Leaking Ford Nine Inch

Hi everyone, i have a 76 Nova street stock with a factory ford nine inch rear end from a 67/68 mustang.I keep having a problem with gear oil leaking into my brake drum on the passenger side. I have changed seals numerous times, i changed the axle, still no luck. I even took some advice and put a piece of folded leather down the tube and it still leaks. Does anybody have some advice or any tricks on what i could do to stop this? Thanks alot!!  

My first thought would be to check and make sure you're getting the right seal. Even though the catalog may list the part no. you're buying as the correct one, catalogs have been known to be wrong every now and then. Check the catalog to a few years before and after your housing and see if the seal part no. changes.

Also, make sure you're installing the seal correctly. On a non-flanged seal, if installed backwards under pressure the seal will leak. In addition to that, talking ot one of our Ford guys, herecommends puting a small bead of silicone behind the seal to help with sealing. He says the reddish coating on the seals isn't always trustworthy.

Second, I'd check to make sure the axle tube hasn't distorted or bent on your rear. This could explain why you're leaking lube into the brakes.