I have a 1998 e320 with 188K miles and a 722.6 transmission. I have heard stories over the years that Mercedes made a mistake by saying these transmissions never need a fluid and filter change. I also hear "experts" say that if there is no problem with the transmission, don't touch it because changing the fluid could cause problems. So, who's right and wrong?? Please don't come up with a political answer and say both answers are correct. There is a slight slip from first to second gear, but if changing the fluid could make the situation worse I won't do it. How could these transmissions be so sensitive?? I don't get it. Does anyone have a good, logical answer??