I want to thank all of you for your useful input.........
I will stick to my old ways, install new filter and new Mercon V, the
fluid Ford recommends....
Thank you for confirming my thoughts on the trans back-flush.
I am not having any problems, just my normal transmission maintenance.
I do have a programmer installed, and I raised the firmness of the shifts.
It has lowered operating temperatures and increased my miles per gallon.
Thanks again, Ron