Ford type "F" has a higher coefficient of friction, then dexron. Back in the day, when Dexron first came out, there were problems of Fords having trans failures. The fluid manufactures, sent out a tech bulletin that said it was OK to use type "F" in vehicles, that called for dexron, but not to use Dexron in vehicles that called for type "F". Dexron would cause the Ford clutches to slip and eventually burn up.
The 904 trans calls for Dexron
