The invention relates to a system for hydraulically adjusting the transmission of a set of continuously variable gear ratios (2) in a motor vehicle. An electric signal (I) controls at least one valve (5), in order to adjust the transmission. The transmission is also maintained in a substantially constant operational mode by the fact that the electric signal is set to a predeterminable value. The valve then, for example, adopts the aforementioned intermediate position (B) (locked position). This operational mode is also known as the ratio-hold mode. The invention is characterised in that the predeterminable value can be modified during the normal operation of the motor vehicle and has the advantage that component tolerances can be compensated during the operation of the vehicle or of the transmission. The adjustment time required during the assembly of the motor vehicle is thus reduced. The invention also compensates for the wear of components during operation, in particular, for a modification to the spring in the valve (for example, sag of the spring).