Abstract: The device comprises a gear shift lever which is supported on a stationary support casing and includes a rod having an upper straight section, an upper sleeve fixed to the upper straight section of the rod, and a lower sleeve mounted on the upper straight section of the rod so that it can slide between a lower end-travel position and an upper end-travel position. The lower sleeve is provided with a male stop element arranged to releasably engage a female stop element provided on the stationary support casing, in such a manner as to lock the gear shift lever in a predetermined reference position. According to the invention, the lower sleeve is arranged to rotate between a first angular position, in which the male stop element is aligned with the female stop element in the vertical direction of sliding of the lower sleeve, and a second angular position, in which the male stop element is rotated 90 degrees relative to the female stop element.