I have a 2002 Dodge Cummins and George and his staff diagnosed my old diesel with a leak from the rear main. I paid Mr. Diesel for the repair and to my dismay I still had a leak. George brought my truck back in and said it was the valve cover gasket and was misdiagnosed. He said the valve cover gasket was going to be repaired free of charge as it was misdiagnosed. This might sound bad however, my truck to this date doesn't leak a drop of oil and has 130k on it. Good crew and very professional!