You will want to use Dex/Merc on it. It's what the transmission was originally supposed to have, there's millions of these transmissions out there (Toyota still uses it) in all sorts of vehicles that have gone well over 1/4 mlliion miles on Dex/Merc and ... it's cheap.
I run the cheapest Dex/Merc I can get. I have used mercon V before. Truth be told, unless you run the thing dry (which I may or may not have done before), you aren't going to kill an AW-4. I have seen them severely overheated and ... they just don't die.
My Jeep gets used like a Jeep should. So it tows, hauls and off roads. Since the gearing sucks on my Focus, I use it in the city too. I have a 15000# transmission cooler on mine. You can DEFINITELY feel a difference. The fluid is warm coming from the radiator transmission cooler and quite cool when it leaves the aux cooler.
Originally Posted By: zrxkawboy
Originally Posted By: GregGA
Dex/Merc. I use Valvoline Maxlife. The AW-4 pan holds 4 quarts. They run hot, so look into a transcooler if it doesn't have one.
+1 to D/M, and Maxlife will work fine. Many people report draining out 4 qt when they pull the drain plug, however, mine would drain more like 2.5 qt, so don't just add 4 qt after draining. Start with 2 qt, check the level, and go from there.
I always get a different amount out of mine. Makes zero sense.