Understanding Semi-Truck Drive Shaft Vibrations

Understanding Semi-Truck Drive Shaft Vibrations

If you experience vibrations while driving, this could be a symptom of numerous problems. It is impossible to determine without proper inspection, but understanding semi-truck drive shaft vibrations can speed up the process of identifying the problem. Know what the three main types of vibrations are and what are the expected causes of each.

The Orders of Driveshaft Vibration

There are three orders of vibration to look out for: first, second, and third. Each is a reference to the number of shakes per revolution of the drive shaft. The first order vibration would be one shake per drive shaft rotation, the second order would be two shakes per rotation, and the third would be three shakes.

What a First Order Vibration Could Mean

When experiencing only one shake per revolution, this could mean several problems have occurred, such as:

  • A component that is rotating at the same speed as the drive shaft is out of round.
  • A component that is rotating at the same speed as the drive shaft is out of balance.
  • Your semi-truck is having drive axle problems.
  • Issues with the drive shaft appearing in vehicles driving at least 30 miles per hour.

What a Second Order Vibration Could Mean

  • Incorrect vehicle trim height.
  • Powertrain mounting problems.
  • Faulty U-joints.
  • Improperly phased or twisted drive shafts.
  • Drive shafts at an improper angle.

What a Third Order Vibration Could Mean

Typically, there is one major problem that causes a third order vibration; the likelihood of experiencing a third order malfunction is far lower than the previous two orders. A third order vibration usually occurs due to a faulty constant velocity joint.

Know the Problem, Know the Solution

Some of the issues your truck may experience can be relatively quick and simple fixes, while others may require you to purchase an entirely new semi-truck drive shaft. Once you understand the vibrations of a semi-truck’s drive shaft, then you will be better equipped to identify the problem and formulate a solution.