Getting To Know Your Suspension - U-Bolts

The U-Bolts In Your Suspension System

If you've been researching commercial vehicle suspension system, then you've probably come across U-bolts. If so, then you've come to the right place. To make sure you have an understanding on how U-bolts work in your semi-truck's suspension system, our experts have put together the following article. Read on to learn more about U-bolts!

What Is A U-Bolt?

"U-Bolts are a crucial part to your truck's suspension. It is curved metal rod that features threads on each end. Since the bolt is curved, it is designed to fit around pipes and tubing. That means U-bolts can secure circular loads and work as a restraint." ( U-Bolt 101: The Simple Facts)

In terms of your fleet truck's suspension, these bolts keep the leaf springs tied together. Without these small but important parts, your truck's suspension wouldn't exist. Leaf springs are attached to the axles with U-bolts so it's a good idea to make sure they are checked regularly when you're inspecting your vehicle's suspension system.

Common U-Bolt Materials

U-bolts can be made up of all kinds of materials. The material that is best for you will depend on application and how often you are on the road with your truck. However, they're usually made of durable metal that is noncorrosive, so it will hold up in humid and salty conditions. Here are some common materials you can find for U-bolts ( U-Bolt 101: The Simple Facts):

• Plain carbon steel
• 304 stainless steel
• 316 stainless steel

When choosing the right U-bolt for your semi-truck, there are also a also several coatings that manufacturers use including:

• Zinc Plating: Zinc plating is a process sin which zinc is added to aa metal using a layer of electricity. It's typically a thinner layer and is often used for indoor applications.


• Hot-Dip Galvanization: Hot-dip galvanization adds zinc, but uses a much thicker coating. Manufacturers dip the bolt in liquified zinc which form a bond, and makes the coating well-suited for high-humidity and high-salt environments.


• Fluoropolymer (Xylan, Teflon, or PTFE) Coating: A fluoropolymer coating is a mixture of elements that are resistant to corrosion. The coating can hold up in extreme hot and cold temperatures without cracking.


• Thermoplastic Coating: There is an added buffer between materials when you use a thermoplastic coating. Metal-on-metal contact can lead to corrosion. A thermoplastic coating adds a protective layer between the pipe and the restraint.

Replacing Your U-Bolts

When installing your U-bolts, it is important to remember to keep your truck on a level surface that is as close to flat as possible. Jack up one side, put the truck on the jack stands and locate the damaged U-bolt that you would like to replace. Take off the nuts of the U-bolt and remove. Old, rusted U-bolts many need to be cut off. Place the new U-bolt around the leaf spring. Connect the two portions of the "U" with two nuts. Use a torque wrench for the installation. Tighten them in a cross pattern, gradually bumping up the torque ( Replacing Your U-Bolts).

Read More About Commercial Truck Suspension Systems

Now that you've had a chance to read more about your heavy-duty truck's U-bolts, you may want to take a look at the rest of the articles we have available on your suspension system. Whether you want to know more about your shocks, leaf springs, or torque rods, we have the article you've been looking for. Click on any of the links below to read more about each of the parts of your suspension system.

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: Leaf Springs
6. Getting To Know Your Suspension: Bushings
7. Getting To Know Your Suspension: Stabilizers

Shop U-Bolts Online Today!

If you are looking for a great deal on replacement U-bolts for your semi-truck's suspension system, then we're the online store for you. With U-bolts from Match Made, Autocar, Meritor, and Hendrickson, we are your one-stop shop for any U-bolt you are looking for. For a great way to make sure you are only using the best possible parts in your fleet vehicle's suspension, choose us!