Differential and Driveline — part 2 of 3 — 1998 Jeep Grand Cherokee ZJ Export Service Manual

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Pages 123–182 · 60 pages · 2 words repaired

(9) Install the brake rotors and calipers. Refer to Group 5, Brakes, for proper procedures.

(10) Install wheel and tire assemblies. (11) Lower the vehicle.

COLLAPSIBLE SPACER

REMOVAL W//PINION INSTALLED

(1) Raise and support the vehicle. (2) Remove wheel and tire assemblies. (3) Remove rear brake rotors and calipers. Refer to Group 5, Brakes, for proper procedures.

(4) Mark the propeller shaft and pinion yoke for installation reference. (5) Remove the propeller shaft from the yoke. (6) Rotate the pinion gear three or four times.

(7) Measure the amount of torque necessary to rotate the pinion gear with a (in. lbs.) dial-type torque wrench. Record the torque reading for installation reference.

(8) Using a short piece of pipe and Holder 6958 to hold the pinion yoke, remove the pinion nut and washer (Fig. 14).

(9) Use Remover C-452 and Wrench C-3281 to remove the pinion yoke (Fig. 15).

(10) Use Remover 7794-A and slide hammer to remove the pinion shaft seal (Fig. 16).

(11) Remove the front pinion bearing using a pair of suitable pick tools to pull the bearing straight off the pinion gear shaft. It may be necessary to lightly tap the end of the pinion gear with a rawhide or rubber mallet if the bearing becomes bound on the pinion shaft. (12) Remove the collapsible spacer.

REMOVAL W/PINION REMOVED

(1) Raise and support the vehicle. (2) Remove wheel and tire assemblies. (3) Remove rear brake rotors and calipers. Refer to Group 5, Brakes, for proper procedures.

(4) Mark the propeller shaft and pinion yoke for installation reference. (5) Remove the propeller shaft from the yoke. (6) Rotate the pinion gear three or four times. (7) Measure the amount of torque necessary to rotate the pinion gear with a (in. lbs.) dial-type torque wrench. Record the torque reading for installation reference.

(8) Remove differential assembly from axle housing. (9) Using Holder 6958 to hold yoke and a short length of 1 in. pipe, remove the pinion yoke nut and washer (Fig. 14).

(10) Using Remover C–452 and Wrench C–3281, remove the pinion yoke from pinion shaft (Fig. 15).

(11) Remove the pinion gear from housing (Fig. 17). Catch the pinion with your hand to prevent it from falling and being damaged.

(12) Remove collapsible spacer from pinion shaft.

INSTALLATION

(1) Install a new collapsible preload spacer on pinion shaft (Fig. 18). (2) If pinion gear was removed, install pinion gear in housing. (3) Install pinion front bearing, if necessary. (4) Apply a light coating of gear lubricant on the lip of pinion seal. Install seal with Installer C-3972-A and Handle C–4171 (Fig. 19).

(5) Install yoke with Screw 8112, Cup 8109, and Holder 6958 (Fig. 20).

(6) If the original pinion bearings are being used, install differential assembly and axle shafts, if necessary.

NOTE: If new pinion bearings were installed, do not install the differential assembly and axle shafts until after the pinion bearing preload and rotating torque are set.

(7) Install the yoke washer and a new nut on the pinion gear. Tighten the pinion nut until there is zero bearing end-play.

(8) Tighten the nut to 271 N·m (200 ft. lbs.).

CAUTION: Never loosen pinion gear nut to decrease pinion gear bearing rotating torque and never exceed specified preload torque. If preload torque or rotating torque is exceeded a new collapsible spacer must be installed. The torque sequence will then have to be repeated.

(9) Using yoke holder 6958, a short length of 1 in. pipe, and a torque wrench set at 474 N·m (350 ft. lbs.), crush collapsible spacer until bearing end play is taken up (Fig. 21).

NOTE: If more than 474 N·m (350 ft. lbs.) of torque is necessary to remove the bearing end play, the collapsible spacer is defective and must be replaced.

(10) Slowly tighten the nut in 6.8 N·m (5 ft. lbs.) increments until the rotating torque is achieved. Measure the rotating torque frequently to avoid over crushing the collapsible spacer (Fig. 22).

(11) Check rotating torque with an inch pound torque wrench (Fig. 22). The torque necessary to rotate the pinion gear should be:

• Original Bearings — The reading recorded during removal, plus an additional 0.56 N·m (5 in. lbs.). • New Bearings — 2 to 5 N·m (15 to 35 in. lbs.).

(12) Install differential assembly and axle shafts, if necessary. (13) Align marks made previously on yoke and propeller shaft and install propeller shaft.

(14) Install rear brake rotors and calipers. Refer to Group 5, Brakes, for proper procedures.

(15) Add gear lubricant, if necessary. Refer to Lubricant Specifications of this section for lubricant requirements.

(16) Install wheel and tire assemblies. (17) Lower vehicle.

AXLE SHAFT

REMOVAL

(1) Raise and support vehicle. Ensure that the transmission is in neutral.

(2) Remove wheel and tire assembly. (3) Remove brake caliper and rotor. Refer to Group 5, Brakes, for proper procedure.

(4) Clean all foreign material from housing cover area.

(5) Loosen housing cover bolts. Drain lubricant from the housing and axle shaft tubes. Remove housing cover. (6) Rotate differential case so that pinion mate gear shaft lock screw is accessible. Remove lock screw and pinion mate gear shaft from differential case (Fig. 23).

(7) Push axle shaft inward and remove axle shaft C–clip lock from the axle shaft (Fig. 24).

(8) Remove axle shaft. Use care to prevent damage to axle shaft bearing and seal, which will remain in axle shaft tube. Also, exercise care not to damage the wheel speed sensor on vehicles equipped with ABS brakes.

(9) Inspect axle shaft seal for leakage or damage. (10) Inspect roller bearing contact surface on axle shaft for signs of brinelling, galling and pitting. If any of these conditions exist, the axle shaft and/or bearing and seal must be replaced.

INSTALLATION

(1) Lubricate bearing bore and seal lip with gear lubricant. Insert axle shaft through seal, bearing, and engage it into side gear splines.

NOTE: Use care to prevent shaft splines from damaging axle shaft seal lip. Also, exercise care not to damage the wheel speed sensor on vehicles equipped with ABS brakes

(2) Insert C–clip lock in end of axle shaft. Push axle shaft outward to seat C–clip lock in side gear.

(3) Insert pinion mate shaft into differential case and through thrust washers and pinion gears.

(4) Align hole in shaft with hole in the differential case and install lock screw with Loctitet on the threads. Tighten lock screw to 19 N·m (14 ft. lbs.) torque.

(5) Install cover and add fluid. Refer to Lubricant Change procedure in this section for procedure and lubricant requirements.

(6) Install brake caliper and rotor. Refer to Group 5, Brakes, for proper procedures.

(7) Install wheel and tire. (8) Lower vehicle.

AXLE SHAFT SEAL AND BEARING

REMOVAL

(1) Remove the axle shaft. (2) Remove the axle shaft seal from the end of the axle shaft tube with a small pry bar.

NOTE: The seal and bearing can be removed at the same time with the bearing removal tool.

(3) Remove the axle shaft bearing from the axle tube with Bearing Removal Tool Set 6310 using Adapter Foot 6310-5 (Fig. 25).

(4) Inspect the axle shaft tube bore for roughness and burrs. Remove as necessary.

INSTALLATION

Do not install the original axle shaft seal. Always install a new seal.

(1) Wipe the axle shaft tube bore clean.

(2) Install axle shaft bearing with Installer 6436 and Handle C–4171. Ensure that the part number on the bearing is against the installer.

(3) Install the new axle shaft seal with Installer 6437 and Handle C–4171 (Fig. 26).

(4) Install the axle shaft.

DIFFERENTIAL

REMOVAL

(1) Raise and support vehicle. (2) Remove the lubricant fill hole plug from the differential housing cover.

(3) Remove the differential housing cover and allow fluid to drain.

(4) Remove axle shafts. (5) Note the installation reference letters stamped on the bearing caps and housing machined sealing surface (Fig. 27).

(6) Loosen the differential bearing cap bolts. (7) Position Spreader W–129–B, utilizing some items from Adapter set 6987, with the tool dowel pins seated in the locating holes (Fig. 28). Install the holddown clamps and tighten the tool turnbuckle finger- –tight.

(8) Install a Pilot Stud C-3288-B at the left side of the differential housing. Attach Dial Indicator C-3339 to pilot stud. Load the indicator plunger against the opposite side of the housing (Fig. 29) and zero the indicator.

CAUTION: Do not spread over 0.38 mm (0.015 in). If the housing is over–spread, it could be distorted or damaged.

(9) Spread the housing enough to remove the differential case from the housing. Measure the distance with the dial indicator (Fig. 30).

(10) Remove the dial indicator. (11) While holding the differential case in position, remove the differential bearing cap bolts and caps.

(12) Remove the differential from the housing. Ensure that the differential bearing cups remain in position on the differential bearings (Fig. 31).

(13) Mark or tag the differential bearing cups to indicate which side of the differential they were removed from.

(14) Retrieve differential case preload shims from axle housing. Mark or tag the differential case preload shims to indicate which side of the differential they were removed from.

(15) Remove spreader from housing.

INSTALLATION

If replacement differential bearings or differential case are being installed, differential side bearing shim requirements may change. Refer to the Differential Bearing Preload and Gear Backlash procedures in this section to determine the proper shim selection.

(1) Position Spreader W–129–B, utilizing some items from Adapter set 6987, with the tool dowel pins seated in the locating holes (Fig. 32). Install the holddown clamps and tighten the tool turnbuckle finger- –tight.

(2) Install a Pilot Stud C-3288-B at the left side of the differential housing. Attach Dial Indicator C-3339 to pilot stud. Load the indicator plunger against the opposite side of the housing (Fig. 29) and zero the indicator.

CAUTION: Do not spread over 0.38 mm (0.015 in). If the housing is over–spread, it could be distorted or damaged.

(3) Spread the housing enough to install the case in the housing. Measure the distance with the dial indicator (Fig. 30). (4) Remove the dial indicator. (5) Install differential case in the housing. Ensure that the differential bearing cups remain in position on the differential bearings and that the preload shims remain between the face of the bearing cup

and the housing. Tap the differential case to ensure the bearings cups and shims are fully seated in the housing.

(6) Install the bearing caps at their original locations (Fig. 33).

(7) Loosely install differential bearing cap bolts. (8) Remove axle housing spreader. (9) Tighten the bearing cap bolts to 77 N·m (57 ft. lbs.) torque.

(10) Install the axle shafts.

DIFFERENTIAL SIDE BEARINGS

REMOVAL

(1) Remove differential from axle housing.

(2) Remove the bearings from the differential case with Puller/Press C-293-PA, C-293-39 Blocks, and Plug SP-3289 (Fig. 34).

INSTALLATION

(1) Using tool C-3716-A with handle C-4171, install differential side bearings (Fig. 35). (2) Install differential in axle housing.

RING GEAR

The ring and pinion gears are service in a matched set. Do not replace the ring gear without replacing the pinion gear.

REMOVAL

(1) Remove differential from axle housing. (2) Place differential case in a suitable vise with soft metal jaw protectors. (Fig. 36)

(3) Remove bolts holding ring gear to differential case.

