jointbeyond center, it should snap over-center in both di-rections when correctly assembled (Fig. 20). TORQUE SPECIFICATIONSPROPELLER SHAFTS AND U-JOINTS Transfer Case Yoke Bolts ...........27 N⅐m (20 ft. lbs.) Pinion Flange Bolts ....................41 N⅐m (30 ft. lbs.)DESCRIPTION ................................................TORQUE Lock Nut ....................................115 N⅐m (85 ft. lbs.) Front Shaft Rear Shaft Transfer Case Yoke Bolts ...........27 N⅐m (20 ft. lbs.) Axle Yoke Bolts ...........................19 N⅐m (14 ft. lbs.) Axle Yoke Bolts ...........................19 N⅐m (14 ft. lbs.) Type 3 Front Shaft