PURPOSE: To shorten the length of an assembly line to the necessary min. length and obtain the functional parts which satisfy the performance simultaneously with the completion of assembly by constituting the titled method from the measurement of a part at the assembly stage of a plurality of constitution parts, assembly adjustment which satisfies the performance, and the assembly of the next constitution part.

CONSTITUTION: Before a tie rod is assembled onto the output shaft 9 of a gear box device A, the assembly performance is measured, and assembly adjustment is carried out until the result of the measurement satisfies the prescribed performance. This assembly adjustment consists of the preload adjustment in which a pressure is applied by the fastening adjustment for a cap 40 and the backlash adjustment in which an adjusting bolt screwed from the vertical direction of a box 24 is fastening-adjusted. In the preload adjustment, the revolution rigidity of the output shaft 9 is adjusted, and then the frictional torque is adjusted, and after the completion of the adjustment, the backlash adjustment is carried out. Since the next constitution parts are assembled when the prescribed performance is satisfied, the need of the processes for readjustment and reinspection can be avoided.