My Makita 4" grinder, over 30 years old, started making some not good sounds today. So I took it apart to check the bevel gears. They actually look great, but the grease looked pretty dried out. It's the original grease, I never thought to put fresh grease in it. What kind of grease is good for an angle grinder? My first thought was Lithium wheel bearing grease, but I thought I'd ask, repacking the grease seems like something others would have done.