I'm a bit stumped on this one. I just got a rebuilt b18a installed in my 1990 DB1 and I have discovered an oil leak coming from where the transmission and block mate up. I took off the flywheel inspection plate to have a look, but the flywheel appears to be clean and oil free. If the main seal was leaking wouldn't the flywheel be soaked in oil? Judging by the way the oil is dripping, I'm doubting that it is the oil pan gasket (I'll try to post some video of it if needed). Opinions and advice appreciated....... TIA.

Here's some pictures :

 

hmmm i would like to know as im having the exact same problem. tried changing the oil pan gasket and no luck, still pissing oil from between the tranny and engine...

 

Oil pan gasket is squished out and is most likely the cause of the leak.

TIP: When installing the gasket, both surfaces should be absolutely dry, any oil on the surfaces will cause the gasket to be squish out as you can see in your pics.