I fastened the servo to the tray using 5 ea. AN3-7A (and one 10A) bolts, torqued to 25 in-lbs.
Next I installed the F-989 push rod that connects from the control rod and bell crank and got it all situated to length and torqued down. I plumbed the bellcrank vertical and then fabricated the push rod for the autopilot servo.
To drill the hole in the bellcrank, Trio said to measure the aervo arm from the pivot point to the cetner of the outer most hole, then use that dimension and measure from the center of the bearing on the bellcrank, up to the hole location. This gives you a 1:1 leverage factor and is what the autopilot gains are set for from the factory.
I used a series of washers to get everything plumb ans straight, the tough part was getting a washer down between the two plates of the bellcrank so I wouldn't smoosh it when the bolt was tightened. I out-smarted it thoug by using a magnet, through the aluminum, to drift the washer down inside, then stabbed a bolt through the hole and washer.
I torqued all the bolts and installed loctite and cotter pin on the servo arm.
