Slewing Bearing – The Complete FAQ Guide

Today, there are different types of slewing bearings. They are primarily used in heavy machinery.

In this article, you are going to learn all about slewing bearings. You are going to understand:

  • What slewing bearings are and how they work
  • Different types of slewing bearings
  • How to get quality slewing bearings for your heavy machinery

Keep reading this article to find out more.


1.  What Is A Slewing Bearing?


A typical slewing bearing is made up of two rings; an outer and inner ring. Either of the rings can incorporate a gear, depending on your machine’s functions. These gears are used. You may also find out that other people call slewing bearings a turntable bearing or a slewing ring, or Swing Bearing.

A slewing bearing has holes drilled on its sides. These holes provide a solid fixation to a structure. Slewing bearings also have seals that protect the rolling elements. These seals are found between the rings.


There are different sizes of slewing bearings. They range from 100mm in diameter to around 15,000mm.

Don’t know your slewing bearing size? Contact us today for the best advice on what to buy. Our skilled support team is always available to provide exceptional parts solutions for you.


2.  What Is A Slewing Bearing Used For?


Slewing means to turn without changing place. As such, a slewing bearing is used to support heavy, slow-turning, or slow-oscillating loads. These loads are often in horizontal platforms such as an excavator or a grapple yarder.


3.  Is A Slewing Bearing the Same As A Slewing Ring?


I’m not going to lie to you:

A slewing bearing is the same as a slewing ring. It is also called a turntable bearing used in heavy machines like excavators and cranes.

Are you in need of slewing rings?

You can contact a professional parts’ company by using the following steps:

  • You’ll first send us an inquiry through our website.
  • Then, we will respond within 24 hours with a quote, considering your requirements and estimated budget.
  • Thirdly, we’ll offer you parts samples to aid you in testing our part’s quality as well as their reliability.
  • Finally, we’ll ship your parts to wherever you are located. We ship our parts safely by first placing them inside rigid cartons. Then, we place the hard cartons in robust wooden boxes to prevent damages.


4.  How Does A Slewing Bearing Work?


In an excavator, a slewing bearing works by using the slewing mechanism – turning without changing place. It works by driving the excavator’s platform relative to its base. The slewing bearing uses two rows of rolling elements.

The other three race elements are applied to the slewing ring – the inner and outer rings, which clamp axially. The excavator can rotate 360 degrees because of the large diameter bearings, which act as joints between the undercarriage and the upper structure.

The slewing bearing can handle all the complexities of the load spectrum – thrust, radial, and tilting moment loads.

Slewing bearings are known for their constant rotating torque, high-speed rotation, and low noise when working.


5.  How Do I Get Quality Slewing Bearings?


You can get world-class slewing bearings by contacting a professional parts company with a proven record.

Here’s the deal:

KS is the world’s leading manufacturer and supplier of excavator parts. You can get your slewing bearings by contacting us today. We’ll then send you a quote within 24 hours, considering your budget and your requirements.

KS will also supply you with high-quality parts for testing its reliability. We’ll finally ship your slewing bearings wherever you are located. You can be sure that your shipment will arrive on time, as we have established a close working relationship with leading logistics companies.

Apart from that, you are also guaranteed a 90-day warranty on your shipped part. In the rare event that your part should be faulty

Contact us today for the best deals on excavator parts.


6.  What Are The Benefits of Using A Slewing Bearing?


Slewing bearings are used in excavators and other heavy machines because their benefits exceed their downsides.

Check this out:

The first reason why slewing bearings are used in excavators is that they have a high load-carrying capacity. They can carry heavy loads efficiently with low noise. Slewing bearings can also handle the complexities of load spectrum – thrust, radial, and tilting moment loads.

The second benefit of using slewing bearings is their long lifespan. They have an immensely long service life, even though they can carry heavy loads. Slewing bearings also have their surfaces protected from corrosion resistance. Their surfaces are polished to shine to prevent rusting and other forms of surface contamination.

Slewing bearings are integratable. They can have additional features such as lubrication systems, driving mechanisms, control devices, etc.

However, one condition has to be met for you to enjoy the benefits of your slewing bearing. You have to acquire your slewing bearing from a reputable parts manufacturer.


7.  How Are Slewing Bearings Made?


Slewing bearings are made from stainless steel. Steel manufacturers sell stainless steel to world-class leading part manufacturers like KS Company. After proper sampling and inspection, the raw stainless steel gets qualified and stored.

Then, forging takes place. Forging stainless steel is the most challenging part. The image below shows the forging process:

After the manufacturing process, the processed part is then packaged and sent over to you.


