a power operating system for opening and closing a vehicle liftgate has a pair of drive units supported on the vehicle pillars at the sides of the liftgate opening . each drive unit includes a vertically oriented channel and a rack bar that moves in the channel . a link is universally attached to the rack bar at one end and universally attached to the liftgate at the opposite end . the rack bar is raised and lowered by a power unit that has a motor driven pinion gear that meshes with the rack bar . raising and lowering the rack bar opens and closes the liftgate via the link .