Needing that much extra fluid after a fliter change AND that it is slipping and charttering means you have bad seals in the tranny. Probably from sitting around a very long time. DON'T drive it slipping or chattering!! IF the seals have dried out, you might be able to re-hydrate them by running the car in park witht he correct fluid for 10-20 minutes idleing. That will get lots of fluid on them. But usually once they have dried out they are not salvageable.