crash together
Of two or more things, to strike each other violently or noisily. A noun or pronoun can be used between "crash" and "together." Our cars crashed together in the middle of the intersection when the other driver ran a red light. My job in the percussion section of the marching band is to crash the symbols together.
crash something together
to bring things together with great force, making a loud noise. Fred crashed the cymbals together and the sound could have wakened the dead. Don't crash those pans together. It drives me crazy.
crash together
to ram or move together with great force. The two cars crashed together, making a loud noise. The ships crashed together, opening a gaping hole in the side of one of them.