Tranny issue on 98 XJ

I went today and checked out a 98 XJ with 115k on it. When I went from reverse to drive, it clunks kinda bad, but it's only going from reverse to drive. When going from park to drive or from drive to reverse, doesn't do it. Anyone have a similar problem? I am really set on this XJ, but that's the only thing that is holding me back. BTW if it matters, The guy had a skyjacker 8" rock ready and kit and SYE professionally installed. The SYE looks like a AA but the driveshaft has a slip joint in the middle. Any help for the newb would be greatly apperciated

locker? My Powertrax No-slip makes some bad noise when going from reverse to drive.

The guy told me that the internals have never been touched in front or rear diffs

More than likely just slopp in the rear end. My 2000 does this too, and to keep it from happening I will put the trans in N just before I come to a stop. Then put it in reverse, or drive. Being a forklift driver however I do sometimes find myself putting it into the oppsite direction while still moving a little bit. I also drive with two feet, and sometimes turn the left blinker on before I back up.:dunno: