The Stovebolt Site Forums The Shop Area General Truck Talk what fluid for chevy auto trans.?

Ok here's the scoop on ATF....
Up untill the 80's.... GM Transmissions used Dextron.. while Ford and Chrysler Products used Type "F" fluid..... (early Packard Ultra-matics and some others used Type "H")

Most automatic trans. and some newer Std Trans now all tend to use Dextron/Mercon ATF.....

The primary difference between the Dextron and Type "F" fluids? is that Dextron has added FICTION MODIFIERS..... For the purpose of those wonderful smooth shifts.. The upside of this is grandma won't feel the tranny shift..... The downside? is that the clutches and bands slide during application.... yes you get a smooth shift...but also build alot of excess heat and friction inside the tranny... This shortens the life of the fluid.. as well as extensivly shortening the life of those clutches and band... requiring more frequent rebuilds.

Most rodders and racers that utilize GM auto trannys use Type "F" in the tranny to get that nice solid shift... without the heat and friction build up. As well as less frequent rebuilds. yes..(smile) Type "F" will work just great..with no problems.
Another note for referance... You will see alot of "special" racing ATF out there.. labled as HURST or B&M....... When I was doing some work with an automotive tech trade school in AZ in the mid 80's...we sent blind samples out to an indipendent testing facility to see just where the differences were.... and basic diff between the B&M and HURST fluids? was the color...otherwise they were basicly Type "F".... and of course the friction modifiers in the Dextron fluid.
I hope this helps clear up the ATF myths....
Michael