Differential - Assembly
ASSEMBLY / BEARING ADJUSTMENT PROCEDUREThe following steps will determine the correct shim thickness required to obtain proper pinion depth. All special tools described in this procedure must be used to obtain correct results.
CAUTION: Failure to adjust pinion depth correctly could cause gear noise or transaxle failure.
(1) Install front transfer shaft bearing cup (Fig. 178). The transfer shaft bearing cup must be installed before making pinion depth measurement. Use special tool 6494 to install bearing cup. There are no shims located behind this bearing cup.
CAUTION: The bearing cup is seated in the case correctly if there is no clearance between the bottom of the bearing cup and case. If a 0.001 inch or 0.002 inch feeler gauge does not fit, the bearing cup is completely seated into transaxle case.
(2) Install centering block (special tool 6549-2) into the transaxle case (Fig. 179). Screw centering block into inner adjuster hole of case until it bottoms. The pegs on the special tool are only used for installation. Orientation with in the case is not required.
(3) Install new front bearing (actual bearing to be used during reassembly) onto gauge disc (special tool 6549-3) (Fig. 180).
(4) Install gauge disc and bearing into case using gauge disc rod Tool 6549-4 (Fig. 181).
(5) Install centering disc (special tool 6494-2) onto gauge disc rod (Fig. 182).
(6) Install centering nut Tool 6549-5 as shown in (Fig. 183).
(7) Hand tighten centering nut until all play in the tool has been removed.
(8) Install dial indicator into locating block Tool 6549-1. Then screw extension rod onto dial indicator.
NOTE: The dial indicator used to make this measurement must have a face that shows 0-50-0 (Special Tool C-3339) readings (Fig. 185). All steps from this point forward will reflect this assumption. This will give you proper shim thickness.
(9) Before making a pinion depth measurement the dial indicator must be zeroed. This is done by placing the dial indicator in the zeroing fixture (special tool 6549-6). Then place the zeroing fixture on a flat surface. Adjust the dial face so the pointer on the dial indicator lines up with the zero (Fig. 186)
(10) Compress the dial indicator slightly and insert dial indicator pin into centering block (Fig. 187).
(11) Pivot dial indicator back and forth (Fig. 188) on centering pin to obtain the shortest distance measurement. This will be the lowest number reading on dial indicator. Record the number obtained. Now rotate the gauge disc clockwise 1/3 of a turn and recheck readings. Record number obtained. Rotate the gauge disc another 1/3 of a turn clockwise and take another reading. Average the three readings. Record this pinion depth measurement. If the readings differ by more than two thousandths recheck gauge disc installation, it may have been installed slightly cocked.
(12) To determine the required shim thickness, the pinion depth measurement must be adjusted. The pinion shim adjustment number is the first of seven digits ink stamped on the shank of the transfer shaft (Fig. 189). Using the adjustment factor chart, convert the adjustment number to the corresponding adjustment factor. Utilizing the pinion depth measurement obtained in Step 11, add or subtract the adjustment factor to calculate the required shim thickness. Refer to pinion head shim chart for shim selections. This is the shim that will be installed between the transfer shaft pinion head and the front transfer shaft bearing. Refer to the following examples for further explanation:
(13) Example 1 in (MM):
- Measured pinion shim depth: °0.789 mm
- Adjustment number on transfer shaft: °+2
- Adjustment factor (mm): °-0.051 mm
- Shim size needed: °0.789-0.051=0.735 mm
(14) Example 2 in (IN):
- Measured pinion shim depth: °0.032 inch
- Adjustment number on transfer shaft: -1
- Adjustment factor (in): +0.001
- Shim size needed: 0.032+0.001= 0.033 inch
(15) Remove dial indicator, gauge disc and centering block from transaxle.
(16) Install shim selected in Step 12 of this procedure onto the transfer shaft (Fig. 189).
(17) Press front transfer shaft bearing onto transfer shaft (special tool 6052). The shim must be in place before pressing on bearing (Fig. 190).
ADJUSTMENT FACTOR CHART
PINION HEAD SHIM CHART
(18) At this point the pinion depth has been determined and the shim has been installed onto the transfer shaft. Before the pinion is installed into the transaxle case, bearing preload must be determined for the differential bearings. The following steps must be performed before the pinion is installed.
