The internal toothed washers actually caused a problem for Fords. They used one at the battery cable to engine block connection. When the washer was sometimes placed between the cable terminal and the cast block there would be only 8 tiny contacts. Lots of vehicles would come in with intermittent no start. Rarely could we recreate the no start. I got a few in that had already been to other dealerships and had the starter replaced. To fix the problem, simply move the toothed washer to between the wire terminal and bolt head. Happy motoring.