I read two pages in search but didn't find what I was looking for. I've got droopy doors, (not drawers). I could buy a rebuild kit but what if the hinges themselves are worn? IF I buy new hinges, is there a way to flute the pins and install a grease fitting to prolong their life? How can I tell if the hinge is too worn for a rebuild kit, ( try rocking the doors to see if there is looseness?)??