When you’re replacing your axle, you need to know:
- Spring Centers
- Hub face measurements
We want to show you how to obtain and use these measurements.
There are multiple ways to determine which axle you need.
The first and easiest option is to check the neck and tongue of your trailer. If you bought a company-made trailer (as opposed to building one yourself from a kit) there should be a tag with the VIN, weight and capacities all there for you. You should find it on the driver’s side of the trailer.
A second way to determine the size axle you need is to measure the diameter of your existing axle. The tube in our video example measures at 2 and 3/8ths of an inch. You can use this measurement to identify the axle. If it is not worn away or otherwise concealed, there may be a number on the axle itself that may be used to identify it.
The third way to identify your axle is via the bolt pattern. That’s how the lugs at the end of the hubs are configured. There are two common bolt patterns for five by four and half or five by five.
You also need to measure the length between two hub faces. Simply begin on the outside of one hub and go to the same thing on the opposite side. Go from the opposite end to opposite end of the spring seat, too.
Common measurements for 3.5k axles include:
This first number is your hub measurement, and second is your spring seat.