Mainshaft and Gears

MAINSHAFT AND GEARS

Disassembly and Assembly
DISASSEMBLY





1. Before disassembling, measure end play of 1st and 2nd main gears.
End play standard value
1st gear: 0.20 - 0.30 mm (0.0079 - 0.0118 inch)
2nd gear: 0.06 - 0.16 mm (0.0024 - 0.0063 inch)

CAUTION: If measurement is outside the standard range, disassemble to check contact surfaces of gear, shaft, and hub. Adjust with snap ring at assembly.





2. Remove the snap ring.
3. Remove C-ring holder, and then mainshaft C-ring.





4. Remove mainshaft rear bearing.
Tool number
A: Commercial service tool
B: Commercial service tool C: ST33052000 ( - )





5. Remove the snap ring.





6. Remove 4th main gear and 5th main gear simultaneously.
Tool number
A: ST33052000 ( - )
B: Commercial service tool
7. Remove adjusting shim.
8. Remove 3rd-4th mainshaft spacer.





9. Remove 3rd main gear, 2nd main gear, 2nd needle bearing, 2nd bushing, 1st-2nd synchronizer hub assembly, 1st main gear, reverse main gear, 1st needle bearing, and 1st bushing simultaneously.
Tool number: KV40105020 ( - )

INSPECTION AFTER DISASSEMBLY
Mainshaft and Gears





^ Check items. If necessary, replace them with new ones.
^ Damage, peeling, dent, uneven wear, bending, and other nonstandard conditions of the shaft.
^ Excessive wear, damage, peeling, and other non-standard conditions of the gears.

Synchronizer





Check items. If necessary, replace them with new ones.
^ Damage and unusual wear on contact surfaces of coupling sleeve, synchronizer hub, and shifting insert.
^ Coupling sleeve and synchronizer hub must move smoothly.





If any crack, damage, or excessive wear is found on cam face of baulk ring or working face of insert, replace it.

Baulk Ring Clearance for Double Cone Synchronizer (1st)





Follow the instructions and inspect the clearance of outer baulk ring, synchronizer cone, and inner baulk ring.

CAUTION: Outer baulk ring, synchronizer cone and inner baulk ring determine the clearances "A" and "B" as an assembly. Replace the outer baulk ring, synchronizer cone and inner baulk ring as an assembly if either of the clearances "A" or "B" exceed the limit value.





^ Using a dial gauge, measure clearance "A" at 2 or more points diagonally opposite, and calculate mean value.
Tool number: ST30031000 (J-22912-01)
Clearance "A"
Standard value: 0.6 - 0.8 mm (0.024 - 0.031 inch)
Limit value: 0.2 mm (0.008 inch)





^ Using a feeler gauge, measure clearance "B" at 2 or more points diagonally opposite, and calculate mean value.
Clearance "B"
Standard value: 0.6 - 1.1 mm (0.024 - 0.043 inch)
Limit value: 0.2 mm (0.008 inch)

Baulk Ring Clearance for Triple Cone Synchronizer (2nd)





Follow the instructions and inspect the clearance of outer baulk ring, synchronizer cone, inner baulk ring.

CAUTION: Outer baulk ring, synchronizer cone and inner baulk ring determine the clearances "A", "B" and "C" as an assembly. Replace the outer baulk ring, synchronizer cone and inner baulk ring as an assembly if any of the clearances "A", "B" and "C" exceed the limit value.





^ Measure clearance "A" at two points or more on the opposite side using a feeler gauge when pressing baulk ring toward clutch gear taper cone, then calculate the average.
Clearance "A"
Standard value: 0.6 - 1.2 mm (0.024 - 0.047 inch)
Limit value: 0.3 mm (0.012 inch)





^ Measure clearance "B" at two points or more on the opposite side using a feeler gauge, then calculate the average.
Clearance "B"
Standard value: 0.6 - 1.1 mm (0.024 - 0.043 inch)
Limit value: 0.2 mm (0.008 inch)





^ Measure clearance "C" at two points or more on the opposite side using a feeler gauge when pressing baulk ring toward clutch gear taper cone, then calculate the average.
Clearance "C"
Standard value: 0.7 - 1.1 mm (0.028 - 0.043 inch)
Limit value: 0.3 mm (0.012 inch)

Bearing





Check items. If necessary, replace them with new ones.
^ Damage and rough rotation of bearing

ASSEMBLY





1. Install reverse main gear.
Tool number
A: ST35321000 ( - )
B: KV40101630 (J-35870)
C: ST38220000 ( - )





CAUTION: Be careful with orientation of reverse main gear.





2. Install 1st bushing.
Tool number
A: ST35321000 ( - )
B: KV38102510 ( - )
C: ST38220000 ( - )
3. Install needle bearing, and then 1st main gear.
4. Install spread spring, shifting insert and 1st-2nd synchronizer hub onto 1st-2nd coupling sleeve.

CAUTION:





^ Be careful with orientation of synchronizer hub.





^ Be careful with orientation of coupling sleeve.





^ Be sure not to hook ends of 2 spread springs (front and back have two each) on same shifting insert.





5. Install 1st gear synchronizer assembly onto mainshaft, and synchronizer hub assembly onto mainshaft.
Tool number
A: ST35321000 ( - )
B: KV38102510 ( - )
C: ST38220000 ( - )

CAUTION:
^ Outer baulk ring, synchronizer cone, and inner baulk ring on 2nd gear-side must have been removed.
^ Be careful with orientation of coupling sleeve.





6. Install 2nd bushing.
Tool number
A: ST35321000 ( - )
B: KV40105710 ( - )
7. Install outer baulk ring, synchronizer cone, and inner baulk ring on 2nd gear-side.
8. Install 2nd needle bearing and 2nd gear.





9. Install 3rd main gear.
Tool number
A: ST35321000 ( - )
B: KV40105710 ( - )

CAUTION: Be careful with orientation of 3rd main gear.

10. Install 3rd-4th mainshaft spacer.





11. Select suitable adjusting shim so that dimension "C1" satisfies standard value, and install it onto mainshaft.
Standard for dimension "C1": 173.85 - 173.95 mm (6.844 - 6.848 inch)





Adjusting Shim

CAUTION: Only one adjusting shim can be selected.





12. Install 4th main gear.
Tool number
A: ST33200000 (J-26082)
B: ST30901000 (J-26010-01)

CAUTION: Be careful with orientation of 4th main gear.





13. Install 5th main gear.
Tool number
A: ST33200000 (J-26082)
B: ST30901000 (J-26010-01)

CAUTION: Be careful with orientation of 5th main gear.





14. Install snap ring onto mainshaft, and check that end play of 5th main gear satisfies standard value.
End play standard value: 0 - 0.1 mm (0 - 0.004 inch)
^ If measurement is outside the standard range, reselect snap ring.





Snap Rings





15. Install mainshaft rear bearing.
Tool number
A: ST30720000 (J-25405)
B: ST30901000 (J-26010-01)





16. Install C-ring onto mainshaft, and check that end play of mainshaft rear bearing satisfies standard value.
End play standard value: 0 - 0.06 mm (0 - 0.0024 inch)
^ If measurement is outside the standard range, reselect C-ring.





C-ring





17. Fit the C-ring holder, and install the snap ring.





18. Check the end play of the 1st and 2nd main gears.
End play standard value
1st gear: 0.20 - 0.30 mm (0.0079 - 0.0118 inch)
2nd gear: 0.06 - 0.16 mm (0.0024 - 0.0063 inch)