rear main seals

[snake]

I would guess that it leaks behind the flywheel and down onto the bendix gear that is an inch or less away from the flywheel?

 

[thegoat4]

You wouldn't be able to feel the play in the crank. The only way to tell for sure would be to dissassemble the engine and plastigauge it.
When you pull the old main seal, inspect it for problems. Check how tight it fits the crank. It could be a seal problem because it is hard to buy quality parts anymore. The new one will probably be made in China.
I've never seen a Ford starter that didn't have a drain hole. It is at the parting line between the nose cone and the main housing. It is usually plugged with clutch material (on a manual).

Well, if it's crankshaft play that's beating out seals, you could feel it. Put a dial indicator at the back of the crank to check up/down movement and lift up on the end of the crankshaft. There isn't a spec for crank vertical play, but the crank journal runout limit is 0.005" IIRC. That would be a practical upper limit on what the seal can withstand.

 

[Psychopete]

Sometimes the crank needs sleeved. The machine shop I dealt with when I was rebuilding my 2.9L had mentioned something about doing this to my crank, apparently it's not uncommon for the 2.9.

I didn't since it didn't seem grooved, fortunately I don't have any leaks now, but I guess there's the chance that it will leak later on because I didn't. I did use a felpro rubber real main seal.

Apparently they're kind of a PITA to install.

If it were me, and I knew for sure I was swapping engines, I'd probably just try and replace the seal itself and throw it back together. If it fixes it, great, if not, oh well. But on the other hand, I don't know how bad it's leaking...

Just something to look into..

Pete