DISASSEMBLY
To detect the real cause of trouble, inspect the following items before disassembling.
- Tooth contact and backlash between hypoid driven gear and drive pinion
- Hypoid driven gear runout on its back surface
- Total preload of drive pinion
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- Set the ST on vise and install the differential assembly to ST. ST 398217700 ATTACHMENT SET
- Remove the oil drain plug and filler plug, and drain the gear oil.
- Remove the air breather cap. NOTE: Do not attempt to replace the air breather cap unless necessary. Whenever the air breather cap is removed, replace it with a new part.
- Remove the bolts, and then remove the rear cover.
- Keep the side retainers separate to make it possible to identify RH and LH sides. Remove the side retainer attaching bolts, set the ST to differential case, and extract the side retainers RH and LH with a puller. NOTE: Each side retainer shim of both sides should be kept together with its mating retainer. ST 398457700 ATTACHMENT
- Pull out the differential case assembly from differential carrier. NOTE: Be careful so that the teeth do not hit against the case.
- When replacing the side bearing, remove the bearing cup from the side retainer using ST. ST 398527700 PULLER ASSY
- Remove the bearing cone with ST. NOTE: Do not attempt to disassemble the parts unless necessary. Set the puller so that its claws catch the edge of the bearing cone. Never mix up the RH and LH bearing races and cones. ST 18759AA000 PULLER ASSY
- Remove the hypoid driven gear by loosening hypoid driven gear bolts.
- Drive out the pinion shaft lock pin from the hypoid driven gear side. NOTE: The lock pin is staked at the pin hole end on the differential carrier. Do not drive it out forcibly before removing the stake. ST 899904100 STRAIGHT PIN REMOVER
- Draw out the pinion mate shaft and remove pinion mate gears, side gears and thrust washers. NOTE: The gears should be marked or kept separated right and left, and front and rear as well as thrust washers.
- Remove the self-locking nut while holding the companion flange with ST. ST 498427200 FLANGE WRENCH
- Extract the companion flange with a puller.
- Press the end of drive pinion shaft and extract it together with rear bearing cone, pinion height adjusting washer and washer. NOTE: Hold the drive pinion so as not to drop it. ST 398467700 DRIFT
- Remove the rear bearing cone from drive pinion by supporting the cone with ST. NOTE: Place the replacer so that its center-recessed side faces the pinion gear. ST 398517700 REPLACER
- Remove the front oil seal from differential carrier using ST. ST 398527700 PULLER ASSY
- Remove the pilot bearing together with the front bearing cone and spacer using the ST. ST 398467700 DRIFT
- When replacing the bearings, hit out the front bearing cup and rear bearing cup in this order using a brass bar.
ASSEMBLY
Note. Assemble in the reverse order of disassembly. Check and adjust each part during assembly. Keep the shims and washers in order, so that they are not improperly installed. Thoroughly clean the surfaces on which the shims, washers and bearings are to be installed. Apply differential gear oil when installing the bearings and thrust washers. Be careful not to mix up the RH and LH bearing races. Use a new O-ring and gasket. Replace the oil seal with a new part at every disassembly. Apply differential gear oil to the lips when installing the oil seal. Be careful not to mix up the oil seal RH and LH.
