are you allowed to use oil or grease on your robot, like WD-40 or petroleum jelly, or is that illegal?

How do I turn this off? (Sorry, couldn’t resist). Let me google that for you?
Can you say: “I have checked the Game Manual and totally overlooked R7e, even when searching for the word grease”?

@HowDoITurnThisOn? please consider reading the game manual, it tells you what is or is not legal.
As @nenik stated, rule R7 says:

I omitted part of R7 to address your question, you really should read the rules though.