Abstract: The invention relates to an improved method for ensuring that at the time of disengagement of a gear in connection with changing gear in mechanical gearboxes without clutch disengagement the engine torque is adjusted to a zero-torque level which is continuously corrected on the basis of the instantaneous acceleration of the engine but also on the basis of the internal friction of the engine and on the basis of any power take-offs being powered by the engine.In gear changing, adjustment begins with a torque reduction at time t.sub.1. The torque is reduced to a zero-torque level M.sub.0 which is continuously variable during the reduction and which is adapted to the current engine deceleration and which is corrected by a friction factor M.sub.f and an acceleration factor M.sub.a. The friction factor M.sub.f is derived from a matrix M.sub.f (n,T) on the basis of current engine speed n and engine temperature T, and the acceleration factor M.sub.