Change-speed gearbox having a gearbox housing which has an auxiliary chamber

A change-speed gearbox of a motor vehicle having a drive input and a drive output shaft which are mounted in a main chamber of a gearbox housing and by which a power flow can be transmitted by the selective actuation of clutches such that, parallel to the drive input and output shafts, an intermediate shaft with an intermediate gearwheel is arranged in an auxiliary chamber of the gearbox housing which communicates with the main chamber, so that when the shifting device is appropriately actuated, a power flow is directed from the drive input shaft, via the intermediate gearwheel of the intermediate shaft, to the drive output shaft to produce a reverse rotation direction of the drive output shaft. The auxiliary chamber, accommodating the intermediate shaft, has a bell-shaped longitudinal section with an oval cross-section.