An Atlas maintenance kit that includes grease, oil, and lubricating contact cleaner is a good investment along with a tube of MASS metal polish to clean wheel wiper strips. I tear down my engines and using a track eraser, scrub all the metal contact parts with these cleaners. I scrub gears and power truck frames with Dawn detergent and a toothbrush, rinse, and let air dry. Once everthing is dry I re-assemble it all with dabs of grease and oil on the moving parts with a round pointed tooth pick. Use only slight amounts of grease and oil. Otherwise, they gum wreak havok on everthing.