You should probably feel a little resistance - your brakes scrubbing lightly (as they should) will cause that. Only way to know for sure is to take a look, I'm not as experienced with rear ends on these as some of the other guys, but I'd venture to guess that if you don't find the problem in the brakes somewhere that you may be looking at a bearing issue. Hopefully someone with lots of experience like TahoeDawg will see this and confirm/deny.
