U-Bolts - Semi Truck

What Are Semi Truck Suspension U-Bolts?


Semi truck U-bolts are steel bolts that come in a variety of lengths and shapes that connect the suspension leaf springs to the axle housing. U-bolts can be round, square, semi round and semi square in shape and vary in lengths of 10 inches to 50 inches. They are used on cars, trucks, SUVs, semi trucks, vans and trailers. 


How Often Should Semi Truck U-Bolts Be Replaced?


Semi truck suspension U-bolts should be inspected annually and replaced if they become stretched, broken, twisted or if they are being removed. U-bolts can last for decades but if they are not installed or torqued properly can become damaged easily as well. If ever replacing a leaf spring the rule of thumb is to always replace the U-bolts at the same time.


What Semi Truck U-Bolts Do I Need?


Unfortutaly there isn't a one fits all semi truck U-bolt so to find out the u bolt you will need we have to do some research and measuring. First we need to know what you are going to be doing with your vehicle. With that information we can determine if we can use raw steel or if we need U-bolts that are coated for protection from the elements. Then we can measure the U-bolt on or off the vehicle. We measure the diameter, the inside to inside measurement, the length and take note of the shape. Now we have all that information we can match up the correct U-bolt.


How To Measure A Semi Truck U-Bolt.


Below are diagrams of how to measure a round, semi round, square and semi square semi truck U-bolt. For each U-bolt you will need to measure the diameter of the rod, the inside diameter and the top of the U-bolt to the bottom of the U-bolt leg. 


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Why Do Semi Truck U-Bolts Wear?


Semi truck U-bolts can wear for multiple reasons. The most common way U-bolts fail is cross threading or stripping the threads on a U-bolt. This occurs when U-bolts are over torqued during installation or the U-bolt nut is not installed correctly before torquing. The result is when removing or tightening the nut on the U-bolt it damages the threads on way up or down or it seizes on the U-bolt and the U-bolt needs to be cut off. Another way U-bolts wear is not being torqued tight enough during installation. This causes the U-bolt to move while driving damaging the U-bolt and potentially other suspension components as well.


Where Can I Buy Semi Truck U-Bolts Online?


Semi truck U-bolts are sold at a variety of locations usually pre bent to specific sizes. Here at Spring works we take non bent rod and bend them to the exact specifications you need. We have a variety of diameters, lengths and all shapes for cars, trucks, semi trucks, RVS and SUVS.