I have had 2 arb diff lock failures. Both times the bearing end carrier broke. In both instances I didn't have any prior warning of the impending failure, although running simex's makes these noises harder to hear.
It appears that the cause of my failure was a modification done by jacMac to machine the opening to allow fitment of larger axles. (this was before the factory 24 spline axle was released). As previously said the ARB lockers are usually very strong and I haven't had any drama's with the replacement lockers made for the 24 spline axle.

