I took an engine repair class here and we got on the topic on fords. He said in some time era ford actually went to a yellow atf to avoid jerking when shift. But it was terrible for the transmission. Anybody anything about this, i was searching but i can't find anything about it and i was curious and wanted to find out more about it. Thanks

 

ATF is red simply because at the refinery a dye is added. The industry decades ago deceded on red to help indentify ATF if there was a leak, as opposed to power steering fluid, motor oil,brake fluid etc. It's possible an ATF that had a yellow dye did not mingle well ATF that had red dye and caused problems that way.