Lesson learned! Well once again my assumption that every symptom demands the most severe and complicated cause. After learning everything I could find out about our autolock hubs, ordering parts and a few tools, mapping out the procedure etc etc etc, it hit me that it seemed strange the hub just quit locking all of a sudden--no intermittent problem or any hint--which I'm sure they could fail like that but seemed strange. Also it was the left hub on a NY state X which usually everything gets crudded up and rusted worse on the rt side. I just pulled the left hub. Lo and behold after removing the retainer ring and pulling out the hub, I'm looking for the rubber o-ring. There wasn't one. I remember I had problems with the older retainer ring popping out so months ago I had changed the ring. Since I had serviced the hubs a couple of months prior so I didn't even think about pulling the hub to look at it again. My only guess is that the o ring got dislodged and was chewed up. Anywho-I put a new o ring on and wha laaa--ESOF is working just fine.