Hello Lawn mower forum. I am Tiny Tinkerer . I am from the generation of rebuild, rebuild, rebuild. I like to keep things going as long as possible. So, now I have a Sears Mastercraft electric lawn mower model # C935. It is almost as old as I am and replacement parts are not available. Luckily I don't think I need any parts, however, when I turned it on last time, it did start to smoke and it sounds like metal rubbing on metal (slightly). I opened it up and it appears that the wrong lubricant was used in the gear box but I am not sure what lubricant to use. Any suggestions would be greatly appreciated.