Abstract: In a gearshift unit for a transmission of a motor vehicle, wherein a driver of the motor vehicle shift the gears of the transmission by means of a gearshift lever and the gearshift unit has a gearshift power-assist unit to enhance the shift force exerted by the driver of the vehicle, a control device is provided which detects a significant increase in a moment of inertia, in excess of a normal amount, of masses to be accelerated in the event of a gearshift in the transmission and actuates the gearshift power assist unit to assist the shift forces only when no significant increase in the moment of inertia has been detected in order to prevent high shifting forces from being generated when they might lead to damage to the transmission.