Slight whining sound at 50mph and above

[chris_h]

Hi,

 

My 350z has just recently started making a quiet whining sound at 50mph and above. I don't believe its engine related as the whine doesn't change with rpm just speed and I don't think its gearbox related as it still makes the sound in neutral/with the clutch press in and in all gears. Does this sound like a wheel bearing or differential issue?

 

The sound gets louder the faster I go and disappears below 50mph.

 

Any help would be appreciated.

 

Thanks