What Is a Trunnion on a Truck?

If you’re wondering what a trunnion is, you’re not alone. A trunnion is a part of a truck that many people don’t know about. It’s an important part of the truck, though, and it plays a big role in how the truck functions. This is because the trunnion is responsible for the truck’s suspension.

The trunnion is a cylindrical part of the truck that connects the axle to the frame. It allows the axle to move up and down, which helps to absorb shocks from bumps in the road. This helps to keep the ride smooth and comfortable for passengers.


What Is a Trunnion Axle?

The Trunnion/Stubby Axle is a short track axle designed for use with high-capacity, low-bed trailers, specialty trailers, construction machinery, and special industrial applications. This type of axle is also a pivot or turntable axle. It consists of a shortened axle shaft that is supported by bearings at both ends and mounted on a rotating platform (trunnion). This arrangement allows the wheels to pivot freely as the trailer turns.

The advantage of this design is that it provides better steering control and stability than a standard axle, making it ideal for heavy loads and off-road conditions. In addition, the shorter axle length reduces the overall length of the trailer, making it easier to maneuver in tight spaces.

What Does a Trunnion Upgrade Do?

The term “trunnion” describes a large bearing or pivot point, usually located at the end of a shaft or other structural member. In the automotive world, trunnions are often found in suspension systems, which act as the pivot point for the suspension components. Over time, these trunnions can become worn, damaging the suspension and adversely affecting vehicle performance. A trunnion upgrade involves replacing the original trunnion with a new, more durable version.

This new trunnion typically features improved materials and a revised design that helps to reduce wear and extend its lifespan. In addition, a trunnion upgrade often provides other benefits, such as increased suspension travel or a reduction in noise and vibration. As a result, a trunnion upgrade can be an effective way to improve the performance of your vehicle’s suspension system.

What Is Trunnion Support?

Trunnion support is a pipe support that is used to reinforce and stabilize piping systems. Trunnions are generally used in instances where little or no movement occurs in the piping system. Trunnions are typically used alongside pipe supports, such as anchors, hangers, and guides. pipe trunnions are often made of metals such as stainless steel or carbon steel. Pipe trunnions are also available in various sizes and configurations to meet the application’s specific needs.

What Is a Barrel Trunnion?

The trunnion is a small metal part that fits inside a firearm’s receiver and helps support the barrel. The trunnion is typically located near the muzzle end of the barrel and is screwed or bolted into place. In some cases, the trunnion may also be used as part of a quick-change barrel system. This allows the barrel to be quickly swapped out, which can be useful for changing between different types of ammunition or for cleaning the barrel.

Trunnions can also be used to secure bolt heads on delayed blowback or gas-operated firearms. This helps to ensure that the bolt remains in place during firing, preventing the weapon from malfunctioning. Overall, the trunnion is a simple but important part of many firearms.

What Is a Trunnion on a Trailer?

A trunnion on a trailer is a load-bearing platform that is welded to the outside of the rear frame beams. Trunnions are typically located between the first and second axles or between the second and third axles. They are used to support the weight of the trailer and distribute the load evenly. Many trailers have multiple trunnions, which helps to distribute the trailer weight more evenly and prevent Trailer axle slippage when braking. Trunnions are an important component of many trailers and play a vital role in ensuring the trailer’s safety and its contents.

Is a Trunnion Upgrade Necessary?

As with any mechanical component, there is always the potential for failure. The trunnions in a GM LS engine are no exception. Over time and under high loads, the original trunnions and bearings can wear out, causing the rocker arms to loosen up and eventually fail. That’s why many performance enthusiasts opt to upgrade their trunnions to aftermarket units.

Aftermarket trunnions are often made from stronger materials and feature improved bearings, which can help to extend the life of your rocker’s arms. In addition, many aftermarket kits come with additional reinforcement plates that can help to further reduce flex and promote durability. So if you’re looking to get the most out of your LS engine, an aftermarket trunnion upgrade may be worth considering.

How Do You Install a Trunnion Kit?

A trunnion kit installation is a great way to upgrade your car’s suspension. The trunnion kit replaces the stock suspension bushings with high-performance polyurethane bushings. This will improve your car’s handling by reducing body roll and increasing steering response. The kit includes all the necessary parts and hardware for a complete installation. Installation is straightforward and can be done in about an hour.

First, remove the old suspension bushings from the car. Next, install the new polyurethane bushings in their place. Finally, reinstall the suspension components and test drive the car to check for proper operation. With a little time and effort, you can upgrade your car’s suspension and improve its performance on the road.


A trunnion on a truck, trailer, or firearm is a small metal part that serves an important purpose. Trunnions help support the barrel of a gun and evenly distribute the trailer’s weight evenly. Many people opt to upgrade their trunnions to aftermarket units for improved performance. Installation of a trunnion kit is relatively easy and can be done in about an hour. With a little time and effort, you can upgrade your car’s suspension and improve its performance on the road.

About the author, Laurence Perkins

Laurence Perkins is the passionate car enthusiast behind the blog My Auto Machine. With over a decade of experience in the automotive industry, Perkins has knowledge and experience with a wide range of car makes and models. His particular interests lie in performance and modification, and his blog covers these topics in-depth. In addition to his own blog, Perkins is a respected voice in the automotive community and writes for various automotive publications. His insights and opinions on cars are highly sought-after.