(19) The following steps will determine how many foot pounds are required on the outer differential adjuster to obtain the correct turning torque.
CAUTION: Failure to set differential bearing preload correctly may cause bearing failure, gear noise and/or axle shaft seal failure.
(20) Remove outer adjuster with special tool 6503 (Fig. 191).
(21) Remove old stub shaft seals. Press inner adjuster seal out with special tool 6502B. Press outer adjuster seal out with special tool 6558.
(22) Install new stub shaft seals in both adjusters using special tool 6558 (Fig. 192).
NOTE: To remove inner and outer adjuster races, use Tool 6062-A. To install inner and outer adjuster races, use Tool 6522 and Tool C-4171.
(23) Lube adjuster threads and O-ring with gear oil before installing. Failure to lube threads will result in thread damage to the adjuster and transaxle case.
(24) Screw in the inner adjuster using special tool 6502B (Fig. 193). The inner adjuster should be screwed in until under-flush with inside of the case (viewed from differential side).
(25) Install differential assembly into the transaxle case (Fig. 194).
(26) Install differential cover (Fig. 195). Do not apply silicone sealant at this time. All bolts should be installed and tightened.
(27) Install seal protector (special tool 6591) as shown in (Fig. 196). Apply a thin film of gear oil on the protector.
CAUTION: Lube threads and O-ring on adjuster before installing. Failure to due so will result in thread damage to the adjuster and transaxle case.
(28) Screw on outer adjuster and tighten adjuster down finger tight (Fig. 197).
(29) Insert special tool 6548 (Fig. 198). This tool will be used to check turning torque of the differential assembly.
CAUTION: Differential bearings must be seated before taking turning torque readings. This is done by rotating the differential three or four turns in both directions.
CAUTION: Turning torque of 19 to 23 inch lbs.. can only be obtained when using new bearings. Do not attempt to obtain this turning torque with used bearings.
(30) Tighten outer adjuster with tool 6503 until 19 to 23 inch lbs. of turning torque is obtained on tool 6548. Record how many foot pounds were required on the outer adjuster to obtain the correct turning torque (Fig. 199). Record the foot pound reading. The reading that you are recording will be used in Step 54 of this procedure.
(31) Remove the differential cover, differential carrier assembly and inner adjuster.
(32) At this point the amount of torque required on the outer differential adjuster has been determined. The transfer shaft can now be installed into the transaxle case. Perform the following steps to install transfer shaft into transaxle case.
(33) Install transfer shaft into transaxle case (Fig. 200).
CAUTION: Bottom of support fixture must be flush with face of bell housing. If the support fixture is not flush, the seals and rear transfer shaft bearing cup will be pressed in cocked.
(34) Install transfer shaft support fixture (special tool 6595) (Fig. 201).
(35) Install transfer shaft seal protector (special tool 6592) (Fig. 202). Apply thin film of gear oil to protector.
(36) Apply a small amount of lube to seal lips and install front transfer shaft seal. The serrated edges must face toward the rear of the transaxle (Fig. 203).
(37) Install seal with special tool 6567A (Fig. 204). Use a press to install seal. The installation tool will set the seal depth. Do not use a hammer to install seal. The seal may be damaged if installed with a hammer.
(38) Install rear transfer shaft seal. The seal must be installed so that the spring side of the seal faces the installation tool (Fig. 205). Use the same special tool (6567A) to install the seal. The installation tool will set the seal depth. Use a press to install this seal. Do not use a hammer.
(39) Install rear transfer shaft cup into case (Fig. 206).
CAUTION: Properly seated cups are essential in correctly setting bearing preload.
(40) Use special tool 6560 to press cup into case (Fig. 207).
(41) Install Transfer shaft preload shim (Fig. 208). Use the original shim that was taken out of transaxle if possible. If original shim is not available, use the thickest shim as a starting point. Refer to Transfer Shaft Rear Shim Chart for available sizes.
Transfer Shaft Rear Shim Chart
(42) Install rear transfer shaft cone. Press cone on transfer shaft using Tool 6560.
(43) Remove transfer shaft support fixture (special tool 6595).
CAUTION: Always use a new transfer shaft nut. Do not reuse old transfer shaft nut.
