Abstract: A variable geometry turbine in which a turbine wheel is mounted to rotate about a pre-determined axis within a housing. A sidewall is displaceable relative to the housing to control the width of a gas flow passage defined adjacent the wheel between the first surface defined by the sidewall and the second surface defined by the housing. The sidewall is mounted in the sidewall cavity within the housing on axially displaceable rods extending parallel to the rotation axis of the wheel. A yoke is pivotally supported within the housing and defines arms each of which extends into engagement with a respective sidewall support rod. The yoke is pivoted relative to the housing to control the position of the sidewall relative to the housing. The yoke is located within a yoke chamber defined by the housing, and lubricant is delivered to the yoke chamber to lubricate both the bearing upon which the yoke is pivotally mounted in the housing and surfaces which interengage the yoke and the sidewall support rods.