nrpetersen
Curmudgeon
On reflection, I went back and listened again to the clatter in your video. My concern is the very premature failure of the original spline system at 19K miles. If this was caused by a radial engine/transmission misalignment (which I'm sure it is) there will be a lot of simultaneous wear on the rear crankshaft main bearing in the direction of the radial misalignment. Yours is one of lowest mileage failures I have seen suggesting the misalignment is very substantial. In the few bikes that have documented the oval crank bearing shell wear from a spline failure, the clearance has been ovality in the vertical direction. But that has been checked on only a couple of bikes. Very certainly, the rear crank bearing clearance was NOT checked on this repair. Why would the shop go looking for consequential damages even if they recognized the possibility?
Just maybe you are the first documented example of engine-transmission misalignment that is horizontal? and what we are hearing is a main bearing knock from horizontal main bearing clearance? If this is the case, the knock would be worse when the clutch is disengaged (handle pulled in) in which case the crank rear would no longer be supported by the transmission input bearing. But as I understand your postings, the noise is worse when the clutch is engaged (handle let out). In this situation the crank rear IS supported by the transmission input bearing which would be comparatively quiet.
If you remove the starter you can see the condition of the spline, and you could determine the clearance direction of the crankshaft.
But no way would I ignore this.
Just maybe you are the first documented example of engine-transmission misalignment that is horizontal? and what we are hearing is a main bearing knock from horizontal main bearing clearance? If this is the case, the knock would be worse when the clutch is disengaged (handle pulled in) in which case the crank rear would no longer be supported by the transmission input bearing. But as I understand your postings, the noise is worse when the clutch is engaged (handle let out). In this situation the crank rear IS supported by the transmission input bearing which would be comparatively quiet.
If you remove the starter you can see the condition of the spline, and you could determine the clearance direction of the crankshaft.
But no way would I ignore this.
