Thin steel shims behind brake pad fell out

On my Dodge van with the Chrysler single-piston front disc brakes, two of the thin steel shims behind one of the brake pads fell out of position, got all bent up, and were dragging on the inside of the rim. So I removed those dragging shims and re-installed everything, hoping that the shims weren't really necessary, but now I've got some rubbing noise coming from that brake caliper when I apply the brakes. How should I correct this problem? Thank you.