C-182 pilot reported flight controls were difficult to move in flight. After landing; ground inspection revealed autopilot servo malfunction.

Narrative

I flew a short cross-country VFR flight on a bumpy warm afternoon. I engaged the auto-pilot and it seemed to operate properly. During descent I disengaged the auto-pilot; heard the auto-pilot disengagement alert sound and noticed that the yoke was difficult to turn to the left. In flight; I was focused on flying the landing pattern and attributed the steering difficulty to the current atmospheric conditions. I was able to wrestle the yoke and land safely. Upon subsequent pre-flight; I noticed that the yoke; when turned to the left; would seem to get hung up; such that you had to force the wheel to the left. I found a local A&P/IA at the airfield (ZZZ). He and I troubleshooted the problem and found that something inside the servo mechanism was broken. If you held the mechanism in your hand and turned it over; you could hear something rolling around on the inside... like a ball bearing or broken part. Upon removal of the servo; the controls moved freely (yoke + ailerons). The A&P/IA installed an overhauled; certified part from Company. We did not open the broken servo to see what had failed; since it was sealed with a certified inspection sticker (and because it would void my ability to get a credit for returning the 'core'). The part that failed is KS-271C; original equipment on my 1998 182S; recently purchased; with full annual inspection at the end of Month Year. So the part that failed was 25 years old. My concern is that this failure caused a potentially dangerous situation in which the primary flight controls are not fully operational.