8.  Why Should I Choose Slewing Bearings From Your Company?


KS is a world-class parts manufacturing and supplying company. With over 10 years of experience in the industry, we manufacture parts according to OEM standards. Our stores currently have 10,000+ parts ready for shipping to your desired destination.

Apart from our vast experience, KS also uses a super-strict quality control process to ensure that all parts are manufactured faultlessly. In the rare event that any of our shipped parts are faulty, we have a 90-day warranty backup.

Our highly trained and skilled service reps are always ready to listen to you, answer your questions. They’ll help you get your parts on time. They are available for you 24/7. KS has established a cordial working relationship with international logistics companies like DHL, TNT, FEDEX, etc.

KS ships parts to different parts of the world. We ship to over 50 countries – we can deliver your parts to wherever you are.

That’s not all…

The best part of it all is our packaging. It ensures that your parts reach you safely. During packaging, we use wooden pallets to support your slewing bearing’s weight as it lies horizontally. The slewing bearing as well as the wooden pallet are then placed inside a wooden box.

It ensures that there is no physical damage to your parts during shipment.

KS ships your packaged parts depending on your desired method. We can ship them via sea or by air, whichever you deem fit.

Do not worry about the method you’ll use to pay us. We accept different payment platforms for payment on your shipped parts. We accept Paypal, Western Union, AliPay, L.C, and T.T.


9.  How Should I Lubricate My Slewing Bearings?


Lubrication is a beautiful way to prevent premature slewing for your slew bearings. There are steps you should follow to ensure that you’ve appropriately lubricated your slewing bearings.

Check them out:

  1. You should relubricate your slewing bearings periodically – Your slewing bearings have a recommended relubrication period. Consider the following example:

A slewing bearing should be relubricated after every year or after every 100 hours of work, whichever comes first. However, if your slewing bearing works continually, it should be relubricated after 20 hours of continuous use.

KS recommends relubricating idle bearings mounted on machines twice per year (after every six months).

  1. Use the recommended lubricant – Different lubricants are made differently. They do not have the same degree of viscosity, and using the wrong lubricant will cost you your slewing bearing.

Contact us today for the best advice on lubricants to use on your slewing bearing.

  1. Over-lubrication:

You may think to yourself:

If I over-lubricate my slewing bearing, it will provide a longer service without lubrication.”

That’s not true. It’s a misconception. Your grease should not purge from your slewing bearing seal. Your excavator’s operating temperature will increase when the machine is working. Excess grease will prevent optimum performance.

  1. Lubrication whenever there is bearing noise – this is another common mistake you shouldn’t make. There are times your bearing will require greasing when it makes noise. However, that shouldn’t be the solution for all similar situations.

Whenever you hear your slewing bearing producing noise, that should notify you of its internal damage. Now, adding grease will only solve the problem temporarily.

Internal failures are usually a result of another underlying issue within your excavator. You need first to identify the root cause of your slewing bearing’s failure so that you can solve the problem permanently.

Constantly changing the slewing bearing will not solve your problem. It will cost you a lot of money until you address the underlying cause.

You can contact us today through our website for advice on your failing excavator parts. We’ll be glad to hear from you and help you solve your problem.


10.  How Can I Prevent Premature Slewing Bearing Surface Wear?


Now, there are steps that you need to follow to the letter to ensure that your slewing bearing does not wear-out prematurely.

Check them out:

  1. Select the Appropriate Slewing Bearing Design:

Selecting the right design is one of the specifications laid out in the OEM documentation. Your bearing should be able to handle heavy loads and work efficiently.

Apart from selecting the appropriate slewing bearing design, you should also select the correct bearing size. The right bearing size can only be determined by contacting a professional parts manufacturing company.

  1. Proper Slewing Bearing Installation:

It’s not all the time that the application of sheer force works when installing your slewing bearing. You need to ensure that you install your slewing bearings properly.

There are steps that you should follow when mounting your slewing drive on your excavator. The image below shows how you should tighten your bolts for maximum slewing efficiency:

After installing your slewing bearing, remember to flush and clean it. After flushing and cleaning, you need to do the most crucial part of lengthening your slewing bearing’s lifespan – lubricating.

  1. Lubrication – You need to lubricate your slewing bearing according to your part’s manufacturer specifications. Without proper lubrication, the slewing bearing will wear out prematurely. It will also reduce the efficiency of your excavator.

Do not over-lubricate your slewing bearing. It will force the machine to work inefficiently while producing a lot of heat.

You also need to use the correct lubricant to ensure that your slewing bearing lasts for long.

Following the above three significant steps will guarantee your slewing bearing longer service life. Remember to contact us for your new slewing bearing in case it is damaged.


11.  What Mistakes Are Made During Slewing Bearing Installation?


Common slewing bearing installation mistakes are what make your slewing bearing have a short lifespan.

