Hydra-matic tranny fluid options?

[DSMtuned]

Hello!

I have a '55 Hydra-matic transmission. I want to change the fluid, but all the shop manual says is to use "GM Hydramatic fluid."

With today's options as far as fluids, what Dextron rating should I use? Do you think I can use synthetic?

Thank you!

-Craig

[Ron Green]

I also own a '55 Hydra-matic tranny and use the Dextron 3 (I believe) however your local NAPA, etc will be able to verify the exact Dextron # you need.

I am a firm believer in synthetic engine oil however I would stick to the correct Dextron tranny fluid especially if this tranny has never been rebuilt.

[Guest De Soto Frank]

From what info I've gotten from various tranny fluid manufacturers (most recently, Valvoline), any of the Dexron Fluids are acceptable replacements for "Automatic Transmission Fluid Type A".

Dexron III is the present version of "Dexron" and is supposed to be a direct replacement for the previous Dexrons...

[bill pritchett]

I have read a few articles where your question came up. I have a 50 Olds. The articles said that GM said the AT fluid was compatible back to 49 so you should be ok.

[DSMtuned]

Thanks for all of the input. I'm looking forward to changing all the fluids in this tank.

-Craig