A hydraulic drive apparatus for powering mechanical components of a pull-type implement, such as a crop harvesting unit, having an elongated extending hitching arm for pivotal attachment to a powered vehicle provided with a power take-off shaft. The drive apparatus includes a hydraulic pump for attachment to the hitching arm, a mechanical drive shaft for operation of the hydraulic pump upon attachment of the drive shaft to the power take-off shaft of the powered vehicle, and connections for hydraulic fluid lines for delivery and return of hydraulic fluid to and from a hydraulic motor for operation of the mechanical components of the pull-type crop harvester. The apparatus may include an articulation assembly to isolate the drive for the pump from movements between the hitching arm and the vehicle.