So yesterday I pulled my AW4 and T-case in my 2000 XJ because i had a broken flex plate, replaced that and my CPS and everything lined back up pretty smooth when re-installing. Now im hearing something between a clicking/grinding/clunking noise only when driving making a slight left turn. Problem doesnt occur when going straight or right. And when i was making sure my 4WD worked a few min ago, when i turned left in 4H going maybe 2 mph the steering wheel bucked and would not make a smooth turn from the front. Made a “woosh clunk” sound.

do you think this could be my front DS or DS U joints thats causing both of these issues?

 

 

Probably drive shaft u joints, trans mount, cross member, or possibly even the exhaust

 

Is it possible you didn't reconnect the transfer case shift linkage correctly?

Sure it's possible that the u-joints are bad, but is it more likely that A - The u-joints suddenly failed at the exact same time you pulled the tranny or B - Something you did or didn't do when pulling the tranny caused the problem that happened immediately after you pulled the tranny.
I'm not trying to be a jerk, just offering perspective.

I would go back and think about the tranny pulling process and think about any point where you had trouble, or "forced" something or something didn't line up right when going back together. One or more of those areas are where I'd focus.

I don't know much about autos, but you have some symptoms like the transfer case is "off", like it isn't fully at the right setting or you didn't tighten something down fully in the mount/driveshaft area... likely on the front shaft.

 

 

Prediction - your buddy installed the front driveshaft backwards..

Seriously though, good luck with it and don't forget to report back if you guys figure it out.