Not to step on your toes Arisley but Brian Thompson advised me against it when I had a stock trans because the schaffers is so slick that the stock converter will slip more. He reccomended just the regular parts store atf.
I know this will sound like heresy, but if the fluid has a MERCON or MERCON V rating it is NOT slicker than non-synthetic. That's a myth and Brian is wrong if he is saying that.
Don't know as all I had was a stock converter at the time. I wonder if any additional slippage could be overcome with an increase in line pressure, but if that was a better way to go, then I suppose he would have suggested that instead....Mark is on, maybe he will chime in.
An increase in line pressure won't help the converter overcome slip. The converter pressure is regulated to 120PSI, so no matter how high line pressure goes the converter won't see over 120PSI.
I was advised the same by Brian. Either use his special blend of Schaffer or regular Dex/Mercon 3. I believe that Blowby uses regular as well. Brian said the synthetic will cause the clutches to slip in a high hp application. So regular it is till next oil change for me. Guess I need to call Brian for some oil soon. Lol.
You can get synthetics that are no more slippery than conventional oils. They have a MERCON V rating. Mobil 1 synthetic ATF is one. If you are looking at #204S ALL-TRANS Supreme Auto Transmission Fluid
http://www.schaefferoil.com/transmission-fluid.html it has a MERCON V and MERCON rating and will NOT be too slick for a stock transmission.
My friend went to ford and for some reason they put mercron 5 in his then i called them and they said they dont make motorcraft mercron 3 anymore
MERCON V is the right fluid. MERCON has been discontinued. There never was a MERCON 3 fluid.
When I got my fluid I got Merc v from the ford shop. That's what it said the 4r100 takes.
They are right. MERCON V is the right fluid.
