An electro-pneumatic changing system for a gearbox (1) in which the gears which are controlled by magnetic valves (41 to 48) are changed pneumatically via servo cylinders (21 to 25), whereby, in normal operation, the magnetic valves (41 to 48) or the central valve block (4) in which the magnetic valves are contained are powered via a compressed air line. During emergency operation, the compressed air is supplied directly via a separate pilot valve (9) to a selection of servo cylinders (21 to 24). There is a second compressed air source (7) linked to a multi-position pilot valve (9) acting as an emergency changing valve. The servo cylinders (21 to 24) for the neutral position and the gears in the emergency change system (R, I, II) may be connected to the second compressed air source (7) via changeover valves (53) and the multi-position pilot valve (9). The compressed air supply may be safeguarded via safety pilot valves (55, 56) mechanically connected to the starting and changing coupling or to the handbrake lever.