I worked with two washer configurations and eventually configured one washer to work either of two ways. Washer needs a 16mm bore 5/8" will work but is really snug. Outside isn't important but I was using 7/8". Important though is the thickness .090 +/- .005 inches. This with a standarg 5/8" snap ring works (most of the time). If one takes a jewlers file and squares the bottom of the snap-ring groove (its a round wire ring and has a round bottom) so the new rectangular snap-ring will not ride up the rounded bottom it works 100%. The other way is use the same washer but with a chamfer on the inside diameter of one side. This way use the origional round wire snap-ring and it's forced into the groove (estimated 800lbs) and works 100%, but the clearances dimensions is really touchy too much metal cant get the ring in to little and the ramps clear. Picture is the first way.