An input shaft is connected to a carrier of first set (P1) and a sun gear of second set (P2) and is connectable to a fifth shaft, which couples a carrier of third set (P3) and is connectable to the housing. The sun gear of the first set (P1) is coupled the housing. The fourth shaft couples the ring gear of third set (P3) and the sun gear of fourth set (P4) and is connectable to the housing. The third shaft couples the ring gear of second set (P2) and the carrier of fourth set (P4). The sixth shaft couples the ring gear of first set (P1) and the sun gear of the third set (P3). The seventh shaft couples the carrier of the second set (P2). The output shaft couples the ring gear of forth set (P4). A clutch releasably connects the output shaft to the seventh shaft.