if it were mine, I'd replace the bearings, you already did most of the work! new bearings , reshim, new seals, and you'll have a box that you KNOW is good to go for a long time.
the problem may be in the clutch, worth checking out since the tranny is out of the way, might as well check the main seal and oil pump o-ring as well since your there, replace if needed.
from the symptons you describe, it sounds like a bad input shaft bearing. I don't trust the old "hand" check method, you just cant duplicate the forces on a bearing by spinning it in your hand. I've had noisy ones that felt fine when I took them out, but after replacing them, the noise was gone.
oil on the clutch is gonna make the clutch slip, but I've never heard any grinding noises from that. worn rivets will make some noise though, but from the ones I've heard, it's more of a rattle, not grinding.
bikerfish screwed with this post 02-19-2013 at 04:19 AM