Which of the following is NOT a common driveline vibration source?

• A. Unbalanced driveshaft
• B. Worn U-joints
• C. Improper driveshaft angles or misalignment
• D. Engine misfire

Answer: (D)

Driveline vibrations come from parts that directly rotate and transfer power from the transmission to the wheels. The typical sources are an out-of-balance driveshaft, which creates a steady vibration that scales with speed; worn U-joints, which can produce noticeable vibration and clunking as joints wear; and improper driveshaft angles or misalignment, which cause binding and vibration through the shaft. Engine misfire, while it can cause roughness or shaking, originates in the engine’s ignition or fuel system and isn’t caused by the driveshaft or its joints. So the vibration source that isn’t a driveline issue is engine misfire.