I've coasted after a pass in neutral for years and never had a problem. The material you are refering to in the pan sounds like band friction material. And since you said the band adjustment was way off I tend to think that enforces my thinking. If you can find the fine mesh type filter over the felt your money ahead. The felt type would cause a whine and usually worse in reverse when the fluid was strianing to be pulled thru felt. I had brand new ones do that!