All kidding aside, none of us can hear the noise from here, but if you were to remove the lower panel or perhaps the back panel, then set the washer to spin, you could probably pinpoint where this grating sound is coming from. Since you seem to have ruled out the tub, maybe the noise is from the pump in front...maybe the belt fell off in back...if so you should be able to pinpoint it.
How about doing a bit closer inspection and try back?
Also, I'll provide the Gallery Service Manual
(7 MB) for your perusal...this should cover your particular Kenmore in disguise