Overhaul

DISASSEMBLY

General

1. Clean exterior of transfer gear assembly.





2. Set transfer gear assembly on vise with attachment and a washer.

3. Remove dust covers.





Output Shaft Side

1. While holding inner nut using output shaft nut wrench tool No. KV48105100, or equivalent, remove lock nut.

2. Remove inner nut.

3. Remove oil seal.

CAUTION:
- Do not damage the input shaft body during oil seal removal. Also, be careful not to damage the oil seal mounting surface.
- Do not re-use the output shaft oil seal.

Input Shaft Side





1. Remove oil seal.

CAUTION:
- Do not damage the input shaft body during oil seal removal. Also be careful not to damage the oil seal mounting surface.
- Do not re-use the input shaft oil seal.

2. Remove snap ring.





3. Remove lock nut with lock nut wrench tool No. KV48104500, or equivalent.





4. Remove front cover. To remove front cover, use a small punch and hammer to tap on the cover from rear side lip.

CAUTION: Position the punch carefully to keep from damaging the front cover gasket and transfer gear housing sealing surface.

NOTE:
- Leave one upper bolt loosely fitted to prevent the front cover from falling down.
- Completely remove gasket from housing and front cover with resin or wooden bar. Do not damage gasket surface.





5. Wipe grease from the input and output gears.

6. Put matching marks on gears.





7. Remove rear cover with pin-type lock nut wrench. Remove thread locker residue from the transfer gear housing using a toothbrush and thinner.





8. While pulling input shaft in the direction of the arrow shown in figure, drive output shaft out using a plastic hammer. (Input shaft cannot be removed before removing output shaft.)

CAUTION: Be careful not to damage thrust bearing between output shaft gear and gear box during removal.

9. Remove thrust bearing, bearing race and O-ring from output shaft.

10. Remove input shaft.


INSPECTION
- Check that needle bearings and output shaft bearing rotate smoothly. Also check them for deformation, or damage. Replace transfer gear box assembly if necessary.
- Check that thrust bearing and bearing race rotate smoothly. Also check them for deformation, or damage. Replace thrust bearing assembly if necessary.
- Check that input shaft bearing of rear cover assembly rotates smoothly. Check it for deformation, or damage. Replace rear cover assembly if necessary.
- Check teeth of input and output shafts for excessive wear chips or cracks. Replace shafts if necessary.


ASSEMBLY





1. Apply grease to needle bearings before installing output shaft and input shaft.

Recommended grease: MULTEMP PS No.2

NOTE: Apply the grease onto the bearings with your finger until the roller cage is packed, making the actual needle bearings difficult to see [2 - 3 grams (0.07 - 0.11 ounce) each].





2. Insert input shaft until it comes in contact with end face of gear box.

NOTE: Output shaft cannot be installed before installing input shaft.





3. Apply MULTEMP PS No. 2 grease to output shaft thrust bearing.

4. Insert bearing race and thrust bearing to output shaft.

NOTE: Insert thrust bearing with roller side towards the bearing race as shown in the illustration.

5. Insert output shaft until it comes in contact with end face of gear box.





6. Insert new O-ring to output shaft.

CAUTION:
- Install O-ring after installing output shaft to housing.
- Cover screw threads of output shaft with tape to prevent damage to O-ring.





7. While pulling output shaft in the direction of the arrow, hand-tighten inner nut.

8. Use Tool to tighten inner nut slightly while holding output shaft gear by hand.

9. Check rotating torque of output shaft gear.

Rotating torque: Approximately 0.15 - 0.20 Nm (1.3 - 1.7 inch lbs.)

10. Check that output shaft has no axial end play by pushing and pulling top of shaft side-to-side. Repeat steps from 8 to 10 if axial end play exists.





11. While holding inner nut using Tool, tighten lock nut using a torque wrench.

Torque: 34 - 53 Nm (25 - 39 ft. lbs.)

12. Measure rotating torque of output shaft using a bar type torque wrench and adapter nut. The rotating speed is 7 - 10 seconds per rotation. If rotating torque is out of specification, loosen lock nut and inner nut. Then repeat from step 7.

Rotating torque: 0.1 - 0.15 Nm (0.9 - 1.3 inch lbs.)

NOTE: If rotating torque is out of specification, rotate the input shaft two turns clockwise, then two turns counterclockwise. Repeat this step 9 times. The turning torque will then meet specification due to conditioning.

CAUTION: Do not allow input shaft to mesh with output shaft while checking output shaft rotating torque.





13. Align matching marks on gears made during disassembly step.

14. Apply thread locker to the circumference of the bottom 3 - 5 threads of the rear cover.





15. Install and hand tighten input shaft rear cover.

NOTE: When the gears mesh with each other, preload occurs and resistance is felt when gears are rotated.





16. Tighten input shaft rear cover until input shaft meshes with output shaft.

NOTE: When the gears mesh with each other, preload occurs and resistance is felt when gears are rotated.





17. While adjusting rear cover, measure rotating torque of input and output shaft (as a unit) with Tools.

Rotating torque: 0.25 - 0.69 Nm (2.2 - 6.1 inch lbs.)





18. While holding rear cover with a pin-type nut wrench, tighten lock nut with Tool.

Torque: 78 - 118 Nm (58 - 87 ft. lbs.)

19. Check rotating torque 360° in both direction. If rotating torque is out of specification, loosen lock nut and repeat steps 17 and 18.

NOTE: If rotating torque is out of specification, rotate input shaft two turns clockwise, then two turns counterclockwise. Repeat this step 9 times. The turning torque will then meet specification due to conditioning.





20. Install snap ring in the groove correctly. When the snap ring is installed correctly, about 2 mm (0.08 inch) gap exists at the snap ring ends.

CAUTION: Do not spread snap ring end gap more than 7 mm (0.28 inch) or else the snap ring will fatigue.








21. Apply ONE-LUBER SG No. 2 grease to input and output seal lips. Install oil seals with drift.

CAUTION: Be careful seal lip does not contact input shaft splines. Pay attention to oil seal direction. Spring side faces inward.





22. Pack input and output shaft gears with 40 - 45 grams (1.41 - 1.59 ounce) of ONE-LUBER SG No. 00 grease.





23. Install front cover using a new gasket.

CAUTION: Do not torque front cover bolts in a circle, torque in an "X" pattern to 7 - 12 Nm (61 - 104 inch lbs.).





24. Apply liquid packing to threads of plug, and tighten it to 8 - 20 Nm (69 - 174 inch lbs.).





25. Measure rotating torque at input shah. Use same torque specification as steps 17 and 18.





26. Locate position of highest torque. While holding the input shaft position at the point of the highest torque, align the mating rib of the input dust cover with the protrusion on the transfer gear housing.

27. Install output dust cover with index mark aligned with casting mark on housing.