You can be forgiven if you've never noticed the axle spring seats in your trailer. They're small, inconspicuous and are usually hidden beneath the axle. The job they do in maintaining your trailer's alignment is not particularly glamorous, but if they suddenly ceased to exist, you'd definitely notice. Your trailer would not only have a much bumpier ride, but it would probably fall apart. That makes axle spring seats pretty important.
An axle spring seat is a small brace that literally sits under the trailer's axle, attaching it to the springs and keeping the axle from falling out. In that role, it serves both to maintain the trailer's alignment and to help absorb shocks. It's a tough piece of metal and very dependable, not needing a lot of maintenance.
The axle spring seat is a small portion of a larger assembly, which also consists of the axle, two or more leaf springs, hangers and, in some cases, an equalizer.
So let's look at how this assembly works. The hangers attach the springs to the trailer. The leaf springs extend from the axle and serve as a shock absorber between the axle and the trailer. If the wheel hits a bump, the spring absorbs it and lessens the effect of the bump on the trailer. For a trailer with two axles, two more leaf springs extend between them, united in the center by an equalizer and attached to the spring seats. This evens out the effects of shocks between the two axles. The axle spring seats serve as anchors for the springs, so they play a central role in this process.
But what if something goes wrong with the axle spring seats? Is this something you should worry about? And if it happens, is there something you can do about in on your own? We'll look into that in the next section.