Transmission Question
 

'82 300TD Automatic Trans. 225k
Bought this car knowing trans. slipped in 3rd and 4th. Found a used trans with 140k on it. The guy installing it has about 200 / 123, 124 and 126's sitting around. He began tweeking the vacumn system and tweeked the slip completely out. He thinks I dont need the tranny transplant now. I drove the car home today and the car accelerates very slow. Once I get to about 40 it will run like a spotted ape. Its just getting the old girl to 40 thats bothering me. Before the vac. tweeking she would jump on 40mph quick. Now it takes along time 4-5 seconds to hit 40. If he tuned the vac. system to get the slip in 3rd to 4th out why is there no take off power. If I have not provide enough information, let me know and I will try harder. Thanks, Treeman:confused:

It looks like the wrong torque converter stall speed (to high) was installed in that car. If you think its vacuum, drive it with the modulator vacuum hose disconnected, as A test.

Do a stall speed test, only for a few seconds; to check the torque converter.
Diesel torque converters stall at about 700 to 900RPMs