put a (monkey) wrench in(to) the works(redirected from putting a wrench in the works)
put a (monkey) wrench in(to) the works
To disrupt, foil, or cause problems to a plan, activity, or project. Primarily heard in US. We had everything in line for the party, but having the caterer cancel on us at the last minute really threw a wrench in the works! It'll really put a monkey wrench into the works if the board decides not to increase our funding for this project.