O.K. I've followed every test procedure I could find on this site for tuning the tranny on my 83' 300D but my problem still exists. At low speed and light throttle there is a very loud clunk on the 4-3 downshift. At higher speed and heavier throttle it will shift really nice. I've tried backing out the modulator and it seems like it doesn't do anything. Is the modulator bad? Any ideas? Thanks very much!