ATF was actually the recommended fluid by Chrysler when these units were in cars in cold climates. I have rebuilt countless 833's in the last 25 years or so and will tell you that in my experience, the ATF doesn't seem to have a negative affect.

BTW. The absolute BEST fluid to run in one of these units is GM Synchromesh. YOu will not believe the shift quality with this fluid in there. That being said, if it were a trailer queen/resto, I would spec gear oil. The "cling" of that heavy stuff helps keep things happy.

MB