what are the problems with a steptronic gearbox?

[CamZo]

Hi guys just want to know whats the pros and cons regarding a steptronic gearbox?

 

[P1000]

If you are asking about the GM5L40e in the e46 330d, please state so, since they are somewhat more troublesome than others. (for one, they are made in france).

 

[CamZo]

Was just asking in general as I dnt have a specific gearbox in mind

 

[P1000]

Okay, in that case. There is nothing fundamentally wrong with them. But they are utterly complicated, and usually don't make it to 300kkm without troubles (design life is 200kkm on ZF boxes). The thing is, they just basically wear like a clutch, since most of the volume of the box is made up of multi-plate wet clutches, at some point they need replacing, and that is quite an expensive ordeal. Modern gearboxes also "ride" these clutches more on switchover to give a smoother gearchange, where the older boxes, that seemed to last forever, would just basically drop the clutch for the next gear.

 

[msm]

Also, part of the problem is BMW's "lifetime gearbox oil policy". No oil last forever ... a bit of preventative maintenance goes a long way in keeping these boxes alive for a bit longer.

 

[tito1]

Hi there, I searched the entire forum for info, we are driving three different steptronic bmw's: an x5 30d (2006) 150 000km, 330ci (2002) 225000km and 330d e46 (2003) 212000km, the 330d runs a gm 390 box, I am not sure about the other vehicles. Observation: if driving in normal auto mode and coming to a stop, both the 330ci and the x5 displays some very harsh downshifts, you can feel the jerk in the drivetrain. the ci worse than all of the other vehicles, so much so it had a replacement guibo disc and centre bearing about two months ago. The 330d on the other hand, displays downshifts especially when coasting downhill that seems excessive (high revs down to almost lowest gear, no jerking) When driven in ds or manual function, none of the cars displays any sign of harsh downshifts! Assist please!