Abstract: The change of deviation angle of universal joints and the angular velocity fluctuation of the driveline in a vehicle using A frame during vibration was analyzed. The installed angle of the rear bridge determines whether the driveline is Z or W arrangement which affects the angular velocity fluctuation in driveline differently during vehicle vibration. When the swing angle of the driveshaft is smaller than that of A frame, Style W is better than Style Z. Equations were given to solve the installed angle of the rear bridge in Z and W arrangements. An approximate way was proposed to decide which arrangement is better for a certain vehicle with A frame.