Abstract: Torque transmitting telescopic apparatus comprising a shaft (1) and a sleeve (2) axially displacable relative to each other and interconnected for rotation in common to transmit torque, in which the sleeve has a polygonal bore cross-section and the shaft has a corresponding polygonal cross-section. The bore and shaft cross-sections are respectively defined by pairs of cooperating surfaces. One surface in each of the pairs has at least three sections including a central section defining a groove (4), narrower than the other cooperating surface of the pair, and outer sections (5,6). A rolling element assembly disposed within each groove (4) is restrained against axial movement relative to at least one of the members comprising the shaft and the sleeve and includes a bed, a plurality of rolling elements and a plate spring. The rolling element assemblies couple the shaft and sleeve for play-free axial translation and torque transmission.