1,002,020. Differential gearing. O. MUELLER. May 6, 1964 [May 31, 1963], No. 18895/64. Heading F2D. In a motor vehicle planetary differential gear slip is resisted by throttling liquid pumped by pistons 54, 55 reciprocated in radial bores in the planet carrier 20 by a cam 48 on one side wheel 38, alternate bores, oppositely phased, communicating with annular ducts 64, 65 which are connected through an exchangeable orifice in an axial bore (Fig. 4, not shown). Make-up liquid is supplied to the duct 65 through an exchangeable orifice in an axial bore (Fig. 4, not shown). Make-up liquid is supplied to the duct 65 through a one-way valve (Fig. 4, not shown) and duct 95, by a pump 80, surplus from which exhausts through a duct 96 and relief valve.