I have an 83 300d with the same problem. I disconnected the vacuum control valve, on top of the valve cover gasket, and plugged off the lines and the 1-2 shift is MUCH better. I am thinking that I have a vacuum leak in the plugged off line somewhere. Now I need to find out what all I just disconnected. I would love to just leave it all unplugged.

Before it felt more like I have been rear ended than a 1-2 shift. Now it's like it should be, firm but right for this stodgy old car.


Jackson