I'm going to thread-jack this since Michael69 got his answer. I have a C6 transmission which the previous owner had rebuilt in 2005. I have the invoice, which doesn't say anything about fluid type - all it says is "stock rebuild." Any way of knowing for sure which ATF should be used. I haven't driven much yet - still tying up the loose ends - but I always thought the shifts were a little firm when I did drive. I attributed that to the R-servo but now you guys got me thinking, cuz I used Type F.Originally, FMX would use 'Type F'. But that is getting real hard to find these days since just about all Fords since 1980 use Dexron/Mercon III, IV or V.
If the trans has been rebuilt just about any time since the mid '80s, those friction materials and seals are made for Dexron/Mercon.
Chime in you trans guys if my memory is foggy on this...
My understanding is that Dexron/Mercon is slippery-er, and you'll get slipping if you use it where Type F is specified. I didn't realize the stuff was getting scarce... it's in all my local chain stores. Can you get type FA? That's a compatible substitute.