How to Determine Replacement Front Axle on a Forest River T21FS

Published 05/18/2022

Question:

I need the front axle for forest river T21fs

asked by: Jeffrey O

Expert Reply:

In order to determine what replacement front axle you need on your Forest River T21FS, there are a few things we need to know.

The first thing we need is the axle's weight rating. This is commonly found on an axle tag or etched on the crosstube itself. Sometimes this information is inside the axle hubs if the axles came as a complete assembly. The axle information can also be found on any paperwork you received from your trailer.

If you cannot find any of the identifying information, the next method is to determine the inner/outer bearing number or determining the inner/outer bearing diameters. I went ahead and attached an image that shows how to measure the inner and outer bearings and where the bearings are located on your axles' spindles. I recommend using calipers for making this measurement like the # PTW80157 because the measurements need to be extremely precise.

After you discover the bearing numbers and/or the bearing diameters, you can then match that information with the axle chart (see attached) to determine the axle capacity. Once you know the capacity, that is when we have a solid direction to take for the correct axles you need.

When you get the correct capacity, you need to consider the distance between the hub face to hub face as well as the spring center to spring center. These lengths provide you with the axle length you need for the replacement.

Once you have explored those methods, feel free to respond with any information you come across.