Lower Main Shaft, Dismantling and Assembly

Lower main shaft, dismantling and assembly

To dismantle
1. Remove the gearbox.
2. Remove the gearcase.





3. Remove the input shaft, lower main shaft and gear lever shaft, 1st/2nd -5th/6th .





4. Remove 6th and the conical roller bearing inner ring. Press off using KM-DT 46773 (87 93 069 Support, to remove, upper main shaft) and DT-46754 ( 87 93 028 Drift, removal of main shafts). Remove 6th and the conical roller bearing outer ring and needle bearing.





5. Remove the shift sleeve to 5th/6th. Remove the shift sleeve, baulk rings and thrust collars.





6. Remove the circlip on the synchromesh assembly 5th/6th with KM-396 or 87 90 180 Pliers.





7. Press off 5th with DT-46756 (87 93 036 Support, to remove, lower main shaft) and DT-46754 (87 93 028 Drift, removal of main shafts). Remove the needle bearing, 6th, baulk rings and synchromesh assembly.





8. Remove 2nd by removing the circlip. Remove the split thrust washer.





9. Remove 2nd with needle bearing, baulk rings, shift sleeve and thrust collars.





10. Remove the circlip on synchromesh assembly 1st/2nd using KM-396 or 87 90 180 Pliers .





11. Remove 1st. Press off with DT-46754 ( 87 93 028 Drift, removal of main shafts). Remove synchromesh assembly 1st/2nd, baulk rings, roller bearings, 1st, and roller bearings.

Assembly





1. Fit 1st and synchromesh assembly 1st/2nd. Fit lower roller bearing (black) and upper roller bearing (white) in 1st and assemble.

Note: down the fitting position, always with the flange (arrows) pointed inward.





2. Fit the baulk rings and the synchromesh assembly in 1st. Check that the gears are fitted correctly (arrow). Hold together the synchromesh assembly and 1st and at the same time press on the lower main shaft with DT-46759 or 87 91 204 Sleeve, bearing race.





3. Fit circlip, synchromesh assembly 1st/2nd. It is important that the circlip is fully engaged. Fit a new circlip with KM-396 or 87 90 180 Pliers.





4. Fit 2nd by fitting the shift sleeve, fitting the thrust collar in the shift sleeve and fitting the baulk rings in the synchromesh assembly. Fit the needle bearing. It is important to check that the gears are fitted correctly. Fit 2nd on the synchromesh assembly 1st/2nd.





5. Fit the split thrust washer by fitting the split thrust washer with holding lugs (arrow) in the lower main shaft. Fit the circlip.





6. Fit 5th and synchromesh assembly 5th/6th. Fit the needle bearing on lower main shaft. It is important to check that the gears are fitted correctly. Fit the synchromesh assembly and the baulk rings on 5th.





7. Hold together the synchromesh assembly and 5th and at the same time press the lower main shaft with DT-46759 or 87 91 204 Sleeve, bearing race.





8. Fit the circlip for synchromesh assembly 5th/6th. It is important that the circlip is fully engaged. Fit a new circlip with KM-396 or 87 90 180 Pliers .





9. Fit 6th by fitting the needle bearing on the main shaft. Fit the shift sleeve on the synchromesh assembly. Fit the thrust collar in the shift sleeve. Fit the baulk rings in the synchromesh assembly. It is important to check that the gears are fitted correctly. Fit 6th on the main shaft.





10. Fit the conical roller bearing inner ring in the gearcase side. Press on with KM 6120 or the pipe from 87 91 261 Puller, pinion





11. Fit the input shaft, lower main shaft and gear lever shaft, 1st/2nd - 5th/6th. Fit in the shafts together.
12. Fit Gearcase, seal .
13. Fit Gearbox assembly .