I found a couple of bike co-ops in the area, but nothing super convenient. It will be a few weeks before I can get there, so for now I'm on my own...

I checked the chain tension and I was getting a fairly consistent tension throughout all positions.

I realized I was getting the grinding even with the chain off, so on to the bottom bracket.

I was able to remove the non-drive side crank (unfortunately after stripping the crank threads) using a hammer to hit the crank as the bb axel was resting on top of a nail punch sticking up out of a 2x4.

I removed the lock ring and the bearing cup on that side and found that one of the bearings was ground up real bad--maybe 10% ground off, and badly pitted and deformed. I'm guessing this grinding bearing was what I was feeling and hearing.

The problem now is I can't remove the drive-side crank arm, because the screw is not centered in the crank, so I can't get a 14mm socket inside to loosen/remove it. With that in the way I can't use the crank puller (not even sure if it is the right tool for these cranks--I had such a hard time getting it in before stripping it). Also, I don't think I have the right tool to get the drive-side bearing cup out of the frame. It looks like I need a very large cone wrench to remove it.

Since I'll probably replace the cranks and bottom bracket at this point anyway I'm thinking to cut the screw so I can remove it with a standard screwdriver.

Any better ideas? Am I missing something?