An assembly for a turbine engine turbine includes a turbine rotor disc centered on a longitudinal axis and a turbine shaft centered on the longitudinal axis and driven in rotation by the rotor disc. Torque from the rotor disc is transmitted to the shaft, wherein the rotor disc is locked in translation relative to the shaft in the direction of the longitudinal axis by a screwed member on the shaft. Torque from the rotor disc is transmitted from the rotor disc to the screwed member when the torque ceases being transmitted from the rotor disc to the shaft. The screwed member has an unscrewing direction identical to the direction of rotation of the rotor disc in operation.