Thanks for another great answer, Pat. I see both sides of the argument. Based on what you wrote, it seems to be that if you change your transmission fluid regularly (well, let's say every 20K miles), the use of a flush machine should be OK. But then again, if you change it that often, well, you probably don't need to be doing it with a flush machine anyway. Yep, there sure are two sides to *that* story!