Long story short, about a month ago the rear end blew up in my '96 Suburban and took almost the entire powertrain behind the transfercase with it. Bad enough that the slip yoke snapped. Anyways, I'm 90% through swapping in a new axle unit and complete driveshaft from a junkyard. I pulled my old tailshaft extension off to check for damage to it or the output shaft, everything looked good so I put a new seal on and installed it. When I went to slide the new driveshaft in, it went about 1 and a half inches and then stopped. Could not get it in an further. So I took the old broken yoke and put it up there and was able to get it to slowly go with a little tapping with the hammer... didn't go for too long, just wanted to see if it would go. I messed around with it for awhile and finally decided to loosen up the bolts on the tailshaft and just cracking those loose was enough to get the yoke to slide in all the way with little effort. But when I tightened the bolts back down (between 30 and 35 ft lbs, my torque wrench sucks) the driveshaft was too tight to slide the back u-joint into the rear axle pinion flange. SO, I loosened the tailshaft and got it in place and tightened everything back up. Any idea whats going on here? I can't imagine the output shaft was bent at all, bearing looked okay... Maybe just the new seal being slightly oblong?