You would have to search for Xmission oil, whatever that is...
http://www.fordbarn.com/forum/showthread.php?t=201304
There are a couple of different types.
I believe this is the one you want..
http://lucasoil.com/products/engine-oil-additives/heavy-duty-oil-stabilizer
Lucas Oil Stabilizer. Run it full strength. Makes the trans shift smooth as glass. I had a howl with std 600W. Gone with LOS.