Second Order Tire Speed Related Vibrations

Second order tire speed related vibrations cause two shakes or disturbances for each revolution of the tire. These vibrations are usually caused by something spinning the same speed as the tire that is out-of-round.

IMPORTANT: A tire and wheel assembly that is out of balance will NEVER cause a second or higher order vibration.

NOTICE: The following items should be checked in the order shown.

Second order tire speed related vibrations are usually caused by:

A tire or wheel that is out of round - Click here to measure tire and wheel runout
Stiff spots in the tire's sidewall. (Radial force variation) - Click here to learn more.
4WD or AWD vehicle with front axle shaft U-joints (Solid Front Axle) - Click here to diagnose.
Drive axle problems. - Click here to diagnose.

Failed or failing U-Joints.

As the axle shaft rotates, the U-joints actually speed up and slow down twice per revolution, this is not a constant velocity device. A U-joint which is failing can cause these speed fluctuations to be felt or heard by the driver of the vehicle. This type of vibration will typically be worse when turning corners. Most vehicles will not have the U-Joints rotating on solid front axles unless the hubs (if equipped) are locked.

To diagnose U-joint problems, perform the following steps:

Remove the propshaft and Inspect the joints for looseness and roughness through their full range of motion.
Look for missing or damaged parts.
Look for signs of rust or lack of lubrication.
Repair or replace as necessary.

This page was last modified Thursday, March 05, 2009 09:02:05 PM