willysmjeeps.com

Did the military ever put overdrives into M38's or M38 A1's? I am assuming that they are a recent aftermarket product. I just installed a Saturn unit from Advance Adapters. I hate to have something that is not original-ish, but I enjoyed having one on my former M38.
By the way, I called Advance Adapters 3 times with install questions, and got some of the best customer service I have ever had, from their tech department. Almost unheard of, these days.[/b]

Overdrives have been around for over a half century. There is probably a few motor pools in the various services that at one time or another probably installed an overdrive in M38's and M38A1's that had a special service environment. Was it common? No.