A window regulator assembly including a shaft having a pinion gear and a counter balance spring mounted on the shaft which winds or unwinds as the shaft rotates. A spring housing is mounted on the shaft. A cable-guiding drum having an inner gear is driven directly by the pinion gear. The drum has a rotational axis that is offset from a rotational axis defined by the shaft, thus providing a mechanical advantage. A casing houses spring housing and the drum in an abutting relationship. A guide such as a rail is disposed on at least one of the spring housing and the drum for maintaining rotational alignment of the drum relative to the shaft.