What kind of fluid?

[noE30]

What kind of transmission fluid are you guys using? I would like to replace mine but I'm not sure what to run. I don't know if anyone has used GM syncromesh but I used it in my gti and it was great. I was thinking about using it in my e30 but I wasn't sure if there was a better option.

Same goes for diff fluid. I've never had a rwd car so I have no idea when it comes to diff fluids. Please give me some info.

Also the car is a 89 325i with a 4.10 lsd.

[drift]

http://www.swepcousa.com/lubesite/highperf.htm

Synthetic Mobil-1 , Red Line , etc

Obviously, don't use transmission fluid on LSD differential, or the other way around.

[GOT8SPD]

people say to use Redline MTF for the tranny, and Redline 75w90 for the diff....i can't find any 75w90 so i was thinking about just going with the Mobil 1 gear oil....it's easy to get at many auto parts stores, but it's synthetic so i'm not sure if it will work well.

I've read people say not to use synthetics with older seals/gaskets because it will leak

[Ryann]

+1 for the Redline MTF.

[Jaxx_]

in my getrag 240 i used royal purple syncromax. GL4/GL5 stuff.

[DJB]

Don't use a GL-5 fluid in the transmission. It needs a GL-4 fluid -- GL-4 fluids won't degrade the bronze synchronizers. If you want synthetic fluid, that pretty much means Redline MTL or MT90.

Several of the specialty oil vendors say "compatible with", "use where X is specified". Those phrases mean that the fluid hasn't been tested to meet the specs. Sometimes that is to avoid the testing fee, but more often it's because they don't bother testing a fluid they know won't meet the specs.

The diff uses a GL-5 fluid. There many good ones out there, including Mobil 1.

[stumble_t]

I only ever run Redline MTL in the transmission.
I've tried to find the castrol the dealer uses in the diff, but it's expensive and they want you to bring your own container, so I went Mobile1. I've also used Valvoline + an added modifier(lsd) to good results as well.