[Keith True]

I think George is right.There really isn't any other reason for a pulley to break like that.Just why it was loose I don't know.Ratchet threads bottom out?Burrs,so when it felt tight it really wasn't?Probably a few other reasons for it to be loose.If you look at it real close with a magnifying glass you are going to see a shiny ring at the very end of the bore,on the engine side.Then,on the bolt end you are going to see another one where the crank ended.Without seeing the pulley I am going to venture a guess that you will also see an imprint of the hex of the ratchet on the face of the pulley.