How Do You Know Your Suspension Is Bad?

The suspension on your truck is incredibly important not only for how your ride feels, but how it operates and handles in general. Understanding what the suspension components are, and how to recognize the signs that they may need repair, are critical to keeping your rig on the road and avoiding expensive repair costs.

We’re going to take a look at semi-truck suspension, and how you can tell that yours needs work. We’ll also cover some of the common problems that happen, and why it’s important to get your suspension issues fixed promptly. In the end, we’ll tell you who you can trust to get the work done right, without having your truck in the shop for longer than needed.


Understanding Truck Suspension

Before getting into the various components of the suspension system on a semi-truck, it’s important to understand what the suspension system is and how it functions on a heavy-duty truck. Suspension systems on semi trucks are critical for maintaining a smooth and comfortable ride, as well as for supporting the combined weight of the vehicle, operator, and all cargo. 

The suspension system provides considerable stability and even weight distribution, which helps ensure that the truck can operate and navigate safely. However, just as with any mechanical system, it will always be vulnerable to wear and tear, which can lead to more suspension problems over time.


Key Components of a Suspension System

There are several important components to a semi-truck or heavy-duty suspension system, each with its specific role or function in helping the truck maintain stability, smooth ride, and agile handling. These components include:

  1. Leaf Springs – Leaf springs are arched bands of spring steel that are bound together in packs. They are connected to the frame of the truck and are tasked with supporting the entire weight of the vehicle while absorbing road shocks.
  2. Shock Absorbers – Shock absorbers are cylinders that are generally filled with gas or hydraulic fluid and are used to help dampen the oscillation of the springs, making the ride smoother, more comfortable, and less bouncy overall.
  3. Air Springs – Air springs are common in newer semis, as they have begun to replace the older leaf springs with more advanced air-filled bladders. They are also adjustable, allowing the driver to be more comfortable.
  4. Torque Rods – These rods connect the axle of the truck to the frame, helping to keep it correctly aligned and stationary. They can eventually wear out or become damaged.
  5. Bushings – Bushings are consumable parts that are generally made from rubber or polyurethane and are designed to reduce friction between two or more components.


Warning Signs of Suspension Damage

Let’s go over a few of the common signs that your semi truck suspension needs to be looked at. You may have noticed one or two of these in your daily drives, and if so, it’s likely time to speak to a professional about getting it serviced.

  1. Excessive Bouncing or Swaying: One of the biggest signs that your truck needs suspension work is when it bounces excessively over bumps, leans too far during turns, or sways while at highway speeds.
  2. Uneven Tire Wear: Another potential warning sign is that the tires of your truck will be wearing unevenly. This is generally attributed to suspension play causing poor alignment and irregular tire wear.
  3. Sagging or Leaning: If you notice that your truck is leaning to one side or the other near the rear of your cabin, it could be a sign that your leaf springs are worn out or damaged.
  4. Poor Handling: Suspension damage can often cause changes in handling, like difficulty steering or a loose feel on the road, that could be signs of damage.
  5. Unusual Noises: Clunking, rattling, squeaking, or other unusual noises while driving can mean some of your suspension components need to be repaired or replaced. Many people are unsure what noises to listen for, but suspension noises are known for being very loud and metallic, particularly when hitting bumps.
  6. Visible Damage: If you inspect your suspension components and see obvious, visible damage, it should go without saying that those components need to be replaced as soon as possible.


measuring s camCommon Suspension Problems & Their Causes

  1. Worn Shocks: Shocks wear out with time and use, and eventually they lose their ability to dampen vibrations. They can also be damaged by hitting larger bumps or holes at higher speeds, such as an unexpected pothole on the highway. Testing your shocks can be difficult without special equipment, so it’s best done by a professional.
  2. Broken or Sagging Leaf Springs: Leaf springs will eventually lose tension or even crack, leading to poor support. Like shock damage, this can also happen after a particularly robust bounce or impact dampening. Have your leaf springs inspected regularly and replaced when needed.
  3. Damaged Air Springs: Air springs can eventually leak, causing them to deflate and diminishing their ability to support the needed weight. There are many reasons that air springs may become damaged, including wear and tear, or incorrect ride settings.
  4. Worn Torque Rods: Worn or bent torque rods can have a considerable impact on axle alignment and can reduce handling. Depending on the power of your truck, your average loads, and your general driving style, you may want to inspect torque rods as often as once a month and replace them as needed.
  5. Worn or Damaged Bushings: Bushings will wear out over time, and can cause excessive play in your suspension. They can wear faster when driving on rougher roads or through rougher terrain like dirt or gravel. Regularly inspect and replace bushings as they wear out.


Partner With Blaine Brothers To Keep Your Ride Smooth

If you’ve started to notice some of the signs that your suspension needs work, or if you’ve visually confirmed that you have damaged components, it’s important to ensure those components are replaced promptly, to avoid more issues. Replacing suspension components on your semi truck can be challenging, even for experienced operators. Reach out to Blaine Brothers today for more information, or to make an appointment for your suspension at one of our locations in Minnesota or Wisconsin.

Blaine, MN


10011 Xylite Street NE
Minneapolis, MN 55449

Cloquet, MN


1325 Hwy 45
Cloquet, MN 55720

Clearwater, MN


750 Heaton BLVD
Clearwater, MN 55320

Baldwin, WI


2500 Alreich Ave
Baldwin, WI 54002



9515 150th Avenue NE
Columbus, MN 55025