throw a (monkey) wrench in the works

US /θroʊ ə ˈmʌŋ.ki rɛntʃ ɪn ðə wɜrks/
UK /θroʊ ə ˈmʌŋ.ki rɛntʃ ɪn ðə wɜrks/
"throw a (monkey) wrench in the works" picture
1.

jogar uma chave de macaco nas engrenagens, atrapalhar, pôr um obstáculo

to cause a problem or difficulty that prevents something from happening or succeeding

:
The sudden resignation of the CEO really threw a monkey wrench in the works for our merger plans.
A renúncia repentina do CEO realmente jogou uma chave de macaco nas engrenagens dos nossos planos de fusão.
We had everything planned, but the bad weather threw a wrench in the works.
Tínhamos tudo planejado, mas o mau tempo jogou uma chave de macaco nas engrenagens.