[rpduc]

According to some of the more experienced folks on this site there is no "official" adjustment procedure outlined in any of the service manuals.

The info I got was that there should be a "slight" amount of preload to hold the actuator arm against the stop. Not very scientific but that's all there is far as I can tell. There were some who reported excessive rattle from the powervalve might be corrected by increasing preload there slightly.

Makes sense to me, YMMV.