Excessive Vibrations: If the drive shaft is damaged or unbalanced, it can cause noticeable vibrations, especially during acceleration. Clunking or Knocking Noises: Worn-out or damaged universal joints (U-joints) can lead to clunking or knocking sounds, especially when changing gears or transitioning between drive and reverse. Leaking Grease: Damaged U-joints or a worn-out seal can cause grease to leak from the drive shaft. Driveshaft Imbalance: An improperly balanced drive shaft can lead to vibrations and noise during driving. Excessive Wear on U-joints: U-joints are prone to wear over time, and if not replaced promptly, they can cause more significant issues with the drive shaft. Physical Damage: Accidents or collisions can damage the drive shaft, leading to issues with its performance.