Grinding Sound At Low Speeds

I am looking for some ideas of what to look for when I put the car in the air tomorrow.

I occasionally hear a grinding sound from the rear of my 97 GT at low speeds. I can't tell if there is a specific side it is coming from, but if I had to guess, I would say the left. To me, it sounds like a rotor with a brake pad that was worn out a long time ago. It is a purely grinding sound that makes me cringe, but has no squeak or squeal to it at all. So far, I have only noticed it at slow speeds, under 20mph. It never occurs while turning left, often occurs when turning right and occasionally occurs while going straight. The noise seems to be completely unrelated to the brakes. On a downhill slope, I released the brakes and heard the noise as the car started rolling forward.

I am a bit baffled as to what the sound would be. My experience with wheel bearings has been that they squeak instead of make grinding noise.

Yup, there is a good reason I don't have aftermarket suspension components. The factory stuff is still working well.

The cause was obvious when I got the wheel off. The inside pad on the drivers side was worn through and contacting the rotor. I guess these pads didn't have sqeakers to indicate when the pads were shot. I got 95k out of the pads, so that's not too bad.