Mainshaft and Gears

DISASSEMBLY

Gear End Play:

1. Before disassembly, check 1st and 2nd main gear end plays.
If not within specification, disassemble and check contact surface of gear, shaft and hub. Then check clearance of snap ring - Refer to "Assembly" below.




2. Press out mainshaft rear bearing.




3. Remove thrust washer and snap ring




4. Press out 5th main gear and 4th main gear.




5. Press out 3rd main gear and 2nd main gear.




6. Remove snap ring.




7. Remove 1st & 2nd synchronizer and 1st main gear.




8. Remove mainshaft front bearing.

INSPECTION




Gear and shaft
- Check shaft for cracks, wear or bending.
- Check gears for excessive wear, chips or cracks.




Synchronizer
- Check spline portion of coupling sleeves, hubs and gears for wear or cracks.
- Check baulk rings for cracks or deformation.
- Check insert springs for deformation.




- Measure clearance between baulk ring and gear (1st & 2nd).

Clearance between baulk ring and gear:
Standard: 1.0 - 1.35 mm (0.0394 - 0.0531 in)
Wear limit: 0.7 mm (0.028 in)




Bearing
- Make sure bearings roll freely and are free from noise, cracks, pitting or wear.

Note: When replacing tapered roller bearing, replace outer and inner race as a set.

ASSEMBLY







1. Place inserts in three grooves on coupling sleeve (1st & 2nd synchronizer).







2. Install 1st main gear and 1st baulk ring.
3. Press on 1st & 2nd synchronizer hub.

Note: Pay attention to its direction.




4. Install coupling sleeve with three inserts and 2nd baulk ring.
5. Select proper snap ring of 1st & 2nd synchronizer hub to minimize clearance of groove and then install it.

Allowable clearance of groove: 0 - 0.1 mm (0 - 0.004 in)
Snap ring of 1st & 2nd synchronizer hub: [1][2]Mechanical Specifications




6. Install 2nd main gear.
7. Press on 3rd main gear.




8. Press on 4th main gear.




9. Press on 5th main gear.
10. Select proper snap ring of 5th main gear to minimize clearance of groove and then install it.

Allowable clearance of groove: 0 - 0.15 mm (0 - 0.0059 in)
Snap ring of 5th main gear: [1][2]Mechanical Specifications




11. Press on thrust washer and press on mainshaft rear bearing.




12. Press on mainshaft front bearing.
13. Measure gear end play as the final check Refer to "Disassembly" above.