an agricultural tractor adjacent to the bevel gear the shaft 10 is provided with a shoulder 14 with which the inner race 16 of a radial cylindrical roller bearing 18 of the nup type is in contact and is supported in the axial direction to the right the inner race 16 is provided with a flange that fixes the bearing rollers in the axial direction only on the side facing the shoulder 14 a further shoulder 20 is provided on the shaft 10 located at a distance from the aforementioned shoulder 14 and which is somewhat smaller than the bearing inner race 16 on the side of the radial cylindrical roller bearing 18 away from the bevel pinion 12 the gearbox shaft 10 engages a thrust bearing assembly having two cylindrical roller thrust bearings 22 24 each of these cylindrical roller thrust bearings 22 24 includes a rotating race 26 28 and a stationary race 30 32 respectively cylindrical rollers and a cage also are arranged between the races 26 and 30 or 28 and 32 respectively each cage contains an inner ring 34 and an outer ring 36 each outer ring 36 is reinforced in its radial direction to prevent any escape of the cylindrical rollers the rotating race 26 of the cylindrical roller thrust bearing 22 is the race nearest to the radial cylindrical roller bearing 18 and is supported axially against the inner race 16 the rotating race 28 of the other cylindrical roller thrust bearing 24 farthest from the radial cylindrical roller bearing 18 and is prevented from any axial movement by a retaining ring 38 this retaining ring 38 engages a groove 39 in the surface of the.