A robotic carton unloader for unloading a carton pile resting on a floor includes a mobile body movable across the floor on more than one wheel. A conveyor system mounted on the mobile body conveys unloaded cartons thereon. A robotic arm assembly has a manipulator head attached to a front end of the upper arm assembly. The manipulator head engages at least one carton at a time from a carton pile resting on a floor for movement to the conveyor system. A built-in jacking apparatus is extendable from the mobile body to a floor to raise the mobile body a distance sufficient to raise at least one of the more than one wheel away from contacting the floor.