I drilled and tapped a small hole(4-40 i believe) in the bottom of my aluminum rear hubs and threaded in a set screw, it pushes up in the center against the hinge pin and takes all the slop out of that area so the pin rotates in the A arms only, not in the aluminum hub. I used to shim everything in my buggy but nowadays not so much..i made a tool with an old shock assembly tool(for V1 shocks) to hold the little plastic washers so i could sand them to any thickness i wanted. Works great for arms, hubs, etc..Basically just the shock tool clipped then sanded down at the tip, it has the same outer diameter as the small washers inner diameter..