11. Both gears are enclosed in a liquid-tight housing containing lubricating oil . 12. During this heating, the lubricating oils are burned off, leaving a dry surface. 13. They refined the viscous substance onsite, making it into lubricating oil and kerosene. 14. Unburnt fuel then leaks past the piston rings and contaminates the lubricating oil . 15. Before the ship sailed, the crew discovered that the barrels of lubricating oil leaked. 16. The latest standard also banned the adding of used lubricating oil ( ULO ). 17. The oil-recovery business collects and recycles used lubricating oils from auto dealers and others. 18. There are small quantities of lubricating oil , probably hydraulic oil. 19. The company also manufactured test equipment for various purposes, including properties of lubricating oil . 20. Also a limited use of talc as friction-reducing additive in lubricating oils is made.
