My 05 Gr Cherokee Lmted, has developed a metallic rubbing noise. It sounds almost like a warped rotor or something scraping against the inside of the wheel. The noise is consistent with how fast I'm going. I was sure it had to do with the wheels, so I jacked each one up, put the vehicle in neutral, and spun the tires, trying to duplicate the noise. I couldn't. Then I. decided to take it for a test drive, this time I put the vehicle in neutral while driving, and the noise goes away instantly, until I put it back in drive. So now I think it might have to do with the drivetrain. Anyone think this is the case? And if so, where's a good place to start?

Had a similar problem on my truck 6 months ago and it was a bad front U joint. The bearings in them go out which causes the grinding noise.