Our airplane is a Cherokee 180 C. Both first servos that were replaced and were definitely on the list. The installation was the first generation GFC 500 and they knew there was a problem. The later servos were also flagged and were replaced for free despite being out of warranty.
There is a revised installation design (involving cable routing around the pully), but we called Garmin and they said we were ok with the original. We will look at that closer now. We're also looking at the static system closer because it's old plumbing. I don't know which servo failed this time because we haven't analyzed the mini yet. but the last one that was replaced was the pitch servo and thats got about 30 hours on it since the replacement. Originally, I also had 1 of the G5s fail. They replaced that too. The heading "wandered" and the GFC 500 would fail. There's redundancy because of the 2 G5's so flipped the HSI/DG to the Attitude indicator and the auto pilot came back on line.