What could cause vibration in a rear wheel drive vehicle equipped with CV u-joints?

Vibration in a rear-wheel drive vehicle equipped with constant velocity (CV) U-joints can indeed be caused by a distorted pinion flange. The pinion flange is critical because it connects the pinion gear of the differential to the drive shaft, and any deformation can lead to imbalance. This imbalance creates excessive vibration when the vehicle is in motion. Moreover, a distorted pinion flange can also affect the alignment of the drive shaft, which can further contribute to vibration issues.

While worn center support bearings and a bent centering ball stud can also contribute to vibration, they are not the most direct causes in the context of the question's focus. Issues with the center support bearings typically arise from wear and age, affecting the stability of the drive shaft. Similarly, a bent ball stud may lead to drive shaft misalignment, but again, the direct impact of a distorted pinion flange on vibration is more pronounced due to its central role in the drivetrain assembly.

Thus, understanding the mechanics of the drive system highlights why the distorted pinion flange is a more specific and direct contributor to the vibrations experienced in such a vehicle setup.