Yup, agree 100%. When the cone bottoms out in the case the cone can no longer grip the sides. Think of it like putting a drinking glass inside another one. When the top glass slides into the bottom one it creates friction. same applies to a cone SG. Now if the top glass is allowed to slide all the way to the bottom, it no longer can "grip" the sides of the bottom glass. By cutting the bottom off the cone you are allowing it to slide farther down there by gripping the sides. At this point you add a shim between the cone and the axle side gear to restore the spring pressure on the cone. I usually cut the cones .080 and add .060 -.080 shim.
