PURPOSE: To secure such a bush built-up body that is large in the degree of freedom of rotation around an axis and displacement in the axial direction by attaching an outer cylinder, a bush of elastic body and a middle cylinder toward the inside from the outside, setting up an inner cylinder as rotatable to the inside and displaceable in the axial direction, and making this inner cylinder biasable in one direction with an elastic member.

CONSTITUTION: A bush built-up body 10 is set up in a connecting part of a trailing arm 70 to a car body at a suspension. When tire 94 bounds during travel, an inner cylinder 18 rotates to a middle cylinder 16 and simultaneously a locus of the trailing arm 70 is changed by action of an assist link 88, whereby the inner cylinder 18 is displaced against spring force of an elastic member 20. With this displacement, a camber angle and a toe-in angle of the tire are changed. Since the inner cylinder 18 is rotatable and displaceable to the middle cylinder 16, the degree of freedrom for each is large. A spring constant of a bush 14 is selectable according to magnitude of load being added to a direction orthogonal with an axis of the inner cylinder 18, so that the degree of freedom for adjustment of the bush 14 is thus enlargeable.