N55 6MT transmission whine

[louder]

Hi

I have a whine that's pissing me off, mostly audible in 1st and 2nd gear. Gearbox is a manual ZF 45 DZ on a F20. The whine goes in a higher frequency when deceleratin and it stops when shifting to neutral or, if in gear, when coming to a full stop.
When I press in the clutch I can hear the part with the whine changing it's speed a bit, but it's still spinning until I come to full stop.
Car has a new clutch and M3 transmission mounts which I guess lessen up a bit the sound insulation, but I remember hearing the whine with stock mounts as well. Also, Active Sound Design is turned off, so every mecanical sound is pretty loud.
The input shaft bearing had a bit of play when I changed the clutch.
So what do you think is at fault here? Is there any change this is something NOT inside the transmission? Is this sound normal for 85.000 km transmission? Could it be the differential? Would be an awesome excuse to get a lsd...

Here is a clip with the sound:
https://www.youtube.com/watch?v=y2t0...ature=youtu.be

Thanks a lot

[MarcoZandrini]

Have you check the fluid level? Has the transmission fluid been changed? It’s a ZF transmission so contact ZF to ask about which fluid is needed and the fluid capacity. Or, go to the local dealer. Changing the fluid would be my first step.

[louder]

Ops, forgot to mention the most important part.... I did change the oil about 5000 km ago with OEM, to required capacity (full). I could not see any leaks, but the old fluid was looking awful. Would you say this noise level is out of ordinary, Marco? Do you have a manual as well?

[MarcoZandrini]

Ok, scratch changing the fluid. Yes, I’m on my 5th bimmer, all manuals.

[louder]

A man with great taste! So all of them of them transmission were silent?

[MarcoZandrini]

Yup, none of the transmissions were noisy. That loose input shaft worries me. How loose was it? It could be the input shaft bearing.

[louder]

The mechanic who changed my clutch said it had play within the limits. Can't say what limits...
I would expect more noise on neutral with the clutch up, if this bearing would be the cause, but the noise is within norms for a manual car, I'd say...
I suppose you can't just change the input shaft bearing, anyways, right?