Worn wheel or driveline bearing noise

[Dustdevil]

I have a 2010 4x4 2500 swd auto. Running down the road at about 25-35 mph I hear what sounds like a worn bearing noise or maybe grinding disk pads on the breaks. I can shut down the engine and coast turning the steering wheel back and forth and the sound stays the same. To me that indicates its not the front hub bearings worn or the side to side loading of the worn bearing would change sound. Also I can ingauge the breaks and not hear or feel any change in sound. When the engine is running and the truck is in gear acclerating or de-acclerating doesn't seem to change the sound I'm hearing eather. That makes me think it's not in the drive train (drive shaft, front and rear end gearing or transfer case). After driving 50 miles at 70 MPH and crawling under the truck and toching ever bearing survace and gear box, transminssion, transfer case, etc none of them feel hot. I'm sure the nose is there at all speeds but its real noticable at the slower speeds. So....what am I missing? The driver side front bearing was change out under warrenty the other day by a Dodge dealer but made no difference at all. Anybody else had this experiance or have an idea what the problem is.
P.S. Same tireson truck before and after noise started.

 

[RVTRKN]

Check your U-Joints, remove your rear drive shaft, and drive it, then the front shaft removed. See if your noise disappears, my 04.5 did this and a drive line mechanic found it that way. One of The U-Joint's was bad on the rear shaft, but tested OK under the usual checking of play and stiffness.

 

[Brocky]

Before you pull the drive shafts. CHOCK THE WHEELS!! and park it in Neutral with the brakes released.. then crawl under and check your U-joints. On big trucks sometimes just the load of the parking brakes prevents the joint from slopping as worn.

 

[jhenderson]

You might also check the dust shields on the brake rotors. Debris can get between the shield and the rotor or the shield can bend slightly and make contact with the rotor. Makes exactly the type of sound you are describing.