Just FYI. I changed The oil in my Blackbird a few days ago. I dropped the drain plug and that washer went somewhere in the corner of my garage never to be found again. I unwillingly screwed the drain plug back in, put in the oil, and waited for the leaking to start. To my surprise, It hasn't leaked a drop. Although I'll probably get one when I get a chance, In reality, it seems that you really don't need that little pissant washer! Ron