Rear Main Seal ?

[Insayn]

My 1976 Bronco had the engine rebuilt 2 years ago. It wasn’t driven much but the rear main started leaking. I figured I’d replace it while I had the C4 transmission out for a rebuild. On the rear main bearing cap I noticed a stud in the channel where the seal sits and that’s what caused then new seal to prematurely wear. When I installed the new seal it pushed up on it a bit and wouldn’t fully seal flush because of that stud (new seal has a metal ring embedded). Well….it’s starting to leak again. Is there a fix to this stud in the channel? I think I noticed in a Nashville Early Bronco video him grinding it off.

 

[jamesroney]

My 1976 Bronco had the engine rebuilt 2 years ago. It wasn’t driven much but the rear main started leaking. I figured I’d replace it while I had the C4 transmission out for a rebuild. On the rear main bearing cap I noticed a stud in the channel where the seal sits and that’s what caused then new seal to prematurely wear. When I installed the new seal it pushed up on it a bit and wouldn’t fully seal flush because of that stud (new seal has a metal ring embedded). Well….it’s starting to leak again. Is there a fix to this stud in the channel? I think I noticed in a Nashville Early Bronco video him grinding it off.

Welcome to the party.
The correct seal for your early small block Ford is a woven rope seal. That stud is an anti-rotation pin, and it is designed to penetrate the woven rope seal, and prevent "spinning the seal" on start up.

The knuckleheads at Fel-Pro decided that a 2 part neoprene seal was a superior seal, and it is certainly easier to install in-frame. But you have to fix the pin, because it is not compatible with the neoprene seal. (as you have discovered.) I used to grind them with a die grinder, but you have to be super careful not to nick the inside of the cap.

So now I drive those pins IN a tiny bit...then grind the the pin almost flush, and then drive the pin BACK. You always have to have something to plug the hole. Some people use a daub of silicone...but I don't. Just don't overdrive it into the pan end seal.

 

[Insayn]

Welcome to the party.
The correct seal for your early small block Ford is a woven rope seal. That stud is an anti-rotation pin, and it is designed to penetrate the woven rope seal, and prevent "spinning the seal" on start up.

The knuckleheads at Fel-Pro decided that a 2 part neoprene seal was a superior seal, and it is certainly easier to install in-frame. But you have to fix the pin, because it is not compatible with the neoprene seal. (as you have discovered.) I used to grind them with a die grinder, but you have to be super careful not to nick the inside of the cap.

So now I drive those pins IN a tiny bit...then grind the the pin almost flush, and then drive the pin BACK. You always have to have something to plug the hole. Some people use a daub of silicone...but I don't. Just don't overdrive it into the pan end seal.

Son of a b$@&#…guess I’ll be using a carbide bit to grind it down.