Hi Barry. What’s the problem and are you talking about the Elevator Trim? If it’s just really stiff, the easiest solution is to lube the control, starting at the cable right behind the panel. Start with SeaFoam DeepCreep and then use LPS spray.
If you’re talking about the Aileron Trim then it may be just the spring. that need replacing. They’re under the front seats.
Hey Dean, It’s the elevator trim and it doesn’t trim all the way, My mechanic thinks it may be jumping a cog in the control box but we haven’t taken the control box out and apart yet. He says notices a slight ‘bump’ when adjusting the trim control on the ground. In the air I was not able trim all the way down, ie had to hold some constant down pressure on the yoke in cruise after adjusting the trim all the way to the stop. I have looked at the control box from under the dash and it looks like to me there may have been some previous repairs where the cable attaches to the control box at some time in the past.