For anyone that has installed a TruTrak AP, you know there are NO instructions, only a few drawings and the drawings don't call out how the washers are to be used on the pushrods that attach the bellcrank to the servo arm. I put a call in to TT this afternoon to ask some questions and I asked them about how the washers are supposed to be configured.
The large OD washer is designed to go on out OUTSIDE of the rod-end bearing. The theory being that if the bearing disintegrated, the washer would capture it and keep it from falling off. (He also said they've never had a single failure.)
Here is a picture of a correctly assembled roll servo, courtesy of Dave Parsons.
And here is a pitch servo installation, ala DP again. :-)
I've suggested that they update their drawings to reflect this because I found quite a few installations that were incorrect in my searching for the right way to do it.