BiTDi - droning from rear. Wheel bearing or worn tyres?

[Crasher]

Just done the alignment an 8K A4 today after we serviced it last week and condemned the tyres; 2 Michelin's Primacy 3's fitted and now it hums when it didn't before...

[nick1212]

Got the Audi technician to sit on the back seats, whilst we went for a drive. He pretty quickly worked out which wheel bearing it was, however I decided to replace both for peace of mind. As you said, when on the ramp no play could be identified with any of the wheels.

[Crasher]

I have had some of these modern wheel bearings making terrible noises just being spun in the air but with zero free play. At least if they grumble when you spin them in the air it makes life easier.

[john2107]

Further update. Took the car into my independent VW Audi specialist yesterday, they confirmed rear offside bearing is noisy and could feel it rumbling when up on the ramp, yet no free play (as Crasher said previously). Booked in to be sorted next week.

So that's NSF and OSR both gone in 3000 miles. I won't get the other 2 done yet but will be listening out for them!! With 4 new tyres and 2 new bearings, I should have a very quiet car!