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- Adjusting preload for front and rear bearings NOTE: Adjust the bearing preload between front and rear bearings with spacer and washer. Pinion height adjusting washer is not affected by this adjustment. The adjustment must not be carried out with oil seal inserted. Install the rear bearing race into the differential carrier using ST1 and ST2. ST1 398477701 HANDLE ST2 398477703 DRIFT 2 Install the front bearing race to the differential carrier using ST1 and ST2. ST1 398477701 HANDLE ST2 398477702 DRIFT Insert the ST1 into carrier with the pinion height adjusting washer and rear bearing cone fitted onto it. NOTE: If tooth contact (drive pinion, hypoid driven gear) is normal in the inspection before disassembling, verify that the washer is not deformed, and then reuse the used washer. Use new rear bearing cone. Install the preload adjusting spacer & washer, front bearing cone, ST2, companion flange, and washer & self-locking nut. ST1 398507702 DUMMY SHAFT ST2 398507703 DUMMY COLLAR Turn the ST1 by hand to smooth the bearing, and tighten the self-locking nut while measuring the initial load or initial torque with a spring scale or torque wrench. Select the preload adjusting washer and spacer so that the specified preload is obtained when nut is tightened to the specified torque. NOTE: Use a new self-locking nut. Measure the preload in direction of tangent to the flange. Be careful not to give excessive preload. When tightening the self-locking nut, lock ST1 with ST2 as shown in the figure. ST1 398507702 DUMMY SHAFT ST2 398507704 BLOCK Tightening torque: 181.5 N.m (18.5 kgf-m, 133.9 ft-lb) Initial load: 17.7 - 38.8 N (1.8 - 4.0 kgf, 4.0 - 8.7 lb) Initial torque: 0.67 - 1.47 N.m (0.07 - 0.15 kgf-m, 0.49 - 1.08 ft-lb) THICKNESS SPECIFICATION Preload adjusting washer Part No. Thickness mm (in) 383705200 2.59(0.1020) 383715200 2.57(0.1012) 383725200 2.55(0.1004) 383735200 2.53 (0.0996) 383745200 2.51 (0.0988) 383755200 2.49 (0.0980) 383765200 2.47 (0.0972) 383775200 2.45 (0.0965) 383785200 2.43 (0.0957) 383795200 2.41 (0.0949) 383805200 2.39(0.0941) 383815200 2.37 (0.0933) 383825200 2.35 (0.0925) 383835200 2.33(0.0917) 383845200 2.31 (0.0909) Preload adjusting spacer Part No. Length mm (in) 383695201 56.2(2.213) 383695202 56.4 (2.220) 383695203 56.6 (2.228) 383695204 56.8 (2.236) 383695205 57.0 (2.244) 383695206 57.2 (2.252)
- Adjusting drive pinion height: Adjust the drive pinion height with washer installed between the rear bearing cone and the back of pinion gear. Attach the ST2. NOTE: At this time, install a pinion height adjusting washer, temporarily selected, or the same as that used before. Measure and record the thickness. ST1 398507702 DUMMY SHAFT ST2 398507701 DIFFERENTIAL CARRIER GAUGE ST3 398507703 DUMMY COLLAR Measure the clearance N between the end of ST2 and the end surface of ST1 by using a thickness gauge. NOTE: Make sure there is no clearance between the case and ST2. ST1 398507702 DUMMY SHAFT ST2 398507701 DIFFERENTIAL CARRIER GAUGE Obtain the thickness of pinion height adjusting washer to be inserted from the following formula, and replace the temporarily installed washer with this one. T = To + N - (H x 0.01) - 0.20 mm (0.0079 in) NOTE: Use copies of this article. THICKNESS SPECIFICATION T Thickness of pinion height adjusting washer mm (in) To Thickness of washer temporally inserted mm (in) N Clearance of thickness gauge mm (in) H Figure marked on drive pinion head Memo: (Example of calculation) To = 2.20 mm (0.0866 in) +1.20 mm (0.0472 in) = 3.40 mm (0.1339 in) N = 0.23 mm (0.0091 in) H = +1 T = 3.40 mm (0.1339 in) + 0.23 mm (0.0091 in) - 0.01 mm (0.0004 in) - 0.20 mm (0.0079 in) = 3.42 mm (0.1346 in) Thickness = 3.42 mm (0.1346 in) Therefore use washer 383605200. THICKNESS SPECIFICATION Pinion height adjusting washer Part No. Thickness mm (in) 383495200 3.09(0.1217) 383505200 3.12(0.1228) 383515200 3.15(0.1240) 383525200 3.18(0.1252) 383535200 3.21 (0.1264) 383545200 3.24 (0.1276) 383555200 3.27(0.1287) 383565200 3.30(0.1299) 383575200 3.33(0.1311) 383585200 3.36(0.1323) 383595200 3.39(0.1335) 383605200 3.42(0.1346) 383615200 3.45(0.1358) 383625200 3.48 (0.1370) 383635200 3.51 (0.1382) 383645200 3.54(0.1394) 383655200 3.57 (0.1406) 383665200 3.60(0.1417) 383675200 3.63(0.1429) 383685200 3.66(0.1441)
- Install the selected pinion height adjusting washer on drive pinion, and press the rear bearing cone into position with ST. ST 398177700 INSTALLER
- Insert the drive pinion into the differential carrier, and install the preselected bearing preload adjusting spacer and washer.
