Autopilots

[side241]

I have a 400A in my T377C. The thnig has worked on navigation, but alt. hold never really worked well. I just attributed the alt. hold problem on simply being the best technology offered in 1968 (but maybe I'm wrong, please advise). But recently, it started to only hold a course intermitantly, because the center manual turn knob seems to not release control of the rolling axis even though the knob is pushed in. For a while, if I jiggled the knob the AP would navigate again, but not anymore. I live close to SoCal, anybody have any recommendations on having it repaired? I fly single pilot IFR often, and would love a reliable AP, but it seems S-Tec did not get an STC for the TURBO 337C, just every other model of 337. All input appreciated,
Ben