Most Accurate Way to Measure the Length of Axle

Updated 08/25/2014 | Published 08/22/2014

Question:

Hello again. It has been brought to my attention from a millright that works in a steel mill that the innermost part of a boat trailer bearing that rides on the spindle should never ever rotate around the spindle or even move the slightest bit. Am I correct in this assumption? What is the easiest way to measure the length of an axle from the ends of the spindle? I have leaf springs on my boat trailer and a couple U bolts that hold the Axle on, so changing the axle out should not be a big deal. Have I forgotten anything?

asked by: Bruce R

Expert Reply:

When it comes to the bearing that rides on the spindle, there really is nothing to keep it from rotating other than the compression from tightening the spindle nut.

The most accurate way to determine the length of your axle is to measure the distance from hub face to hub face (A) and spring center to spring center (B). I have attached a picture to illustrate this measurement. With only one hub on the trailer, to obtain measurement A you would need to double measurement C and add it to B. (C x 2) + B = A

These measurements are very important since the axle beam comes with the spring seats welded on. By measuring (B) it will ensure that the spring seats match the location of the leaf springs on your trailer. Measurement (A) is to ensure that you get an axle of the correct width so that nothing hits the frame or that the wheels stick out too far from your trailer.

expert reply by: Leah S