- Press-fit the front bearing cone into case with ST1, ST2 and ST3. ST1 398507703 DUMMY COLLAR ST2 399780104 WEIGHT ST3 899580100 INSTALLER
- Insert the spacer, then press-fit the pilot bearing with ST1 and ST2. ST1 399780104 WEIGHT ST2 899580100 INSTALLER
- Fit a new oil seal with ST. NOTE: Press-fit until the oil seal end comes 1 mm (0.04 in) inward from end of carrier. Apply differential gear oil to the oil seal lips. ST 498447120 INSTALLER
- Press-fit the companion flange with ST1 and ST2. NOTE: Be careful not to damage the bearing. ST1 899874100 INSTALLER ST2 399780104 WEIGHT
- Apply seal material on the drive pinion shaft thread and new self-locking nut seat. SEAL MATERIAL THREE BOND 1324 (Part No. 004403042) or equivalent
- Attach a new self-locking nut and tighten it with the ST. ST 498427200 FLANGE WRENCH Tightening torque: 181.5 N.m (18.5 kgf-m, 133.9 ft-lb)
- Assembling differential case Install the side gears and pinion mate gears, with their thrust washers and pinion mate shaft, into the differential case. NOTE: Apply gear oil on both sides of the washer and on the side gear shaft before installing. Insert the pinion mate shaft into the differential case by aligning the lock pin holes. Measure the side gear backlash. Side gear backlash: 0.10 - 0.20 mm (0.004 - 0.008 in) Adjust the backlash as specified by selecting side gear thrust washer. THICKNESS SPECIFICATION Side gear thrust washer Part No. Thickness mm (in) 383445201 0.75 - 0.80 (0.0295 - 0.0315) 383445202 0.80 - 0.85 (0.0315 - 0.0335) 383445203 0.85 - 0.90 (0.0335 - 0.0354) Check the condition of rotation after applying differential gear oil to the gear tooth surfaces and thrust washer surfaces. After inserting the pinion shaft lock pin into differential case, stake the both sides of the hole to prevent pin from falling off.
- Install the driven gear to the differential case. NOTE: Before installing bolts, apply seal material to bolt threads. SEAL MATERIAL THREE BOND 1324 (Part No. 004403042) or equivalent Make sure there is no clearance between the differential case and driven gear. Tighten the bolts diagonally. Tightening torque: 103 N.m (10.5 kgf-m, 76.0 ft-lb)
- Press the side bearing into differential case using ST. ST 398487700 DRIFT
- Press the side bearing outer race into side retainer using ST. ST 398417700 DRIFT
- Side retainer shim adjustment The hypoid driven gear backlash and side bearing preload can be adjusted by the side retainer shim thickness. Install the differential case assembly into differential carrier in the reverse order of disassembly. NOTE: Be careful so that the teeth do not hit against the case. Install the side retainer shims and O-ring to retainers RH and LH on which they were installed. NOTE: Replace the O-ring with a new part. Replace broken or corroded side retainer shims with a new part of the same thickness. THICKNESS SPECIFICATION Side retainer shim Part No. Thickness mm (in) 383475201 0.20 (0.0079) 383475202 0.25 (0.0098) 383475203 0.30(0.0118) 383475204 0.40(0.0157) 383475205 0.50(0.0197) Align the arrow mark on differential carrier with the arrow mark on side retainer during installation. NOTE: Be careful that side outer race is not damaged by the bearing roller. Tighten the side retainer bolts. Tightening torque: 10.5 N.m (1.1 kgf-m, 7.7 ft-lb) Measure the backlash between the hypoid driven gear and drive pinion. Set the magnet base on differential carrier. Align the contact point of dial gauge with the tooth surface of hypoid driven gear, and move the hypoid driven gear while securing the drive pinion. Read the value indicated on dial gauge. If the backlash is not within the range of specifications, adjust the side retainer shim using the following procedures. When backlash is less than 0.1 mm (0.004 in): Reduce the hypoid driven gear rear face shim thickness and increase the hypoid driven gear tooth surface side shim thickness. When backlash exceeds 0.2 mm (0.008 in): Increase the hypoid driven gear rear face shim thickness and reduce the tooth surface side shim thickness. Backlash: 0.10 - 0.20 mm (0.004 - 0.008 in) At the same time, measure the total preload of the drive pinion. Compared with the resistance when differential case is not installed, if the total preload is not within specification, adjust the thickness of side retainer shims, increasing/reducing both shims by an even amount at a time. Total preload: 20.7 - 54.4 N (2.1 - 5.5 kgf, 4.7 - 12.2 lbf)
