That is usually a pretty good sign that it is a rear main seal leak, assuming that you have a rear main seal. As you will see in the tech post, you have to remove the pan for starters, to replace it. I tried the method in the post and I could not get the old one out. I read about another method of removing the tranny, ( I would think clutch and flywheel) all the main bearing caps (that means the front cover too) and pulling the crank down some as it is still suspended by the rods. I think that would work for sure.
