An assembly for operating a wheelchair is provided. The assembly has a support frame with a planar support surface and a motor support assembly positioned on the planar support surface such as to be able to slide. The motor support assembly supports a motor which is coupled to a pinion gear. The assembly further has a linkage assembly for coupling the motor support assembly to the support frame. A handle member is coupled to the linkage assembly and is adapted to move the motor support assembly along the planar support surface. A method for engaging gears of a motorized vehicle (e.g. a wheelchair) is also provided. The method comprises moving a handle generally upwardly, which causes the linkage assembly to slide the motor support assembly along the planar support surface of the support frame until the pinion gear engages and meshes with a bull gear of the motorized vehicle.