OK to use synthetic oil in trans and diff?

[cory58]

I want to replace the trans and diff oils in my E12 for the first time during my ownership. It's older than any other BMW I've owned by 10+ years. Is it ok to use synthetic oil or should I stick with conventional for the trans and diff? It's the only BMW I've owned that leaks zero fluids!

Thanks, Cory

[PatinaBeforePolish]

I’ve been using Redline MTL in the transmission and Redline 75/90 in the differential with no problems. Trans actually shifted more smoothly when I switched to Redline which was around 8 years ago.

[cory58]

I’ve been using Redline MTL in the transmission and Redline 75/90 in the differential with no problems. Trans actually shifted more smoothly when I switched to Redline which was around 8 years ago.

Thank you!

[528i-1981]

https://www.firstfives.org/phpBB-3.2.1/ ... hp?p=31333

I recall this being discussed here when I changed mine. LOL Cory, you initiated that thread four years ago. I think we all have E12 items that have been pending for that long or longer. Anyway there's good info in that thread. I've had no issues since making the switch. Cheers!