Jim,
I have explained this problem several times to Airpac/Skymaster and they never fixed the problem so... I came up with a fairly simple solution.

Drill a hole in the side of the trunion so that the hole enters the strut cavity centered. Tap the hole for a 4/40 set screw. With the clamp bolt loose, slide the stut into the trunion. Insert the 4/40 setscrew and butt it up to the strut, does not need to be cranked tight. Rotate the strut for correct wheel alignment and tighten the clamp bolt down. The set screw works like a shim and will lock the strut in place.
The other option.... I sell HD truinions from Sierra which are drilled a few thousands undersize. These trunions lock down on the SM struts without issue...
Todd