A double arm tailgate window regulator comprising a toothed sector for each arm, the sectors being mounted with the toothed portions in minimum clearance condition. A separate drive pinion is in mesh with each sector and said pinions are in mesh with each other. Due to the minimum clearance between the toothed sectors, the pinions are substantially displaced from a line joining the pivot axes of the sectors. One of the pinions is directly connected to a motor through planetary gearing.