So I went out this morning and pulled the valve covers. I was checking the adjustment nuts for tightness and this one just about fell off. Notice the different color of the rocker arm too.
IMO (I've posted this before but have been poo poo'd but I'm going to say it anyway) if you have the adjuster so short that the nut is loading the adjuster where the tool goes in (I can't think of the name of what to call it) it will break the adjuster.
Said in simple talk, the adjuster is too short. The lock nut is pulling on the adjust exactly at the bottom of the adjustment hole. It will fail on a regular basis.
