I have a 1995 SL500 with 27,000 miles and for some reason I can't find the oil leak. It came into my shop with the valve cover leaking because the customer had someone replace it improperly and it turned out to be a bad oil cap. I replaced the valve cover gasket and oil cap but I still have a small leak at the bottom of the bell housing. It's not the rear main seal. Anyone have any suggestions?