I would say modern Ford transmissions are about the best available by the Big Three.
Obviously GM is still stuck trying to use the basic 700-r4 with a myriad of upgrades, but still having sun shell failures, etc..
Having worked at a large GM dealership recently I've seen the failures coming in the door, OFTEN.
Chrysler jsut doesn't have there stuff right either. GM and Chrysler transmissions are lucky to make it to the 100K mile mark these days it seems.
Ford however with the E4OD, AOD-E, etc.. seems to be having decent luck as far as I know...
Haven't heard of too may trans failures in the Mustangs, Lightnings, etc....
I use and recommend Dexron in my builds, however Type F is not going to kill a trans.
It is rougher on the friction materials, causes them to break down faster. But... We're not expecting a racing trans to have frictions last 10 yrs anyway.
I had some literature somewhere on Type F and friction materials..
You can also check with major clutch manufactureres such as Alto, BW, and Raybestos and see what they recommend... it ain't F...
IMO,
I have noticed Type F to cause some "varnishing" if not changed often. Not sure if it is the heat, repeated thermal cycling, whatever.
I've played with the tractor fluid mix. Seems to work fine for me too.
I don't have long term results yet so we'll see.
