aw4 tailshaft, bushing?

My xj is a 99 sport 2wd, 4dr model w/ 89k miles. Very little maintenance has ever had to be done. For some time I have noticed a high speed vibration in the front end, thought the tires needed to be balanced. The other day on the highway it felt like my u-joints were going bad. Checked 'em out, they are good. Checked the rear end, no problem. It seems to have some movement at the transmission tail shaft and that rear seal is is leaking (don't worry, been checking the fluid and the level hasn't budged). My problem is that I cannot find any thing having to do with an AW4 tail shaft bushing. Is there one? Or is the slip yoke the problem? I have great axcess to parts suppliers and lists, and for the chrysler tranny they sell the bushing and seal as a set. But AW only lists the seal. HELP! I want to fix the problem before it mushrooms. Can't really afford to tear into it without knowing what to expect, know what I mean?

use it as an excuse to do a 4wd swap

You will need to go to a transmission parts wholesaler to get the bushing for the extension housing. I was able to get them from toyota years back, but forgot what toyota model it was for... Maybe just search the wrecking yard for another extension housing... I hope this helps...

Scott.

I do have a 4wd swap in the plans for it.
So you think I should just switch out the whole rear extension? I was hoping to just do the bushing and seal. How in depth would that be, I wanted to take care of this myself if possible. I guess what I really need is a diagram of the tranny to see what I'm in for.