Whistling when going backwards (ZF AT8)

Hello,



I've a 2014 M235i with the ZF HP8 automatic transmission.



When going backwards a bit faster than for parking I noticed a whistling coming from the gearbox.

I drove a similar car (2014 M135i AT8) with the same AT, and it has also this whistling when going backwards.



You can hear it on this video (not mine) : http://ift.tt/1z5YIBe



I'm pretty sure it's not the normal noise of a going backwards gearbox.

I drove a third car (2012 M135i AT8) and it has also this whistling.



On a French forum dedicated to the One and Two, we are around ten owners complaining about that. Some only hears this whistling after 15.000 km.



One guy on this forum contacted ZF France and they replied :

Quote:

"I come to you pursuant to information that I requested from our support department in Germany for your noise when going backwards. Cases of damage planetary gears train No. 3 can produce this noise. No information was given to me on the lifetime of a gearbox experiencing this problem. We advise you to get closer to BMW for support for this repair.

And then, ZF France contacted his dealership to report this problem to BMW France. And to confirm that ZF will replace the gearbox under warranty.





Do you have this whistling too ?