View Full Version : Tru Trak pitch servo install question- RV-7

04-09-2018, 11:07 PM
Got a used Alt Hold setup going in my RV-7.
Wondering about the bolt direction for the pushrod onto the elevator bellcrank.
The bolt head faces toward F-728A Bellcrank Channel.
Seems if the nut ever dropped off and the bolt began to work out, it could extend out to the F-728A channel and then extend past in the up elevator movement and possibly lock things up. (yes, better with a picture).

The Vans plans have the bolt for the top pushrod going the other way with the threads facing the F-728A channel.
Any reason why NOT to switch the servo pushrod bolt around on the bellcrank?

04-10-2018, 06:57 PM
It can go either way.

04-11-2018, 09:08 AM
Consider replacing the nylock nut with a castellated/cotterpin setup so you won't have to worry about the nut backing off.

Ralph Inkster
04-11-2018, 01:14 PM
Don't forget to put a spacer washer in the bellcrank so the bolt doesn't deform it.

04-11-2018, 02:28 PM
Ralph, yup got the washer in. Went almost too easy. was expecting a few drop-&-finds with the install.

Raymo. I thought about a castle nut and cotter pin. Just wasnt wild about having to back off the torque if needed for the pin line up.

Thanks for the replies.

04-12-2018, 07:16 AM
If you can get the correct torque and install the cotter pin, fine. If you can't, use a self-locking (nylock or all metal) nut. Rod end ball joints must have the ball captured so the ball rotates in it's race. That's why self locking nuts are acceptable for the control surface hinges. There is no rotation at the bolt.