Late Shifting on 380sl 107

Ever since I gunned my engine and activated the automatic downshift while entering a hwy a few days ago, my 81 380sl has been shifting
late from 1st to 2nd . If I'm not mistaken, it used to shift at about 2000 RPM during light acelleration, but now its not shifting until it about 3200 RPM.
It happened once before a few weeks ago under the same conditions, and eventually went back to normal. So I'd like to find out what's going on.
The kickdown switch is up and seems to be OK, but I understand that there's 1) a solenoid on the tranny that can stick, and 2) a ball and rod somewhere on the engine that can be used to adjust the shifting, However, I don't know where either are, and my CD isn't working properly.
Can anyone tell me exactly where to look for these parts and/or the number of the file on the CD, since I can read it if I can find it.
Thanks a lot in advance.
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