Correct me if I'm wrong but shouldn't there be a bolt and washer holding the auxiliary pully on?
The last time I removed that pully was 2013 - see below
It looks like it has sheared off. That bolt isn't really under any strain so maybe I over tightened it and cracked it but didn't realise and in time it has fallen off.
I always tighten bolts to the torque specified in the service notes so can't really understand it. I think I have been driving with it like that for a while. Doesn't look like a new break

Question now is what do I do about it
