I found this info maybe it will help
Vibration in a driveshaft can be caused by many conditions. One of the most common cause of driveline vibration are worn U-joints or slip splines, out-of-balance components, yokes out of phase or misaligned angles, approaching critical speed range, and yoke ears that are not concentric with the splines. Vibrations problems must be diagnosed accurately and corrected quickly to avoid damage to the driveline components.
It is often difficult to determine if a vibration of vehicle is coming from the driveshaft or something else. Here are some things to think about while you are troubleshooting any driveshaft problem.
First, Second and Third Order Driveshaft Vibrations
A First order driveshaft vibration will cause one shake or disturbance for each revolution of the driveshaft.
IMPORTANT: Anything that is out of balance will only cause a first order vibration, never any higher order vibrations.
First order driveshaft vibration is usually caused by:
- A component rotating the same speed as the driveshaft that is out-of-round.
- A component rotating the same speed as the driveshaft that is out-of-balance.
- Drive axle problems.
- Driveshaft balance issues can generally be felt at vehicle speeds over 30mi./h
A Second order driveshaft vibration will cause two shakes or disturbances for each revolution of the driveshaft.
IMPORTANT: A component that is out of balance will NEVER cause a second or higher order vibration, only a first order vibration.
Second order driveshaft vibration is usually caused by:
- Incorrect Vehicle Trim Height
- Powertrain Mounting Problems
- Failed or Failing U-Joints
- Improperly phased or twisted driveshafts
- Improper driveshaft angles. Driveshaft angle problems can be felt at very low speeds, and higher speeds
- Drive Axle Problems
Please go to our Driveline Angle Analysis Page for more information.
Third order driveshaft vibration will cause three shakes or disturbances for each revolution of the driveshaft.
This type of vibration is very rare and will not be present on vehicles with Cardan U-joints.
IMPORTANT: A component that is out of balance will NEVER cause a third or higher order vibration, only a first order vibration.
Third order driveshaft vibrations are usually caused by:
- Failed, failing or binding Constant Velocity (CV) Joints.
- Remove the driveshaft and rotate the CV-joint through its full range of motion while feeling for any rough spots or looseness.
