Exploded View

1. Mainshaft front bearing outer race
2. Mainshaft front bearing inner race 3. Mainshaft
4. 1st main gear
5. 1st inner baulk ring 6. 1st synchronizer cone 7. 1st outer baulk ring 8. 1st-2nd coupling sleeve 9. Insert key
10. 1st-2nd synchronizer hub 11. 2nd outer baulk ring 12. 2nd synchronizer cone 13. 2nd inner baulk ring 14. 2nd main gear
15. Bushing
16. 3rd main gear
17. Mainshaft adjusting shim 18. 4th main gear
19. 5th main gear
20. 6th main gear
21. Mainshaft rear bearing inner race 22. Mainshaft rear bearing outer race 23. Snap ring
24. Mainshaft rear bearing adjusting shim

: Apply gear oil.

: Replace the parts as a set.

: Select with proper thickness.

: Always replace after every
disassembl

Disassembly

CAUTION:
• Fix mainshaft in a vise with back plate, and then remove gears and snap rings.

• For removal of snap ring, set snap ring pliers and flat pliers at both sides of snap ring. While expanding snap ring with snap ring pliers, move snap ring with flat pliers.

• Disassemble gear components putting direction marks on the parts that never affect any functions.

1. Remove snap ring (1).

2. Remove 6th main gear (1) and mainshaft rear bearing inner race (2), as per the following procedure.

a. Set a puller [Commercial service tool] to 6th main gear.

b. Remove mainshaft rear bearing inner race and 6th main gear, using the drift (A) [SST: ST33052000].

3. Remove 4th main gear (1) and 5th main gear (2), as per the following procedure.

a. Set a puller [Commercial service tool] to 4th main gear.

b. Remove 5th main gear and 4th main gear, using the drift (A) [SST: ST33052000].

4. Remove mainshaft adjusting shim.

5. Remove 1st main gear (1), 1st-2nd synchronizer hub assembly (2), 2nd main gear (3), and 3rd main gear (4), as per the following procedure.

a. Set a puller [Commercial service tool] to 1st main gear.

b. Remove 3rd main gear, busing, 2nd main gear, 2nd inner baulk ring, 2nd synchronizer cone, 2nd outer baulk ring, 1st-2nd synchronizer hub assembly, 1st outer baulk ring, 1st synchronizer cone, 1st inner baulk ring, and 1st main gear, using the drift (A) [SST: ST33052000].

c. Remove insert keys and 1st-2nd coupling sleeve from 1st-2nd synchronizer hub.

6. Remove mainshaft front bearing inner race (1), as per the following procedure.

a. Set a puller [Commercial service tool] to mainshaft front bearing inner race.

b. Remove mainshaft front bearing inner race, using the drift (A) [SST: ST33052000].

Assembly

CAUTION:
• Select mainshaft rear bearing adjusting shim, as per the following procedure when replacing mainshaft adjusting shim, 6th main gear, 5th main gear, or 4th main gear.

- Replace mainshaft adjusting shim.

• For installation of snap ring, set snap ring pliers and flat pliers at both sides of snap ring. While expanding snap ring with snap ring pliers, move snap ring with flat pliers.

1. Install mainshaft front bearing inner race (1), using the drift (A) [SST: ST36720030].

CAUTION:
Replace mainshaft front bearing outer race and mainshaft front bearing inner race as a set

.

2. Apply gear oil to 1st inner baulk ring, 1st synchronizer cone, 1st outer baulk ring, 2nd inner baulk ring, 2nd synchronizer cone, and 2nd outer baulk ring.

CAUTION:
• Replace 1st inner baulk ring, 1st synchronizer cone, and 1st outer baulk ring as a set.

• Replace 2nd inner baulk ring, 2nd synchronizer cone, and 2nd outer baulk ring as a set.

3. Install insert keys and 1st-2nd coupling sleeve to 1st-2nd synchronizer hub.

CAUTION:
Replace 1st-2nd synchronizer hub and 1st-2nd coupling sleeve as a set.

4. Install 1st main gear (1), 1st inner baulk ring, 1st synchronizer cone, 1st outer baulk ring, 1st-2nd synchronizer hub assembly (2), 2nd inner baulk ring, 2nd synchronizer cone, and 2nd outer baulk ring.

5. Install bushing (3), using the drift (A) [SST: KV32102700].

6. Install 3rd main gear (1) and 2nd main gear (2), using the drift (A) [SST: KV32102700].

7. Measure dimension “L” as shown in the figure. Select mainshaft adjusting shim (1) according to the following list, and then install it to mainshaft.

2 : Mainshaft
3 : 3rd main gea

8. Install 4th main gear (1), using the drift (A) [SST: KV32102700].

9. Install 5th main gear (1), using the drift (A) [SST: KV32102700].

10. Install 6th main gear (1), using the drift (A) [SST: KV32102700].

11. Install mainshaft rear bearing inner race (1), using the drift (A) [SST: ST30901000].

CAUTION:
Replace mainshaft rear bearing inner race and mainshaft rear bearing outer race as a set.

12. Install snap ring.

CAUTION:
Never reuse snap ring.

Inspection

INSPECTION AFTER DISASSEMBLY

Mainshaft and Gear Check the following items and replace if necessary.

• Damage, peeling, bend, uneven wear, and distortion of shaft.

• Excessive wear, damage, and peeling of gear.

Synchronizer Hub and Coupling Sleeve Check the following items and replace if necessary.

• Breakage, damage, and unusual wear on contact surface of coupling sleeve, synchronizer hub, and insert key.

• Coupling sleeve and synchronizer hub move smoothly.

Baulk Ring
Check contact surface of baulk ring cam and insert key for excessive wear, uneven wear, bend, and damage. Replace if necessary.

Bearing
Check bearing for damage and unsmooth rotation. Replace if necessary.

CAUTION:
• Replace mainshaft front bearing outer race and mainshaft front bearing inner race as a set.

• Replace mainshaft rear bearing inner race and mainshaft rear bearing outer race as a set.