You may wonder why I'm saying it's the crank seal and not the oil pan, despite the oil running along the pan's seam a little ways (as my friend suggested). There was a very light shine of wetness all the way around the crank. The other side's seal also leaks. And in the middle, no leaks. Besides, the oil pan service doesn't require my having the trans off, or even the passenger side CV shaft removed. Later problems.