trans fluid - redux

[jwetering]

OK guys.

I know it's been covered because there are exactly two strong but entirely different recommendations on the internet regarding the correct fluid to use in a Getrag 240 / m42 setup.

Mine driveline was pulled from a 1990 318i. There are no tags on teh graebox.

Do I use ATF or do I use a 75-90 gear oil like Redline MTL ?

Thanks

[bmwman91]

Just run Redline MTL or MT90 (MT90 is a little thicker, but I found it reduces the transmission rattle with my light flywheel a little). I've run it for almost 2 decades in G240's and not had a single issue, despite mine having the ATF sticker. If you live somewhere where it gets very cold, maybe stick with MTL since MT90 could make cold shifts a little harder.