Originally Posted by wsudu

Funny that I ran across this thread as I am flushing mine right now and I am taking a break for the Sealant to seal up before I get going again. Ok...I have debated this in my head for a week on which Fluid to use. I live in KC and I called every dealer in town. They all said use DEX III and I made them to look it up as well. A couple said you could use Type IV but not the other way around and those 3 dealers who told me that also said there was really no benefit especially if you add the extra 2 dollars a quart. Dex III Toyota brand is Very hard to find in the quart here. Most sold Mag 1 or something else at the dealer in the quart. I decided that I will use OEM this time because it is so much cheaper...it is the OE fluid.. and I prefer to change more often than later. And I am a Mobil synthetic guy. That is what is in the ATF now, and in everything else, motor, gears, transfer case. Some might think I am taking a step backwards, but I got 19 (a few extra) quarts of Toyota ATF for $55, half that of M1. Just my 2 cents