I have never seen or heard of that bushing wearing out. I would think there must be a reason like it's spinning on the hub when it shouldn't be...something. Inspect the splines on the cam plate as they may be stripped. As for the cover bearing my 15's was bone dry and I was going to replace it but without a puller I couldn't get it out even with heating the cover in that area so with the seal pulled I was able to clean it up with spray braklean and pack grease from the back side to the front through the center, then reinstalled the seal. I now grease it whenever I have the cover off and it's holding up fine. I don't think that primary bushing is replaceable through CFM but may be through CVTeck. Don't hold your breath though.