[Aaron09128i]

Hi all, I've got a '13 335i xdrive with 67K miles. I've had a slight noise for last few thousand miles that seems driveline related. I only hear it when at speed, but it is easier to hear at low speed due to less wind and/or tire noise. I recently replaced wheels and tires, so I can eliminate the tires as the source of the noise. It's hard to explain, but seems proportional with speed, with some kind of friction that's not even through the 360 degree rotation of whatever is causing the noise. So, the intensity of the sound varies through each rotation. I'm guessing the frequency at something like two to three times per second at 25 mph for each cycle, double that at 50 mph.

Is there a common driveline or bearing issue that could be causing this noise?

I'm planning on getting the differential fluid and possibly AT fluid changed next week (tracking the ZF AT fluid discussion)

Thanks