You can either pull the shim out or just let it rub the rotor until you
replace the pads again. In the latter case, there'll be no significant
damage beyond the rotor eating up the shim.
the shim is cutting grooves in the rotor hub. only about .60, but as the
outside pad wears down, it moves more inward and cuts new grooves, now
have 2 grooves on each front hub
