UrS4boy

There are five possibilities:

1. Transmission fluid leaking past the input shaft seal
2. Engine oil passing through the rear crank seal
3. Clutch fluid (actually brake fluid) leaking past a failed slave cylinder.
4. Loose bolt machining a hole through the bellhousing and into the transmission, letting tranmission fluid into the bellhousing
5. Dual Mass Flywheel Failure, letting its grease out.

All the the following PNs refer to the S2, the UrS4/S6 and the RS2.

The transmission input shaft seal is PN 016311113B



It lives behind the Item 20 "guide sleeve" in this diagram:



And the guide sleeve is behind the Item 16 clutch operating arm:



Here is the transmission input shaft with the clutch operating arm and guide sleeve removed showing the input seal buried deep in the transmission housing, just inside the triangular boss for the guide sleeve attachment:



Here is a photo of a leaking transmission input shaft seal that leaked enough transmission fluid to cause the clutch disc to start slipping even though the clutch was relatively new.


Photo Courtesy of Juvkam78 here.

Here is the input shaft seal, as sold by ECS Tuning:


016311113B - Input Shaft Seal - ES#258771

The Crank Seal is Item 7 "sealing flange" PN 068103171F which is both the frame holding the seal and the seal. Both the 068103171F and the separate seal 068198171 (no frame)(85 x 105 x 12mm) can be purchased separately in the aftermarket (ebay, FAP 99, etc).





Just the seal, PN 068198171, from FAP 99:



eBay sealing flange (photo courtesy of Yodafro)



And finally the Slave Cylinder, Item 30, PN 4A0721261





Here is a photo from "rxl" showing Failure Mode 3:





Brian C's slave cylinder installation