There are chains to both cones. One cone has the shield well attached, the other end, the shield (tube) keeps popping out of the cone. There are no chains to the shields (tubes).there are usually plastic pins that push in to hold the round cone end that covers the U joint onto the tube. usually the chains are hooked to the cone and both sections of shield should have chains that keep them from rotating. are you missing a chain so that one tube is fixed and the other rotating?