The problem you're showing is caused by the drum(s) taking a hard hit on the end of the axle, which can snap off the inner bearing shoulder on one side, causing not only the drum to migrate to one side but also the noise you hear (which is the inner shoulder). This can happen during shipment. It's extremely rare, we've only seen a few dozen in the last 20 years (after many thousands of drums produced for all the brands we supply) and the shoulder has been beefed up several times over the 20 year life of the mold but we can't anticipate all the abuse it may see. We still support all of the original rollers we built that are in still service after two decades with new belts and feet that typically wear out with time, and are happy to do it!

The screw is there for dynamic balance.. we use a 2-plane dynamic balancer to identify any slight dynamic imbalance and use screws to offset, much like wheel weights on your car. It serves no other purpose.

We have always honored lifetime warranty on our rollers regardless if you're the original purchaser. Please accept our apologies for the damaged drums you've received, and allow us to get you rolling again! --Pete