sanity check,
My rear diff is leaking and i was momentarily confused by this lingo. Is this right?

Output shaft seal - goes in the differential
Audi Output Shaft Seal - Genuine 01V409399A | FCP Euro

axle shaft seal - goes on the actual axle
Audi VW Axle Shaft Seal - CRP 018409399 | FCP Euro

 

Be careful. I don't have the numbers on hand, but just a few weeks agree I dealt with same thing. Orderedfrom fcp too. They gave me a seal that was much to small. And it's been said before, but I'll say it again. Remove fi'll plug first. And axles don't need to come out. Unbolt FRom rear diff, jack up which ever side your working ons corresponding wheel. With some wiggling it comes right out. Driver side other kinda helps to remove a few exhaust hangers and lower the exhaust a little