Drive train - angle of the dangle

[eschaider]

If your tail shaft ends up below the centerline of your pinion, you have some fairly significant problems! Here is a graphic of the correct alignment (top pic) and various versions of bad alignment;


You want the top solution. The happy angle threshold is somewhere between 4 and 7 degrees. Bigger and smaller angles will work, but they will bring varying levels of vibrational unhappiness. Really big angles will rock you and eventually result in parts breakage. A zero or near zero angle will use up u-joints. Unequal angles are just stupid bad.