Abstract: A transport unit usable in a flexible assembly system and comprising an automatic guided vehicle and a work carrier positioned to the rear thereof. The work carrier is of a U shape with a pair of spaced legs extending from a base and having free ends, each of which rotatably mount tooling for engaging opposite ends of a component of the device to be assembled. Drive mechanism is provided for elevation of the work carrier and rotation of the tooling to orient the component at a desired height and at a desired rotative position for ease of assembly of components thereto. The tooling on the work carrier rotates about an axis and engages a component of the device to be assembled whereby the rotative axis is close to the center of gravity of the device to be assembled to minimize the power requirements in rotation thereof. The transport unit has additional structural features facilitating assembly operations and safety of operation.