A system for controlling the clearance distance between an impeller blade tip of a centrifugal compressor and a radially inner surface of an impeller shroud in a turbine engine. The system comprises a thermal driver coupled between the impeller shroud and engine casing by hinged linkages. The thermal driver includes an annular ring and annular seal which together define thermal driver cavity. Relatively warm or relatively cool air supplied to the thermal driver cavity cause expansion and contraction, respectively, of the annular ring which is translated by linkages into axially forward and aft motion, respectively.