Tonight I modified my Axiom Journey Adjustable 2429 Rear Rack.  I put two additional 5mm bolts into the adjusting rod, making my rack permanently fixed in this position forever.  I drilled and tapped the solid aluminum rod with surprising precision.  I put lock washers on and used blue thread locker to keep the rack in place.

The rack shook itself loose after a few hundred miles.  I did not purchase another rack because no other rack can carry 110 pounds for the same price as this rack (I like that it's overkill for touring).  I was very lucky to have discovered the problem before I had any serious accident.  My LBS mechanic said that he has seen similar problems on Axiom racks.

I have no idea if this is a repair Axiom would ever recommend but I think my logic is sound.  It seems inadequate to hold the adjustment in place with only one bolt.  I doubt I will have any more problems.....comments?