Why does your truck vibrate while driving?

Unless it is caused by pavement or road conditions, the likely causes are:

• Tires out of balance
• Tires bouncing due to worn shock absorbers
• Unevenly worn tires with "cupping" at the edges
• Worn out U-joints in the drive shaft
• Loose lug nuts on wheels

Worn U-joints in the drive shaft become more noticeable the faster the vehicle is traveling, and the vibration will still be present if the transmission is shifted into neutral or the clutch is disengaged, allowing the truck to coast.