Upgrading to a Double-Cardan Drive Shaft: A Solution for Angle-Related Vibrations

If you're upgrading or replacing the drive shaft in your Jeep, Toyota, or other truck or SUV, you may be wondering what type of drive shaft is best for your vehicle. One decision you'll need to make is whether to use a single-cardan or double-cardan drive shaft.

A single-cardan drive shaft, also known as a conventional or non-constant velocity (CV) drive shaft, has a single universal joint at each end. This type of drive shaft can be prone to vibrations when the operating angle of the drive shaft is too severe.

A double-cardan drive shaft, also known as a CV drive shaft, has two universal joints at the upper end of the drive shaft, near the transfer case or transmission. The two universal joints work together to reduce vibrations and provide smoother operation, even at severe operating angles. This type of drive shaft is often used in Jeeps and other off-road vehicles because it provides the smoothest drive shaft operation. A common misconception about the double cardan is that the second joint will allow the shaft to flex twice as far before binding. This is not true. It may flex a little further before binding but will not always flex further than a single joint. Again, smooth operation is the purpose of the double cardan. 

So, when should you consider upgrading to a double-cardan drive shaft? First, if your stock shaft is/was a double cardan you should almost always replace it with a double cardan. The change from single to double cardan is often made on lifted vehicles that are experiencing angle-related drive shaft vibrations. When a vehicle is lifted, the operating angle of the drive shaft can become too severe for a single-cardan drive shaft to operate smoothly, causing annoying drive shaft vibrations and potential damage to the drive shaft and other drivetrain components.

Upgrading to a double-cardan drive shaft can help reduce vibrations and wear, but it's important to note that the change may require modifications to your vehicle such as installing a slip yoke eliminator on your transfer case and/or adjusting your pinion angle with shims or adjustable control arms. 

In summary, if your vehicle is experiencing drive shaft related vibrations after installing a lift, you should upgrade to a double cardan drive shaft.