I've been a big ford man for years & have always loved the older mercedes se models. I purchased a 1977 280 se for almost nothing with 140,000 miles on the clock from a dear old lady & it ran very well for 6 months but now it won't move. The tranny oil is clean & its full. A friend towed it home & the engine was running so i put it in drive to see what happened. Around 20mph the tranny started working but when i slowed down it appeared to be in neutral. My guess & i'm only guessing is that it is either vacuum problem, o ring or maybe the governor. I've also considered the torque convertor but feel its unlikely because it made no noise at all, it just wouldn't move when i stopped the car. I would appreciate any help I can get.