Had a rattle from the chime box on my Jacks Open and noticed a rubber grommet was missing and parts were pretty worn. I ordered a chime rebuild kit from PBR but noticed another problem when I started disassembling. One of the 3 plungers has it's plastic tip completely worn down wedged. I'll order new plungers but curious what could of caused this to happen so it doesn't happen again. Bad coil? It seems like it would take a lot of force to wedge itself into end like that. Any ideas?