(4) Using a soft hammer, drive ring gear from differential case (Fig. 36).

INSTALLATION

CAUTION: Do not reuse the bolts that held the ring gear to the differential case. The bolts can fracture causing extensive damage.

(1) Invert the differential case and start two ring gear bolts. This will provide case-to-ring gear bolt hole alignment.

(2) Invert the differential case in the vise. (3) Install new ring gear bolts and alternately tighten to 95–122 N·m (70–90 ft. lbs.) torque (Fig. 37).

(4) Install differential in axle housing and verify gear mesh and contact pattern.

PINION GEAR

The ring and pinion gears are serviced in a matched set. Do not replace the pinion gear without replacing the ring gear.

REMOVAL

(1) Remove differential from the axle housing. (2) Mark pinion yoke and propeller shaft for installation alignment. (3) Disconnect propeller shaft from pinion yoke. Using suitable wire, tie propeller shaft to underbody.

(4) Using Holder 6958 to hold yoke and a short length of 1 in. pipe, remove the pinion yoke nut and washer (Fig. 38).

(5) Using Remover C–452 and Wrench C–3281, remove the pinion yoke from pinion shaft (Fig. 39).

(6) Remove the pinion gear from housing (Fig. 40). Catch the pinion with your hand to prevent it from falling and being damaged.

(7) Use Remover 7794-A and slide hammer to remove the pinion shaft seal (Fig. 41).

(8) Remove oil slinger, if equipped, and front pinion bearing. (9) Remove the front pinion bearing cup with Remover C-4345 and Handle C–4171 (Fig. 42).

(10) Remove the rear bearing cup from housing (Fig. 43). Use Remover D-149 and Handle C–4171.

(11) Remove the collapsible preload spacer (Fig. 44).

(12) Remove the rear bearing from the pinion with Puller/Press C-293-PA and Adapters C-293-40 (Fig. 45).

Place 4 adapter blocks so they do not damage the bearing cage.

(13) Remove the depth shims from the pinion gear shaft. Record the thickness of the depth shims.

INSTALLATION

(1) Apply Mopart Door Ease, or equivalent, stick lubricant to outside surface of bearing cup.

(2) Install the pinion rear bearing cup with Installer D-146 and Driver Handle C–4171 (Fig. 46). Ensure cup is correctly seated.

(3) Apply Mopart Door Ease, or equivalent, stick lubricant to outside surface of bearing cup.

(4) Install the pinion front bearing cup with Installer D–130 and Handle C–4171 (Fig. 47).

(5) Install pinion front bearing, and oil slinger, if equipped.

(6) Apply a light coating of gear lubricant on the lip of pinion seal. Install seal with Installer C-3972-A and Handle C–4171 (Fig. 48).

NOTE: Pinion depth shims are placed between the rear pinion bearing cone and pinion gear to achieve proper ring and pinion gear mesh. If the factory installed ring and pinion gears are reused, the pinion depth shim should not require replacement. If required, refer to Pinion Gear Depth to select the proper thickness shim before installing rear pinion bearing.

(7) Place the proper thickness depth shim on the pinion gear.

(8) Install the rear bearing and slinger, if equipped, on the pinion gear with Installer W-262 (Fig. 49).

(9) Install a new collapsible preload spacer on pinion shaft and install pinion gear in housing (Fig. 50). (10) Install pinion gear in housing.

(11) Install yoke with Installer Screw 8112, Cup 8109, and holder 6958 (Fig. 51).

(12) Install the yoke washer and a new nut on the pinion gear and tighten the pinion nut until there is zero bearing end-play.

(13) Tighten the nut to 271 N·m (200 ft. lbs.).

CAUTION: Never loosen pinion gear nut to decrease pinion gear bearing rotating torque and never exceed specified preload torque. If preload torque or rotating torque is exceeded a new collapsible spacer must be installed. The torque sequence will then have to be repeated.

(14) Using yoke holder 6958, a short length of 1 in. pipe, and a torque wrench set at 474 N·m (350 ft. lbs.), crush collapsible spacer until bearing end play is taken up (Fig. 52).

NOTE: If the spacer requires more than 474 N·m (350 ft. lbs.) torque to crush, the collapsible spacer is defective and must be replaced.

(15) Slowly tighten the nut in 6.8 N·m (5 ft. lbs.) increments until the rotating torque is achieved. Measure the rotating torque frequently to avoid over crushing the collapsible spacer (Fig. 53).

(16) Check bearing rotating torque with an inch pound torque wrench (Fig. 53). The torque necessary to rotate the pinion gear should be:

• Original Bearings — 1 to 3 N·m (10 to 20 in. lbs.).

• New Bearings — 2 to 5 N·m (15 to 35 in. lbs.). (17) Install differential in housing.

FINAL ASSEMBLY

(1) Scrape the residual sealant from the housing and cover mating surfaces. Clean the mating surfaces with mineral spirits. Apply a bead of Mopart Silicone

Rubber Sealant, or equivalent, on the housing cover (Fig. 54).

Install the housing cover within 5 minutes after applying the sealant.

(2) Install the cover on the differential with the attaching bolts. Install the identification tag. Tighten the cover bolts to 41 N·m (30 ft. lbs.) torque.

CAUTION: Overfilling the differential can result in lubricant foaming and overheating.

(3) Refill the differential housing with gear lubricant. Refer to the Lubricant Specifications section of this group for the gear lubricant requirements.

(4) Install the fill hole plug.

DISASSEMBLY AND ASSEMBLY

STANDARD DIFFERENTIAL

DISASSEMBLY

(1) Remove pinion gear mate shaft lock screw (Fig. 55).

(2) Remove pinion gear mate shaft. (3) Rotate the differential side gears and remove the pinion mate gears and thrust washers (Fig. 56).

(4) Remove the differential side gears and thrust washers.

ASSEMBLY

(1) Install the differential side gears and thrust washers.

(2) Install the pinion mate gears and thrust washers.

(3) Install the pinion gear mate shaft. (4) Align the hole in the pinion gear mate shaft with the hole in the differential case and install the pinion gear mate shaft lock screw.

(5) Lubricate all differential components with hypoid gear lubricant.

TRAC-LOK DIFFERENTIAL

The Trac–lok differential components are illustrated in (Fig. 57). Refer to this illustration during repair service.

DISASSEMBLY

(1) Clamp Side Gear Holding Tool 6965 in a vise. (2) Position the differential case on Side Gear Holding Tool 6965 (Fig. 58).

(3) Remove ring gear, if necessary. Ring gear removal is necessary only if the ring gear is to be replaced. The Trac-lok differential can be serviced with the ring gear installed.

(4) Remove the pinion gear mate shaft lock screw (Fig. 59).

(5) Remove the pinion gear mate shaft. If necessary, use a drift and hammer (Fig. 60).

(6) Install and lubricate Step Plate C-6960-3 (Fig. 61).

(7) Assemble Threaded Adapter C-6960-1 into top side gear. Thread Forcing Screw C-6960-4 into adapter until it becomes centered in adapter plate.

(8) Position a small screw driver in slot of Threaded Adapter C-6960-1 (Fig. 62) to prevent adapter from turning.

(9) Tighten forcing screw tool 122 N·m (90 ft. lbs.) maximum to compress Belleville springs in clutch packs (Fig. 63).

(10) Using an appropriate size feeler gauge, remove thrust washers from behind the pinion gears (Fig. 64).

(11) Insert Turning Bar C-6960-2 in case (Fig. 65). (12) Loosen the Forcing Screw C-6960-4 in small increments until the clutch pack tension is relieved and the differential case can be turned using Turning Bar C-6960-2.

(13) Rotate differential case until the pinion gears can be removed.

(14) Remove pinion gears from differential case.

(15) Remove Forcing Screw C-6960-4, Step Plate C-6960-3, and Threaded Adapter C-6960-1.

(16) Remove top side gear, clutch pack retainer, and clutch pack. Keep plates in correct order during removal (Fig. 66).

(17) Remove differential case from Side Gear Holding Tool 6965. Remove side gear, clutch pack retainer, and clutch pack. Keep plates in correct order during removal.

ASSEMBLY

NOTE: The clutch discs are replaceable as complete sets only. If one clutch disc pack is damaged, both packs must be replaced.

Lubricate each component with gear lubricant before assembly.

(1) Assemble the clutch discs into packs and secure disc packs with retaining clips (Fig. 67).

(2) Position assembled clutch disc packs on the side gear hubs.

(3) Install clutch pack and side gear in the ring gear side of the differential case (Fig. 68). Be sure clutch pack retaining clips remain in position and are seated in the case pockets.

(4) Position the differential case on Side Gear Holding Tool 6965.

(5) Install lubricated Step Plate C-6960-3 in lower side gear (Fig. 69).

(6) Install the upper side gear and clutch disc pack (Fig. 69).

(7) Hold assembly in position. Insert Threaded Adapter C-6960-1 into top side gear.

(8) Insert Forcing Screw C-6960-4.

(9) Tighten forcing screw tool to slightly compress clutch discs.

(10) Place pinion gears in position in side gears and verify that the pinion mate shaft hole is aligned.

(11) Rotate case with Turning Bar C-6960-2 until the pinion mate shaft holes in pinion gears align with holes in case. It may be necessary to slightly tighten the forcing screw in order to install the pinion gears.

Installation

(12) Tighten forcing screw to 122 N·m (90 ft. lbs.) maximum to compress the Belleville springs.

(13) Lubricate and install thrust washers behind pinion gears and align washers with a small screw driver. Insert mate shaft into each pinion gear to verify alignment. (14) Remove Forcing Screw C-6960-4, Step Plate C-6960-3, and Threaded Adapter C-6960-1.

(15) Install pinion gear mate shaft and align holes in shaft and case. (16) Install the pinion mate shaft lock screw finger tight to hold shaft during differential installation.

If replacement gears and thrust washers were installed, it is not necessary to measure the gear backlash. Correct fit is due to close machining tolerances during manufacture.

(17) Lubricate all differential components with hypoid gear lubricant.

CLEANING AND INSPECTION

AXLE COMPONENTS

Wash differential components with cleaning solvent and dry with compressed air. Do not steam clean the differential components.

Wash bearings with solvent and towel dry, or dry with compressed air. DO NOT spin bearings with compressed air. Cup and bearing must be replaced as matched sets only.

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

• Smooth appearance with no broken/dented surfaces on the bearing rollers or the roller contact surfaces.

• Bearing cups must not be distorted or cracked. • Machined surfaces should be smooth and without any raised edges.

• Raised metal on shoulders of cup bores should be removed with a hand stone.

• Wear and damage to pinion gear mate shaft, pinion gears, side gears and thrust washers. Replace as a matched set only.

• Ring and pinion gear for worn and chipped teeth.

• Ring gear for damaged bolt threads. Replaced as a matched set only.

• Pinion yoke for cracks, worn splines, pitted areas, and a rough/corroded seal contact surface. Repair or replace as necessary.

• Preload shims for damage and distortion. Install new shims, if necessary.

TRAC-LOK

Clean all components in cleaning solvent. Dry components with compressed air. Inspect clutch pack plates for wear, scoring or damage. Replace both clutch packs if any one component in either pack is damaged. Inspect side and pinion gears. Replace any gear that is worn, cracked, chipped or damaged. Inspect differential case and pinion shaft. Replace if worn or damaged.

