I noticed today that my rear passenger-side wheel seems to squeak for the first few minutes of driving. It's not a constant squeak... it's more like a *squeak* *squeak* *squeak* *squeak* and the frequency changes in proportion with speed. When I step on the brakes, the squeaking noise turns into a faint grinding noise. After driving for a few minutes, the noise disappears completely. Does anyone have any idea what this might be? Time for new rotors?

 

First is to raise the wheel and jackstand the weight on the right rear.

Release the parking brake, key on, so transmission may be shifted in neutral. The "squeaking wheel" should now be free to spin.

Rotate the tire, listen and feel for the squeak. Try to isolate it to the brake dragging or the axle drive shaft CV joint. Remove the wheel to further locate the noise source. Suspect too, one of the hub bearings if the squeak is towards the outside.

If brake drag is the noise problem, consider having the brakes bled. or removed and inspected. Check the disk edge for one of the pads to be worn more than it's mate.
If the CV joint, inspect the rubber boot for tear or cuts, allowing the grease to leak out and water in. If this is the case, the axle half shaft needs replacing, with it's CV joints and boots.

Don't be afraid to jack up and jackstand the left rear also. Then you can start the engine, place it in gear and listen for the squeaking.

Reapply the parking brake and place transmission back into park and remove the key, prior to lowering the corners back to the ground.