[racerx004]

Haven't had that problem my self, but a bent driveshaft seems EXTREMELY unlikely unless your doing some major off-roading. Probably just a bad u-joint. The drive shaft will look bent since it is not moving the way it should (if the u-joint is frozen then it will stay in one spot and not spin straight). Once you take it down you'll be able to tell which one it is.
I would fix the seal though cause if the fluid gets to low, and you put it in
4X4, that could bad news for the transfer case.