First, thanks to all of those who replied.
There's a special washer that goes between the bolt and the pulley. This
washer was bent in so that it was touching on the outer race of the bearing,
causing a squealling noise. I could tell it was touching by the witness
marks left on the back of the washer. I put the bolt through the washer and
positioned it on a vise so that it would bend the washer where the witness
marks were when I hit the bolt head with a hammer.
There was still a small squeal that went away when I sprayed silicone spray
on the back of the belt and I saw the surfaces on the idler and water pump
pulleys clean up to bright and shiney (both driven by the back of the belt).
I then sprayed chlorinated brake cleaner on the belt and pulleys to clean
the silicone off. After letting it set so the brake cleaner could evaporate
I replaced the belt with a new Gatorback.
Best Wishes to all,