gearbox faults after m3 subframe installation

dr.rabia.e92 · 01-14-2025, 11:27 AM

hello everyone,
i have a bmw 335 e92 dct 2009 , i installed a m3 subframe with ratio 3.85 (for manual transmission) .
after we finished installing everything , i went for drive , the car is undriveable shaking and confused.
we checked codes and we find that there are gearbox faults .
i think that this happened because the ratio are different, the ratio for the dct was 2.56 and the new diff is 3.85 .
what can i do ?
do you think that software for the gearbox will help ?

CarAbuser · 01-15-2025, 03:47 AM

You need to tune the DCT to update the final drive ratio. You can get some like Olza to do it for a couple of hundred.

01-14-2025, 11:27 AM	#1
dr.rabia.e92 Registered 0 Rep 4 Posts Drives: bmw 335 e92 dct . stage 2+ mhd Join Date: Sep 2024 Location: israel iTrader: (0)	gearbox faults after m3 subframe installation hello everyone, i have a bmw 335 e92 dct 2009 , i installed a m3 subframe with ratio 3.85 (for manual transmission) . after we finished installing everything , i went for drive , the car is undriveable shaking and confused. we checked codes and we find that there are gearbox faults . i think that this happened because the ratio are different, the ratio for the dct was 2.56 and the new diff is 3.85 . what can i do ? do you think that software for the gearbox will help ? Attached Images
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01-15-2025, 03:47 AM	#2
CarAbuser Lieutenant Colonel 493 Rep 1,555 Posts Drives: Z4 35i DCT / E92 335i DCT Join Date: Jul 2010 Location: United Kingdom iTrader: (0)	You need to tune the DCT to update the final drive ratio. You can get some like Olza to do it for a couple of hundred.
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