goanywhere

Hey guys, I recently ahd to replace my stock front axle with another from a junkyard (banged some mounting brackets up pretty good in the Sierras and couldn't get a good alignment done - time for a lift? )
The replacement axle was a dana 30, just like mine, went on beautifully, everything straight and all that. Problem is when I threw her into 4, one wheel seems like it's dragging (passenger side). I will try and coast along with all 4 wheels engaged and she kind of grinds to a quick stop. The best way to disengage the four wheel drive is to drive backwards for about 10 feet too. I'm thinking because it's a limited slip diffy something has gone funny under the pumpkin, but I wanted to see what anyone here thought.
U joint went on fine and tight, in case anyone is wondering, and when I had the axle out, I spun one wheel to make sure everything was ok and I watched the other wheel (or hub I guess) spin ok too, in the opposite direction, though not constantly. Maybe something isn't meshing then. hmm