After much research and reading I have decided to do tranny fluid flush descrbed so well and often on this site I have put this off so long because of all the old tells if this was done on a hi-milage rig it would surely cause tranamission problems. My question today is has anyone used Valvoline Max Dextron/Mercon High Milage this is @ the local auto zone for 20 bucks
a gal. I plan on the oem filter don`t want to change to synthetic as my concern is to not change to much and cause anything to cost a tranny to fail with over 280K onthe clock and no history before 250K when I bought it this rig has had all fluids change including brake fluid flush in the past 20K just always been scared to flush the transmission. Thanks in advace for all the help.

 

Here is a great thread on how to flush the transmission with pictures.

Mark Kovalsky who was a Ford Transmission Engineer apart of the 4r100 program has talked about using the appropriate fluids and how MerconV is compatible with ours. I would personally shy away from the valvoline dex/merc stuff as it is no longer licensed and tested for compatibility.

https://www.ford-trucks.com/forums/1...l#post12824085

 

If it were mine I'd change the fluid using THIS procedure. Synthetic fluid won't cause any more problems than non-synthetic. That's just another myth.

If your trans is in good shape this can only help it. If your trans has already failed, but still hanging on, this won't save it.

 

Thanks Bently: Since I posted it finaly sunk in what Mark K. said that nobody was minding the spec. for the regular Mercon atf. and are goning to look futher for Mortorcraft Mercon V . Thanks again for the reply.

 

Mark the trans. shifts good the only time it gives reason for concern is if it is left not started for 7 to 10 days in colder weather the first 2 or 3 shift cycles it has what I have heard others say about the shutter problem but after few miles temp. gets up shifts perfect. Thanks again for the reply.