Getting To Know Your Suspension - Leaf Springs

How A Leaf Spring Works In Your Semi-Truck

Leaf springs are one of the most important components in your semi-truck's suspension system designed to help keep you stable while you're on the road. If you've been researching suspension systems, then it's likely you've come across leaf springs. In order to help guide you along your journey, our experts have put together the following article on the leaf springs in your commercial vehicle. Read on to learn more about leaf springs!

What Is A Leaf Spring?

Commonly used in heavy-duty trucks, a leaf spring is formed into a slender arc-shaped length of spring steel. In its most commonly occurring configuration, the center of the arc provides location for the axle, while loops at either end attach to your semi-truck's chassis. A leaf spring can be made from several leaves stacked on top of each other in several layers, with leaves that are progressively shorter.

Leaf springs serve locating and springing functions. While the interleaf friction provides a damping action, it is not well controlled and results in static friction in the motion of the suspension. For this reason, some manufacturers have used mono-leaf springs.

Leaf springs also provide comfort by minimizing the vertical vibration caused by the uneven road geometry. The desired leaf spring material should have high strength and low elasticity.

How Often Should I Change My Leaf Springs?

If not maintained regularly, your semi-truck's leaf springs won't last as long as the manufacturer intended. A well-maintained vehicle's leaf springs can last well over 100,000 miles before they need to be replaced. On average, a set of leaf springs might last about 200,000 miles. Most leaf springs will last for several years, but cargo load and exposure to the elements can cause extra strain or corrosion that may shorten the time between replacements.

Signs You Need To Replace Your Leaf Springs

Much like any of the parts in your truck's suspension system, there are several comfort and control features to look out for that will not work properly if your leaf springs are out of commission. Common signs you need to replace your leaf springs include the presence of cracks and fractures, or a change in the way your vehicle drives. You may also notice your vehicle leans to one side when there is no load present. Other signs that your leaf springs need repair or replacement occur while you are driving and can include one or more of the following symptoms:

1. Difficulty steering or vehicle pulling to one side as you drive
2. Feeling even small bumps as you drive down the road
3. Your truck nose dives, leans back or rolls with momentum

Leaf Spring Bushings

Leaf spring bushings work with leaf springs and other suspension system components to provide the support that gives your truck a smooth ride and handling. Leaf spring bushings help absorb shock and pressure caused by flexing leaf and coil springs. If you have bad leaf spring bushings you will feel every bump on the road, your truck will pull to one side, or the truck will dive or lean with momentum. If you notice any of these symptoms you should have your leaf spring bushings immediately inspected by a shop that specializes in leaf spring repair.

Read More About Suspensions

The system of parts that make up your commercial vehicle's suspension functions are important to know if you want to avoid costly repairs in the future. Now that you know more about the leaf springs in your semi-truck, you may want to learn a little more about the rest of the components in your suspension system. Click on any of the links below to see articles on your heavy-duty vehicle's suspension.

1. Getting To Know Your Suspension System
2. Getting To Know Your Suspension: Shock Absorbers
3. Getting To Know Your Suspension: Shocks vs. Struts
4. Getting To Know Your Suspension: Torque Rods
5. Getting To Know Your Suspension: U-Bolts
6. Getting To Know Your Suspension: Bushings
7. Getting To Know Your Suspension: Stabilizers

Shop Suspension Parts Today

As you now know, leaf springs are an incredibly important part of your semi-truck's comfort and control system while you are driving. If you've been looking to replace the leaf springs in your semi-truck's suspension system, then you've come to the right place. With replacement leaf springs from Dayton, Hendrickson, and Meritor, you won't have any issue finding the right aftermarket part for your commercial vehicle.