Just finished rebuilding a 440. Fired it up and I have a big oil leak between the engine and transmission. It was a two peice rear seal and I know the seal lip goes towards the inside. The oil plugs are all there, and I am making decent oil pressure, so I think the plugs are ok. If I managed to reverse one of the main seals how bad would it leak? The crankcase is vented, so there is no internal preassure pushing the oil past the seal. Any other suggestions?

Thanks,

Prob have to drop the pan & basic visual & see what the prob is. Good luck, oil leaks are always a pain

You have both the plugs or oil sender in rear of top of block tight? Valve covers okay?

It's none of the easy fixes. Pulled the transmission shield, its leaking between the engine and transmission.

Thanks,

I've got the exact same issue on my 383. Engine is fresh and rear main was leaking.I pulled the pan and main seal and found absolutely nothing wrong. Installed a new seal and pan gasket.Ran the motor for 20 minutes and everything was looking good. Shut the engine off and had 3 drips on the floor.It's better but not gone.

Ive been fighting the same problem since last summer with my new 440 in my Road Runner. Ive put 3 new rear main seals in it and each time seams ok till i drive it 5 miles or more then it starts leaving a puddle. I hate oil leaks and have stained my new exhaust with oil! I called Mancini Racing and bought one of the billet rear main seal retainers and the brownish colored seals. Put it in a few weeks ago and have about 200 miles on the car now and thats with a 4.10 dana so you know its winding up out on the highway and NO LEAKS!!!!!!!!!!!!!! My sugestion, call Mancini!!!

I have not done it yet but it's been suggested to somwwhat smooth the serrations as they were for OE rope seals and will cause probs w the neoprene seals that most of us go w. That might exp why alot of leaks start after a bit of run time