Garbage Disposal Makes Grinding Noise?

Do you run water when you're using it? I need to keep a slow stream of water going from before I turn it on until after I turn it off and it stops moving. That way it doesn't make nearly as much noise for me.

I would first try to lubricate it with a light oil 3 in1 or something along those lines. If this does not do the trick you could have something that is binding in the blades and then disslodges. You will have to disconnect the power, and remove and turn the unit upside down, there should be an allen head shaft at the bottom of the unit, put an allen wrench in it and turn it clockwise and then counterclockwise a few times and re-install it.