Many people forget about the hard trails leaf spring when they inspect their trailer or perform annual maintenance. It is easy to do being this form of suspension does not have the same issues as traditional shocks. However, neglecting them entirely can lead to a complete failure of the suspension, leaving you stranded and damaging your tire and axle.

It is important to understand how trailer leaf springs actually work. Take the time to also understand what damage you should look for and repair before hauling your trailer around Michigan.

How Leaf Springs Work

Trailer leaf springs are actually very simple mechanical designs, and work incredibly well to support your trailer. They are simply a series of bowed spring steel that attach to your trailer above or below your axle. Depending on the particular spring your trailer uses, it may be a single plate, or may be a series of plates mounted together.

For single plate springs, they are usually thick in the middle and tapper out toward the edges. These provide the least weight-bearing capacity.

Multi-plate springs, on the other hand, can bear substantial weight, depending on their design. In the middle of the bundle, they are bolted together using a philister bolt. In many models, the bundle will be held together toward the ends with a rebound clip. The spring then bolts to the frame of the trailer on either one or both ends, depending on the design.

While these springs are very resilient, the Michigan winters can wreak havoc on them. You are likely to see at least one of three types of damage, and should check for them before heading out after the winter.

Rusted Spring Leafs

Due to the salt, the cold moisture, and then the warmer weather we see around the state, one of the most common forms of damage is rust. Just like any other type of steel exposed to the elements, your leaf spring will eventually rust, and you need to be aware of when it does.

A little bit of surface rust is nothing to be concerned about, and can easily be cleaned off with a little effort. However, when that rust becomes more substantial, and you start having large chunks of rust coming off, you have need to keep an eye on it.

This larger rust problem compromises the strength of the spring, reducing its load bearing capacity. When the spring has started to substantially rust, you run the risk of either cracking or separating your springs. These other two problems run a substantial risk of a complete failure while you are hauling your rig.

Cracked Spring

Cracks in your spring usually appear near the philister bolt or at the ends near the eye that connects it to the frame. In many cases, these cracks are caused by a weakened spring or overloading the trailer.

When you see a crack, you should replace the spring before hauling with the trailer again. A cracked spring can lead to a catastrophic failure without any advanced notice. These failures become a hazard to you, your cargo, your trailer, and anyone on the road around you.

Separated Spring

The various plates in your leaf spring should be tight, and from a distance almost look like a solid piece. If you see any light between your spring leafs, you have a problem, and it will not provide the support it should.

When a leaf spring is aging, you may notice the ends separating. This is indicative of overloading the spring’s capacity. You may also notice this if the rebound clips have failed or broken. The plates will also naturally fatigue over time, and not rebound as quickly.

When you see separation in your spring, you know your weight capacity has been compromised. Separated springs can also cause the springs to break unpredictably, leading to more substantial problems.

Take the time to inspect your leaf springs every year at the beginning and end of your hauling season. If you notice any of these problems, plan to replace your springs before continuing your adventures.