I have a tendency sometimes to be blunt but i would never intentionally insult anyone. so maybe we could start over.

This expansion theory that is being kicked around in this post is way off base. A steel pushrod 3ft long will grow by .040" with an increase of 200 deg F. I doubt the pushrod in question is anywhere near that length. For the sake of this discussion let's say it is 6" long. That pushrod would get longer by .007" if the temp rose by 200 degF, one turn on the clevis would make it change more than this. A rise of 200deg is doubtful because if we started with an ambient temp inside the fuselage of 100 deg F a final temp of 300F would be burning paint off. Another thing that shoots this theory full of holes is that glass has nearly the same coefficient of thermal expansion as steel so any rise in temperature that would lengthen the pushrod would also lengthen the fuse and everything inside it.

now back to a more plausable explanation for aptor's problem.
Some people have had problems with gyros in there jets drifting. Bob Violet recommends that you warm the gyro with a heat gun to note the drift. I would suspect that servos also have a temp range during certification and that temperature outside that range might affect the servo similar to the way it does a gyro.