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Dec 6th 2020

How Do Leaf Spring Shackles Work?

How Do Leaf Spring Shackles Work?

Leaf springs have been around since the beginning of automobile manufacturing. Although they aren't necessary for your average passenger car, leaf springs are the default suspension system for trucks and off-road vehicles. They balance the weight of your pickup while absorbing shocks from speed bumps and uneven ground. But without shackles, they're quite ineffective.

Leaf spring shackles affect the ride quality and suspension travel of an automobile. They are vital components in your truck's leaf spring suspension system. General Spring has a range of shackle kits available for you to purchase when the old ones wear out, so you can keep your set of wheels rolling. When it's time to replace your shackles, it's necessary to know what their purpose is and how to install new versions.

Purpose of Leaf Spring Shackles

Most people already know the purpose of leaf springs — centering the truck's axle and supporting the vehicle's weight — but what do leaf spring shackles do?

Shackles allow your vehicle's springs to travel through a range of lengths as you drive over different terrains, such as bumps, rocks, uneven dirt and potholes. They ensure the length of your leaf springs changes accurately during suspension movements.

For example, as leaf springs compress, they become longer, while the spring arc turns flatter. When the pickup's leaf springs relax during downward wheel travel, they become shorter, while the arc returns to its normal state. The shackles allow these movements. Without them, your truck's leaf spring suspension system can bottom out, causing a rough ride and inadequate handling.

As the springs flex up and down from road conditions, their length changes from the shackle's eye to the main eye. Because the mounted main eye cannot move, the shackle eye allows the springs' length to change. The other purpose of leaf spring shackles is to keep your vehicle balanced.

Shackles exist at the rear end of each leaf spring within the suspension system . They connect the springs to your vehicle's frame through an eye spring bolt.

Because leaf springs can't take on all the work, they rely on shackles to flex and adequately run the suspension system. Think about how your tires react when driving over a speed bump. The suspension responds to the bump, and the shackles allow the springs to absorb the obstacle's force instead of hitting the ground. Your pickup's tires will remain in contact with the pavement with suspension shackles in place.

Pros and Cons of Leaf Spring Shackles

Leaf spring shackles ensure your truck endures many years of operating in various driving and weather conditions. Although vehicles come with stock versions of shackles, many people opt for more extended varieties . Benefits of longer shackle lengths compared to factory types include:

  • Axle rotates downward at the shackle side.
  • Shackle mount experiences increased leverage.
  • Suspension down travel increases.
  • Suspension height increases.
  • The pinion angle increases.

One drawback of having longer shackles is that their caster angles will change, resulting in front-axle steering issues. Increasing or decreasing the shackle length will affect the movement of your truck's springs. Depending on the extremity of the changes you make, you may find it more challenging to steer compared to smaller alterations. Lengthier shackles also result in a decrease in departure and approach angles.

Symptoms of Worn-Out Shackles

We all know general wear and gear can cause cracks and corrosion on almost every vehicle component. The worst thing you can do is allow the symptoms to persist until they cause major damage to your pickup , making it less reliable.

When you're aware of the possible symptoms of worn shackles, you can combat any issues right away to ensure the integrity of your vehicle's suspension system. Signs of worn-out shackles include:

  • A harsh ride: If your tires are lifting off the ground and you aren't experiencing a smooth ride, it can be a sign of bound-up bolts and pins in the shackles, causing the springs not to flex.
  • Leaning vehicle: If your truck is leaning to one side, it can be from worn shackles.
  • Broken springs: If you notice your leaf springs are becoming faulty more regularly, worn shackles may be the culprit.
  • Odd noises: If you start hearing snapping, clunking or popping sounds, worn or broken shackle components can be at fault by allowing excessive movement in the system.

Your shackles can also sustain damage from overtightening. Because their success depends on their ability to move, tightening them too much will cause them not to move. A quick tip is to tighten them and then loosen each bolt by a small turn.

Shackles can even become inverted by moving past their axis of movement. When this occurs, the leaf springs keep the shackles locked in place, negating their purpose. Inverted parts can result in massive damage to the truck if you don't make corrections quickly. Some signs of an inverted shackle are loud snapping noises and a cloud of dust. You can fix the situation by lifting the vehicle and leveraging the shackle back into its position.

Keeping an eye out for definitive symptoms can help you stay on top of shackle maintenance and repairs.

How to Replace Leaf Spring Shackles

Although your shackles have high levels of endurance, they will wear out over time like any other vehicle components. When you need to replace your leaf spring shackles, don't procrastinate — it can cause severe damage to your undercarriage.

Invest in a new leaf spring shackle kit that matches your truck's make and model. Consider the length of the components as they relate to your automobile's size. The longer the shackles, the more ground clearance your pickup or off-roader will have. Shorter solutions are ideal for lowering your vehicle.

Installing leaf spring shackles is a simple process if you have the correct replacement kit and tools:

  1. Use floor jacks to elevate your truck's rear end.
  2. Place jack stands under the vehicle and bring them down to drop the suspension.
  3. Remove the lower mounting bolt that connects the shackle and spring.
  4. Take out the upper mounting bolt that joins the chassis and shackle.
  5. Dislodge the worn shackle and replace it with a new one by using a new mounting bolt.
  6. Put the shackle in alignment with the spring eye and work them together.
  7. Connect the spring eye and shackle with mounting bolts.
  8. Elevate the truck and remove the jack stands.
  9. Lower the vehicle down using the floor jacks, and check the shackles.
  10. Make sure the bolts are fastened under the weight of your truck.

Replacing your leaf spring shackles will ensure a smooth ride as you traverse over different terrains, making your vehicle safer and more comfortable.

Get New Shackles From General Spring

Leaf spring shackles are integral components in your truck's suspension structure that allow the springs to function correctly. General Spring provides shackle kits for a range of makes and models at competitive prices to ensure your truck or off-roader is in great shape.

As a nation-wide brand, we specialize in high-quality leaf springs and their attaching parts. Our experts can customize leaf springs for any application — including older vehicles — and we always check the part quality before shipping our orders quickly and efficiently.

Order new shackles online from General Spring or reach out to our support team for more information. We have been an authority in leaf springs and suspensions since 1965, and we have the solutions you need.

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