charcoaldabs,

The bearings for the main shaft is probably your problem, there is one on the top of the main frame and one on the bottom, where the shaft goes thru. Just get your dremel out, or a file and remove some of the high spots off the top of the main shaft a little, until you can get the bearings off.

I had this problem today, I'm replacing a tail boom too. Take the whole thing apart, great leaning experience..

Dave Choppersrule