I cleaned everything and the place where it starts seeping out is the bottom of the extension housing gasket. I used my cheapo borescope to check all around and that was the only place where it came out. And it's not just a little, it's like a quart when the car sits for a few days. The housing of the slant 6 trans appears to be in good shape, so I will probably put a new seal in it and use that one - in case that was part of the problem.