Abstract: A window regulator assembly is provided that includes a guide defining a path. A window bar assembly having a window mounted thereon is supported on the guide and is movable along the path. A manual or automatic actuator is interconnected with a drum for rotationally driving the drum. A pair of cables each include an end connected to the drum with the opposing end connected to the guide. The cables are arranged in a pull-pull relationship between the drum and guide. A portion of the cables is wrapped about the circumference of the drum. A drum biasing assembly, which may include a mandrel urged into bore of the drum by a spring, expands the circumference of the drum to take up the slack in the cables. The drum includes radial grooves that divides the drum into sectors that are movable relative to one another by the mandrel.