I'm sure many folks here know of this trick to lengthen the life of a 5er lube plate but this one is new to me:
one problem with these plates comes when the teeth (for lack of a better term) no longer grip the pinbox's pin, thusly falling off when the camper is unhooked from its tow vehicle .... to tighten up the teeth all one has to do is place the plate on a flat, hard surface and strike them with a hammer .... works best if the direction of the blow is toward the center opening in the plate .... doing so lengthens the teeth and the plate will once again be held securely in place
Jim