Mainshaft

Fig. 4 Exploded view of mainshaft assembly:

1. Using suitable tool, support 2nd speed gear and push rear end of mainshaft to remove bearing inner race, gear bearing sleeve, 1st speed gear, spacer if equipped, 1-2 synchronizer assembly and 2nd speed gear.
2. Remove snap ring from front end of mainshaft.
3. Remove 3-4 synchronizer assembly, 3rd speed gear and needle bearing.

Fig. 5 Synchronizer ring clearance:

4. With synchronizer assembled to cone of each gear, ensure dimension "A," is at least 0.020 inch. If not, replace synchronizer ring and/or gear.
5. Inspect all components for damage or wear, replacing as necessary.

Fig. 6 Cross-sectional view of mainshaft assembly:

6. Assemble mainshaft as shown noting the following:

Fig. 7 3-4 synchronizer hub installation:

a. Install 3-4 synchronizer hub with smaller diameter side (A) of center boss directed toward front.

Fig. 8 Assembling synchronizer hub to sleeve:

b. Assemble synchronizer hub to sleeve so center tooth (T) between 2 missing teeth will touch synchronizer key.
c. When synchronizer springs are installed, ensure front and rear springs do not face in same direction.
d. Select and install thickest replacement mainshaft snap ring that will fit in groove.
e. Ensure 3rd speed gear turns smoothly.
f. After installing 2nd speed gear, 1-2 synchronizer assembly, and 1st speed gear, push bearing spacer firmly toward 1st speed gear and ensure 1st and 2nd speed gears turn smoothly.
g. Check all parts for free movement, then press center bearing inner race onto mainshaft.