I am going to be servicing my Ford 8.8 soon, and wanted to know if I need to add Motorcraft Friction Modifier in with the Valvoline 75-140? I’ve read mixed things from adding it in with Valvoline will ruin the clutches and also the opposite that you indeed need to add it. I know that Valvoline contains friction modifier already. Just looking for the right answer.
Big thanks in advance.
Big thanks in advance.