Motor vehicle gearbox

A motor vehicle gearbox, comprising at least two concentrically arranged, alternately drivable first and second input shafts (6,9), first and second intermediate shafts (12,15), primary gears (10,11) which are carried by the first input shaft (6) and the first intermediate shaft (12) and which mesh with one another for transmitting torque from the first input shaft (6) to the first intermediate shaft (12), primary gears (13, 14) which are carried by the second input shaft (9) and the second intermediate shaft (15) and which mesh with one another for transmitting torque from the second input shaft (9) to the second intermediate shaft (15), an output shaft (20), gears (16,17,18,19,21,22) carried by the intermediate shafts and the output shaft which mesh with one another in pairs for transmitting torque from either of the intermediate shafts to the output shaft and of which at least one gear in each pair is a disengageable wheel, together with synchromesh members (30), which comprise on the one hand a pair of synchromesh gears (32,33) of different diameters supported on the one intermediate shaft (12), which gears are in drive engagement with gear rims (13,39) on the one input shaft (9), and on the other friction members (34), by means of which a drive connection can be established between either synchromesh gear (32,33) and the intermediate shaft (12) in order to adjust the rotational speed of the intermediate shaft, which is drive-connected to the currently undriven input shaft, to a rotational speed determined by the gear selected, at least one synchromesh gear (33) being coordinated with clutch members (60), which are designed to lock the synchromesh gear on the intermediate shaft, characterized in that the latter synchromesh gear (33) is designed to be locked on its shaft (12) when the currently undriven input shaft is disengaged, in order to permit torque transmission from the one intermediate shaft (12) to the output shaft (20) by way of the currently undriven input shaft (9) and the second intermediate shaft (15).