How Suspension Bolts Work

Using Suspension Bolts

These simple U-bolts play an important role in holding vehicles and trailers together.
These simple U-bolts play an important role in holding vehicles and trailers together.
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If you're installing suspension bolts to hold your suspension system together and connect it to the vehicle or trailer, then congratulations. You are using suspension bolts for their intended purpose. Just remember that certain bolts are designed for very specific parts of the suspension. If you need to replace a bolt, you'll want to make sure you have the right size and variety of bolt required.

If you decide to replace suspension bolts on your own instead of taking your vehicle or trailer to a professional garage, make sure to take precautions. Before you disassemble even part of your suspension system, be certain to support the vehicle or trailer body off the ground in the same way you would if you were changing a flat tire. Never place jacks or supports on the suspension system itself. You want to elevate the heaviest part of the trailer or vehicle (the body), so you can work on the much lighter suspension.

Bolts designed to rotate, such as shackle bolts, require greasing so they can move. As with any lubricated mechanical part, occasionally you may need to reapply the grease. On many modern vehicles, these parts are sealed effectively for life, but older vehicles and trailers sometimes require greasing through vehicle or grease zerks (also known as grease nipples or grease fittings). These tiny holes can accommodate the tip of a grease gun. If your vehicle or trailer features these fittings, you'll want to apply more of the manufacturer-recommended lubricant regularly.

Explore the links below to learn even more about towing.


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More Great Links


  • "4Crawler Offroad Custom Spring Shackles." Oct. 13, 2008. (Oct. 16, 2008)
  • Fuller, John. "How Leaf Springs Work." Sept. 25, 2008. (Oct. 16, 2008)
  • "The Suspension Bible." Car Bibles. (Oct. 16, 2008)
  • "Trailer Suspension Maintenance." Cerka Industries. 2008. (Oct. 16, 2008)