Type of Trans fluid

[Barnum]

I need to change the trans fluid in my 54. What is the correct type for the hydramatic?

[hollenway]

Found on the net:

The primary difference between the new ATF lubricants and their predecessors is their viscosity. The new fluids are lower viscosity; their kinematic viscosity is typically on the order of 6 centiStoke (cSt) at 100 degrees C, while the older fluids are in the range of 7.0 to 7.5 cSt (heavier) at 100 degrees C. The lower viscosity helps improve low temperature performance and reduces friction for potential improvements in fuel economy
. The additive mix in the newest fluids also offers improved oxidation stability, shear stability and friction durability to provide more consistent shift performance over the life of the fluid.

What does this mean for collector car owners?

The good news is that all the new ATF lubricants are backward compatible. That is, Dexron-IV can be used in all GM transmissions back to the beginning. The same is true for Chrysler’s ATF+4 for all prior Chrysler transmissions unless Dexron was specified, and Mercon V for Ford transmissions. The only exception is the 1961 to ’81 Ford transmissions that require Type F fluid.

[HJ-ETEX]

There is a Mercon V? And I thought Dexron III claimed it could be used in place of Type F. I have heard some drag racers using non-Ford automatics thought there was an advantage to using Type F over Dexron.

[Barnum]

Thanks for the info....just wanted to be sure

[blackcat429cj]

Ford Type A, Type F, and Type FA are the same.  Using a Dextron/Mercon type fluid as a replacement will cause leaks.  I wouldn't recommend unless seals etc are replaced and compatible.

[kndllmtt]

I have heard some drag racers using non-Ford automatics thought there was an advantage to using Type F over Dexron.

The way it was explined to me was as follows...
The reason was that unlike GM and Chrysler, Ford decided to control their shift firmness by "Friction modifiers" in the fluid, instead of in the valve body like GM and Chrysler. So what happened was when you put Type F in a GM or Chrysler trans you got a firmer shift, at the cost of a varnish buildup in the trans. The reverse happened if you put Dextron III in a ford trans.