PURPOSE: To ease layout and improve durability of the captioned air suspension for a car by arranging a universal joint connection point between an engine output shaft and a propeller shaft on the same level with the pivot of a leaf spring eye.

CONSTITUTION: A connection point for a universal joint 12 between an output shaft 2 for a speed change gear 15 and a propeller shaft 11 is arranged on the same horizontal axis 0 with the center of a pivot pin of an eye 10 of a leaf spring 7. Thus, an axle 5 swings, with the pivot pin of the eye 10 for the leaf spring 7 as a fulcrum, due to vertical movement of a drive shaft 4 during traveling of a car. Since a fulcrum of sway of the propeller shaft 11 due to swing of the axle 5 is on the same level with the connecting point 12 of said shaft to the output shaft 2 and the eye 10 of the leaf spring 7, no external force acts on the propeller shaft 11. Accordingly, any damage is prevented and durability is improved, layout being eased.