KitchenAid ice maker won't crush ice

Ice won't crush.
Makes ice fine and the chute is clear. I removed all ice from bin, washed, cleaned, dried. If I hold the door button closed and push the ice for crushed ice the teeth turn as they are supposed to, but if I drop a piece of ice in the bin, it stops and makes a grinding sound like it doesn't have the power to crush the ice. If I press the button for cubes, the teeth reverse and the ice drops out. I have checked the connection between the bin and the motor and the teeth are fine and engaged. (I had to replace the teeth on the bottom of the bin once a couple of years ago.) I am guessing that the motor must have some sort of clutch which is not working properly?

Dave