Hey,
I have this humming sound coming from the back when driving over 60 km/h..
I had my rear bearings changed about 5000km ago (back in last November, with parts bought at Audi, not choppers.. unless the mechanic didn't use what I brought him.. LOLL)

When I turn left Or Right, the humming doesn't seem to go away. Also, I got the car lift off the ground and the rear right wheel didn't have any bad bearing symptoms. On the other hand, my rear-left wheel could be budged slightly upwards and downwards, but not sideways..

Also, my rear brake disks are really..really worn, could that be the cause? (like a warp or something)

I'm asking, since I don't want to have my rear bearings changed Again.. since mechanics charge so much for these types of jobs -_-'.. especially if that isn't the problem.

 

stop putting people in the back of your car that can't sing

j/k without a better description of "humming sound" it could be just about anything. Initially I would suspect tires, but since you mentioned that your rotors appear worn that could also be the problem, along with dragging brakes or just about anything to do with the suspension.

 

make sure your lug bolts are in all the way, when i took my wheels off, then put them back on they felt like they were tight but when i would drive like you said, it would vibrate and sound really scary which is because the wheel itself was loose. use a metal brush/brush grinder to clean out the bolts, and put some anti-seize on them if that is the problem. if not good luck

 

I know I can rule out the tires, cause I changed my rear tires not to long ago, and the sound still persists. My friend took a look at the back and he didn't see any major suspension issues that could cause the sound (I had the shocks and some stuff changed).

I guess I could try changing my rotors and pads, since they are really due anyways..

 

This just happened to me. I was driving on the freeway, and my left front wheel had a humming sound that was getting progressively louder. I pulled off the freeway, had my friend get out, and listen as I drove around him in a circle. As I was doing this he noticed some of my lug bolts were loose. We jacked the car up, reset the wheel and this cured the humming. Definitely worth checking out.

 

okay,
i'll give it a shoot tmr..
I'll report back afterwards.. hope it's something as simple as that XD