Abstract: An improved hydraulic actuator for use as a swing motor in a material handling apparatus of the type having a vehicle mounted boom. Two embodiments are disclosed and each includes a vertically disposed, double-acting cylinder having an internal, vertically reciprocal piston. The cylinder may be disposed between yoke arms mounting a boom and provision is made for securing the cylinder to the vehicle frame. A coupling device is secured to one of the yoke arms and has a first splined surface while means are carried by the piston and movable therewith and include a second splined surface slidably engaging the first splined surface.