This weekend was nice in Wi, 50*!!! so I was under my truck lookin at the exhaust and noticed oil dripping from the bottom of the bellhousing area. Looking around I seen that it's starting to seep out from the area between the block and the trans. I'm guessing it's the rear main seal taking a s***, becuase I've read they are troublesome in these engines. How much will it cost to fix (avg.) and if I let it go what problems am I looking at?