Are you sure the clip is snapping over the posts 100% It's a tough squeeze, I had to use a flat head to push it down hard enough, but once it snapped on it was super tight and is a PITA to get back off (I know b/c I had to remove them twice to get rivets tightened). I know the first time I installed mine I thought they were on all th wway but I still had a little ways to go.