A modular passenger seat system includes a passenger seat having a seat leg with a distal end portion. The distal end portion includes a tube. The tube includes a sidewall having a first aperture and a second aperture. The modular passenger seat system includes a first detent member and a second detent member disposed within the first aperture and the second aperture in the sidewall of the tube. Each of the first detent member and the second detent member is configured to extend through the first aperture and the second aperture when the tube is received within the bushing. The modular passenger seat system includes a shaft movably disposed within the seat leg. The shaft has a lower end which when displaced against a biasing member enables the first detent member and the second detent member to retract inwardly into the tube.