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How to Measure Your Trailer Axle

Learn the key dimensions to measure for replacing your trailer axle below.

Before You Measure:

A nine digit axle serial number is etched into the axle tube near the center on the rear side, you may need to use a wire brush or a piece of chalk over the numbers to help bring out the engraving better. If you are able to locate the number reach out to one of our parts professionals so they may assist you. 

Hub Face Measurement:

This measurement is critical for ensuring the axle fits correctly under your trailer and aligns properly with the wheels. This measurement is taken from the outside face of one hub to the outside face of the opposite hub.  

Missing Axle Hubs? Here's How to Measure:

This can be done by measuring from the outside brake flange face to outside brake flange face on the opposite end. The flanges are located at the end of each axle where the hub typically sits. 

Add Space for the Missing Hub:

Inches to add for each axle capacity:

      1. 2K lb Axles - 7 Inches
      2. 3.5K lb Axles - 6 Inches
      3. 6K-8K lb Axles - 9 Inches

Spring Centers Measurement:

This is the distance between the center points of the spring mounting pads. This ensures proper axle alignment with the trailer's suspension system. It is a crucial piece for weight distribution, ride quality and overall towing stability. Measure from center to center of each axle spring.

Tube Diameter Measurement:

Measure from top to bottom of the axle tube, the diameter corresponds to the capacity of the axle. Below are common measurements for the corresponding axles:

  1. 1-2K Axles - 1-1/2" to 1-3/4"
  2. 3.5K - 2-3/8"
  3. 5.2-7K - 3"
  4. 8K - 3-1/2"
  5. 9K - 4"
  6. 10K - 5"

Questions?

Reach out to one of our part experts using the "Customer Support" chat box at the bottom of the screen or give us a call at 1-866-335-5464 and we can help you find the correct axle.