- Recheck the backlash between the hypoid driven gear and drive pinion. Backlash: 0.10 - 0.20 mm (0.004 - 0.008 in)
- Check the driven gear runout on its back surface, and make sure that the pinion and driven gear rotate smoothly. If the hypoid driven gear runout on its back surface exceeds the specification, check for any foreign objects between the hypoid driven gear and differential case, and for any deformation of the case or gear. Hypoid driven gear back surface runout: 0.05 mm (0.002 in)
- Checking and adjusting the tooth contact of hypoid driven gear Apply red lead evenly to the both side of three or four teeth on hypoid driven gear. Check the contact pattern after rotating the hypoid driven gear several revolutions back and forth until a definite contact pattern appears on the hypoid driven gear. When the contact pattern is not correct, readjust. NOTE: Be sure to wipe off the red lead after the adjustment is completed. Correct tooth contact Check item: Tooth contact pattern is slightly shifted toward toe side under no-load rotation. (When driving, it moves towards the heel side). Face contact Check item: Backlash is too large . Contact pattern Corrective action: Increase thickness of drive pinion height adjusting washer in order to bring drive pinion close to hypoid driven gear. Flank contact Check item: Backlash is too small . Contact pattern Adjustment: Reduce the thickness of pinion height adjusting washer according to the procedure for bringing the drive pinion away from hypoid driven gear. Toe contact (inside contact) Check item: Contact area is too small . Contact pattern Adjustment: Reduce the thickness of pinion height adjusting washer according to the procedure for bringing the drive pinion away from hypoid driven gear. Heel contact (outside end contact) Check item: Contact area is too small . Contact pattern Corrective action: Increase thickness of drive pinion height adjusting washer in order to bring drive pinion close to hypoid driven gear.
- If proper tooth contact is not obtained, once again adjust the drive pinion height by changing the RH and LH side retainer shims and the hypoid gear backlash. Drive pinion height ST1 398507702 DUMMY SHAFT ST2 398507701 DIFFERENTIAL CARRIER GAUGE T = To + N - (H x 0.01) - 0.20 (mm) Place: T = Thickness of pinion height adjusting washer (mm) To = Thickness of washer temporally inserted (mm) N = Clearance of thickness gauge (mm) H = Figure marked on drive pinion head (2) Hypoid gear backlash Backlash: 0.10 - 0.20 mm (0.004 - 0.008 in)
- Remove the RH and LH side retainers.
- Install new O-rings to side retainers of both sides.
- Install oil seal to side retainers of both sides. Refer to «REPLACEMENT»(ref-325345-S42606294282009071800000) , Rear Differential Side Oil Seal.
- Align the arrow mark on differential carrier with the arrow mark on side retainer during installation.
- Apply liquid gasket to the bolt with arrow marks, and install the side retainer. Liquid gasket: THREE BOND 1110B (Part No. K0879Y0020) or equivalent Tightening torque: 10.5 N.m (1.1 kgf-m, 7.7 ft-lb)
- Install the new gasket and rear cover, and tighten the bolts to specified torque. Tightening torque: 9.5 N.m (3.0 kgf-m, 21.8 ft-lb)
- Install the air breather cap.
- Install the oil drain plug and filler plug. Tightening torque: 49 N.m (5.0 kgf-m, 36.1 ft-lb)