well, turns out that the passenger side inner brake pad was worn down to the metal causing the rasping/grinding sound, although the outer front pad looked fine. Looked at driver side pads and both were worn down to nothing. Rotors on both horribly scored and almost certainly warped.

About 60k miles on the semi metalilc pads and rotors. Funny thing, until the grinding started after the tire change, there was no indication of ANY brake wear problem -- quiet even braking, no sounds, no vibrations (not even the typical warning noises that come from worn pads) and the brakes even passed safety inspection a week earlier.

The installer swears he didn't overtorque lug nuts and even if he did, a warped rotor wouldn't cause pad wear like that to happen.

Aside from just miles or overtorquing, any thoughts on what could cause the extreme wear on the pads...and even more confusing...why would the one outside pad be okay?

thanks ggaarryy