Mainshaft and Gears
MAINSHAFT AND GEARSDisassembly and Assembly
DISASSEMBLY
1. Before disassembling, measure the end play of the 1st and 2nd main gears as shown.
End play standard values
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 the measurement is outside the standard value, disassemble to check the contact surfaces of the gear, shaft, and hub. Adjust with the snap ring at assembly.
2. Remove the snap ring.
3. Remove the C-ring holder, and then mainshaft C-ring as shown.
4. Remove the mainshaft rear bearing, adjust shim, and 6th main gear using Tool as shown.
Tool number
A: Commercial service tool
B: ST33052000 ( - )
5. Remove the 5th-6th mainshaft spacer.
6. Remove the 4th main gear and 5th main gear simultaneously using Tool as shown.
Tool number
A: ST33052000 ( - )
B: Commercial service tool
7. Remove the adjusting shim.
8. Remove the 3rd-4th mainshaft spacer.
9. Remove the 3rd main gear, 2nd main gear, 2nd gear needle bearing, 2nd bushing, 1st-2nd synchronizer assembly, 1st main gear, reverse main gear, 1st gear needle bearing, and 1st bushing simultaneously using Tool as shown.
Tool number: KV40105020 ( - )
INSPECTION AFTER DISASSEMBLY
Mainshaft and Gears
Check the items listed as shown. If necessary, replace them with new ones.
^ Damage, peeling, dent, uneven wear, and bending of the mainshaft.
^ Excessive wear, damage and peeling of the mainshaft gears.
Synchronizer
Check the items listed as shown. If necessary, replace them with new ones.
^ Damage, excessive wear on contact surfaces of the coupling sleeve, synchronizer hub, and shifting insert.
^ Coupling sleeve and synchronizer hub must move smoothly as shown.
^ If any cracks, damage, or excessive wear is found on the cam face of baulk ring or working face of the insert as shown, replace it.
Triple Cone Synchronizer (1st and 2nd)
^ Check the clearance of the outer baulk ring, synchronizer cone, and inner baulk ring of the 1st and 2nd triple cone synchronizers, using the procedure.
CAUTION: The outer baulk ring, synchronizer cone, and inner baulk ring operate as a set to control the clearances "A", "B", and "C". If the measured clearances exceed the service limit value, replace the components as a set.
NOTE: To calculate the mean value of two or more measured values, add the highest and lowest measured values and divide by two.
1. Press the baulk ring on to the clutch gear taper cone by hand, then measure the clearance "A" at two or more points diagonally opposite with a feeler gauge, and then calculate the mean value.
Clearance "A"
Standard: 0.6 - 1.2 mm (0.024 - 0.047 inch)
Limit: 0.3 mm (0.012 inch)
2. Measure clearances "B" at two or more points diagonally opposite with a feeler gauge, and then calculate the mean value.
Clearance "B"
Standard: 0.6 - 1.1 mm (0.024 - 0.043 inch)
Limit: 0.2 mm (0.008 inch)
3. Press the baulk ring on to the clutch gear taper cone by hand, then measure the clearance "C" at two or more points diagonally opposite with a feeler gauge, and then calculate the mean value.
Clearance "C"
Standard: 0.7 - 1.1 mm (0.028 - 0.043 inch)
Limit: 0.3 mm (0.012 inch)
Bearing
Check the item listed. If necessary, replace it with a new one.
^ Damage and rough rotation of the bearing as shown.
ASSEMBLY
1. Install the reverse main gear using Tools as shown.
Tool number
A: ST35321000 ( - )
B: KV40101630 (J-35870)
C: ST38220000 ( - )
CAUTION: Install with the orientation of reverse main gear as shown.
