An agricultural baler is provided having an adjusting arrangement between a tow bar and a frame, that maintains the spatial relationships existing in the baler constant so that there is no effect upon the flow of the crop. The use of a sensor and a positioning arrangement provides the assurance that the repositioning is not dependent upon the capability of an operator, and finally the arrangement of the sensor in the region of the take-up device sees to it that the signals are transmitted at the exact time, not too soon and not too late.