Vehicle Speed Related Vibrations

A vehicle speed related vibration will usually always occur at the same vehicle speed regardless of engine RPM. This type of vibration cannot be detected with the vehicle stopped.

After your road test, mark the point on the vibration worksheet where your Vibration RPM and your Engine RPM readings intersect. The point of intersection should be on or near a vibration line on the vibration worksheet. Each line is identified with an abbreviation like T1. T1 represents a first order tire speed related vibration.

Vehicle Speed Related Vibrations can be classified into two categories:

Tire Speed Related Vibrations, (T1, T2, or T3 on the vibration worksheet). A tire speed related vibration will usually appear at higher vehicle speeds (50 mph and above).
Propshaft Speed Related Vibrations, (P1, P2, or P3 on the vibration worksheet). A propshaft speed related vibration will usually appear at mid-range vehicle speeds (25 - 50 mph). This type of vibration usually gets worse at higher vehicle speeds.
Trailer Tire Speed Related Vibrations, (TT1, TT2, or TT3 on the vibration worksheet). A trailer tire speed related vibration will usually appear at higher vehicle speeds (50 mph and above).
HUMMER H1 Half-shaft Speed Related Vibrations, (H1 or H3 on the vibration worksheet). A half-shaft speed related vibration will usually appear at mid to high range vehicle speeds. This type of vibration usually gets worse at higher vehicle speeds.

This page was last modified Thursday, March 05, 2009 09:02:04 PM