Abstract: In an all-wheel driven field tractor whose front-axle differential (6) and rear-axle differential (15) are permanently driven in arable land by output shafts (2 and 3) of a gear change (1) so that a rigid connection exists between front and rear axles, the higher speeds of the front axle (7) appearing when cornering must be compensated. Besides, a mechanism for compensating the axle speeds must be adapted to be integrated in the field tractor without substantial constructural changes. For this purposse there is situated between the crown gear (12) and the differential cage (14) of the rear-axle differential (15) a clutch (16) designed as a control slip clutch having its slip status regulated according to the parameters of the track radius to be executed and/or the traction needed.