I am using automatic transmission fluid Type F as after run oil ( I have a bunch left over from when I had an old Fairmont). Someone at my field said I should use Dextron or Mercon, but not Type F.

Is this true? Why is Type F bad? What have I done to my engines?

Thanks

There are those who agree with that statment, and many who do not. I think it is just fine as an after run oil but that's my opinion.

Cheers,

Chip

Type F has a friction agent in it. You shoud use dextron or mercon.

Type "F" transmission fluid was for the old Ford C-4 style transmissions with friction bands in them. Note: That the "F" stands for FORD. Or FRICTION if you will?

The big fords had a C-6 style transmission that used Mercon which is the same oil as GM's Dexron. All later Fords with the 4 speed and computer controlled transmissions used the Mercon/Dexron oil.

It is difficult to find type "F" ATF anymore.

Most all ATF at the store is Mercon-Dexron.

Do something else with your type "F". Don't use it in your model engines. You probably havn't hurt anything yet.

Enjoy,

Jim

As vlizard said...ATF type F has a "friction enhancer" in it.
Now what exactly the friction enhancer is or what it does is
beyond me. But I have to believe it would not be good to
put in your model engine.

Stick with Dexron or Mercon ATF. Works just fine.
I personally use a 50/50 mix of Marvels Mystery Oil
and Dexron III ATF.

Mike Hammer

For accuracy's sake - Ford Type F ATF (the actual specification designation is Ford "ESW-M2C33-F", commonly referred to as "Type F" to differentiate from the earlier versions with their earlier - A, B, etc. - suffix designations of the ESW-M2C33 specifications as the spec was updated. While it is convenient to think of the 'F' as for Ford this isn't the reason.) does not have any friction modifiers in it. When it was shown by my company's (Exxon Chemical Company) chemists that one could formulate an ATF that met the GM and Ford ATF requirements with one additive formulation, Ford didn't like the concept of someone using GM's DEXRON ATF in their transmissions, even though all the test requirements were met. So, based on absolutely no technical reason, Ford inserted a single sentence into their Ford Type F specification that read..."This formulation shall not contain any friction modifiers".

All the above being said, I would use the most recent version of any ATF, since the test requirements - including the rust protection properties - for the ATFs are constantly being updated. You don't care about the frictional requirements of an ATF for an after run oil, you care about the rust protection during storage.

I understand the latest formulation of GM's DEXRON is synthetic, ought to be good stuff!

OK. Thanks for all the great information. I'll trash the old Type F ATF. I should have known better - anything to do with that old Fairmont is cursed.