Transmission fluid for hard to shift manual 128

[GabeMG]

Hi everyone,
My 6 speed 1er has about 170k miles on it.
It’s becoming harder and harder to put it into gear, I fear my synchros are going out…
Right now I have the BMW manual trans fluid in there, it’s about 15k miles old. Just replaced all the shifter bushings and trans mounts.

Can anyone recommend a trans fluid I should try? I’ve heard a lot of good things about GM ATF, and Redline D4 ATF.

[fast1eddy]

I use Redline D4 but your problem maybe clutch related. My E36 M3 was very difficult to shift until I replaced the clutch. Like butter after that.

[cerealwars]

Originally Posted by fast1eddy

I use Redline D4 but your problem maybe clutch related. My E36 M3 was very difficult to shift until I replaced the clutch. Like butter after that.

This is a great point - could your pressure plate slowly be giving out? I've never experienced it myself, but seems like that might cause these symptoms.

Maybe you can remove the factory clutch stop to get a little bit extra travel out of the pedal, and push the pressure plate in a little more. Only thing is you might risk trashing the master and slave cylinders because their pistons will be out of their usual travel path. Might be worth trying, probably less of a pain than taking the trans out, which sounds like the alternative.

[4JawChuck]

Try bleeding the clutch cylinder, it uses the same reservoir as the brakes so to fill it you need to overfill the brake reservoir.

Easy two person task, one pumping the clutch pedal and another cracking the bleeder from below.


Have you removed the restrictor yet? Now is the time to do it.

[GabeMG]

Originally Posted by fast1eddy

I use Redline D4 but your problem maybe clutch related. My E36 M3 was very difficult to shift until I replaced the clutch. Like butter after that.

That’s really valuable knowledge, how did you determine that it was the clutch and not something else?

[GabeMG]

Originally Posted by cerealwars

This is a great point - could your pressure plate slowly be giving out? I've never experienced it myself, but seems like that might cause these symptoms.

Thanks for the insight! How could I determine that this is the issue?

[GabeMG]

Originally Posted by 4JawChuck

Try bleeding the clutch cylinder, it uses the same reservoir as the brakes so to fill it you need to overfill the brake reservoir.

Easy two person task, one pumping the clutch pedal and another cracking the bleeder from below.


Have you removed the restrictor yet? Now is the time to do it.

I have actually bled the brake/cluch recently-ish. The fluid level hasn’t changed color or level in the year and a half since I flushed it. I actually do own a restrictor bypass but never installed it.