a torque - transmitting device including a casing inside which a gearwheel is mounted such that it can move by means of at least one rolling bearing housed in a side wall of the casing , the bottom of the casing being shaped to form an oil reserve in which part of the wheel is intended to be immersed , the casing additionally including an oil recuperator wiper arranged in the side wall housing the rolling bearing , above the latter . the oil recuperator wiper includes removable means of attachment to the casing , these means of attachment being accessible from outside the casing .