Trunnion

Trunnion – Free Movement Suspension

As you look at the parts on your car that you take for granted to work well and to provide a secure frame for your vehicle, you’ve probably never really taken a second to think about where they came from or what inspired their design. Most of the parts on your car probably seem purely functional, and you are right, almost all mechanical elements on modern vehicles were created through the trial and error process of the vehicles that came before them. If you were to examine your suspension system in this way, you would notice the trunnion, which was inspired by old war cannons.

Now, if you think about a war time cannon, the last thing that probably comes into your mind is a smooth easy ride, but one element of the cannon’s design came in very handy when it came to bringing free movement to the suspension of the modern car. In the most basic terms, a trunnion is a round or cylindrical part that protrudes from another element, and one that facilitates mounting and pivoting around that cylindrical part. You can see it used this way on old style cannons, that used it as a point for rotating the cannon up to be loaded and then back down into firing position.

On your car, the trunnion suspension works in a similar way to the old cannon. On older model cars, such as those that were made by the Triumph Motor Company, this part of the suspension allows the back wheel hub to move freely in relation to the chassis. This part can also be mounted in the front of the car in order to allow the front wheel hub to move freely with adjustments to the steering. In these older model cars the part was made from bronze or brass and was known to fail on a regular basis.

Newer pickup trucks, such as those made by Chevy and GMC, the trunnion is not necessarily associated with the vehicle’s suspension system. Instead it is a part of the tailgate attachment system and is used to allow the quick placement or removal of the truck’s tailgate when necessary. Because of this unique tailgate design, the door can be taken off or replaced without the use of any tools, making it quite convenient for the driver. If you are looking to replace this part in your older car, be sure to research the best materials for a strong performance.