I thought I had an engine oil leak, but my mekanic located it to right front output shaft seal. He said that replaceing the seal would not be a problem, but he thinks there is to much play in "diff bearing/cv flange bearing" and that's the main reason the seal won't seal and it would still leak even with a new seal.

He doesen't do transmission work so I got refered to another shop. Before I leave it in their hands I really would appreciate som more info.

So what needs to be done here??? It's on a 2000 S4 Tiptronic 120k

You mean its leaking from the rear prop seal? Thats not a transmission leak, its a differential leak. Replacing the seal will fix that with no problem. The only leak you're gonna see from the tranny is either at the pan or near the bell housing where the torque converter is. Changing the rear prop shaft seal is simple, play doesn't matter.

The leak is on the right output shaft that is going to the front wheel.

So the play will be inproved if the seal is replaced?? There was more play on the leaking side.

Oh its on a side? I've never seen anything ever leak from that seal, are you sure its not just grease leaking from the inner CV boot? Does the fluid look heavy and black? Or light and brown? That would make a very large difference. Play still doesn't matter that much, its designed to move in and out.

I just got the seal replaced on the right side front diffrential. I hope this will do the job.