In the morning after starting and backing up my car (1993 600SEL w/ 720.45 auto trans) my transmission leaks oil about 1/4 cup. When put it in drive and subsequently in reverse it does not leak. The transmission shifts smoothly. If I start in the morning and go into drive there is no leak. The transmission fluid level is correct. The leak appears to be coming from the torque converter area. The drain plug on the converter is not leaking. Because of the quantity of fluid leaking it appears to be a purge. Is there an overfill protection circuit in the transmission that could be faulty?

John