Go to good ball bearing swivels I tried some cheaper ball bearing swivels and still had the same problem. Also make sure your clevis is spinning freely. They can get sand in them and might need cleaned out, or might need replaced if they have extra material in them from the mold process. I have had this with the plastic ones where there is a little plastic lent from molding them. When the good bb swivels start to stick run them under fresh water and it flushes any sand out and you can use them again.