A gearbox for a roller in a spinner wrench is provided. In some embodiments, the gearbox can be disposed internally to the roller and can include a sun and planet type epicyclical gear-reduction assembly. In further embodiments, the gearbox can include a second sun and planet type epicyclical gear-reduction assembly to provide for a second, or final, stage reduction. Some embodiments can provide for reduction-ratios close to 3:1 and can be driven by a relatively small motor. The planet gears can be used to drive an annular gear which can spin the roller. In some embodiments, the gearbox can use high-capacity bearings.