Hydramatic Transmission Fluid

[crystalblue2244]

I had a call the other day from a fellow who had just purchased a nice '54 wagon (lucky devil!). He asked me about the transmission fluid-- like what kind. Well I've had a couple '54s in past years, but the operative words here are "past years". I wasn't sure.
I am thinking that I had used regular 10 weight detergent motor oil, as recommended in a book that is probably long gone. I am almost positive that this is what I used, and it worked just fine. I remember a day of draining and refilling of transmission and torque converter (boy, that is a process!).
I was not confident enough to tell him to go ahead and use the 10 wt. Can anyone enlighten me if this is correct procedure, or is there something better to use? Sure don't want something too "caustic" for old seals. (I remember a fellow when I was in the Air Force as an F-100 Crew Chief who tried a couple of quarts of "jet oil" in his car-- it just about ate all the seals right out!).
Thanks.

[spike421]

From the '48 - '53 Hydramatic Transmission Manual, "use only Automatic Transmission Fluid type A, qualification number, AQ - ATF." I'm guessing '54 would be the same.

spike421

[50scars]

Use DEXTRON II. The Mercon stuff works fine, too. Kind of stay away from the Stuff designed for Fords, like Type F. It will work, but the shifts are jerkier.

[engineer]

you can still buy type A fluid which is what those trans used.