2. Install the 1st bushing using Tool as shown.
Tool number
A: ST35321000 ( - )
B: KV38102510 (J-35870)
C: ST38220000 ( - )
3. Install the needle bearing, and then the 1st main gear.
4. Install the spread spring, shifting insert, and a new 1st-2nd synchronizer hub onto the 1st-2nd coupling sleeve.
CAUTION:
^ Install with the orientation of the new synchronizer hub as shown.
^ Do not reuse 1st-2nd synchronizer hub
^ Install with the orientation of coupling sleeve as shown.
^ Do not hook the ends of the two spread springs (front and back have two each) on the same shifting insert.
5. Install the 1st gear synchronizer assembly onto the mainshaft, and the synchronizer hub assembly onto the mainshaft using tool as shown.
Tool number
A: ST35321000 ( - )
B: KV38102510 (J-35870)
C: ST38220000 ( - )
CAUTION:
^ Outer baulk ring, synchronizer cone, and inner baulk ring on the 2nd gear-side must have been removed.
^ Install the coupling sleeve with the proper orientation.
6. Install the 2nd bushing using Tool as shown.
Tool number
A: ST35321000 ( - )
B: KV40105710 ( - )
7. Install the outer baulk ring, synchronizer cone, and inner baulk ring on 2nd gear-side.
8. Install the 2nd needle bearing and 2nd gear.
9. Install the 3rd main gear.
Tool number
A: ST35321000 ( - )
B: KV40105710 ( - )
CAUTION: Install the 3rd main gear with the orientation as shown.
10. Install the 3rd-4th mainshaft spacer.
11. Measure the dimension "C1". Select a suitable adjusting shim so that the dimension "C1" satisfies the standard dimension specification, and install it onto the mainshaft.
Standard for: 173.85 - 173.95 mm (6.844 - 6.848 inch) dimension "C1"
CAUTION: Only 1 adjusting shim can be selected.
Adjusting Shim
12. Install the 4th main gear with the specified orientation, using Tool as shown.
Tool number
A: ST33200000 (J-26082)
B: ST30901000 (J-26010-01)
CAUTION: Install the 4th main gear with the orientation as shown.
13. Install the 5th main gear with the specified orientation, using Tool as shown.
Tool number
A: ST33200000 (J-26082)
B: ST30901000 (J-26010-01)
CAUTION: Install the 5th main gear with the orientation as shown.
14. Install the 5th-6th mainshaft spacer.
15. Install the 6th main gear using Tool as shown.
Tool number
A: ST33200000 (J-26082)
B: ST30901000 (J-26010-01)
16. Select the 6th main adjusting shim and then install it onto the mainshaft.
^ Calculate thickness "S" of 6th main adjusting shim by procedure so that end play dimension between 6th main gear and mainshaft rear bearing becomes the dimension specified.
End play: 0 - 0.1 mm (0 - 0.004 inch)
Dimension "S" = ("S1" - "S2") - End play
"S": Thickness of adjusting shim a
"S1": Dimension from mainshaft standard face to mainshaft rear bearing press-fit end face
"S2": Dimension from mainshaft standard face to 6th main gear end face
CAUTION: Only 1 adjusting shim can be selected.
Adjusting Shim
a. Using a height gauge, measure the dimension "S1 " and "S2" as shown.
b. Install the selected 6th main adjusting shim to the mainshaft.
17. Install the mainshaft rear bearing using Tool as shown.
Tool number
A: ST30720000 (J-25405)
B: ST30901000 (J-26010-01)
18. Install the C-ring onto the mainshaft, and check that the end play of mainshaft rear bearing meets specifications.
End play standard value: 0 - 0.06 mm (0 - 0.0024 inch)
^ If the measurement is outside the specified standard value, reselect a new C-ring.
C-ring
19. Fit the C-ring holder, and install the snap ring as shown.
20. Check the end play of the 1st and 2nd main gears as shown.
End play standard values
1st gear: 0.20 - 0.30 mm (0.0079 - 0.0118 inch)
2nd gear: 0.06 - 0.16 mm (0.0024 - 0.0063 inch)