What is the best cleaning agent for getting heavy oxidation off of a transmission case? This case I'm inquiring is heavy oxidated but looks like it could clean up and still be usable. It has been sitting weather exposed and completely empty for some time. I know it will need thorough inspection and vacuum checks and pressure checks before calling it a good case. I was just wondering what some of you guys use to get a case that's been weathered back to looking like it was brand new again? Sorry if this has been already a discussion, I couldn't find anything in relation.