PRESOAK PLATES AND DISC

Plates and discs with fiber coating (no grooves or lines) must be presoaked in Friction Modifier before assembly. Soak plates and discs for a minimum of 20 minutes.

ADJUSTMENTS

PINION GEAR DEPTH

GENERAL INFORMATION

Ring and pinion gears are supplied as matched sets only. The identifying numbers for the ring and pinion gear are etched into the face of each gear (Fig. 70). A plus (+) number, minus (–) number or zero (0) is etched into the face of the pinion gear. This number is the amount (in thousandths of an inch) the depth varies from the standard depth setting of a pinion etched with a (0). The standard setting from the center line of the ring gear to the back face of the pinion is 96.850 mm (3.813 in.). The standard depth provides the best teeth contact pattern. Refer to Backlash and Contact Pattern Analysis Paragraph in this section for additional information.

Compensation for pinion depth variance is achieved with select shims. The shims are placed under the inner pinion bearing cone (Fig. 71).

If a new gear set is being installed, note the depth variance etched into both the original and replacement pinion gear. Add or subtract the thickness of the original depth shims to compensate for the difference in the depth variances. Refer to the Depth Variance charts.

Note where Old and New Pinion Marking columns intersect. Intersecting figure represents plus or minus amount needed.

Note the etched number on the face of the drive pinion gear (–1, –2, 0, +1, +2, etc.). The numbers represent thousands of an inch deviation from the standard. If the number is negative, add that value to the required thickness of the depth shim(s). If the number is positive, subtract that value from the thickness of the depth shim(s). If the number is 0 no change is necessary. Refer to the Pinion Gear Depth Variance Chart.

PINION GEAR DEPTH VARIANCE

ADJUSTMENT

Measurements are taken with pinion cups and pinion bearings installed in housing. Take measurements with a Pinion Gauge Set, Pinion Block 6735, Arbor Discs 6732, and Dial Indicator C-3339 (Fig. 72).

(1) Assemble Pinion Height Block 6739, Pinion Block 6735, and rear pinion bearing onto Screw 6741 (Fig. 72).

(2) Insert assembled height gauge components, rear bearing and screw into axle housing through pinion bearing cups (Fig. 73).

(3) Install front pinion bearing and Cone 6740 hand tight (Fig. 72).

(4) Place Arbor Disc 6732 on Arbor D-115-3 in position in axle housing side bearing cradles (Fig. 74). Install differential bearing caps on Arbor Discs and tighten cap bolts. Refer to the Torque Specifications in this section.

NOTE: Arbor Discs 6732 have different step diameters to fit other axle sizes. Pick correct size step for axle being serviced.

(5) Assemble Dial Indicator C-3339 into Scooter Block D-115-2 and secure set screw.

(6) Place Scooter Block/Dial Indicator in position in axle housing so dial probe and scooter block are flush against the surface of the pinion height block. Hold scooter block in place and zero the dial indicator face to the pointer. Tighten dial indicator face lock screw.

(7) With scooter block still in position against the pinion height block, slowly slide the dial indicator probe over the edge of the pinion height block. Observe how many revolutions counterclockwise the dial pointer travels (approximately 0.125 in.) to the out-stop of the dial indicator.

(8) Slide the dial indicator probe across the gap between the pinion height block and the arbor bar with the scooter block against the pinion height block (Fig. 75). When the dial probe contacts the arbor bar, the dial pointer will turn clockwise. Bring dial pointer back to zero against the arbor bar, do not turn dial face. Continue moving the dial probe to the crest of the arbor bar and record the highest reading. If the dial indicator can not achieve the zero reading, the rear bearing cup or the pinion depth gauge set is not installed correctly.

(9) Select a shim equal to the dial indicator reading plus the drive pinion gear depth variance number etched in the face of the pinion gear (Fig. 70) using the opposite sign on the variance number. For example, if the depth variance is –2, add +0.002 in. to the dial indicator reading.

(10) Remove the pinion depth gauge components from the axle housing

DIFFERENTIAL BEARING PRELOAD AND GEAR BACKLASH

Differential side bearing preload and gear backlash is achieved by selective shims inserted between the bearing cup and the axle housing. The proper shim thickness can be determined using slip-fit dummy bearings D-348 in place of the differential side bearings and a dial indicator C-3339. Before proceeding with the differential bearing preload and gear backlash measurements, measure the pinion gear depth and prepare the pinion gear for installation. Establishing proper pinion gear depth is essential to establishing gear backlash and tooth contact patterns. After the overall shim thickness to take up differential side play is measured, the pinion gear is installed, and the gear backlash shim thickness is measured. The overall shim thickness is the total of the dial indicator reading, starting point shim thickness, and the preload specification added together. The gear backlash measurement determines the thickness of the shim used on the ring gear side of the differential case. Subtract the gear backlash shim thickness from the total overall shim thickness and select that amount for the pinion gear side of the differential (Fig. 76).

SHIM SELECTION

NOTE: It is difficult to salvage the differential side bearings during the removal procedure. Install replacement bearings if necessary.

(1) Remove side bearings from differential case. (2) Install ring gear, if necessary, on differential case and tighten bolts to specification.

(3) Install dummy side bearings D-348 on differential case.

(4) Install differential case in axle housing.

(5) Insert Dummy Shims 8107 (0.118 in. (3.0 mm)) starting point shims between the dummy bearing and the axle housing (Fig. 77).

(6) Install the marked bearing caps in their correct positions. Install and tighten the bolts.

(7) Thread guide stud C-3288-B into rear cover bolt hole below ring gear (Fig. 78).

(8) Attach dial indicator C-3339 to guide stud. Position the dial indicator plunger on a flat surface on a ring gear bolt head (Fig. 78).

(9) Push firmly and hold differential case to pinion gear side of axle housing.

(10) Zero dial indicator face to pointer. (11) Push firmly and hold differential case to ring gear side of the axle housing.

(12) Record dial indicator reading. (13) Add the dial indicator reading to the starting point shim thickness to determine total shim thickness to achieve zero differential end play.

(14) Add 0.008 in. (0.2 mm) to the zero end play total. This new total represents the thickness of shims to compress, or preload the new bearings when the differential is installed.

(15) Rotate dial indicator out of the way on guide stud.

(16) Remove differential case, dummy bearings, and starting point shims from axle housing.

(17) Install pinion gear in axle housing. Install the yoke and establish the correct pinion rotating torque.

(18) Install differential case and dummy bearings in axle housing (without shims) and tighten retaining cap bolts.

(19) Position the dial indicator plunger on a flat surface between the ring gear bolt heads (Fig. 78).

(20) Push and hold differential case toward pinion gear.

(21) Zero dial indicator face to pointer. (22) Push and hold differential case to ring gear side of the axle housing.

(23) Record dial indicator reading. (24) Subtract 0.002 in. (0.05 mm) from the dial indicator reading to compensate for backlash between ring and pinion gears. This total is the thickness of shim required to achieve proper backlash.

(25) Subtract the backlash shim thickness from the total preload shim thickness. The remainder is the shim thickness required on the pinion side of the axle housing.

(26) Rotate dial indicator out of the way on guide stud.

(27) Remove differential case and dummy bearings from axle housing.

(28) Install new side bearing cones and cups on differential case.

(29) Install spreader W-129-B, utilizing some components of Adapter Set 6987, on axle housing and spread axle opening enough to receive differential case.

(30) Place side bearing shims in axle housing against axle tubes.

(31) Install differential case in axle housing. (32) Rotate the differential case several times to seat the side bearings.

(33) Position the indicator plunger against a ring gear tooth (Fig. 79).

(34) Push and hold ring gear upward while not allowing the pinion gear to rotate.

(35) Zero dial indicator face to pointer. (36) Push and hold ring gear downward while not allowing the pinion gear to rotate. Dial indicator reading should be between 0.12 mm (0.005 in.) and 0.20 mm (0.008 in.). If backlash is not within specifications transfer the necessary amount of shim thickness from one side of the differential housing to the other (Fig. 80).

(37) Verify differential case and ring gear runout by measuring ring to pinion gear backlash at several locations around the ring gear. Readings should not vary more than 0.05 mm (0.002 in.). If readings vary more than specified, the ring gear or the differential case is defective.

After the proper backlash is achieved, perform the Gear Contact Pattern Analysis procedure.

GEAR CONTACT PATTERN ANALYSIS

The ring and pinion gear teeth contact patterns will show if the pinion gear depth is correct in the axle housing. It will also show if the ring gear backlash has been adjusted correctly. The backlash can be adjusted within specifications to achieve desired tooth contact patterns.

(1) Apply a thin coat of hydrated ferric oxide, or equivalent, to the drive and coast side of the ring gear teeth.

(2) Wrap, twist, and hold a shop towel around the pinion yoke to increase the turning resistance of the pinion gear. This will provide a more distinct contact pattern.

(3) Using a boxed end wrench on a ring gear bolt, Rotate the differential case one complete revolution in both directions while a load is being applied from shop towel.

The areas on the ring gear teeth with the greatest degree of contact against the pinion gear teeth will squeegee the compound to the areas with the least amount of contact. Note and compare patterns on the ring gear teeth to Gear Tooth Contact Patterns chart (Fig. 81) and adjust pinion depth and gear backlash as necessary.

SPECIFICATIONS

194 RBI AXLE

DESCRIPTION SPECIFICATION Axle Type . . . . . . . . . . . . . . . .Semi–Floating Hypoid Lubricant. . . . . . . . . .SAE Thermally Stable 80W–90 Lubricant Trailer Tow . . . . . . . . .Synthetic 75W–140 Lube Capacity . . . . . . . . . . . . . . . . .1.66 L (3.50 pts.) Axle Ratios. . . . . . . . . . . . . . . . .3.07, 3.55, 3.73, 4.10 Differential Bearing Preload . . . . .0.1 mm (0.004 in.) Differential Side Gear

Clearance . . . . . . . . . . . . .0–0.15 mm (0–0.006 in.) Ring Gear Diameter . . . . . . . . . . .19.2 cm (7.562 in.) Ring Gear Backlash . . . .0–0.15 mm (0.005–0.008 in.) Pinion Std. Depth . . . . . . . . . . .92.08 mm (3.625 in.) Pinion Bearing Preload-

Original Bearings . . . . . . .1–2 N·m (10–20 in. lbs.) Pinion Bearing Preload-

New Bearings . . . . . . . .1.5–4 N·m (15–35 in. lbs.) Maximum Carrier Spread . . . . . .0.51 mm (0.020 in.)

194 RBI AXLE

DESCRIPTION TORQUE Bolt, Diff. Cover . . . . . . . . . . . . .41 N·m (30 ft. lbs.) Bolt, Bearing Cap . . . . . . . . . . .77 N·m (57 ft. lbs.) Nut, Pinion . . . . . . . . . . . . . . . . . . . . .271–474 N·m

(200–350 ft. lbs.) Screw, Pinion Mate

Shaft Lock . . . . . . . . . . . . . . . . . . . . . .16.25 N·m

(12 ft. lbs.) Bolt, Ring Gear . . . . . . .95–122 N·m (70–90 ft. lbs.) Bolt, ABS Sensor. . . . . . . . . . . . .8 N·m (70 in. lbs.)

