Davidgoose

I can’t stress this enough, don’t discount your wheel bearings. I am a very experienced ex Mechanic and had the same bearing noise on my A4. It sounded like it came from the centre front of the car and the usual test, of cornering left or right made no difference, indicating that it wasn’t a wheel bearing. I was convinced it was a diff issue, however I thought I’d change the wheel bearing as it’s a fast job and the bearings are relatively cheap. I never expected it to cure the bearing noise but it did. Clearly the hub fitted bearings, are not effected by cornering as the noise remained constant. So, if you have a humming bearing noise from the front of your Audi, odds on that it’s a wheel bearing. A tip if you do it yourself, heat the hub bearing bolts if they are tight. Mine were solid.