For large-sized buses with hydrodynamic retarders (auxiliary brakes), the propeller shaft connection (end yoke) does not have an appropriate structure, and therefore, the bearing stopper of the cross-shaped joint (spider) on the end yoke may get worn out from repetitive starts and stops or may be damaged at the time of assembling the propeller shaft. If this problem is left unattended, the bearing may start to wobble, which can cause the propeller shaft to vibrate excessively, and in the worst case, the bearing fixing bracket or bolt could break and cause the propeller shaft to fall off.