My Janome Jem is no oiling. I took it apart (I have two) and the gears are silicone from the looks of them. Silicone needs heat to lubricate so if you don't run you machine at least once a year the silicone gears will be dry when first starting it. If very dry they could crack. Don't set a no oil machine in the closet or shelf for years. I doubt the newer machines have any metal gears, I haven't seen any in all the new machines I seen at the repair shop opened up.