PURPOSE: To enable arbitrary adjustment of a car height during running, by a method wherein a coil spring type strut type wheel suspension device is constituted such that an upper spring sheet is vertically moved through the working of a screw mechanism through rotation of a motor-driven rod.

CONSTITUTION: With a motor 18 run forwardly and reversely by an operator, a rod 12 is rotated through a reduction gear mechanism 17 and a gear 16. This causes a sun gear 13 also to be rotated togetherwith the rod 2, and a planetary gear 10 to be rotated on the sun gear 13. A screw member 9 is threadedly upward and downward carried, and an upper spring sheet 8 is vertically moved along a support member 11, i.e., a member on the rod 2 side to adjust a car height. This constitution enables a car height to be adjusted according to an operator's will even during running.