Don't really know if that's what it's called but the one I put in mine keep tearing and leak. They seem to all be made of cork which is preformed into a bell shape and my wrench said he doesn't know if anyone makes these out of better material. Hopefully someone here will know.
I did a search and found some info but it sounded like guys were talking about a different part and pics posted or linked to didn't show any bell shaped preformed gasket.
I have to have mine replaced every several months. Can't afford to convert to open drive line.
Thanks for any/all replies
Mark