Do I have to add a friction modifer in my fear diff on my 2007 F250, 6.0. I plan on using royal purple 75w-140? I have read conflicting posts. Anybody use arch oil in any of their differentials?
Can I use royal purple max at in my transfer case?
hey guys. recently ive done some maintenance/ minor upgrades on the ol girl... replaced cracked Y-pipe, oil change to rotella t6, coolant flush (made sure to use distilled for final flush and motorcraft gold coolant), fuel filters, mishimoto 200 thermostat, and TSD daily street tune... and it...