Not a transmission xpert but just had a bit of experience with a Porsche Automatic. My 740i manual seems to indicate that a bad pump would bring about all sorts of driving problems as in no shifting. I would get a second opinion quickly before he destroys something on your vehicle! If you were in South Carolina I could recommend a reliable shop. The front seal is a good bet on this problem as it is a common leak point. GOOD LUCK! Jim H.