wings rock when Auto pilot engaged

[georgeb]

Evening all,

I've started getting a rocking motion when activating my King Autopilot. Regardless of mode, Nav, or HDG, as soon as I activate it the elevators start an up and down motion that causes the wings to rock. It's relatively smooth and switches back and forth between wings about every second. Still tracks well, but what started out as an occasional rocking has pretty much turned permanent. Any ideas out there would be greatly appreciated.

Thank you

 

Edited August 30, 2018 by georgeb

[ArtVandelay]

It might have lost the signal to it’s AI or TC(STEC) that tells it it’s attitude so it doesn’t know when it’s level.

[Eraaen]

I've only had this problem in extreme cold temps at high altitude.  It's only happened twice, and I mean COLD, and at 23/24k.  Both times, if I just held/steadied the yolk the problem disappeared.  I wrote it off to extreme cold air effecting the auto pilot combined with thin air.  But, I'd love to hear if this is something else I need to be concerned about.