Re: 7.3 4r100 trans fluid question
Use the procedure stated above. I used amsoil and noticed a big change. I've heard alot of good about schaeffers on hear but we had some problems with it at work in equipment(weren't transmissions) but it was the same fluid so I opted not to go with that.
2003 F-250 CCLB 7.3L
4" lift and PMF traction bar/block setup running 35s on 20x12s. Intake, exhaust, PHP Hydra w/ Gearhead tunes, gauges
2005 F-350 CCLB 6.0L
6" lift on 20x10s and 37s, studded, deleted, Powermax and Livewire with Quicktricks tunes, exhaust, intake (Wife's Truck)