What crush washer? I've never used one and the owner before didn't either, and it doesn't leak. I thought it odd, but the parts guy said there wasn't one (1996 T-100). I must admit that the bolt acts peculiar when you remove it. The first couple of turns it spins easy and then more resistance so you have to use the wrench. I thought maybe the threads were intentionally deformed so that it wouldn't fall out on its own if the bolt loosens. Also you need to loosen it a couple of turns before any oil starts to drain, so the threads themselves must be sealing.