In Reply to: Re: Main bearing clearancing posted by Tom Foster on December 10, 1999 at 16:41:29:
Your advisor is correct regarding sand paper of any type. They were originally serviced with a babbit scraper. I've done it succesfully but couldn't really give you a step by step.
I would suggest checking a little further. The bluing is a good idea as you can learn much from the pattern it will provide. Also see how much loosening of the bolts is required for it to spin freely. If it only requires a little then the shims could be bad from overtorquing.
This may be a long shot since the rear main cap is strong and well supported, but I've seen this problem with rods more than once. See the image regarding rods.
I don't check in here often so email me if it looks like we are headed in the right direction.