Im getting my new to me picker ready to go, and was getting the vines, and corn stalks that were wrapped around various shafts cut off. I noticed that the idler sprockets on the gathering chains were loose, and one was tight. i took a couple of them apart, and to my surprise there is no bearing. Just a male, and female cone(for lack of the correct term). I checked my manual, im not missing any parts, and the lubrication guide makes no mention of lubricating them. I dont think grease would be the answer, it would collect dirt and dust. It seems it needs something? Maybe dry graphite? What do you guys think?