Hello,

I have a 2001 Accord EX (4-cyl). While driving there is rear
undercarriage noise at all speeds. The sound is a low frequency
vibration that varies with the current speed being traveled. The
sounds appears to becoming equally from the rear left and rear right
corner of the car. There is no connection to RPMs or engine activity.
The faster the wheels spin, the louder is gets. At 40MPH the vibration

hits a painful, headache inducing, frequency. The faster I go the
higher the frequency. 40MPH is bad, so is 65MPH, but the sound is
always noisy. Back seat passengers really notice it.

A full tire rotation made no difference. Now what?

Thanks!