Hi,
I have read some previous posts on this subject, but I just wanted to clarify a few things. The shims are only used if there is lateral movement of the pitch and aileron bell cranks. There should be no lateral movement of the the elevator bell cranks as they will be pressed and tightened together against the frame. If a shim has to installed I take it is is the last thing to go on shaft before you put the screw in? Last question, if you do need to file the threads of the balls of the bell crank is the best thing to do to remove the balls from the bell crank first and put a nut on the ball and then file?
Cheers,
Ali