Here are some observations and an idea but please be aware that I have only seen pictures of this set up and never had my hands on one. My experience is with Velocette motorcycles and in 50 or more years I have never had any problems with this design of Cush drive. The Velocette engine breathes through the drive side main bearing giving a continual oil mist to the heart of the Cush drive in the primary chain case. this is just one of many areas which leak oil and if there is no leaking then the primary chain case has to be drained of oil occasionally.
The trouble with grease is that it does not easily return to a mating face when it has been scraped, squeezed or pressed out. Add to this the centrifugal force effect which causes the grease to be thrown to the outside of the cylindrical housing leaving any air to collect in the middle, where the bits needing lubrication are and you see that it is a very difficult thing to keep lubricated.
If an oil slot were cut across the face of the splined sleeve where it butts up to the shoulder of the crankshaft then the engine would breathe along the splines delivering a small but continuous flow of oil to the centre of the Cush drive mating parts - right where you need it. You might also need a hole or two drilled at the bottom of the splines, half way along, to let the oil spray out directly between the two cam faces. The down side of this would be the need to drain it off regularly but this could be done by replacing the grease nipple with a drain plug and no more onerous than regular greasing? Would the assembly be sufficiently oil tight to keep the oil in till you drained it? - don't know. Be aware of the balance issue if you replace the grease nipple with a drain plug.
On the subject of balance, I note that your alternator rotor has been balanced ( row of drilled holes round one side). If the whole assembly was balanced together and your rotor turned independently when it's splines failed this could have caused problems.
All conjecture really but I hope it gives you some ideas - that type of Cush drive works on so many motorcycles I can see no reason why it won't work on the M3W - just needs some thought.
Good luck
Phil
Last edited by Phil Bleazey; 19/10/19 08:12 AM. Reason: more info
