There is a copy of the lube order dated 1944 (its on g503.com) that shows the transmissions are filled with (IIRC) 15 qts of 10-20 weight engine oil. Stick a fork in it, its done.

As a reenactor (WWII, 45th and 25th inf Div) I have met A LOT of vets from WWII. I have heard it all. From absolutely rare tidbits of daily life to outright errors. One vet said the M1919a4 we had was never used in WWII, another said he never saw a 5 gallon gas can, other claimed the M1 held 20+ rounds... like a Tommy gun. So yeah.. vets do recollect things in ways that are not entirely accurate. We never corrected them, it is not the palace for a student of history to argue with a person that was there.... but we also don't spread misinformation... no matter the source.

If you want to pick nits and say that there were automatic transmissions in WWII fine, but they essentially were a moot point and did not contain 'ATF' as the post said. So no, ATF was NEVER poured in the intakes of WWII vehicles. ATF at the time was engine oil. Well, I'll say that there may have been some Joe Dope that though he could lubricate the valves if he poured it into the intake. People do all kinds of weird things out of ignorance (proper term).

I keep forgetting that on the internet you must be 115% accurate and concise or the person on the erroneous end will cling to whatever crumb of ambiguity is available to contradict you.