need to change fluid and filter on 97 F150 4.6 with 4R7OW trans. It says to use Mercon only but I can't find any . Will Mercon V be the same thing , or should I go to a syn. fluid. It has 74,000 miles on it and a leaking front seal. I am going to replace the seal and change fluid at the same time and am looking for more info.

 

Valvoline maxlife fluid, the only fluid you need and will work wonders on your old trans. It works with Mercon and Mercon V applications

 

Ford has quit making Mercon. They have stated to use Mercon-V in it's place.

The brand is up to you, personally I'd get a good name brand fluid or one that is on sale.

racin4ds is a perfect example of someone that truly believes one fluid is better than all others. Whether or not that is the case.

 

The type of trans fluid is most important. Go online and find the type that is compatible with your vehicle's transmission and use the brand of your choice. Today's friction materials have more cross-compatible fluids but that was not true years ago. Dexron was very different from Type F etc.
Use the brand's compatibility recommendation for the type tested to work in your vehicle.