Main Shaft and Gear

Disassembly





1. Using a press to remove reverse main gear bushing, mainshaft bearing and 4th main gear.
2. Remove 3rd-4th main spacer.





3. Using a press to remove 1st main gear and 3rd main gear.

CAUTION:
Never damage baulk ring.

4. Remove 1st needle bearing.





5. Using a press to remove 1st gear bushing, 1st-2nd synchronizer assembly and 2nd main gear.

CAUTION:
Be aware that when using the press, if mainshaft gear positioner catches on the V-block, etc., mainshaft could be damaged.

6. Remove 2nd needle bearing.





7. After removing snap ring, using a press to remove 6th main gear and 5th-6th synchronizer assembly.
8. Remove 6th needle bearing.

Assembly
1. Install 5th-6th coupling sleeve and 5th-6th shifting inserts in 5th-6th synchronizer hub.

CAUTION:

^ Install 5th-6th coupling sleeve with the large chamfer on the rear side.
^ Never reuse 5th-6th coupling sleeve and 5th-6th synchronizer hub.
^ Replace 5th-6th coupling sleeve and 5th-6th synchronizer hub as a set.

2. Install 5th-6th spread springs in 5th-6th shifting inserts.

CAUTION:

^ Never install 5th-6th spread spring hook onto the same 5th-6th shifting insert.

^ Be careful with the shape of reverse shifting insert to avoid misassembly.





3. Apply recommended grease to 6th needle bearing.
4. Install 6th needle bearing, 6th main gear and 6th baulk ring on mainshaft and then using an inserter [SST: ST30911000 ( - )] and a press to press fit 5th-6th synchronizer assembly.

CAUTION:

^ When press fitting, install with the side having the three boss edge oil grooves facing the rear side.

NOTE:





5th and 6th baulk rings have three spaces that four gear teeth are missing as shown in the figure.





5. Select and install a snap ring so that the end play comes within the standard value.
End play: Refer to TM-75, "End Play". End Play

CAUTION:
Never reuse snap ring.

6. Install 1st-2nd coupling sleeve and 1st-2nd shifting inserts into 1st-2nd synchronizer hub.

CAUTION:

^ Install 1st-2nd coupling sleeve with the thicker flange faced the front side.
^ Never reuse 1st-2nd coupling sleeve and 1st-2nd synchronizer hub.
^ Replace 1st-2nd coupling sleeve and 1st-2nd synchronizer hub as a set.

7. Install 1st-2nd spread springs in 1st-2nd shifting inserts.

CAUTION:

^ Never install 1st-2nd spread spring hook onto the same 1st-2nd shifting insert.

^ Be careful with the shape of reverse shifting insert to avoid misassembly.





8. Apply recommended grease to 2nd needle bearing.
9. Install 2nd main gear, 2nd needle bearing, 2nd inner baulk ring, 2nd synchronizer cone and 2nd outer baulk ring on mainshaft and then using a support ring [SST: ST27861000 ( - )] and a press to press fit 1st-2nd synchronizer assembly.

CAUTION:
^ Replace 2nd inner baulk ring, 2nd synchronizer cone and 2nd outer baulk ring as a set.

^ When press fitting, install with the side having the three boss edge oil grooves facing the front side.

NOTE:





1st baulk ring has three spaces that four gear tooth is missing and 2nd baulk ring has three spaces that two gear teeth are missing.





10. Using a support ring [SST: ST27861000 ( - )] and a press to press fit 1st gear bushing.





11. Apply recommended grease to 1st needle bearing.
12. Install 1st outer baulk ring, 1st synchronizer cone, 1st inner baulk ring, 1st needle bearing and 1st main gear on mainshaft and then using the inserter [SST: ST30022000 ( - )] and a press to press fit 3rd main gear.

CAUTION:
^ Never reuse 3rd main gear.
^ Replace 1st outer baulk ring, 1st synchronizer cone and 1st inner baulk ring as a set.





13. Install 3rd-4th main spacer on mainshaft and then using the inserter [SST: ST30022000 ( - )] and a press to press fit 4th main gear.

CAUTION:
^ Never reuse 4th main gear.
^ When installing, set boss to rear side.





14. Using the inserter and a press to press fit mainshaft bearing onto mainshaft.





15. Using the inserter [SST: ST30911000 ( - )] and a press to press fit reverse main gear bushing onto mainshaft.

Inspection

MAINSHAFT AND GEAR





If the contact surface on each gear and mainshaft, etc. has damage, peeling, abrasion, dent, bent, or any other damage, replace the components.

SYNCHRONIZER

Synchronizer Hub and Coupling Sleeve





^ If the contact surface on coupling sleeve, synchronizer hub and shifting insert has damage or abrasion, replace the components.
^ Coupling sleeve and synchronizer hub shall move smoothly.

Baulk Ring and Spread Spring





^ If the cam surface on baulk ring or contact surface on insert has damage or excessive wear, replace with a new one.
^ If spread spring is damaged, replace with a new one.

Baulk Ring Clearance for Single Cone Synchronizer (6th and Reverse)





^ Push baulk ring on the cone and measure the clearance between baulk ring and cone. If the measurement is below limit, replace it with a new one.
Clearance
Standard value: Refer to TM-75, "Baulk Ring Clearance". Baulk Ring Clearance
Limit value: Refer to TM-75, "Baulk Ring Clearance". Baulk Ring Clearance

Baulk Ring Clearance for Triple Cone Synchronizer (1st and 2nd)





^ Check the clearance between outer baulk ring (1), synchronizer cone (2), and inner baulk ring (3) as follows.

CAUTION:
The clearances "A", "B" and "C" are controlled with outer baulk ring, synchronizer cone, and inner baulk ring as a set. Replace them as a set if the clearances are outside the limit value.





1. Measure the clearance "A" at 2 points or more diagonally opposite using a feeler gauge (B) when pressing outer baulk ring (1), synchronizer cone (2), and inner baulk ring (3) toward gear taper cone (C). And then calculate mean value.
Clearance "A"
Standard value: Refer to TM-75, "Baulk Ring Clearance". Baulk Ring Clearance
Limit value: Refer to TM-75, "Baulk Ring Clearance". Baulk Ring Clearance





2. Measure the clearance "B" at 2 points or more diagonally opposite using a feeler gauge (A). And then calculate mean value.
1: Outer baulk ring
2: Synchronizer cone
Clearance "B"
Standard value: Refer to TM-75, "Baulk Ring Clearance". Baulk Ring Clearance
Limit value: Refer to TM-75, "Baulk Ring Clearance". Baulk Ring Clearance





3. Measure the clearance "C" at 2 points or more diagonally opposite using a feeler gauge (A) when pressing outer baulk ring (1), synchronizer cone (2), and inner baulk ring (3) toward gear taper cone (B). And then calculate mean value.
Clearance "C"
Standard value: Refer to TM-75, "Baulk Ring Clearance". Baulk Ring Clearance
Limit value: Refer to TM-75, "Baulk Ring Clearance". Baulk Ring Clearance

Bearing





If the bearing does not rotate smoothly or the contact surface on ball or race is damaged or peeled, replace with new ones.