What are the causes of torsional vibration and shaking in the driveshaft?
1 Answers
The causes of torsional vibration and shaking in the driveshaft include: bending deformation and eccentricity of the driveshaft; loss of balance in the driveshaft; detachment of balance plates on the driveshaft; wear of the universal joint (cross pin and needle bearings); loose connection bolts of the rear axle flange on the driveshaft, etc. Here are the detailed explanations: 1. When starting the car, if the body shakes accompanied by a "clunking" impact sound; and during driving, a periodic noise can be heard from the chassis, which becomes louder as the speed increases; in severe cases, the cab vibrates, and holding the steering wheel causes numbness in the hands, all of which are symptoms of driveshaft torsional vibration failure. 2. When the technical condition of the driveshaft is good, the amplitude of bending vibration is small, and the shaking and noise are not obvious. When its technical condition deteriorates, the amplitude of bending and torsional vibration increases, the vibration becomes intense, and may even cause body shaking, accompanied by noticeable periodic noise that intensifies with increasing speed. 3. Vibration during acceleration at speeds of 30~50 km/h is caused by an inappropriate angle between the driveshaft and the pinion gear axis in the rear axle. This can be mitigated by reinforcing the rear suspension with some form of overload auxiliary leaf spring to ensure the pinion gear and driveshaft operate at the correct angle. 4. Vibration during deceleration at speeds of 30~50 km/h is usually the opposite of the above, caused by an excessive angle between the pinion gear and the driveshaft axis. This vibration is more intense and is often due to sagging suspension components and front springs. If the vibration becomes more severe with increasing speed, it is due to unbalanced or poorly assembled transmission components, requiring a balance performance check.
