What still surprises me is that the jerking is not/ barely (in 3rd gear) noticeable in the 1st, 2nd, and 3rd gears!
The point machine doesn't care
which track you are on.
Hmm, strange. What is the speedometer doing, and is it working correctly?
Try adjusting the speed limiter on the transmission and see if that eliminates the jerking.
The speed limiter is located above/to the side of the differential (at least in my A3, manufactured in 7/9).
Sure, I can try. I'm open to anything, as long as I don't have to disassemble anything that I won't be able to put back together.
Does the GRA also receive the signal from this transmitter? It actually works quite well, and the speedometer also works (and now lights up in the most beautiful blue ).
But I'll just put it aside for now...