As the name suggests, a U-bolt is a bolt in the shape of the letter U. It has screw threads on both ends, and as U-bolts are used to attach the leaf springs to the axle in your suspension. They are a pivotal component with which you should be very familiar if you intend to do any work yourself.
Frequently asked questions... get up to speed on the basics about U-bolts.
What are U bolts made of?
U-bolts are available in standard sizes or in many cases custom made, manufactured in a range of materials like carbon steel, alloy steel, stainless steel, zinc, fluorocarbon, cadmium and hot dipped galvanized coatings.
It doesn't matter what type of bend the U-bolt has, they are measured the same way: Diameter x Distance Between Legs x Leg Length.
What type of bends do U-bolts come in?
U-bolts are produced in three bend types: Round, Semi-Round or Square. You will need to know what bend type you need before purchasing.
Can U-bolts be reused?
In most cases, if not all, U-bolt manufacturers recommend that you never reuse them.
Why do U-bolts have to be tightened properly?
The tighter a U-bolt is fastened, the less likely it is that there will be any movement, which means the less wear and tear is sustained to the U-bolt.
TOP SAFETY TIP
The most important thing to know about U-bolts...
When U-bolts are tightened in your vehicle by the manufacturer on the factory floor, the metal is stretched as a part of the production process. It is crucial that U-bolts be replaced when your suspension system is replaced, because by its very nature the stretching process loses the U-bolt integrity - so it's much weaker. Therefore, even though a used U-bolt might look tight when screwed in, it is not... and this lack of strength will put extra pressure on the centre bolts in the springs, which will mean they'll move or snap, enabling the diff to move and the leaves to spread. Appropriately strong U-bolts are manufactured using high tensile steel, designed to the correct length of thread for larger, heavy duty spring packs.
TOP FITTING TIP
U-bolts need to be re-tightened to the recommended torque 500-1000km after they are fitted otherwise they may come loose due to the forces they endure from that ever flexing leaf spring pack.