Squeaking noise under truck.

[rs74]

I had this squeaking start yesterday. First I thought it might have been front end related. I jacked up the front end and rotated the wheels and heard nothing. That might mean nothing since there was no weight on the wheels but that is what I have done. I got under the truck today and can spin the front drive shaft both ways freely. I noticed what seemed like the sound I am hearing coming from the front out put of the transfercase. I greased the ujoints just to make sure and no difference. Is there a press in bearing right there or what could be making that noise. Should the driveshaft be spinning while driving since I can spin by hand when not running?