A control system for the transmission of an agricultural vehicle or an industrial off-highway vehicle, wherein the system comprises a controller of the clutch, connected thereto to supply an operating signal, a plurality of sensors suitable for measuring a plurality of characteristic quantities of the transmission and connected to the controller to supply a plurality of signals proportional to the quantities, a torque processor suitable for calculating a reference torque and connected to the controller to supply thereto a signal proportional to the reference torque, and a thermal load managing device suitable for receiving at least some of the plurality of quantities and for receiving the reference torque in order to calculate at least one operative datum on which the thermal power exchanged in the clutch is dependent. The control system is suited to process the operative datum to operate the transmission so as to limit the temperature in the clutch.