My local Chevy dealership is top notch. When our 2006 Equinox was having its whine issue keep coming back. They first thought it was a bad bearing. Replaced, noise went away. 3000 miles later noise came back. Replaced whole bearing assembly. Noise went away again. 3000 miles later the noise came back again( convenient that the problem comes back in time for the oil change right?
) This time the dealer was going to keep the 'Nox until they find the true cause. After 2 days they found out it was the rear driveshaft. Replaced it and the noise hasn't been back since.