Trim Problems - solved

[Emmet]

I just want to share my experiences with a partially stiff trim which only occured during flight.

During the last year we were chasing this problem and worked mainly on the jackscrew (changed bearings etc.).

While installing a GFC 500 we found what I am pretty sure was the source of the problem:

the torque tube runs through a needle bearing below the trim servo and this bearing was completly dry 

and didn‘t move at all. So don‘t focus only on the jackscrew, but give this bearing a little attention and make 

sure it runs freely and lubricate it regularly.

[carusoam]

Emmet,

Got a pic of the area/part/location?

Best regards,

-a-

[Emmet]

I am currently on holiday, but will make a picture and post it here when I am back

[PT20J]

It's in the tail immediately aft of the avionics tray. It's the carrier bearing to support the trim torque tube at the point where the trim servo sprocket attaches. I believe it's a Bendix-King part. The maintenance manual calls for yearly inspection and lubrication (but I think it's often overlooked).

Skip

[Yetti]

Check and clean and regrease the chain.  Clean and lube all ujoints