Transmission

[81'300d]

Newbee needs help. My vehicle is a 1981 300d with auto trans. I purchased the vehicle with the intent to restore the car. The problem is that the transmission shifts hard.

It seems from reading posts that this is most likely a vaccum problem. Seem to be the consenus that it is from the (what I call) black box on top of the engine.

However, the posts do not seem to address my specific problem which is that the vehicle will shift automatically but 1-2 is hard (will make head move) , 2-3 very noticable (will at times make tires chirp) and the reaminder are at high rpm.

If I let off the gas before the shifts the car will shift much more smoother if almost unnoticable. 1-2 by 10 mph, 2-3 by 25-30 mph and 3-4 at 40-45 mph.

Please help with this dichotomy is it a manual or auto?????

Also, the ac/heat, door locks, windows and other accessories (vac controled) all work properly.