Originally posted by Auditor_Kevin:
As far as fatigue being a factor - I've only had the mounts for a year, so we're talking about probably a dozen or so uses. I take the mounts off when not hauling my kayaks.
Perhaps taking them off and on over a period of time weakened the threads or something? I believe the mighty mounts are meant to stay on there for a good long time. I have had a set on my rack for ages without any sign of abnormal wear or breakage. Good luck.