SPECIAL TOOLS

194 RBI AXLE

GENERAL INFORMATION

216 RBA AXLE . . . . . . . . . . . . . . . . . . . . . . . . . . 88 LUBRICANT SPECIFICATIONS . . . . . . . . . . . . . . 88 DESCRIPTION AND OPERATION

STANDARD DIFFERENTIAL . . . . . . . . . . . . . . . . 89 TRAC-LOK OPERATION . . . . . . . . . . . . . . . . . . . 89 DIAGNOSIS AND TESTING

BEARING NOISE . . . . . . . . . . . . . . . . . . . . . . . . 90 DRIVELINE SNAP . . . . . . . . . . . . . . . . . . . . . . . 91 GEAR NOISE . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 GENERAL INFORMATION . . . . . . . . . . . . . . . . . 90 LOW SPEED KNOCK . . . . . . . . . . . . . . . . . . . . . 91 TRAC–LOK DIFFERENTIAL NOISE . . . . . . . . . . 91 TRAC–LOK TEST . . . . . . . . . . . . . . . . . . . . . . . 94 VIBRATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 SERVICE PROCEDURES

LUBRICANT CHANGE . . . . . . . . . . . . . . . . . . . . 94 REMOVAL AND INSTALLATION

AXLE SHAFT SEAL AND BEARING . . . . . . . . . 100 AXLE SHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 COLLAPSIBLE SPACER . . . . . . . . . . . . . . . . . . . 97 DIFFERENTIAL SIDE BEARINGS . . . . . . . . . . . 103

GENERAL INFORMATION

216 RBA AXLE

The 216 Rear Beam-design Aluminum (RBA) axle housing has an aluminum center casting (differential housing) with axle shaft tubes extending from either side. The tubes are pressed into the differential housing to form a one–piece axle housing. The integral type housing, hypoid gear design has the center-line of the pinion set below the center-line of the ring gear.

The axle has a vent hose to relieve internal pressure caused by lubricant vaporization and internal expansion.

The axles are equipped with semi–floating axle shafts, meaning that vehicle load is supported by the axle shaft and bearings. The axle shafts are retained by C–clips in the differential side gears.

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

For vehicles equipped with ABS brakes, the axles have a tone ring pressed onto the axle shaft. Use care when removing axle shafts to ensure that the tone wheel or the wheel speed sensor are not damaged.

216 RBA AXLE

INDEX

page page

DIFFERENTIAL . . . . . . . . . . . . . . . . . . . . . . . . . 101 FINAL ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . 108 PINION GEAR . . . . . . . . . . . . . . . . . . . . . . . . . 104 PINION SHAFT SEAL . . . . . . . . . . . . . . . . . . . . . 95 REAR AXLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 RING GEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 DISASSEMBLY AND ASSEMBLY

STANDARD DIFFERENTIAL . . . . . . . . . . . . . . 108 TRAC-LOK DIFFERENTIAL . . . . . . . . . . . . . . . . 108 CLEANING AND INSPECTION

AXLE COMPONENTS . . . . . . . . . . . . . . . . . . . . 112 TRAC-LOK . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 ADJUSTMENTS

DIFFERENTIAL BEARING PRELOAD AND

GEAR BACKLASH . . . . . . . . . . . . . . . . . . . . . 115 GEAR CONTACT PATTERN ANALYSIS . . . . . . . 117 PINION GEAR DEPTH . . . . . . . . . . . . . . . . . . . 113 SPECIFICATIONS

216 RBA AXLE . . . . . . . . . . . . . . . . . . . . . . . . . 119 TORQUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 SPECIAL TOOLS

216 RBA AXLE . . . . . . . . . . . . . . . . . . . . . . . . . 119

The 216 RBA axle has the assembly part number and gear ratio listed on a tag. The tag is attached to the differential housing by a cover bolt. Build date identification codes are stamped on the cover side of an axle shaft tube.

The differential case is a one-piece design. The differential pinion mate shaft is retained with a threaded pin. Differential bearing preload and ring gear backlash is adjusted by the use of selective spacer shims. Pinion bearing preload is set and maintained by the use of a collapsible spacer (Fig. 1).

LUBRICANT SPECIFICATIONS

A multi–purpose, hypoid gear lubricant which conforms to the following specifications should be used. Mopart Hypoid Gear Lubricant conforms to all of these specifications.

• The lubricant should have MIL–L–2105C and API GL 5 quality specifications.

• Lubricant is a thermally stable SAE 80W–90 gear lubricant.

• Lubricant for axles intended for heavy-duty or trailer tow use is SAE 75W–140 SYNTHETIC gear lubricant.

Trac-lok differentials require the addition of 4 oz. of friction modifier to the axle lubricant. The 216

RBA axle lubricant capacity is 2.25 L (4.75 pts.) total, including the friction modifier if necessary.

CAUTION: If axle is submerged in water, lubricant must be replaced immediately to avoid possible premature axle failure.

DESCRIPTION AND OPERATION

STANDARD DIFFERENTIAL

The differential gear system divides the torque between the axle shafts. It allows the axle shafts to rotate at different speeds when turning corners.

Each differential side gear is splined to an axle shaft. The pinion gears are mounted on a pinion mate shaft and are free to rotate on the shaft. The pinion gear is fitted in a bore in the differential case and is positioned at a right angle to the axle shafts.

In operation, power flow occurs as follows: • The pinion gear rotates the ring gear • The ring gear (bolted to the differential case) rotates the case

• The differential pinion gears (mounted on the pinion mate shaft in the case) rotate the side gears

• The side gears (splined to the axle shafts) rotate the shafts

During straight-ahead driving, the differential pinion gears do not rotate on the pinion mate shaft. This occurs because input torque applied to the gears is divided and distributed equally between the two side gears. As a result, the pinion gears revolve with the pinion mate shaft but do not rotate around it (Fig. 2).

When turning corners, the outside wheel must travel a greater distance than the inside wheel to complete a turn. The difference must be compensated for to prevent the tires from scuffing and skidding through turns. To accomplish this, the differential allows the axle shafts to turn at unequal speeds (Fig.

3). In this instance, the input torque applied to the pinion gears is not divided equally. The pinion gears now rotate around the pinion mate shaft in opposite directions. This allows the side gear and axle shaft attached to the outside wheel to rotate at a faster speed.

TRAC-LOK OPERATION

In a conventional differential, if one wheel spins, the opposite wheel will generate only as much torque as the spinning wheel.

In the Trac-lok differential, part of the ring gear torque is transmitted through clutch packs which contain multiple discs. The clutches will have radial grooves on the plates, and concentric grooves on the discs or bonded fiber material that is smooth in appearance.

In operation, the Trac-lok clutches are engaged by two concurrent forces. The first being the preload force exerted through Belleville spring washers within the clutch packs. The second is the separating forces generated by the side gears as torque is applied through the ring gear (Fig. 4).

The Trac-lok design provides the differential action needed for turning corners and for driving straight ahead during periods of unequal traction. When one wheel looses traction, the clutch packs transfer additional torque to the wheel having the most traction. Trac-lok differentials resist wheel spin on bumpy roads and provide more pulling power when one wheel looses traction. Pulling power is provided continuously until both wheels loose traction. If both wheels slip due to unequal traction, Trac-lok operation is normal. In extreme cases of differences of traction, the wheel with the least traction may spin.

DIAGNOSIS AND TESTING

GENERAL INFORMATION

Axle bearing problem conditions are usually caused by:

• Insufficient or incorrect lubricant. • Foreign matter/water contamination. • Incorrect bearing preload torque adjustment. • Incorrect backlash. Axle gear problem conditions are usually the result of:

• Insufficient lubrication. • Incorrect or contaminated lubricant.

• Overloading (excessive engine torque) or exceeding vehicle weight capacity. • Incorrect clearance or backlash adjustment. Axle component breakage is most often the result of:

• Severe overloading. • Insufficient lubricant. • Incorrect lubricant. • Improperly tightened components.

GEAR NOISE

Axle gear noise can be caused by insufficient lubricant, incorrect backlash, tooth contact, or worn/damaged gears.

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

When road testing, accelerate the vehicle to the speed range where the noise is the greatest. Shift out-of-gear and coast through the peak–noise range. If the noise stops or changes greatly:

• Check for insufficient lubricant. • Incorrect ring gear backlash. • Gear damage. Differential side and pinion gears can be checked by turning the vehicle. They usually do not cause noise during straight–ahead driving when the gears are unloaded. The side gears are loaded during vehicle turns. A worn pinion gear mate shaft can also cause a snapping or a knocking noise.

BEARING NOISE

The axle shaft, differential and pinion gear bearings can all produce noise when worn or damaged. Bearing noise can be either a whining, or a growling sound.

Pinion gear bearings have a constant–pitch noise. This noise changes only with vehicle speed. Pinion bearing noise will be higher because it rotates at a faster rate. Drive the vehicle and load the differential. If bearing noise occurs, the rear pinion bearing is the source of the noise. If the bearing noise is heard during a coast, the front pinion bearing is the source.

Worn or damaged differential bearings usually produce a low pitch noise. Differential bearing noise is similar to pinion bearing noise. The pitch of differential bearing noise is also constant and varies only with vehicle speed.

Axle shaft bearings produce noise and vibration when worn or damaged. The noise generally changes when 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 noise level. Where axle bearing damage is slight, the noise is usually not noticeable at speeds above 30 mph.

LOW SPEED KNOCK

Low speed knock is generally caused by a worn U–joint or by worn side–gear thrust washers. A worn pinion gear shaft bore will also cause low speed knock.

VIBRATION

Vibration at the rear of the vehicle is usually caused by a:

• Damaged drive shaft. • Missing drive shaft balance weight(s). • Worn or out–of–balance wheels. • Loose wheel lug nuts. • Worn U–joint(s). • Loose/broken springs. • Damaged axle shaft bearing(s). • Loose pinion gear nut. • Excessive pinion yoke run out. • Bent axle shaft(s). Check for loose or damaged front–end components or engine/transmission mounts. These components can contribute to what appears to be a rear–end vibration. Do not overlook engine accessories, brackets and drive belts.

All driveline components should be examined before starting any repair.

Refer to Group 22, Wheels and Tires, for additional vibration information.

DRIVELINE SNAP

A 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/case clearance The source of a snap or a clunk noise can be determined with the assistance of a helper. Raise the vehicle on a hoist with the wheels free to rotate. Instruct the helper to shift the transmission into gear. Listen for the noise, a mechanics stethoscope is helpful in isolating the source of a noise.

TRAC–LOK DIFFERENTIAL NOISE

The most common problem is a chatter noise when turning corners. Before removing a Trac-lok unit for repair, drain, flush and refill the axle with the specified lubricant. Refer to Lubricant change in this Group.

