Lg washing machine with an intermittant grinding noise on fast spin.
Have checked it with same load as customer used when it did it but as usual no noise when we visited and tested it, spent an hour checking it and could not get it to fail.
I had this problem only this weekend with my own LG direct drive machine. Rumbling and grating noise – similar to a drum pulley scraping the back of a plastic drum or a broken spider. But not all the time.
Turned out to be a sock in the drum!! 😯 Heater out and removed it. Perfect!! That could be your problem. 😉