Originally posted by InitialD
You can check if the clutch bell is warped. Spin in on the crankshaft with a new set of bearing in to see if it wobbles.
I'm surprise to hear that the crankshaft is straight after the incident.
I checked the bell, too. I mounted it as normal, so it was pretty near the clutch and span it - it seemed to spin smooth and straight and still does
But when I have a look at the metal shielded bearing nearest the engine end - it has been rubbing the clutch bell, as around its circumference there are three "rub" stripes, i.e. it has been rubbing the inside of the clutch bell - that should never happen. I think the hit bent the clutchbell or crankshaft to such a small degree that it is impossible/very difficult to see the resulting damage, but at +35,000 revs, the forces generated by the wobble caused the bearings to slowly disintegrate.