A container of Mopart Trac-lok Lubricant (friction modifier) should be added after repair service or during a lubricant change. After changing the lubricant, drive the vehicle and make 10 to 12 slow, figure-eight turns. This maneuver will pump lubricant through the clutches. This will correct the condition in most instances. If the chatter persists, clutch damage could have occurred.

| CONDITION POSSIBLE CAUSES CORRECTION
WHEEL NOISE 1. Wheel loose. 1. Tighten loose nuts.
2. Faulty, brinelled wheel bearing. 2. Faulty or brinelled bearings must be replaced.
AXLE SHAFT NOISE 1. Misaligned axle shaft tube. 1. Inspect axle shaft tube alignment, Correct as necessary.
2. Bent or sprung axle shaft. 2. Replace bent or sprung axle shaft.
3. End play in drive pinion 3. Refer to Drive Pinion Bearing Pre-Load Adjustment.
bearings.
4. Excessive gear backlash 4. Check adjustment of ring gear backlash and pinion gear.
. between ring gear and pinion Correct as necessary.
gear.
5. Improper adjustment of drive 5. Adjust drive pinion shaft bearings.
pinion gear shaft bearings.
6. Loose drive pinion gearshaft 6. Tighten drive pinion gearshaft yoke nut with specified torque.
yoke nut.
7. Improper wheel bearing 7. Readjust as necessary.
adjustment.
8. Scuffed gear tooth contact 8. If necessary, replace scuffed gears.
surfaces.
AXLE SHAFT BROKE 1. Misaligned axle shaft tube. 1. Replace broken axle shaft after correcting axle shaft tube
alignment.
2. Vehicle overloaded. 2. Replace broken axle shaft. Avoid excessive weight on vehicle.
3. Erratic clutch operation. 3. Replace broken axle shaft after inspecting for other possible
causes. Avoid erratic use of clutch.
4. Grabbing clutch. A. Replace broken axle shaft. Inspect clutch and make necessary
repairs or adjustments.
DIFFERENTIAL CASE 1. Improper adjustment of 1. Replace cracked case; examine gears and bearings for possible
CRACKED differential bearings. damage. At reassembly, adjust differential bearings properly.
2. Excessive ring gear backlash. 2. Replace cracked case; examine gears and bearings for possible
damage. At reassembly, adjust ring gear backlash properly.
3. Vehicle overloaded. 3. Replace cracked case; examine gears and bearings for possible
damage. Avoid excessive weight on vehicle.
A. Erratic clutch operation. 4, Replace cracked case. After inspecting for other possible
causes, examine gears and bearings for possible damage.
Avoid erratic use of clutch.
DIFFERENTIAL GEARS 1. Insufficient lubrication. 1. Replace scored gears. Scoring marks on the drive face of gear
SCORED teeth or in the bore are caused by instantaneous fusing of the
mating surfaces. Scored gears should be replaced. Fill rear
differential housing to required capacity with proper lubricant.
Refer to Specifications.
2. Improper grade of lubricant. 2. Replace scored gears. Inspect all gears and bearings for
possible damage. Clean and refill differential housing to
required capacity with proper lubricant.
3. Excessive spinning of one 3. Replace scored gears. Inspect all gears, pinion bores and shaft
wheelltire. for damage. Service as necessary.
LOSS OF LUBRICANT 1. Lubricant level too high. 1. Drain excess lubricant by removing fill plug and allow lubricant
to level at lower edge of fill plug hole.

| CONDITION POSSIBLE CAUSES CORRECTION
LOSS OF LUBRICANT 2. Worn axle shaft seals. 2. Replace worn seals.
3. Cracked differential housing. 3. Repair or replace housing as necessary.
4. Worn drive pinion gear shaft 4. Replace worn drive pinion gear shaft seal.
seal.
5. Scored and worn yoke. 5. Replace worn or scored yoke and seal.
6. Axle cover not properly sealed. 6. Remove cover and clean flange and reseal.
AXLE OVERHEATING 1. Lubricant level too low. 1. Refill differential housing.
2. Incorrect grade of lubricant. 2. Drain, flush and refill with correct amount of the correct
lubricant.
3. Bearings adjusted too tight. 3. Readjust bearings.
4. Excessive gear wear. 4. Inspect gears for excessive wear or scoring. Replace as
necessary.
5. Insufficient ring gear backlash. 5. Readjust ring gear backlash and inspect gears for possible
scoring.
GEAR TEETH BROKE 1. Overloading. 1. Replace gears. Examine other gears and bearings for possible
(RING GEAR AND PINION) damage.
2. Erratic clutch operation. 2. Replace gears and examine the remaining parts for possible
damage. Avoid erratic clutch operation.
3. Ice-spotted pavements. 3. Replace gears. Examine the remaining parts for possible
damage. Replace parts as required.
A. Improper adjustments. 4. Replace gears. Examine other parts for possible damage.
Ensure ring gear backlash is correct.
AXLE NOISE 1. Insufficient lubricant. | 1. Refill axle with correct amount of the proper lubricant.
Also inspect for leaks and correct as necessary.
2. Improper ring gear and drive 2. Check ring gear and pinion gear teeth contact pattern.
pinion gear adjustment.
3. Unmatched ring gear and drive 3. Remove unmatched ring gear and drive pinion gear.
pinion gear. Replace with matched gear and drive pinion gear set.
4. Worn teeth on ring gear or 4. Check teeth on ring gear and drive pinion gear for correct
drive pinion gear. contact. If necessary, replace with new matched set.
5. Loose drive pinion gear shaft 5. Adjust drive pinion gearshaft bearing preload torque.
bearings.
6. Loose differential bearings. 6. Adjust differential bearing preload torque.
7. Misaligned or sprung ring gear. 7. Measure ring gear runout.
8. Loose differential bearing cap 8. Tighten with specified torque
bolts
J9503-4

TRAC–LOK TEST

WARNING: WHEN SERVICING VEHICLES WITH A TRAC–LOK DIFFERENTIAL DO NOT USE THE ENGINE TO TURN THE AXLE AND WHEELS. BOTH REAR WHEELS MUST BE RAISED AND THE VEHI- CLE SUPPORTED. A TRAC–LOK AXLE CAN EXERT ENOUGH FORCE IF ONE WHEEL IS IN CONTACT WITH A SURFACE TO CAUSE THE VEHICLE TO MOVE.

The differential can be tested without removing the differential case by measuring rotating torque. Make sure brakes are not dragging during this measurement.

(1) Place blocks in front and rear of both front wheels.

(2) Raise one rear wheel until it is completely off the ground.

(3) Engine off, transmission in neutral, and parking brake off. (4) Remove wheel and bolt Special Tool 6790 to studs.

(5) Use torque wrench on special tool to rotate wheel and read rotating torque (Fig. 5).

(6) If rotating torque is less than 22 N·m (30 ft. lbs.) or more than 271 N·m (200 ft. lbs.) on either wheel the unit should be serviced.

SERVICE PROCEDURES

LUBRICANT CHANGE

(1) Raise and support the vehicle. (2) Remove the lubricant fill hole plug from the differential 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 original sealant from the housing and cover surfaces.

(6) Apply a bead of Mopart Silicone Rubber Sealant, or equivalent, to the housing cover (Fig. 6).

Install the housing cover within 5 minutes after applying the sealant.

(7) Install the cover and any identification tag. Tighten the cover bolts to 41 N·m (30 ft. lbs.) torque.

(8) For Trac–lok differentials, a quantity of Mopart Trac–lok lubricant (friction modifier), or equivalent, must be added after repair service or a lubricant change. Refer to the Lubricant Specifications section of this group for the quantity necessary.

(9) Fill differential with Mopart Hypoid Gear Lubricant, or equivalent, to bottom of the fill plug hole. Refer to the Lubricant Specifications section of this group for the quantity necessary.

CAUTION: Overfilling the differential can result in lubricant foaming and overheating.

(10) Install the fill hole plug and lower the vehicle. (11) Trac–lok differential equipped vehicles should be road tested by making 10 to 12 slow figure-eight turns. This maneuver will pump the lubricant through the clutch discs to eliminate a possible chatter noise complaint.

REMOVAL AND INSTALLATION

REAR AXLE

REMOVAL

(1) Raise and support the vehicle.

(2) Position a suitable lifting device under the axle.

(3) Secure axle to device. (4) Remove the wheels and tires. (5) Remove the brake rotors and calipers from the axle. Refer to Group 5, Brakes, for proper procedures.

(6) Disconnect parking brake cables from brackets and lever.

(7) Remove wheel speed sensors, if necessary. Refer to Group 5, Brakes, for proper procedures.

(8) Disconnect the brake hose at the axle junction block. Do not disconnect the brake hydraulic lines at the calipers. Refer to Group 5, Brakes, for proper procedures.

(9) Disconnect the vent hose from the axle shaft tube.

(10) Mark the propeller shaft and yokes for installation alignment reference.

(11) Remove propeller shaft. (12) Disconnect stabilizer bar links. (13) Disconnect shock absorbers from axle. (14) Disconnect track bar. (15) Disconnect upper and lower suspension arms from the axle brackets.

(16) Separate the axle from the vehicle.

INSTALLATION

NOTE: The weight of the vehicle must be supported by the springs before suspension arms and track bar fasteners can be tightened. If the springs are not at their normal ride position, vehicle ride height and handling could be affected.

(1) Raise the axle with lifting device and align coil springs.

(2) Position the upper and lower suspension arms on the axle brackets. Install nuts and bolts, do not tighten bolts at this time.

(3) Install track bar and attachment bolts, do not tighten bolts at this time.

(4) Install shock absorbers and tighten nuts to 60 N·m (44 ft. lbs.) torque.

(5) Install stabilizer bar links and tighten nuts to 36 N·m (27 ft. lbs.) torque.

(6) Install the wheel speed sensors, if necessary. Refer to Group 5, Brakes, for proper procedures.

(7) Connect parking brake cable to brackets and lever.

(8) Install the brake rotors and calipers. Refer to Group 5, Brakes, for proper procedures.

(9) Connect the brake hose to the axle junction block. Refer to Group 5, Brakes, for proper procedures.

(10) Install axle vent hose.

(11) Align propeller shaft and pinion yoke reference marks. Install U-joint straps and bolts. Tighten to 19 N·m (14 ft. lbs.) torque.

(12) Install the wheels and tires. (13) Add gear lubricant, if necessary. Refer to Lubricant Specifications in this section for lubricant requirements.

(14) Remove lifting device from axle and lower the vehicle.

(15) Tighten lower suspension arm bolts to 177 N·m (130 ft. lbs.) torque.

(16) Tighten upper suspension arm bolts to 75 N·m (55 ft. lbs.) torque.

(17) Tighten track bar bolts to 100 N·m (74 ft. lbs.) torque.

PINION SHAFT SEAL

REMOVAL

(1) Raise and support the vehicle. (2) Remove wheel and tire assemblies. (3) Remove rear brake rotors and calipers. Refer to Group 5, Brakes, for proper procedures.

(4) Mark the propeller shaft and pinion yoke for installation reference. (5) Remove the propeller shaft from the yoke. (6) Rotate the pinion gear three or four times. (7) Measure the amount of torque necessary to rotate the pinion gear with a (in. lbs.) dial-type torque wrench. Record the torque reading for installation reference.

(8) Using a short piece of pipe and Holder 6958 to hold the pinion yoke, remove the pinion nut and washer (Fig. 7).

(9) Use Remover C-452 and Wrench C-3281 to remove the pinion yoke (Fig. 8)

(10) Use Remover 7794-A and slide hammer to remove the pinion shaft seal (Fig. 9)..

INSTALLATION

(1) Apply a light coating of gear lubricant on the lip of pinion seal. Install seal with Installer C-3972-A and Handle C-4171 (Fig. 10).

(2) Install yoke on the pinion gear with Installer C-3718 and Holder 6958 (Fig. 11).

CAUTION: Do not exceed the minimum tightening torque when installing the pinion yoke retaining nut at this point. Damage to collapsible spacer or bearings may result.

(3) Install a new nut on the pinion gear. Tighten the nut only enough to remove the shaft end play.

