I currently have the rear cover off of the truck, and have drained the old oil. I am not able to feel any unusual movement in the bearings, and see no evidence of metal in the oil. I am waiting on a cover gasket, and will put her back together later this week with fresh oil, and see if that makes any difference. If that doesn't work, I also bought a new center support bearing, and will install that as well. We will get to the bottom of this sooner or later.