A multi-speed transmission having seven forward and one reverse gear. An Input shaft couples sun gear of second gear set (P2) and detachably couples shaft (5), which couples the carrier of third gear set (P3) and shaft (4). Shaft (4) couples the carrier of second gear set (P2) and detachably couples housing and shaft (6). Shaft (6) couples sun gear of third gear set (P3) and ring gear of first gear set (P1). Shaft (3) couples ring gear of second gear set (P2) and carrier of first gear set (P1). Sun gear of first gear set (P1) is fixed to housing. Output shaft couples ring gear of third gear set (P3). Either shaft (5) is detachably connected to housing (G) and shaft (3) is detachably connected to shaft (6) or shaft (3) is detachably connected to housing (3) and to shaft (5).