What are the causes of driveshaft imbalance?
2 Answers
The causes of driveshaft imbalance are: 1. The balance weights on the driveshaft have fallen off; 2. The driveshaft is bent or the driveshaft tube is dented; 3. The driveshaft tube and universal joint are not properly welded, or the driveshaft has not undergone dynamic balance testing and calibration; 4. The sliding yoke is misaligned during installation, causing the universal joint yokes at both ends of the driveshaft to not be in the same plane, failing to meet the constant velocity transmission condition. The symptom of driveshaft imbalance is that when the universal joint yoke and sliding yoke are in good technical condition, the vehicle emits a periodic noise during driving, with the noise increasing as the speed rises, and may even be accompanied by body vibration, causing numbness when holding the steering wheel.
In my automotive repair work, I've observed common causes of driveshaft imbalance. Primarily, the shaft itself may leave the factory with defects, possibly due to manufacturing errors causing center of gravity deviation. Another issue arises during installation, such as flange bolts not being tightened properly or misaligned; once loosened, vibrations occur. There's also the case of shaft deformation during use – collisions or overloading can cause significant bending, directly affecting balance. Poor maintenance is another factor, as worn universal joints develop increased clearance, leading to severe shaking during operation. Corrosion acts as a silent killer, with rainwater erosion causing uneven thickness in certain sections. These compounding issues accelerate driveshaft system damage, making replacement costly. Regular inspection of shaft condition is crucial for prevention.