I know you like to keep going to the hyds system for some reason. it really really really sounds like you want to take your hyds apart.. so.. you might as well start there, as you mention it in each post.
once you get that done, then come back and we can talk about your tranny input shaft.
going down hill puts oil against the seal.. if the seal is bad.. that's when it leaks.
as to a bearing be bead.. that's conjecture. We KNOW a seal is bad because of the leak. We are GUESSING it is a bearing because of the bad seal, and metal. it could still just be a chewed up seal that was installed incorrectly that then wadded up and spun, etc... won't know anything till you get the bellhousing open to see the input shaft.
But no problem.. you go take your hyds apart and get that itch scratched.. then we can work on your input shaft.
So you're telling me I put that seal wrong or incorrectly...ok...guess I'll have to do that again. I'll be a professional, I've taken it apart two times already. This will be my third time.