Front Driveshaft Clunk/Misalignment?

1989 XJ, 203K + miles, 5" lift, D30. I went wheelin' last December and possibly flexed too much and maybe pushed the driveshaft into the oil pan (?). There was a clunking in the front when I shifted into 2WD at the trailhead. I replaced the u-joint when I got home, no problem. Now I've only been on one light wheeling trip since then and that was about a month ago. This morning I drove to work and the clunk is back; the ujoint looks like it blew out the retainer clip again, had to pull the shaft in the parking lot.

Any ideas? Trackbar adjustment? Worn yoke?

Don't worry about the track bar - you should only adjust that if your entire axle is offset to either side an undesireable amount. Also, small variations side to side will not have There are a lot of factors that can make a joint fail. If the shaft is badly balanced, it could do this, although you should feel a vibration in it if it is that bad. Are you getting a vibration, or is everything normal until it all the sudden fails?

If a retainer clip comes out and it's not related to a break, it is likely it was not seated completely.

The retainer clips were seated correctly both times - I made sure with a socket and a couple taps of a hammer. The "shoulders" don't appear to be worn. Maybe just cheaply-made clips not in tolerance? Both were Autozone joints; the first a Brute Force, the latest a Duralast.

Upon further inspection, it wasn't the missing clips. Somebody tried to steal my wheels again. All the lugs on the driver front wheel were loose except the lock lug, and a couple lugs on the driver rear were loose as well. This is the side that is against a building when I park; this has happened before and there were "suspects" that people have seen lurking around the cars. My friend chased these thugs away from my XJ last week. I thought they were after my stereo again, but I guess they will take what they can get, and aluminum is up to 75 cents/lb now. I think I know where those cinder blocks came from...

13mm/half inch and 8mm box end wrenches, and I bet the u-joint doesn't give me any trouble until I slam the shaft into the oil pan again. Maybe I need to stack a couple more hockey pucks on the spring perches?