(44) Install a new transfer shaft nut (Fig. 209). Tighten nut to 271 Nm (200 ft. lbs.). Use special tools 6497 holder and 6498 shaft socket to tighten nut.
CAUTION: Failure to set the transfer shaft turning torque correctly may cause transfer shaft bearings or seals to fail. Be sure transfer shaft does not have end play. If end play exists, install a thinner preload shim.
(45) Check the turning torque of the transfer shaft using a torque wrench (Fig. 210). The turning torque should be 0.5 to 1.3 Nm (5 to 12 inch lbs.). If the turning torque is too high, install a thicker transfer shaft preload shim. If the turning torque is too low, install a thinner transfer shaft preload shim.
CAUTION: A press and special tool 6589 must be used when staking the transfer shaft nut. Do not use a hammer and the special tool to stake nut. If a hammer is used; seal, bearing, and/or tool damage may result. Also the stake will not be seated against the shaft correctly. This will allow the nut to loosen.
(46) After the correct turning torque is obtained, use special tool 6589 to stake the new transfer shaft nut (Fig. 211). Be sure that the tool arms line up with slots in the transfer shaft. Use a press with the special tool to make the stakes in the nut.
CAUTION: Failure to stake the transfer shaft nut correctly may allow the nut to loosen during transaxle operation. This will cause transaxle failure.
(47) At this point the transfer shaft, new oil seals, pinion depth and transfer shaft preload have been set. The following steps will set the backlash between the transfer shaft and the ring gear.
(48) Install vent baffle. Apply sealer as shown in (Fig. 213).
(49) Install new inner adjuster O-ring. Lube inner adjuster threads and O-ring. Then install inner adjuster flush with differential side of case.
(50) Install differential assembly (with ring gear attached) into transaxle case (Fig. 214).
(51) Transfer shaft to ring gear backlash should be 0.006 inch to 0.009 inch thousands of an inch. To get the backlash close enough to measure, perform the following steps. Hold the transfer shaft with one hand and rock the ring gear back and forth (Fig. 215). You should feel some backlash between the gears. If no backlash is felt use special tool 6502B to turn the inner adjuster so that it raises the differential assembly. This will increase backlash. If there is too much backlash, use special tool 6502B to turn the inner adjuster so that it lowers the differential assembly. This will decrease backlash. Recheck the backlash after each adjustment.
(52) Apply a 1/8 inch bead of sealant to differential cover flange. Then install differential cover with sealant (Fig. 216) and tighten cover bolts.
(53) Install seal protector (special tool 6591) on shaft (Fig. 217).
CAUTION: Lube threads and O-ring on adjuster before installing. Failure to due so will result in thread damage to the adjuster and differential cover.
(54) Install outer adjuster with new O-ring (Fig. 218). Torque the outer adjuster (special tool 6503) to the torque reading recorded in Step 30. Then seat bearings by turning differential three or four revolutions in both directions. Tighten adjuster a second time to same torque recorded in Step 30. Again reseat bearings. Repeat this sequence until correct adjuster torque is maintained.
(55) To check and/or adjust backlash, remove the inspection plug from the top of the differential. Install dial indicator as shown in (Fig. 219). The tip of the dial indicator must be perpendicular against one of the ring gear teeth. Hold transfer shaft with locking pliers. Move ring gear back and forth with special tool 6548. Read the amount of backlash with dial indicator. Backlash should be 0.006 inch to 0.009 inch thousands of an inch.
(56) If there is too much backlash, loosen the outer adjuster with special tool 6503. Then turn the inner adjuster so that it moves away from the ring gear. After adjusting the inner adjuster, retighten the outer adjuster to the torque recorded in Step 30. The inner adjuster should be turned in small increments.
(57) If there is not enough backlash, loosen the outer adjuster with special tool 6503. Then turn the inner adjuster so that it moves towards the ring gear. After adjusting the inner adjuster, retighten the outer adjuster to the torque recorded in Step 30. The inner adjuster should be turned in small increments.
(58) Once backlash is with in specifications, recheck backlash in four spots on the ring gear 90 degrees apart. All four readings should be within specifications.
(59) Install inner and outer adjuster locking brackets.
(60) Install new inspection plug. Use a wooden block to tap inspection plug into place.
(61) Fill differential. It is easier to fill the differential prior to installing the transaxle back into the vehicle.