An improved rear-view wiping mirror assembly is described in which a rear-view mirror has placed against it a horizontal wiper connected at both ends to a bracket. The wiper is driven in oscillation by a vertically-positioned improved helical screw having expanded reversing grooves and a tanged cylinder member. The entire drive mechanism is contained within a sealed enclosure which includes yieldable seals through which the bracket oscillates. Ease of manufacture and reliability are enhanced through minimization of parts, molding of the oscillation mechanism, and utilization of a single connecting rod/guide rod member.