Hi all, so today on the way to work my front passenger wheel started grinding after going over a dig out part of a road filled with limestone. I thought a rock kicked up in between the rotor and pad as there was a groove in the rotor when I got to work. Came home, disassembled that brake assembly and no rock. Took boots off pistons and cleaned and greased everything. Still have the grinding issue. Anyone know what it may be? My other thought was wheel bearing. It’s a 2007 LS460 base with 152k miles.