You can oil plastic gears as well as metal gears. (nylon gears are sometimes recommended to be oiled). Some warn plastics can't take all types of grease for some reason, depending on the ingredients. Don't stray too much from the recommended oils for sewing machines, some lubricants can contain harsher ingredients. Basic sewing machine oil, Finish Line Ceramic Wet Lube and Trilfow should be safe. Unless it's in a place where it might dribble where it shouldn't (like motor, worm gear on the 201-2) oil can be used. A good oil will coat gears well, not fling off. It needs more frequent application than grease, and it can be a disadvantage if it needs a lot of dissasembly to reach the parts. Singer recommended oil on all the meshing gears for the 201, except for 201-2, for the set of direct drive gears in connection with the hand wheel. It wasn't until a bit into the 50s they they started recommending grease for these gears in general, like the 401. Oil often comes out better than grease in tests, it's only under certain conditions grease turns out to have advantages; oil will work well on open gears under the base. I use Finish Line Ceramic Wet Lube (light oil with teflon) on my 201 (belt driven motor) and I like it better than grease.
Last edited by Mickey2; 09-03-2016 at 03:37 PM.