(4) Rotate the pinion shaft using a (in. lbs.) torque wrench. Rotating resistance torque should be equal to the reading recorded during removal, plus an additional 0.56 N·m (5 in. lbs.) (Fig. 12).

(5) If the rotating torque is low, use Holder 6958 to hold the pinion yoke (Fig. 13), and tighten the pinion shaft nut in 6.8 N·m (5 ft. lbs.) increments until proper rotating torque is achieved.

CAUTION: If the maximum tightening torque is reached prior to reaching the required rotating torque, the collapsible spacer may have been damaged. Replace the collapsible spacer.

(6) Align the installation reference marks on propeller shaft and yoke and install the propeller shaft.

(7) Add gear lubricant to the differential housing, if necessary. Refer to the Lubricant Specifications for gear lubricant requirements.

(8) Install brake rotors and calipers. Refer to Group 5, Brakes, for proper procedures.

(9) Install wheel and tire assemblies. (10) Lower the vehicle.

COLLAPSIBLE SPACER

REMOVAL W//PINION INSTALLED

(1) Raise and support the vehicle. (2) Remove wheel and tire assemblies. (3) Remove rear brake rotors and calipers. Refer to Group 5, Brakes, for proper procedures.

(4) Mark the propeller shaft and pinion yoke for installation reference. (5) Remove the propeller shaft from the yoke. (6) Rotate the pinion gear three or four times. (7) Measure the amount of torque necessary to rotate the pinion gear with a (in. lbs.) dial-type torque wrench. Record the torque reading for installation reference.

(8) Using a short piece of pipe and Holder 6958 to hold the pinion yoke, remove the pinion nut and washer (Fig. 14).

(9) Use Remover C-452 and Wrench C-3281 to remove the pinion yoke (Fig. 15).

(10) Use Remover 7794-A and slide hammer to remove the pinion shaft seal (Fig. 16).

(11) Remove the front pinion bearing using a pair of suitable pick tools to pull the bearing straight off the pinion gear shaft. It may be necessary to lightly tap the end of the pinion gear with a rawhide or rubber mallet if the bearing becomes bound on the pinion shaft. (12) Remove the collapsible spacer.

REMOVAL W/PINION REMOVED

(1) Raise and support the vehicle. (2) Remove wheel and tire assemblies. (3) Remove rear brake rotors and calipers. Refer to Group 5, Brakes, for proper procedures.

(4) Mark the propeller shaft and pinion yoke for installation reference. (5) Remove the propeller shaft from the yoke. (6) Rotate the pinion gear three or four times. (7) Measure the amount of torque necessary to rotate the pinion gear with a (in. lbs.) dial-type torque wrench. Record the torque reading for installation reference.

(8) Remove differential assembly from axle housing.

(9) Using Holder 6958 to hold yoke and a short length of 1 in. pipe, remove the pinion yoke nut and washer (Fig. 14).

(10) Using Remover C–452 and Wrench C–3281, remove the pinion yoke from pinion shaft (Fig. 15).

(11) Remove the pinion gear from housing (Fig. 17). Catch the pinion with your hand to prevent it from falling and being damaged.

(12) Remove collapsible spacer from pinion shaft.

INSTALLATION

(1) Install a new collapsible preload spacer on pinion shaft (Fig. 18). (2) If pinion gear was removed, install pinion gear in housing. (3) Install pinion front bearing, if necessary.

(4) Apply a light coating of gear lubricant on the lip of pinion seal. Install seal with Installer C-3972-A and Handle C–4171 (Fig. 19).

(5) Install yoke with Installer C–3718 and Holder 6958 (Fig. 20).

(6) If the original pinion bearings are being used, install differential assembly and axle shafts, if necessary.

NOTE: If new pinion bearings were installed, do not install the differential assembly and axle shafts until after the pinion bearing preload and rotating torque are set.

(7) Install the yoke washer and a new nut on the pinion gear. Tighten the nut to 298 N·m (220 ft. lbs.) minimum. Do not over–tighten. Maximum torque is 380 N·m (280 ft. lbs.).

CAUTION: Never loosen pinion gear nut to decrease pinion gear bearing rotating torque and never exceed specified preload torque. If preload torque is exceeded a new collapsible spacer must be installed. The torque sequence will then have to be repeated.

NOTE: If the spacer requires more than 280 ft. lbs. torque to crush, the collapsible spacer is defective.

(8) Using yoke holder 6958, a short length of 1 in. pipe, and a torque wrench set at 380 N·m (280 ft. lbs.), crush collapsible spacer until bearing end play is taken up (Fig. 21). (9) Slowly tighten the nut in 6.8 N·m (5 ft. lbs.) increments until the rotating torque is achieved. Measure the rotating torque frequently to avoid over crushing the collapsible spacer (Fig. 22).

(10) Check rotating torque with an inch pound torque wrench (Fig. 22). The torque necessary to rotate the pinion gear should be:

• Original Bearings — The reading recorded during removal, plus an additional 0.56 N·m (5 in. lbs.). • New Bearings — 2 to 5 N·m (15 to 35 in. lbs.). (11) Install differential assembly and axle shafts, if necessary.

(12) Align marks made previously on yoke and propeller shaft and install propeller shaft.

(13) Install rear brake rotors and calipers. Refer to Group 5 Brakes, for proper procedures.

(14) Add gear lubricant, if necessary. Refer to Lubricant Specifications of this section for lubricant requirements.

(15) Install wheel and tire assemblies.

(16) Lower vehicle.

AXLE SHAFT

REMOVAL

(1) Raise and support vehicle. Ensure that the transmission is in neutral.

(2) Remove wheel and tire assembly. (3) Remove brake caliper and rotor. Refer to Group 5, Brakes, for proper procedure.

(4) Clean all foreign material from housing cover area.

(5) Loosen housing cover bolts. Drain lubricant from the housing and axle shaft tubes. Remove housing cover.

(6) Rotate differential case so that pinion mate gear shaft lock screw is accessible. Remove lock screw and pinion mate gear shaft from differential case (Fig. 23).

(7) Push axle shaft inward and remove axle shaft C–clip lock from the axle shaft (Fig. 24).

(8) Remove axle shaft. Use care to prevent damage to axle shaft bearing and seal, which will remain in axle shaft tube. Also, exercise care not to damage the wheel speed sensor on vehicles equipped with ABS brakes.

(9) Inspect axle shaft seal for leakage or damage. (10) Inspect roller bearing contact surface on axle shaft for signs of brinelling, galling and pitting. If any of these conditions exist, the axle shaft and/or bearing and seal must be replaced.

INSTALLATION

(1) Lubricate bearing bore and seal lip with gear lubricant. Insert axle shaft through seal, bearing, and engage it into side gear splines.

NOTE: Use care to prevent shaft splines from damaging axle shaft seal lip. Also, exercise care not to damage the wheel speed sensor on vehicles equipped with ABS brakes

(2) Insert C–clip lock in end of axle shaft. Push axle shaft outward to seat C–clip lock in side gear.

(3) Insert pinion mate shaft into differential case and through thrust washers and pinion gears.

(4) Align hole in shaft with hole in the differential case and install lock screw with Loctitet on the threads. Tighten lock screw to 19 N·m (14 ft. lbs.) torque.

(5) Install cover and add fluid. Refer to Lubricant Change procedure in this section for procedure and lubricant requirements.

(6) Install brake caliper and rotor. Refer to Group 5, Brakes, for proper procedures.

(7) Install wheel and tire. (8) Lower vehicle.

AXLE SHAFT SEAL AND BEARING

REMOVAL

(1) Remove the axle shaft. (2) Remove the axle shaft seal from the end of the axle shaft tube with a small pry bar.

NOTE: The seal and bearing can be removed at the same time with the bearing removal tool.

(3) Remove the axle shaft bearing from the tube (Fig. 25) with Bearing Removal Tool Set 6310 using Adapter Foot 6310-5.

(4) Inspect the axle shaft tube bore for roughness and burrs. Remove as necessary.

INSTALLATION

Do not install the original axle shaft seal. Always 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 the bearing is against the installer.

(3) Install the new axle shaft seal (Fig. 26) with Installer 6437 and Handle C–4171.

(4) Install the axle shaft.

DIFFERENTIAL

REMOVAL

(1) Remove axle shafts. (2) Note the orientation of the installation reference letters stamped on the bearing caps and housing machined sealing surface (Fig. 27).

(3) Remove the differential bearing caps. (4) Position Spreader W–129–B with the tool dowel pins seated in the locating holes (Fig. 28).

(5) Install the hold down clamps and tighten the tool turnbuckle finger–tight.

(6) Install a Guide Pin C-3288-B at the left side of the differential housing. Attach dial indicator to housing pilot stud. Load the indicator plunger against the opposite side of the housing (Fig. 28) and zero the indicator.

(7) Spread the housing enough to remove the case from the housing. Measure the distance with the dial indicator (Fig. 28).

CAUTION: Do not spread over 0.50 mm (0.020 in). If the housing is over-spread, it could be distorted or damaged.

(8) Remove the dial indicator. (9) Pry the differential case loose from the housing. To prevent damage, pivot on housing with the end of the pry bar against spreader (Fig. 29).

(10) Remove the case from housing. Mark or tag bearing cups and outboard shim(s)/spacer(s) (selected thickness) to indicate which side they were removed from.

INSTALLATION

(1) Position Spreader W–129–B with the tool dowel pins seated in the locating holes (Fig. 28). Install the hold down clamps and tighten the tool turnbuckle finger–tight.

(2) Install a Guide Pin C-3288-B at the left side of the differential housing. Attach dial indicator to housing pilot stud. Load the indicator plunger against the opposite side of the housing (Fig. 28) and zero the indicator.

(3) Spread the housing enough to install the case in the housing. Measure the distance with the dial indicator (Fig. 28).

CAUTION: Do not spread over 0.50 mm (0.020 in). If the housing is over-spread, it could be distorted or damaged.

(4) Remove the dial indicator.

(5) Install differential and outboard shim(s)/spacer(s) (selected thickness) in housing.

(6) Install case in the housing. Tap the differential case with a rawhide or rubber mallet to ensure the bearings are fully seated in the differential housing (Fig. 30).

(7) Remove the spreader.

(8) Install the bearing caps at their original locations (Fig. 31). Tighten the bearing cap bolts to 77 N·m (57 ft. lbs.) torque.

(9) Install axle shafts.

DIFFERENTIAL SIDE BEARINGS

REMOVAL

(1) Remove differential case from axle housing. (2) Remove the bearings from the differential case with Puller/Press C-293-PA, Adapters C-293-42, and Plug C-293-3 (Fig. 32).

INSTALLATION

(1) Using tool C-4340 with handle C-4171, install differential side bearings (Fig. 33).

(2) Install differential case in axle housing.

RING GEAR

The ring and pinion gears are service in a matched set. Do not replace the ring gear without replacing the pinion gear.

REMOVAL

(1) Remove differential from axle housing. (2) Place differential case in a suitable vise with soft metal jaw protectors. (Fig. 34)

(3) Remove bolts holding ring gear to differential case.

(4) Using a soft hammer, drive ring gear from differential case (Fig. 34).

INSTALLATION

CAUTION: Do not reuse the bolts that held the ring gear to the differential case. The bolts can fracture causing extensive damage.

(1) Invert the differential case and start two ring gear bolts. This will provide case-to-ring gear bolt hole alignment.

