top of page

Understanding the Swivel Joint in an Excavator

Writer's picture: RALPH COPERALPH COPE


In the world of earthmoving machinery, the swivel joint is one of the most critical hydraulic components that enable the smooth and efficient operation of an excavator. Without it, an excavator’s upper structure would be unable to rotate without twisting and damaging its hydraulic hoses. But what exactly does this component do, and why is it so important?

The swivel joint—sometimes called a rotary manifold—is responsible for transmitting hydraulic oil between the upper and lower structures of the excavator. It allows the hydraulic fluid to pass to the track motors even while the upper structure rotates continuously, ensuring uninterrupted movement.


How Does a Swivel Joint Work?

An excavator consists of two main sections: the upper structure (house, boom, and bucket) and the lower structure (undercarriage and tracks). These sections must function independently, especially when the upper part rotates while the tracks remain stationary.

The swivel joint is positioned at the connection between the upper and lower structures. Inside this component, multiple hydraulic channels are aligned in a cylindrical shape, allowing fluid to pass through without obstruction while the joint rotates freely.

The key parts of a swivel joint include:

  • Rotary Housing – The outer body that rotates with the upper structure.

  • Stationary Core – The inner part that remains fixed to the undercarriage.

  • Sealing Rings and Bearings – Ensure smooth operation and prevent hydraulic leaks.

  • Multiple Oil Channels – Designed to accommodate different hydraulic circuits.


Why is the Swivel Joint So Important?

  1. Enables 360-Degree Rotation – Excavators rely on unrestricted rotation to perform efficiently in digging, loading, and lifting tasks.

  2. Prevents Hydraulic Hose Twisting – Without a swivel joint, the hydraulic hoses supplying fluid to the track motors would twist and fail.

  3. Ensures Continuous Hydraulic Flow – This component allows fluid pressure to be maintained while the upper body rotates.

  4. Reduces Downtime and Maintenance Costs – A properly functioning swivel joint minimizes the risk of hydraulic failures, which could lead to costly downtime.

  5. Improves Operator Efficiency – By allowing seamless movement, the swivel joint helps operators perform tasks more quickly and efficiently.

  6. Enhances Safety – Unreliable or failing swivel joints can lead to hydraulic failures that compromise safety on construction sites.


Common Issues and Failures in Swivel Joints

Swivel joints, like any hydraulic component, are subject to wear and tear. Here are some of the most frequent issues:

  • Hydraulic Leaks – Worn-out seals or cracks in the housing can cause hydraulic oil to leak, leading to performance loss.

  • Restricted Rotation – Dirt, debris, or internal damage can obstruct smooth rotation.

  • Pressure Drop – A worn-out or damaged swivel joint can cause hydraulic pressure loss, affecting the performance of the track motors.

  • Internal Wear and Corrosion – Over time, the metal surfaces inside the swivel joint may degrade, reducing efficiency.

  • Seal Failure – Seals are crucial for preventing leaks. Poor maintenance or contaminated hydraulic fluid can accelerate seal failure.

  • Blockages in Oil Channels – Contaminants or debris in the hydraulic oil can clog the channels, disrupting the flow of hydraulic fluid.


Signs That Your Swivel Joint Needs Attention

Recognizing early warning signs can prevent expensive repairs and downtime. Look out for these indicators:

  • Unusual Noises – Grinding or squealing noises may suggest internal wear.

  • Slow or Jerky Movement – If the excavator moves unevenly, it could mean the swivel joint is restricting hydraulic flow.

  • Leaks Around the Swivel Joint – Even minor leaks should be addressed before they become major problems.

  • Loss of Hydraulic Power – If the excavator struggles to rotate or loses track power, the swivel joint could be at fault.

  • Overheating Hydraulic System – A faulty swivel joint can disrupt hydraulic flow, causing excessive heat buildup.


Maintenance Tips to Extend the Life of a Swivel Joint

To keep an excavator’s swivel joint in top condition, follow these best practices:

  • Regular Inspections – Check for leaks, wear, and rotational issues.

  • Keep it Clean – Dirt and debris can enter the seals and compromise performance.

  • Use Quality Hydraulic Oil – Contaminated or low-quality hydraulic fluid can accelerate wear.

  • Replace Seals on Schedule – Preventive seal replacement can prevent costly failures.

  • Lubricate as Required – Some swivel joints may have lubrication points to minimize friction.

  • Monitor Hydraulic Pressure – Sudden drops in pressure could indicate issues with the swivel joint.

  • Follow Manufacturer Recommendations – Always adhere to the maintenance schedule provided by the manufacturer.


Repair or Replace? Choosing the Right Solution

If an excavator’s swivel joint is experiencing minor issues like seal leaks, replacing the seals may be a cost-effective solution. However, if the damage is extensive, replacing the entire unit is often the best choice to avoid further operational problems.

A new OEM swivel joint can be extremely expensive, making a high-quality used or refurbished OEM option a more cost-effective choice.


Why Choose a Used OEM Swivel Joint from Vikfin?

At Vikfin, we specialize in providing high-quality used OEM excavator parts, including swivel joints that have been thoroughly tested to ensure reliability. Here’s why Vikfin is the best choice:

  • Guaranteed Quality – Every part is inspected and tested for performance.

  • Cost Savings – Get premium OEM parts at a fraction of the cost of new ones.

  • Expert Knowledge – Our team understands excavator components and ensures you get the right part for your machine.

  • Reduced Downtime – Quick sourcing of parts helps minimize project delays.

  • Inventory for Multiple Brands – We carry swivel joints for major brands like Caterpillar, Komatsu, Volvo, Hitachi, and more.

  • Environmentally Friendly – Reusing high-quality OEM parts reduces waste and environmental impact.


Conclusion

The swivel joint is a small but essential part of an excavator’s hydraulic system, enabling continuous rotation without disrupting hydraulic flow. Keeping this component in optimal condition is vital for maximizing machine efficiency and minimizing downtime.

If you’re facing issues with your excavator’s swivel joint, contact Vikfin today for a high-quality used OEM swivel joint that ensures your machine runs smoothly while keeping costs down.


Comments


Workshop Locations

Durban: Bux Farm

Johannesburg: Benoni

Vikfin logo

Telephone/WhatsApp

083 639 1982 (Justin Cope) - Durban

071 351 9750 (Ralph Cope) - Johannesburg

©2019 by Vikfin (PTY) Ltd. 

bottom of page