A decoupler with free wheel system and vibration dampening comprising: a pulley, a shaft actuated by the pulley, a hub having a first hub piece and a second hub piece, the hub being coupled between the inner race of the pulley and the outer surface of the shaft at least one journal element between the shaft and pulley a torsion spring, and a clutch spring wherein the first hub piece is coupled in a torsion proof manner on the shaft and the second hub piece is mounted around the shaft and can rotate relative to it, the torsion spring is arranged between the outer race of the hub and the inner race of the pulley having a first end operatively couplable to the pulley and a second end operatively couplable to the second hub piece, and the clutch spring is arranged internally to the torsion spring and is frictionally couplable to the hub for transmission of torque to the shaft, the decoupler further comprises a washer mounted by interference fit with the shaft and extending radially to the pulley, the washer being arranged in contact with a face of a radial wall of the second hub piece, the washer has a shoulder on its face in contact with the wall, wherein the wall has a shoulder on its face in contact with the washer, the wall and washer are positioned so that the shoulder of the washer is angularly displaced relative to the shoulder of the wall, so that when an overload is applied to the second hub piece, the shoulder of the washer rotates and overlaps the shoulder of the wall, causing the second hub piece to move toward the first hub piece and the first and second hub pieces (4, 6) are locked by interference between them. a pulley, a shaft actuated by the pulley, a hub having a first hub piece and a second hub piece, the hub being coupled between the inner race of the pulley and the outer surface of the shaft at least one journal element between the shaft and pulley a torsion spring, and a clutch spring wherein the first hub piece is coupled in a torsion proof manner on the shaft and the second hub piece is mounted around the shaft and can rotate relative to it, the torsion spring is arranged between the outer race of the hub and the inner race of the pulley having a first end operatively couplable to the pulley and a second end operatively couplable to the second hub piece, and the clutch spring is arranged internally to the torsion spring and is frictionally couplable to the hub for transmission of torque to the shaft, the decoupler further comprises a washer mounted by interference fit with the shaft and extending radially to the pulley, the washer being arranged in contact with a face of a radial wall of the second hub piece, the washer has a shoulder on its face in contact with the wall, wherein the wall has a shoulder on its face in contact with the washer, the wall and washer are positioned so that the shoulder of the washer is angularly displaced relative to the shoulder of the wall, so that when an overload is applied to the second hub piece, the shoulder of the washer rotates and overlaps the shoulder of the wall, causing the second hub piece to move toward the first hub piece and the first and second hub pieces (4, 6) are locked by interference between them.