One of the most misunderstood things in drivetrain technology is understanding the driveshaft angle and what its effects are on a vehicle. We will try to make this as simple as possible. As a driveshaft turns at a given angle, the joint moves in a forward to back motion. The first spot is the transmission angle and second is the shaft's angle. The movement makes an X on paper if you were to map it out. Quite simply, if the X or angle measurement on the top isn't the same as on the bottom, you will end upwith a bicycle cranktype movement. In other words, one movement will not counteract the other movement. Most angle vibrations are in the lower MPH range (30-45mph) but can be seen higher. If you have a vibration under 15 mph, more than likely, there is something bent under the vehicle.
Please Use The Above Chart To Check Your Driveshaft Angle
The Picture above show a simple driveline and how its angles are laid out. This is a text book layout and if you can achieve angles like this, please do. But remember, its not a perfect world and there are different factors to deal with when building a car. With all the vehicles we have been under, it never ceases to amaze us, what should work doesn't and what shouldn't work does. The point we're trying to make is to get the angles as close as possible. If there is a problem , it can be taken care of at that time. If you have a vehicle that has a problem and don't know what to do, contact us and we will help you as much as we can. Make sure both the top and bottom angle do not exceed 4 degrees. If they do, it will need some sort of C.V. or double cardan style joint.