Arrived on site and customer stated that the disposal was turning on , but a metal on metal sound was occurring while it ran. Customer asked if I could take it apart and save the unit , which I went ahead and proceeded with. I took apart the disposal and found debri that may have been related to the issue. I also noticed some rust occurring which also could be related to some of the noise as well. I then went ahead and installed the disposal back in place and tested it a few times while running water, which seemed to work. If unit continues to grind , I would recommend replacing as the rust could be breaking down.