2006 Explorer Drivetrain Vibration

[Dag06XLT]

35-40mph very obvious vibration/humming that sounds exactly like wheel bearing but both are new Motorcraft (MC) hubs. Sound based on speed and does not change with on/off throttle so eliminating pinion, maybe. Doing the "S" turning test, louder left quieter going right which told me a bad right front bearing. With 145k miles, I just replaced bad left bearing a couple months ago and the right one yesterday w/MC. I've been doing some searching but a bit stumped now so looking for som advise form here. I'm doing the tire rotation today. Thanks!

 

[Explorer_PL]

I have replaced the bearings probably more than 10 times by now (230k miles). On few occasions I missed the target and replaced the good one, so lately, I jack up the car all 4 wheels, and go under with a stethoscope while someone is holding the car steady at about 30-40 mph (make sure you have the car secured properly) .

On these cars the sounds go around from corner to corner, and it's very misleading.
Last time I thought my front diff was humming but it was just just the front u-joint on the small front driveshaft, $ 20 fixed that so that may be something else to look at.