According to the supported drive shaft manufacturer, with the popularization of automobiles in daily life, people have increasingly high requirements for vehicle handling stability and riding comfort. Therefore, the NVH (Noise, Vibration, Harshness) issue of automobiles has become a focus of attention among university experts, scholars, and enterprise engineers. Vibration in the automotive transmission system has always been one of the key concerns in the R&D process. As a core component of the transmission system, the drive shaft is prone to causing vehicle vibration during high-speed rotation.

The manufacturer states that as a critical part of the transmission system, the drive shaft plays a role in transmitting power, torque, and motion during vehicle operation. In the drive shaft assembly, the rear constant-velocity universal joint is connected to the rear final drive, the intermediate support is fixed to the vehicle body via bolts, and the flexible disc coupling is connected to the transfer case. Among these, the intermediate support and flexible disc coupling are made of rubber, which can absorb impact loads in the transmission system and dampen torsional vibration.

The centrifugal force caused by the unbalanced mass of the drive shaft is equivalent to a periodic disturbing force acting on the entire system. This disturbing force is excited by the continuous high-speed rotation of the engine, so even though the intermediate support and flexible disc coupling absorb part of the energy, the system vibration caused by the periodic disturbing force will not be attenuated.
Typically, the causes of drive shaft wobble and vehicle body shudder are the bending of the drive shaft tube. That is, increasing the amplitude of the drive shaft's bending vibration can enhance the centrifugal force, resulting in intense shudder and abnormal noise.

The manufacturer provides the following troubleshooting methods:
If the vehicle body shudders during startup and abnormal noise from the chassis is heard, check whether the connections between the universal joint and the transmission flange, as well as the rear axle, are loose, or whether the fit clearance between the spline and spline sleeve is excessive.

If periodic noise from the drive shaft is heard while the vehicle is moving, and the noise intensifies as the speed increases, it may be due to drive shaft bending or torsion, and the shaft should be removed for inspection.

Generally, abnormal noise from the drive shaft is caused by damage, wear, deformation, or loss of dynamic balance of related components, which will all lead to vehicle operation failures.

The manufacturer recommends the following inspection methods:
1.After parking the vehicle, manually swing the drive shaft under the car to check for loose parts.
2.Inspect whether the universal joint cross shaft and bearings are worn or loose, whether the intermediate bearing of the drive shaft is 3.worn, whether the intermediate rubber pad is damaged, or whether the hanger is loose.

During normal vehicle operation, the drive shaft transmits power. If the bolts of the drive shaft loosen or fall off while the vehicle is moving, it may cause mechanical failures and even serious hazards. There are many reasons for the loosening of drive shaft bolts. Only by accurately identifying the main causes can correct maintenance and inspection be performed on the vehicle, and preventive measures be taken to avoid accidents.