A gearshifting unit for a vehicle transmission (6) comprising a main
transmission part (10) manually shifted by the vehicle driver using a
gearshift lever (16) and one range change group transmission (14) shifted
by valves (44, 46). The gearshifts are manually preselectable by the
vehicle driver using a gearshift lever (16), the same as a power
assistance device (74) for shifting the gear steps in the main
transmission part (10) and one electronic control device (20) which
actuates the valves (44, 46). In a method for reducing the power
assistance, a neutral position is detected in the manually shifting main
transmission part (10) and once the neutral position is determined, the
gearshift begins in the range change group transmission part (14) and the
power assistance is engaged with a delay.