Grinding sound from rear quick release I heard a grinding noise from the rear wheel on my mountain bike. I took out the quick release and saw that it's full of dust. Before my last long ride, I serviced my rear hub by removing the cassette, re-greasing the ball bearings, etc. I did not open the free-hub body, but I did remove it to get to the bearings.

I flipped my bike upside down and took out the quick release. The sound went away when I removed the quick release, but came back when I re-inserted it. It was also quite a tight fit. Is it normal for the quick release to become dirty on the inside? Should there be seals somewhere? Can I put grease on the quick release after cleaning it?
It’s possible you have a bent or broken axle, which is the only reason a skewer would rub against the hub. Disassemble the inner hub and inspect.