Sounds right,armature broke and its riding around on the surface putting a nice grove .Youll need to drop the pan to retreive various metaLparts also if it is the vp.Try to gather all the evidense .I had this happen put the pump only lost the bearings and case,with no bearing it was eventually going to end up with a broken arm by wear,caught in time.Theirs around 12 small bearings in that case.