friction modifier in differential?
I got new mag-hytec diff pans for my truck and Im changing the differential fluid. The manual says 75w-140 for the rear and I forget what it is for the front but it doesn't say anything about using any kind of friction additive. Do I need to use any? if so how much? Im gonna use Valvoline fluid or maybe amsoil if I decide to drop the extra cash to buy it and go pick it up. thanks for the help
2008 Ford F250 6.4 PSD. Spartan 350, 5inch Flo-pro, downpipe, AFE stage 2, Intercooler pipe, ZEX nitrous, TS-MP8, Elite wastegate/EGR delete, ARP studs, CFM plenum, pro comp trac bars, Airdog 150, ATS 5-star, Mag-Hytec pans, Readylift, 35's, Road Armor front, Fab four rear bumper.