Joe, it's not the cams that are the issue, as the 830 and 730 series also have metal cams, it's the gear that drives them is nylon and they do periodically need replacing(every 35 years or so). My 830 model is the model that came out before the 930(older). I replaced this nylon camstack gear and shaft in mine. The whole shebang has to come out-all cams and shaft. Of course putting a new one back in messes with all the internal components and it needs adjustment. Putting any grease on nylon gears is a bit controversial. Some will say it leads to attracting dirt and dust and others say it's fine. It's up to you. Personally, I only grease metal on metal gears. I know some of the lubricant does eventually make it to the nylon gears, but I don't put it there on purpose. If the nylon gear was making a noise or causing problems, it would probably not hurt to grease it, but I would probably just oil it as the manual states. You can ask Cathy what her opinion of this is, but I follow this same logic with my Elnas and leave well enough alone.