My differential has been leaking since I got my car. I finally got around to replacing the cover gasket and filling it with some redline. However, it has been less than a week since I did that and it is still leaking. It is not coming from the cover gasket. It is something further up towards the transmission. But I am sure the gear oil is coming from the differential. Is there another gasket of some sort up there that should be routinely replaced as well? I did not see anything, so if anyone has advice or suggestions I would appreciate them.