Dana’s new on-highway tandem axle – the Torsionally Tuned-40® – reduces destructive drivetrain damage caused by adverse driveline angles.

This innovative axle is designed to reduce vibration by avoiding excessive universal joint accelerations that can lead to failures and expensive repairs.  At the same time, the Torsionally Tuned-40 axle actually improves axle and driveline durability while minimizing size, cost, and weight.

The new design maintains consistent angles between the forward and the rear tandem axles for a variety of ride height settings that maintain proper universal joint cancellation angles.  The result is dramatic improvements in driveline torsional performance. With this innovation, drivetrain components perform well within their intended limits.  The entire drivetrain, from the clutch to the tires, performs at optimal operating standards to minimize destructive drivetrain vibrations compared to standard tandem configurations.

Damaging inter-axle angles and vibrations are caused by a number of factors, which include the type of suspension and ride height, torque, Gross Axle Weight rating, fifth wheel location and variations, installation angles, axle spacing, inter-axle shaft length, and manufacturing variations. 

The Torsionally Tuned-40 axle is engineered to reduce or eliminate these negatives and at the same time improve durability.  It is available in a variety of axle ratios.

With the Torsionally Tuned-40 axle, the vehicle can be specified with 25-degree Dana/Spicer SPL yokes and drivelines, to save additional weight and cost.  The parallel installation also allows the use of brackets common to both axles.