Possible Clues:

• Oil change, to a mechanic
• One promoting free movement Tory leader's demoted twice
• Oil job, informally
• ___ job (bit of garage work)
• Oil perhaps observed from below in defective bulldozer
• Lubricate, for short
• ___ job (mechanic's task)
• Oil, informally
• ___ job (garage service)
• Engine oil, for short