Hard downshift when warm, 96 C280

[forp]

'96 C280, 165,000 Miles
150,000 miles on it when I bought it. Had my local indy do the 150K service
which included the tranny fluid and filter. Thanks to the many threads I found here
I learned how to adjust the Bowden cable and the vacuum modulator so that it shifts just right. However... The 4-3 downshift is uncomfortably sharp sometimes creating an audible thunk but only after it has thoroughly warmed up. When cold the 4-3 shift is as smooth as can be. All other up and down shifts are great. It also did this before I did the tranny adjustments. Cold, great, warmed-up, bad.
Thanks up front for any help.

Dan

[Oz 300te]

How did you go with this I have the same issue in a 300te, the previous owner thought it was the 3-2 shift that was thumping but he was wrong it is the 4-3 shift.