A turbocharger having a variable-nozzle assembly, comprising: a compressor housing and a compressor wheel mounted in the compressor housing and connected to a rotatable shaft, and a turbine housing and a turbine wheel mounted in the turbine housing and connected to the rotatable shaft, the turbine housing defining a chamber surrounding the turbine wheel for receiving exhaust gas from an engine and for supplying the exhaust gas through a nozzle leading from the chamber generally radially inwardly to the turbine wheel; a nozzle ring having opposite first and second faces, the nozzle being defined between the second face and an opposite wall, the nozzle ring having a plurality of circumferentially spaced-apart bearing apertures each extending axially from the first face to the second face; a plurality of vanes disposed in the nozzle and each having a proximal end and a distal end, the proximal ends of the vanes being proximate the second face of the nozzle ring, axles being joined to the proximal ends and being received into the bearing apertures of the nozzle ring and being rotatable in the bearing apertures, the vanes being rotatable between a closed position and an open position; a plurality of vane arms adjacent the first face of the nozzle ring and respectively affixed rigidly to the axles, each vane arm having a free end; a unison ring positioned generally coaxially with the nozzle ring with a face of the unison ring opposing the first face of the nozzle ring, the unison ring being engaged with the free ends of the vane arms and being rotatable about an axis of the nozzle ring so as to pivot the vane arms, thereby pivoting the vanes in unison, the unison ring being rotatable between a closed position corresponding to the closed position of the vanes and an open position corresponding to the open position of the vanes; a vane sealing member having a portion disposed between the second face of the nozzle ring and the proximal ends of the vanes; and a cam arrangement by which the unison ring engages the vane sealing member during rotation of the unison ring to the closed position, the cam arrangement being configured to move the vane sealing member in a first axial direction against the proximal ends of the vanes when the unison ring is moved to the closed position such that clearances between the vane sealing member and the proximal ends are reduced or eliminated, and being configured to allow the vane sealing member to move in a second axial direction opposite to the first axial direction when the unison ring is moved out of the closed position. a compressor housing and a compressor wheel mounted in the compressor housing and connected to a rotatable shaft, and a turbine housing and a turbine wheel mounted in the turbine housing and connected to the rotatable shaft, the turbine housing defining a chamber surrounding the turbine wheel for receiving exhaust gas from an engine and for supplying the exhaust gas through a nozzle leading from the chamber generally radially inwardly to the turbine wheel; a nozzle ring having opposite first and second faces, the nozzle being defined between the second face and an opposite wall, the nozzle ring having a plurality of circumferentially spaced-apart bearing apertures each extending axially from the first face to the second face; a plurality of vanes disposed in the nozzle and each having a proximal end and a distal end, the proximal ends of the vanes being proximate the second face of the nozzle ring, axles being joined to the proximal ends and being received into the bearing apertures of the nozzle ring and being rotatable in the bearing apertures, the vanes being rotatable between a closed position and an open position; a plurality of vane arms adjacent the first face of the nozzle ring and respectively affixed rigidly to the axles, each vane arm having a free end; a unison ring positioned generally coaxially with the nozzle ring with a face of the unison ring opposing the first face of the nozzle ring, the unison ring being engaged with the free ends of the vane arms and being rotatable about an axis of the nozzle ring so as to pivot the vane arms, thereby pivoting the vanes in unison, the unison ring being rotatable between a closed position corresponding to the closed position of the vanes and an open position corresponding to the open position of the vanes; a vane sealing member having a portion disposed between the second face of the nozzle ring and the proximal ends of the vanes; and a cam arrangement by which the unison ring engages the vane sealing member during rotation of the unison ring to the closed position, the cam arrangement being configured to move the vane sealing member in a first axial direction against the proximal ends of the vanes when the unison ring is moved to the closed position such that clearances between the vane sealing member and the proximal ends are reduced or eliminated, and being configured to allow the vane sealing member to move in a second axial direction opposite to the first axial direction when the unison ring is moved out of the closed position.