Thursday, January 7, 2010

How to Measure a Spring Axle



Measuring Spring and Torsion Axle (PDF)

This is the first video in our Trailer Canada how to video series.
This video will show you how to properly measure a spring axle.
Please note all dimensions are expressed in imperial units which are inches and feet.

Before you get started we recommend that you gather the following: an assistant, a tape measure, two straight edges, bolt circle template which you can download in a PDF format from our website, a notepad, a pen and a digital caliper.

Here we are measuring the bolt pattern from a five bolt spring axle. If you have an axle with a five bolt wheel, you will need to check the wheel bolt pattern or bolt circle. You can download the bolt circle template from our website. Measuring the bolt circle pattern will ensure that if you order an axle your wheels will fit onto the hubs. The most common bolt pattern on a trailer with five bolt wheels is a five on four and a half inch bolt pattern. For axles with a six bolt wheel, the bolt pattern is six on five and one half and for axles with eight bolt wheels, the bolt pattern is eight on six and one half.

First thing we are going to do is measure the axle tube diameter. The axle tube diameter indicates to us the capacity of the axle. In this case we have a measurement of two and three eighth inches which means it's a thirty five hundred pound axle. Next thing we'll do is remove the wheels from the axle. This will expose the hub faces so that we can take an accurate measurement. We'll take our straight edges, put them along the hub face and we are showing a measurement of seventy three inches. So, seventy three inches is the hub face to hub face measurement. Make sure you write your measurements down so you don't forget.

Next, we're going to measure the spring seats. What we call spring center to spring center.
These are the spring seats. You must measure from center to center of the spring seats. Hold it right to the center of that hole. You'll need to specify whether the springs are underslung or overslung. This is an overslung spring setup and this is an underslung spring setup.
We are showing a measurement of fifty eight inches. So our spring center to spring center measurement is fifty eight inches and that gives us our basic dimensions.

Now you are ready to order an axle.
It is important that we get precise measurements from you so that the axle will fit.

Production: Ron Belzil
Multi Media: Darrell Drouin
Script: and Creative Nathan Belzil
Many thanks to Marvin Bjornstad and Darren Pratch of Portage College