Abstract: A hydroformed driveshaft tube formed using a hydroforming process is provided. The hydroformed driveshaft tube comprises a first end portion, a second end portion, and a middle portion. The middle portion is at least partially defined by a circular arc shaped surface of revolution. At least a portion of the middle portion has a diameter greater than a diameter of the first end portion and the second end portion. The middle portion comprises a first distension, a constriction, and a second distension and is formed between the first end portion and the second end portion. The constriction is formed between the first distension and the second distension and the middle portion affects a critical speed and a breathing mode frequency of the hydroformed driveshaft tube. The hydroformed driveshaft tube reduces a cost of a driveshaft assembly.

Abstract: Structure of a cross universal joint is achieved in which the fact that an excessive torque was applied to a universal joint due to a collision accident or mishandling can be easily determined afterwards. Protrusions 20, which are straight lines as seen from the outside surface sides of linking arm sections 15c of a yoke 12c, are formed on the outside surfaces of the linking arm sections 15c. When an excessive torque acts and the linking arm sections 15c are plastically deformed, the protrusions 20 change from a straight line to a non-straight line. From this change it is possible to easily confirm that an excessive torque has been applied to a cross universal joint that includes this yoke 12c. Moreover, when the space between the inside surfaces of the linking arm sections 15c is taken to be D, and the length in the axial direction of the linking arm sections 15c is taken to be L, the dimensions of the parts of the yoke 12c are regulated so that the relation 3<L/D?4 is satisfied.

Abstract: An automotive shaft assembly is provided including a first barshaft having a first connection end and a second barshaft having a second connection end. A connection tube rotationally engages the first connection to the second connection end and includes a shear diameter configured to experience shear failure in the presence of an overload torque such that the first connection end is rotationally disengaged the said second connection end.