squeaky wheel

From the proverb "the squeaky wheel gets the grease"/oil.

squeaky wheel (plural squeaky wheels)

1. A complainer; one who speaks out when there are problems (often pejorative).
   • 1997, Lauch Faircloth, editor, Hud Rebuilding and Loan Guaranty Program‎:

     When I went to those who we needed to get the resources from, I got the title of being the squeaky wheel. Everyone is not going to be a squeaky wheel, but I believe that if we want something and are persistent enough, we will get it...

2. Of several problems, the most apparent or the most urgent.
   • 1999, State of the Petroleum Industry; Hearing the Committee on Energy & Natural Resources, U.S. Senate‎:

     And it is pretty hard to get government, as you know, ahead of the curve. We always respond to the squeaky wheel when things get bad, but you know, clearly there is food for thought in the observation of where we are in our commodity industries.

• spokesperson
• troublemaker
• whiner
• See also Thesaurus:complainer