Abstract: An earth-moving machine includes a coupling releasably joining a bucket to an end of a dipper stick. The coupling includes a hook pivotably coupled to the dipper stick about a first axis and configured to engage a pin secured to the bucket. The coupling further includes a pair of pins coaxially disposed along the axis and movable between an extended position in which the pins are received within a pair of spaced openings on the bucket to join the bucket to the dipper stick and a retracted position in which the pins are removed from the openings. The pins are actuated between the extended position and the retracted position by an actuator disposed along the axis between the pins. The actuator preferably includes a cylinder, first and second pistons disposed within the cylinder and coupled to the first and second pins, respectively, and at least one source of hydraulic pressure fluidly coupled to the cylinder to pressurize the cylinder and to move the first and second pistons and the first and second pins.