Abstract: A road surface treating apparatus including a wheel-supported framework having forwardly extending arms pivotally carried thereon. The arms have a transversely extending tool bar mounted to their forward ends. A tool-supporting frame is detachably and adjustably mounted on the tool bar. A cutter drum housing is pivotally mounted on the tool-supporting frame for floating pivotation about a horizontally extending, fore-and-aft axis to facilitate side-to-side rocking movement of the drum housing. A cutter drum is rotatably mounted in the housing and carries circumferentially spaced rows of cutter blades each mounted for rotation about a horizontal axis. A pair of horizontally spaced, shock absorber units is connected between the housing and tool-supporting frame to damp and smooth the side-to-side rocking movement of the housing and the cutter drum mounted therein.