I have had a continuous problem with the Vandercook 215 form rollers dropping down too low due to the hex bolts working themselves loose. We tighten these by hand because with a wrench, they get too tight and the rollers won’t turn freely. Is this an indication that there is something wrong with the bearing blocks? We have nyliners in place, too. For years I have just accepted this as press aging, something to be watched from time to time, but I’m hoping there might just be a cure. Any help appreciated. I have photos if that would be helpful.