Is it normal to shift abruptly when the engine is cold or when you put your foot down on it? My wife jumps out of her seat when that happens and kinda makes your heart stop for a second. I just had a major service done at MB, the transmission oil changed and vacuum system checked at MB. They found a problem with the vacuum system and corrected it which has fixed it slightly. I also took it to an independent transmission specialist who said that the autobox was in fine but there is a problem with the vacuum system, he said to take back to MB and get it checked. Back at MB they said there is nothing wrong. Has anyone got any suggestions or has had similar problems?