PURPOSE: To keep up the strength of a rack as well as to secure both ideal toe change and steering characteristics, by installing both external and internal threads in the rack and a ball joint each, while checking a relative rotation betwen these threads by means of a clock nut and a pin.

CONSTITUTION: When a ball joint 4 is set to a rack 2, first of all, an outer end part of the rack 2 is projected out of a gear housing 1, a state under which a lock nut 11 is screwed in a thread part 9 of the rack 2. Then, an external thread 6 installed in a socket part 5 of the ball joint 4 is screwed in an internal thread 3 of the rack 2, rotating the external thread 6, whereby a center P is set to a position where both ideal toe change and steering characteristics may be brought into full play. Successively, with the lock nut 11 rotated, both external and internal threads 6 and 3 and are coupled together. And, a pin 12 is pressed in an outer end part of the rack 2 and a through hole 13 and a hole 14 made up in the external thread 6 whereby a relative rotation between both external and internal threads 6 and 3 is checked in this way.