(2) Invert the differential case in the vise. (3) Install new ring gear bolts and alternately tighten to 95–122 N·m (70–90 ft. lbs.) torque (Fig. 35).

(4) Install differential in axle housing and verify gear mesh and contact pattern.

PINION GEAR

NOTE: The ring and pinion gears are service in a matched set. Do not replace the pinion gear without replacing the ring gear.

REMOVAL

(1) Remove differential assembly from axle housing. (2) Mark pinion yoke and propeller shaft for installation alignment. (3) Disconnect propeller shaft from pinion yoke. Using suitable wire, tie propeller shaft to underbody.

(4) Using Holder 6958 to hold yoke and a short length of 1 in. pipe, remove the pinion yoke nut and washer (Fig. 36).

(5) Using Remover C-452 and Wrench C-3281, remove the pinion yoke from pinion shaft (Fig. 37).

(6) Remove the pinion gear from housing (Fig. 38). Catch the pinion with your hand to prevent it from falling and being damaged.

(7) Remove the pinion seal with a slide hammer or pry out with bar.

(8) Remove oil slinger, if equipped, and the front pinion bearing.

(9) Remove the front pinion bearing cup with Remover D-103 and Handle C-4171 (Fig. 39).

(10) Remove the rear bearing cup from housing (Fig. 40). Use Remover C-4307 and Handle C-4171.

(11) Remove the collapsible preload spacer (Fig. 41).

(12) Remove the rear bearing from the pinion with Puller/Press C-293-PA and Adapters C-293-42 (Fig. 42).

Place 4 adapter blocks so they do not damage the bearing cage.

(13) Remove the pinion depth shims from the pinion gear shaft. Record the total thickness of the depth shims.

INSTALLATION

(1) Apply Mopart Door Ease stick lubricant to outside surface of bearing cup. Install the pinion rear bearing cup with Installer C-4308 and Driver Handle C-4171 (Fig. 43). Ensure cup is correctly seated.

(2) Apply Mopart Door Ease stick lubricant to outside surface of bearing cup. Install the pinion front bearing cup with Installer D-129 and Handle C-4171 (Fig. 44).

(3) Install pinion front bearing and oil slinger, if equipped. Apply a light coating of gear lubricant on the lip of pinion seal. Install seal with Installer C-3972-A and Handle C-4171 (Fig. 45).

NOTE: Pinion depth shims are placed between the rear pinion bearing cone and pinion gear to achieve proper ring and pinion gear mesh. If the factory installed ring and pinion gears are reused, the pinion depth shim should not require replacement or adjustment. Refer to Pinion Gear Depth paragraph in this section to select the proper thickness shim before installing rear pinion bearing cone.

(4) Place the proper thickness pinion depth shim on the pinion gear.

(5) Install the rear bearing (and slinger if used) on the pinion gear with Installer 6448 (Fig. 46).

(6) Install a new collapsible preload spacer on pinion shaft (Fig. 47). (7) Install pinion gear in housing.

(8) Install yoke with Installer C-3718 and holder 6958 (Fig. 48).

(9) Install the yoke washer and a new nut on the pinion gear. Tighten the nut to 298 N·m (220 ft. lbs.) minimum. Do not over-tighten. Maximum torque is 380 N·m (280 ft. lbs.). pinion gear nut to decrease

CAUTION: Never loosen pinion gear nut to decrease pinion gear bearing preload torque and never exceed specified preload torque. If preload torque is exceeded a new collapsible spacer must be installed. The torque sequence will have to be repeated.

NOTE: If the spacer requires more than 280 ft. lbs. torque to crush, the collapsible spacer is defective.

(10) Using yoke holder 6958, a short length of 1 in. pipe, and a torque wrench set at 380 N·m (280 ft. lbs.), crush collapsible spacer until bearing end play is taken up (Fig. 49). (11) Slowly tighten the nut in 6.8 N·m (5 ft. lbs.) increments until the rotating torque is achieved. Measure the rotating torque frequently to avoid over crushing the collapsible spacer (Fig. 50).

(12) Check bearing rotating torque with an inch pound torque wrench (Fig. 50). The torque necessary to rotate the pinion gear should be:

Original Bearings — 1 to 3 N-m (10 to 20 in. Ibs.).

•

• New Bearings — 2 to 5 N·m (15 to 35 in. lbs.).

(13) Align previously made marks on yoke and propeller shaft and install propeller shaft.

(14)

Install differential housing into the axle housing.

FINAL ASSEMBLY

(1) Scrape the residual sealant from the housing and cover mating surfaces. Clean the mating surfaces with mineral spirits. Apply a bead of Mopart Silicone Rubber Sealant, or equivalent, on the housing cover (Fig. 51).

Install the housing cover within 5 minutes after applying the sealant.

(2) Install the cover on the differential with the attaching bolts. Install the identification tag. Tighten the cover bolts to 41 N·m (30 ft. lbs.) torque.

CAUTION: Overfilling the differential can result in lubricant foaming and overheating.

(3) Refill the differential housing with gear lubricant. Refer to the Lubricant Specifications section of this group for the gear lubricant requirements.

(4) Install the fill hole plug.

DISASSEMBLY AND ASSEMBLY

STANDARD DIFFERENTIAL

DISASSEMBLY

(1) Remove pinion gear mate shaft lock screw (Fig. 52).

(2) Remove pinion gear mate shaft. (3) Rotate the differential side gears and remove the pinion mate gears and thrust washers (Fig. 53).

(4) Remove the differential side gears and thrust washers.

ASSEMBLY

(1) Install the differential side gears and thrust washers.

(2)

Install the pinion mate gears and thrust washers.

(3) Install the pinion gear mate shaft. (4) Align the hole in the pinion gear mate shaft with the hole in the differential case and install the pinion gear mate shaft lock screw.

(5) Lubricate all differential components with hypoid gear lubricant.

TRAC-LOK DIFFERENTIAL

The Trac–Lok differential components are illustrated in (Fig. 54). Refer to this illustration during repair service.

DISASSEMBLY

(1)

Clamp Side Gear Holding Tool 6963-A in a vise.

(2) Position the differential case on Side Gear Holding Tool 6963-A (Fig. 55).

(3) Remove ring gear, if necessary. Ring gear removal is necessary only if the ring gear is to be replaced. The Trac-Lok differential can be serviced with the ring gear installed.

(4) Remove the pinion gear mate shaft lock screw (Fig. 56).

(5) Remove the pinion gear mate shaft. If necessary, use a drift and hammer (Fig. 57).

(6) Install and lubricate Step Plate C–4487–1 (Fig. 58).

(7) Assemble Threaded Adapter C–4487–3 into top side gear. Thread Forcing Screw C–4487–2 into adapter until it becomes centered in adapter plate.

(8) Position a small screw driver in slot of Threaded Adapter C–4487–3 (Fig. 59) to prevent adapter from turning.

(9) Tighten forcing screw tool 122 N·m (90 ft. lbs.) (maximum) to compress Belleville springs in clutch packs (Fig. 60).

(10) Using an appropriate size feeler gauge, remove thrust washers from behind the pinion gears (Fig. 61).

(11) Insert Turning Bar C–4487–4 in case (Fig. 62).

(12) Loosen the Forcing Screw C-4487-2 in small increments until the clutch pack tension is relieved and the differential case can be turned using Turning Bar C-4487-4.

(13) Rotate differential case until the pinion gears can be removed.

(14) Remove pinion gears from differential case.

(15) Remove Forcing Screw C–4487-2, Step Plate C-4487-1, and Threaded Adapter C-4487-3.

(16) Remove top side gear, clutch pack retainer, and clutch pack. Keep plates in correct order during removal (Fig. 63).

(17) Remove differential case from Side Gear Holding Tool 6963-A. Remove side gear, clutch pack retainer, and clutch pack. Keep plates in correct order during removal.

ASSEMBLY

NOTE: The clutch discs are replaceable as complete sets only. If one clutch disc pack is damaged, both packs must be replaced.

Lubricate each component with gear lubricant before assembly.

(1) Assemble the clutch discs into packs and secure disc packs with retaining clips (Fig. 64).

(2) Position assembled clutch disc packs on the side gear hubs.

(3) Install clutch pack and side gear in the ring gear side of the differential case (Fig. 65). Be sure clutch pack retaining clips remain in position and are seated in the case pockets.

(4) Position the differential case on Side Gear Holding Tool 6963-A.

(5) Install lubricated Step Plate C–4487–1 on side gear (Fig. 66).

(6) Install the upper side gear and clutch disc pack (Fig. 66).

(7) Hold assembly in position. Insert Threaded Adapter C–4487–3 into top side gear.

(8) Insert Forcing Screw C–4487–2.

(9) Tighten forcing screw tool to slightly compress clutch discs.

(10) Place pinion gears in position in side gears and verify that the pinion mate shaft hole is aligned.

(11) Rotate case with Turning Bar C–4487–4 until the pinion mate shaft holes in pinion gears align with holes in case. It may be necessary to slightly tighten the forcing screw in order to install the pinion gears.

Installation

(12) Tighten forcing screw to 122 N·m (90 ft. lbs.) to compress the Belleville springs.

(13) Lubricate and install thrust washers behind pinion gears and align washers with a small screw driver. Insert mate shaft into each pinion gear to verify alignment. (14) Remove forcing screw, threaded adapter, and step plate.

(15) Install pinion gear mate shaft and align holes in shaft and case. (16) Install the pinion mate shaft lock screw finger tight to hold shaft during differential installation.

If replacement side and/or pinion gears and thrust washers were installed, it is not necessary to measure the side gear backlash. Correct fit is due to close machining tolerances during manufacture.

(17) Lubricate all differential components with hypoid gear lubricant.

CLEANING AND INSPECTION

AXLE COMPONENTS

Wash differential components with cleaning solvent and dry with compressed air. Do not steam clean the differential components.

Wash bearings with solvent and towel dry, or dry with compressed air. DO NOT spin bearings with compressed air. Cup and bearing must be replaced as matched sets only.

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

• Smooth appearance with no broken/dented surfaces on the bearing rollers or the roller contact surfaces.

• Bearing cups must not be distorted or cracked. • Machined surfaces should be smooth and without any raised edges.

• Raised metal on shoulders of cup bores should be removed with a hand stone.

• Wear and damage to pinion gear mate shaft, pinion gears, side gears and thrust washers. Replace as a matched set only.

• Ring and pinion gear for worn and chipped teeth.

• Ring gear for damaged bolt threads. Replaced as a matched set only.

• Pinion yoke for cracks, worn splines, pitted areas, and a rough/corroded seal contact surface. Repair or replace as necessary.

• Preload shims for damage and distortion. Install new shims, if necessary.

TRAC-LOK

Clean all components in cleaning solvent. Dry components with compressed air. Inspect clutch pack plates for wear, scoring or damage. Replace both clutch packs if any one component in either pack is damaged. Inspect side and pinion gears. Replace any gear that is worn, cracked, chipped or damaged. Inspect differential case and pinion shaft. Replace if worn or damaged.

PRESOAK PLATES AND DISC

Plates and discs with fiber coating (no grooves or lines) must be presoaked in Friction Modifier before assembly. Soak plates and discs for a minimum of 20 minutes.

