Patent ID: 8397598

Claim:
Motor-vehicle gearbox comprising: an engagement sleeve movable between a neutral position and one engagement position for engagement of one given gear, a sliding shift fork operatively connected to the engagement sleeve for controlling the movement thereof between the neutral position and the engagement position, a linear hydraulic actuator having a plunger, wherein the plunger is connected to the shift fork for controlling the translational movement thereof and has three positioning notches equally spaced in the sliding direction of the plunger, a linear position sensor able to provide a signal indicative of the position of the plunger of the linear hydraulic actuator, a position-marking ball adapted to engage alternatively in one of the three positioning notches to hold the engagement sleeve in the neutral position or in the engagement position, a first axial abutment surface for stopping the movement of the shift fork in the direction from the neutral position to the engagement position and a second axial abutment surface for stopping the movement of the shift fork in the direction from the engagement position to the neutral position, wherein in the neutral position the shift fork is axially spaced from the second axial abutment surface by a distance which is larger than the sensibility of the linear position sensor, but smaller than the travel the plunger must run in order for the position-marking ball to shift from the positioning notch corresponding to the neutral position to the adjacent positioning notch.