My wife's G35x '04 with 72k miles is making a hum that sounds like loud snow tires. It changes with road speed and gets louder as you go faster...

Any ideas?

 

Any suspension/wheel modifications to the car? Alignment in spec? How do the tires look?

 

My guess is feathered, cupped, or worn out tires.

 

The car is all factory, and dealer serviced till now. It has recent tires and recent alignment.
It sounds like we have deep snow tread tires on there, like you would have on a big plow truck.

I am thinking it's differential or otherwise drive train related. Has anyone else heard noise like this?

We have chased thumping noises in the past (that felt like wheel damage but wasn't) and it was both times damaged tires. The oem bridgestone tires are not too robust; cord/ply damage from pot holes.

 

Is there any vibration associated with the noise? Perhaps the wheel bearings?

 

No vibration, no signs of a loose front end. The shocks don't feel good to me any more at 72k miles.
We had the compression rods done at 30k, and have had all the services done including accessory belts and pulleys.

 

It WAS a wheel bearing. I found out that the dealer replaced the drivers side front wheel bearing like 5k miles ago, but not the right side which was the one.
I have never heard a wheel bearing sound like that, I will have to keep an open mind in the future.

Thanks for the help, I had feared a bad transmission or differential.