ADJUSTMENTS

PINION GEAR DEPTH

GENERAL INFORMATION

Ring and pinion gears are supplied as matched sets only. The identifying numbers for the ring and pinion gear are etched into the face of each gear (Fig. 67). A plus (+) number, minus (–) number or zero (0) is etched into the face of the pinion gear. This number is the amount (in thousandths of an inch) the depth varies from the standard depth setting of a pinion etched with a (0). The standard setting from the center line of the ring gear to the back face of the pinion is 109.52 mm (4.312 in.). The standard depth provides the best teeth contact pattern. Refer to Backlash and Contact Pattern Analysis Paragraph in this section for additional information.

Compensation for pinion depth variance is achieved with select shims. The shims are placed under the inner pinion bearing cone (Fig. 68).

If a new gear set is being installed, note the depth variance etched into both the original and replacement pinion gear. Add or subtract the thickness of the original depth shims to compensate for the difference in the depth variances. Refer to the Depth Variance charts.

Note where Old and New Pinion Marking columns intersect. Intersecting figure represents plus or minus amount needed.

Note the etched number on the face of the drive pinion gear (–1, –2, 0, +1, +2, etc.). The numbers represent thousands of an inch deviation from the standard. If the number is negative, add that value to the required thickness of the depth shim(s). If the number is positive, subtract that value from the thickness of the depth shim(s). If the number is 0, no change is necessary. Refer to the Pinion Gear Depth Variance Chart.

PINION GEAR DEPTH VARIANCE

ADJUSTMENT

Measurements are taken with pinion cups and pinion bearings installed in housing. Take measurements with Pinion Gauge Set 6955, Dummy Bearing/ Arbor Disc Set 6956, and Dial Indicator C-3339 (Fig. 69).

(1) Assemble Pinion Height Block 6739, Pinion Block 8144, and rear pinion bearing onto Screw 6741 (Fig. 69).

(2) Insert assembled height gauge components, rear bearing and screw into axle housing through pinion bearing cups (Fig. 70).

(3) Install front pinion bearing and Cone 6740 hand tight (Fig. 69).

(4) Place Arbor Disc 6927 on Arbor D-115-3 in position in axle housing side bearing cradles (Fig. 71). Install differential bearing caps on Arbor Discs and tighten cap bolts. Refer to the Torque Specifications in this section.

NOTE: Arbor Discs 6927 have different step diameters to fit other axle sizes. Pick correct size step for axle being serviced.

(5) Assemble Dial Indicator C-3339 into Scooter Block D-115-2 and secure set screw.

(6) Place Scooter Block/Dial Indicator in position in axle housing so dial probe and scooter block are flush against the surface of the pinion height block. Hold scooter block in place and zero the dial indicator face to the pointer. Tighten dial indicator face lock screw.

(7) With scooter block still in position against the pinion height block, slowly slide the dial indicator probe over the edge of the pinion height block. Observe how many revolutions counterclockwise the dial pointer travels (approximately 0.125 in.) to the out-stop of the dial indicator.

(8) Slide the dial indicator probe across the gap between the pinion height block and the arbor bar with the scooter block against the pinion height block (Fig. 72). When the dial probe contacts the arbor bar, the dial pointer will turn clockwise. Bring dial pointer back to zero against the arbor bar, do not turn dial face. Continue moving the dial probe to the crest of the arbor bar and record the highest reading. If the dial indicator can not achieve the zero reading, the rear bearing cup or the pinion depth gauge set is not installed correctly.

(9) Select a shim equal to the dial indicator reading plus the drive pinion gear depth variance number etched in the face of the pinion gear (Fig. 67) using the opposite sign on the variance number. For example, if the depth variance is –2, add +0.002 in. to the dial indicator reading.

(10) Remove the pinion depth gauge components from the axle housing

DIFFERENTIAL BEARING PRELOAD AND GEAR BACKLASH

Differential side bearing preload and gear backlash is achieved by selective shims inserted between the bearing cup and the axle housing. The proper shim thickness can be determined using slip-fit dummy bearings 6929-A in place of the differential side bearings and a dial indicator C-3339. Before proceeding with the differential bearing preload and gear backlash measurements, measure the pinion gear depth and prepare the pinion gear for installation. Establishing proper pinion gear depth is essential to establishing gear backlash and tooth contact patterns. After the overall shim thickness to take up differential side play is measured, the pinion gear is installed, and the gear backlash shim thickness is measured. The overall shim thickness is the total of the dial indicator reading, starting point shim thickness, and the preload specification added together. The gear backlash measurement determines the thickness of the shim used on the ring gear side of the differential case. Subtract the gear backlash shim thickness from the total overall shim thickness and select that amount for the pinion gear side of the differential (Fig. 73).

DIFFERENTIAL PRELOAD AND GEAR

BACKLASH SHIM SELECTION

NOTE: It is difficult to salvage the differential side bearings during the removal procedure. Install replacement bearings if necessary.

(1) Remove side bearings from differential case. (2) Install ring gear on differential case and tighten bolts to specification.

(3) Install dummy side bearings 6929-A on differential case.

(4) Install differential case in axle housing.

(5) Insert Dummy Shim 8107 (0.118 in. (3.0 mm)) starting point shims between the dummy bearing and the axle housing on side of differential (Fig. 74).

(6) Install the marked bearing caps in their correct positions. Install and snug the bolts.

(7) Thread guide stud C-3288-B into rear cover bolt hole below ring gear (Fig. 75).

(8) Attach dial indicator C-3339 to Guide Stud C-3288-B. Position the dial indicator plunger on a flat surface between the ring gear bolt heads (Fig. 75).

(9) Push and hold differential case to pinion gear side of axle housing.

(10) Zero dial indicator face to pointer.

(11) Push and hold differential case to ring gear side of the axle housing.

(12) Record dial indicator reading. (13) Add the dial indicator reading to the starting point shim thickness to determine total shim thickness to achieve zero differential end play.

(14) Add 0.012 in. (0.3 mm) to the zero end play total. This new total represents the thickness of shims to compress, or preload the new bearings when the differential is installed.

(15) Rotate dial indicator out of the way on guide stud.

(16) Remove differential case, dummy bearings, and starting point shims from axle housing.

(17) Install pinion gear in axle housing. Install the yoke and establish the correct pinion rotating torque.

(18) Install differential case and dummy bearings in axle housing (without shims) and tighten retaining cap bolts snug.

(19) Position the dial indicator plunger on a flat surface between the ring gear bolt heads (Fig. 75).

(20) Push and hold differential case toward pinion gear.

(21) Zero dial indicator face to pointer. (22) Push and hold differential case to ring gear side of the axle housing.

(23) Record dial indicator reading. (24) Subtract 0.002 in. (0.05 mm) from the dial indicator reading to compensate for backlash between ring and pinion gears. This total is the thickness of shim required to achieve proper backlash.

(25) Subtract the backlash shim thickness from the total preload shim thickness. The remainder is the shim thickness required on the pinion side of the axle housing.

(26) Rotate dial indicator out of the way on guide stud.

(27) Remove differential case and dummy bearings from axle housing.

(28) Install new side bearing cones and cups on differential case.

(29) Install spreader W-129-B on axle housing and spread axle opening enough to receive differential case and side bearing shims.

(30) Place side bearing shims in axle housing against axle tube ends.

(31) Install differential case in axle housing. (32) Remove spreader from axle housing. (33) Rotate the differential case several times to seat the side bearings.

(34) Position the indicator plunger against a ring gear tooth (Fig. 76).

(35) Push and hold ring gear upward while not allowing the pinion gear to rotate.

(36) Zero dial indicator face to pointer. (37) Push and hold ring gear downward while not allowing the pinion gear to rotate. Dial indicator reading should be between 0.12 mm (0.005 in.) and 0.20 mm (0.008 in.). If backlash is not within specifications transfer the necessary amount of shim thickness from one side of the axle housing to the other (Fig. 77).

(38) Verify differential case and ring gear runout by measuring ring to pinion gear backlash at several locations around the ring gear. Readings should not vary more than 0.05 mm (0.002 in.). If readings vary more than specified, the ring gear or the differential case is defective.

After the proper backlash is achieved, perform the Gear Contact Pattern Analysis procedure.

GEAR CONTACT PATTERN ANALYSIS

The ring and pinion gear teeth contact patterns will show if the pinion gear depth is correct in the axle housing. It will also show if the ring gear backlash has been adjusted correctly. The backlash can be adjusted within specifications to achieve desired tooth contact patterns.

(1) Apply a thin coat of hydrated ferric oxide, or equivalent, to the drive and coast side of the ring gear teeth.

(2) Wrap, twist, and hold a shop towel around the pinion yoke to increase the turning resistance of the pinion gear. This will provide a more distinct contact pattern.

(3) Using a boxed end wrench on a ring gear bolt, Rotate the differential case one complete revolution in both directions while a load is being applied from shop towel.

The areas on the ring gear teeth with the greatest degree of contact against the pinion gear teeth will squeegee the compound to the areas with the least amount of contact. Note and compare patterns on the ring gear teeth to Gear Tooth Contact Patterns chart (Fig. 78) and adjust pinion depth and gear backlash as necessary.

SPECIFICATIONS

216 RBA AXLE

DESCRIPTION SPECIFICATION Axle Type . . . . . . . . . . . . . . . .Semi–Floating Hypoid Lubricant. . . . . . . . . .SAE Thermally Stable 80W–90 Lubricant Trailer Tow . . . . . . . . .Synthetic 75W–140 Lube Capacity . . . . . . . . . . . . . . . . .2.25 L (4.75 pts.) Axle Ratios. . . . . . . . . . . . . . . . . . . . . . . . . .3.55/3.73 Differential Bearing Preload . . . . .0.1 mm (0.004 in.) Differential Side Gear

Clearance . . . . . . . . . . . . .0–0.15 mm (0–0.006 in.) Ring Gear Diameter . . . . . . . . . . . . .216 mm (8.5 in.) Ring Gear Backlash . . . . . . . . . . . . . . .0.13–0.20 mm

(0.005–0.008 in.) Pinion Std. Depth. . . . . . . . . . .109.52 mm (4.312 in.) Pinion Bearing Preload-

New Bearings . . . . .2.26–4.52 N·m (20–40 in. lbs.) Pinion Bearing Preload-

Original Bearings . . . . . . .1–3 N·m (10–20 in. lbs.) Maximum Carrier Spread . . . . . .0.51 mm (0.020 in.)

TORQUE

DESCRIPTION TORQUE Bolts, Diff. Cover . . . . . . . . . . . .41 N·m (30 ft. lbs.) Bolts, Diff. Bearing Cap . . . . . .85 N·m (63 ft. lbs.) Bolts, Ring Gear. . . . . . . . . . . .108 N·m (80 ft. lbs.) Screw, ABS Sensor . . . . . . . . . . .8 N·m (70 in. lbs.) Screw, Pinion Gear Mate

Shaft Lock . . . . . . . . . . . . . . . . . . . . . . .17.6 N·m

(13 ft. lbs.) Nuts, Brake Backing Plate. . . .61 N·m (45 ft. lbs.) Nut, Pinion Gear—

Minimum * . . . . . . . . . . . . .298 N·m (220 ft. lbs.) Nut, Pinion Gear—Maximum * . . . . . . . .380 N·m

(280 ft. lbs.)

NOTE: *Refer to Pinion Gear Removal and Installation procedures for proper pinion nut tightening instructions. Do not exceed 380 N·m (280 ft. lbs.) during collapsible spacer crushing procedure.

SPECIAL TOOLS

216 RBA AXLE