For the companion flange of the propeller shaft between the rear-front axle and the rear-rear axle of low-floor 6x4 or 8x4 vehicles, because the strength and the tightening torque of the pinion gear shaft and the through shaft are not appropriate, the castle nut may loosen, or the thread sections of the pinion gear shaft and the through shaft may break. If either occurs, in the worst case, the propeller shaft between the rear-front axle and the rear-rear axle could fall off, causing the vehicle to stall. Note: This problem was reported as RJ-0910-0 on 23rd January 2003 and RJ-1257-0 on 7th October 2004, but the measures specified in those recalls turned out to be insufficient, so new measures are introduced and the subject vehicles are revised in this recall.