So... last year I changed my manual trans fluid with what my BMW zentrum told me was the proper fluid. I have a 2010 US spec 6MT 135i. The car came with BMW fluid MTF-LT-3. My dealer said that LT-3 is now superceeded to LT-4. So I got 2.5L of LT-4 and changed my fluid last year. I did not really notice much a change in shifter effort.
The first time I changed the tranny fluid was at 52K kms. What came out was dark black fluid. I was glad I changed it. I also changed teh rear diff fluid with Castrol's SAF-XJ 75w140.
A little background... my shifter was always balky shifting from 1st to 2nd gear. Especially when the trans was cold. It would almost feel like it wanted to grind. But I never did make any noises - just that the gear lever was hard to move into 2nd gear. Later on when I had a performance SSK instaled the problem was the same. It just always balked when cold or on fast shifts when the trans was hot.
A few weeks ago I finally got around to changing my trans fluid again. This time I used a trans fluid I was familar with(I used Redline's ATF-D4 in my manual trans e36 years ago with great results). I used Redline's ATF-D4 trans fluid for my 135i manual trans. Redline says it can be used in BMW's even though it is a ATF fluid, for a manual trans use. Do you own research... but I am hapy with my choice.
From the moment I drove ten feet - I knew I made the right choice! The shifter effort is lighter and all that notchyness is gone. No more balking or problems when shifting from 1st to 2nd!! It really feels like a different transmision. Smooth as silk. I would highly reccomend using Redline's AFT-D4 to anyone sitting on the fence. I really can not believe I waited so long to try it. Partly it was warranty worries. But in the end you really have to pay to play. And I was at the point where this balky shifter was really starting to bother me.
Take a look at my pics. I think they say a lot about BMW's "lifetime fluids" nonsense!! Just look at the bottle on the left!! That is LT-4 with only 26K kms!!!! I wonder how bad it would look after 100K kms or 200K kms!!!
BMW MTF-LT-4 trans fluid. Left old used for 26K kms!
Right one, new LT-4 fluid.
old MTF-LT-4, new LT-4, new R.L. ATF-D4
