Mainshaft

Assembly Note
Clutch hub

NOTE:
a. The synchronizer rings all have the same basic shape; therefore, be careful to select the correct ones.
- The 5th and reverse synchronizer rings are the smallest.
- The 5th has notches in the teeth.
- The 4th and 3rd are the next size up and are exactly the same.
- The 2nd and 1st are the biggest and are exactly the same.
b. There are two types of synchronizer key.







Standard dimensions are as follows.




c. Press each clutch hub assembly onto the mainshaft in the proper direction.
d. Install the clutch hubs with the chamfer of the inner gear teeth as shown.






CAUTION: Align the synchronizer ring groove and clutch hub key during installation.




1. Place the 2nd gear and the 1st/2nd clutch hub assembly on a press, and press the mainshaft in.




2. Place the 3rd gear, needle bearing, and 3rd/4th clutch hub assembly in position, and press the 3rd/4th clutch hub assembly onto with the SST.




3. Fit the snap ring to the front of the mainshaft.




4. Install the 1st gear, and thrust washer.




Countershaft
Press the inner race of the countershaft center bearing onto the countershaft with the SST.




Measurement of bearing thrust play
Mainshaft bearing
1. Measure the depth of the mainshaft bearing bore in the transmission case.




2. Measure the mainshaft bearing snap ring height. The difference between the two measurements indicates the required thickness of the adjust shim.

Standard thrust play: 0 - 0.1 mm (0 - 0.004 in)

Adjusting shim thickness: 0.1 mm (0.004 in), 0.3 mm (0.012 in)




Countershaft front bearing
1. Measure the depth of the countershaft front bearing bore in the transmission case depth B.




2. Measure the countershaft front bearing snap ring height (A).
3. Choose an adjusting shim that will allow the difference between the two measurements to be equal to the standard bearing height.

(A) - (B) + Adjust shim(s) = 0.9 - 1.0 mm (0.035 - 0.039 in)

Standard installed bearing height: 0.9 - 1.0 mm (0.035 - 0.039 in)

Adjust shim thickness: 0.1 mm (0.004 in), 0.3 mm (0.012 in)




Transmission case
1. Position the 1st and 2nd shift forks and the 3rd and 4th shift forks in the grooves of the clutch hub and sleeve assemblies.
2. Install the needle bearing and main drive gear on the front of the mainshaft.




3. Position the countershaft gear in the case, making sure that the countershaft gears engage each gear of the mainshaft assembly.

NOTE: Check that the friction gear engages the main drive gear.




Bearing for transmission case
1. Install the correct shim on the rear of the mainshaft as determined in the measurement of bearing thrust play.
2. Drive on the mainshaft bearing with a suitable pipe.




3. Drive the countershaft center bearing onto the rear of the countershaft with the SST.




4. Install the bearing cover.

Tightening torque: 18 - 26 N.m (1.8 - 2.7 m-kg, 13 - 20 ft-lb)




5. Install the SST between the 4th synchronizer ring and synchromesh gear on the main drive gear.




6. Drive on the main drive gear bearing with the SST.




7. Install the snap ring to secure the main drive gear bearing.




8. Install the correct shim in the countershaft front bearing bore as determined by the measurement of bearing thrust play.
9. Drive on the countershaft front bearing with the SST.




10. Install the snap ring to secure the countershaft front bearing.

NOTE: Do not confuse the countershaft front and mainshaft rear bearing snap rings. The countershaft snap ring is smaller.