The engine drives the gear from the upper left via the input shaft. In all gears except the fourth, the torque is transmitted initially via z1 and z2 to the countershaft. Then, depending on the forward gear, a further gear drive with two gear wheels is involved. In the case of the reverse gear (9, 10), an intermediate gear is added but which is not included in the calculation. The transmission then carries on to the top right, mostly to the cardan shaft