A decoupler assembly for transferring torque between an endless drive element and a shaft , comprising: a hub that is adapted to be coupled to the shaft such that the shaft co-rotates with the hub about a rotational axis; a pulley having an outer surface and an inner surface , wherein the outer surface is adapted to engage the endless drive element , wherein a bearing is positioned between the inner surface of the pulley and the hub , and wherein the hub includes a pulley support surface that slidingly supports the inner surface of the pulley , wherein the bearing and the pulley support surface together support the pulley for rotation relative to the hub ; a dampening spring positioned to transmit torque between the hub and a carrier ; and a helical clutch spring , wherein the clutch spring expands radially to operatively connect the pulley and the carrier when the pulley is rotated faster than the hub in a first rotational direction, thereby driving the hub with the pulley , and wherein the clutch spring contracts radially to operatively disconnect the pulley and the hub when the pulley rotates more slowly than the hub in the first rotational direction, wherein the pulley and the hub cooperate to define a chamber in which the clutch spring is disposed, and which includes a gap (G) between the pulley support surface and the inner surface of the pulley , wherein the chamber is filled with a lubricant , characterised in that there is provided by the lubricant within the gap (G) a lubricated pulley-support-surface-material to pulley-inner-surface-material contact between the pulley support surface and the inner surface of the pulley : a hub that is adapted to be coupled to the shaft such that the shaft co-rotates with the hub about a rotational axis; a pulley having an outer surface and an inner surface , wherein the outer surface is adapted to engage the endless drive element , wherein a bearing is positioned between the inner surface of the pulley and the hub , and wherein the hub includes a pulley support surface that slidingly supports the inner surface of the pulley , wherein the bearing and the pulley support surface together support the pulley for rotation relative to the hub ; a dampening spring positioned to transmit torque between the hub and a carrier ; and a helical clutch spring , wherein the clutch spring expands radially to operatively connect the pulley and the carrier when the pulley is rotated faster than the hub in a first rotational direction, thereby driving the hub with the pulley , and wherein the clutch spring contracts radially to operatively disconnect the pulley and the hub when the pulley rotates more slowly than the hub in the first rotational direction, wherein the pulley and the hub cooperate to define a chamber in which the clutch spring is disposed, and which includes a gap (G) between the pulley support surface and the inner surface of the pulley , wherein the chamber is filled with a lubricant , characterised in that there is provided by the lubricant within the gap (G) a lubricated pulley-support-surface-material to pulley-inner-surface-material contact between the pulley support surface and the inner surface of the pulley : <EOS>