I'm rebuilding what appears to me to be a typical 9" with a Track Loc (clutch type limited slip) carrier. I didn't have a known leak at the wheel seals. I discovered one side was a little moist with
oil, when I pulled it apart. The axle surface where the seal rides shows some wear, but I think a new seal will hold.
I expect an axle tube could hold all the
oil that is in the pumpkin. In a long hard corner, most of it may end up there. Certainly the level at the ring a pinion is going to drop on any corner. I thought it kind of made sense to put them in.
I drive it on the street mostly. At the London show I usually take it around the auto cross course a half dozen or so times. I was aware the dirt track guys use these seals. I just wondered what the folks on this forum thought. Looks like there's not a lot of opinions out there. I guess most feel it is not needed. I expect not, no harder than I am on it.