Abstract: In a vehicle's driveline, the clutch between drive engine and gearbox has the task of ensuring a final speed adjustment between the engine and the gearbox at the time when the clutch pedal is allowed to rise on completion of a gear change. The invention has the object of reducing the stress on the clutch and the disadvantages which arise from a lengthy sliding-in process with large speed differences. This is achieved by adjusting the engine speed to the gear being engaged, so that only a small speed difference has to be absorbed in the clutch.

Abstract: A process for correcting the torque to which an engine is adjusted before a gear disengagement, preferably on an automated gear change of a stepped gearbox without using any clutch. Immediately after a gear has been disengaged, the engine is adjusted towards a zero torque (M.sub.0) which will maintain the engine speed (n) constant during the gear disengagement. This zero-torque level is stored in a matrix for the relevant operating point given by at least the engine speed (n) and the engine temperature (T). During a fixed measuring period after the gear disengagement when the gearbox is in neutral position, the acceleration of the engine when it is run with the relevant zero torque is detected. Thereafter any acceleration detected is converted to a corresponding torque, which represents an error in the modulated zero torque.

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.