2005 Oddy with about 70K miles. Recently put on new tires (AVID TRZs) and the sound is still there although different. I chalk this up to it previously being a combination of tire noise and ??? Noise comes from the rear end, sounds like the right rear. It is a constant humming with a slight vibration. Sound get louder with speed, is unaffected by braking (except decreases as the van slows) and really noticeable from 25 MPH and up. Seems to decrease when turning left and gets louder when turning right. (i.e. louder with more pressure on the right side) Climbed around the back while the wife was driving using a ratchet extension and screwdriver as a stethoscope, pretty sure it is the right side. I think it might be the bearings and have tried the search function. Any help diagnosing is appreciated.