What I think you're looking at are the spacers between the swing arm and the rear hub. The rubber washers you're talking about are the seals that keep dirt/grit out of your bearings and the grease in. The spacers press against the bearings inside the hub and the seals ride on these spacers. Mine squeeks just a bit sometimes but nothing really loud...I notice it mostly when I'm pushing it for point a to point b.
