Abstract: A drive-transmitting arrangement for use in a motor vehicle, fork-lift truck or industrial machinery includes a differential or epicyclic gear assembly having an input member and two output members. One of the output members is connected, directly or indirectly, to the operating element of a hydraulic pump so as to drive the pump and the outlet line of the hydraulic pump contains a control valve which may be responsive to the parameters of an engine connected to the input member of the gear assembly. Adjustment of the setting of the valve means varies the resistance to movement of the pump operating element so as to vary the ratio of the gear assembly.