Which transmission oil for 5-speed

[back_mtn_boy]

I've been reading some of the older postings concerning transmission oils, but they seem to all be concerned with automatics or the 6-speed Getrag transmissions in the E39 540's.

I have a 1997 528i 5-speed (build date 9/96). The transmission has the "orange" sticker specifying ATF oil. I want to change the fluid since the car has 90,000 miles and I don't think it has been done. The service manual with this car specified changing the transmission fluid every other service II interval.

My question is: should I use ATF and if I do, is synthetic ATF OK to use? Specifically, is it OK to use something like Royal Purple Synchromax? The recommended fluids in the TIS all appear to be mineral oil based.

Thanks - John

[Nick325xiT 5spd]

Use the OEM fluid.

I hear good things about Royal Purple but have ni experience.

Don't use redline. I don't like it, and I know of at least one bad experience with it.