1989 Rolex Datejust

Question

I had my watch serviced for the first time last year by EMW's Eric Martin. It only needed the winding crown replaced when I sent it in but he said it needed a inversor wheel as it was worn and could not be warranteed without it. It has worked perfectly until today when it just stopped running. Second hand won't move no matter how much it is wound. I have not yet contacted EMW but was curious if there was a part called a inversor wheel.Robert