Abstract: An assembly for converting the one-directional power transmission of a conventional power ratchet wrench into alternating transmission of the power to the wrench's driver head in both the clockwise and counter-clockwise direction without moving the rotational direction selected by the wrench's rotation direction selector subassembly from a first selected position. A scraper attachment attaches to the driver head of the wrench and an engagement arm connects the body of the attachment directly and tightly to the ratcheting section of the wrench. A scraper blade is pivotally connected to the body of the attachment and extends in a generally perpendicular direction from the axis of rotation of the body member. Operation of the wrench results in oscillating arcuate rotation of the scraper blade as it is pressed upon the surface to be scraped.