The best part, however, is that you can prevent premature slewing bearing failure by avoiding the following mistakes:

1.Carrying the Slewing Bearing in Any Position

When KS packages your slewing bearings and other excavator parts, we ensure that we’ve packaged them in the correct order. It helps avoid damages during transport.

A slewing bearing must strictly be carried horizontally. If you must carry it in another position, you’ll require special techniques that will ensure the slewing bearing does not get damaged. The equipment you choose to use should be able to support the weight of your slewing bearing.

2. Cutting Protective Seals During Unpacking

When unpacking your slewing bearings, you’ll find out that KS uses a special packaging paper for protection. You have to ensure that you cut that paper on the outer diameter instead of the upper and lower faces. It is a common mistake many people make.

3.Using Excessive Force To Fix the Slewing Bearing in Place

It seems logical to hammer your slewing bearing to mount it to place – but that will only damage it.

Force is not always the answer to fitting your slewing bearing.

As much as the raceway and rolling elements are hardened during manufacturing, they can still get damaged. Hammering your slewing bearing will leave dents on its surface. It will drastically reduce its service life as well.

If fitting your slewing bearing is difficult, you can check the shaft’s diameter, burrs as well as dirt, and other unwanted materials. If everything seems to be okay, use a pressing machine to mount the slewing bearing. Remember to apply pressure equally. It’ll help you avoid unnecessary damages.

4. Improper Tightening of Bolts

When mounting your slewing bearing on your excavator, you need to tighten its bolts according to the manufacturer’s specifications.

The image below shows how to tighten your bolts:

When you tighten your slewing bearing bolts using the above formula, you increase its lifespan and enhance its torque.


12.  How Can I Prevent Premature Slewing Bearing Failure?


All slewing bearings will eventually be replaced. Premature slewing bearing failure costs you a lot of money without fully enjoying the damaged slewing bearing’s benefits.

There are 5 steps that you can follow to prevent premature slewing bearing failure. Check them out:

1. Correct Slewing Bearing Selection

Apart from identifying your slewing bearing’s correct dimension, it is important to acquire it from a reputable company. Buying your slewing bearing from a good company ensures that you have a high-quality and durable excavator part.

You’ll also have customer support to answer your questions and clear any doubts that you may have. They’ll also help you get your slewing bearing on time.

2. Proper Lubrication

Proper lubrication is one of the primary causes of your slewing bearing’s long service life. Applying too little or excessive lubricant is not advisable. When you apply too little of it, the slewing bearing will have to bear a lot of friction when carrying loads.


Contrary to that, applying excessive lubrication is also a wrong move. When the lubricant starts purging from your slewing bearing’s seal, there will be the generation of a lot of heat. This will force your machine to work ineffectively and inefficiently.

You also need to use the correct type of lubricant. Different lubricants are made differently. They do not have the same degree of viscosity, and using the wrong lubricant will cost you your slewing bearing.

3. Seals

Seals prevent premature slewing bearing damage by protecting their internal components from external contaminants. You’ll need to use the correct seals, considering your excavator’s working environment.

If you need seals, you can acquire them from a professional company with a great track record. When seals are exposed to high temperatures for long, they become brittle. You, therefore, need to buy strong and long-lasting seals.

4. Proper Fitting

Using excessive force is not always the solution to fitting your slewing bearing. You should also not use unstable heat, for example, naked heat. It’ll get damaged because its internal structure will be weakened.

In case you choose to use a pressing machine, ensure that the pressure is applied uniformly.

If you are in doubt about what to do, please contact us today. Our highly-trained and skilled service reps are always available to listen to you and help you out. You can also post your question on our website, and we’ll get in touch within 24 hours.

5. Periodic Monitoring

You’ll probably not know when your slewing bearing starts failing. You’ll only realize it when your excavator becomes inefficient and produces a lot of noise and heat. Is there any way to prevent this situation before it occurs?


You can prevent this issue by monitoring the condition of your slewing bearing periodically. Periodic monitoring of your slewing bearing’s condition reduces the risks of premature failure.

To discover more about how you can prevent premature failure in your slewing bearing, you can contact your service reps today.


13.  Where Is the Slewing Bearing Located in An Excavator?


A slewing bearing is what connects the undercarriage and the cabin. It helps the excavator change its position without moving.

The following image will help you understand where best to find the slewing bearing:


14.  What Is the Price of A Slewing Bearing?


I’m not going to lie to you:

Slewing bearings are not cheap. They’ll cost you $1,000+, depending on your specifications. This means that you have to take care of your slewing bearing to avoid incurring unnecessary costs.

If your slewing bearing fails, please feel free to contact us for more information on how you can get brand new, high-quality slewing bearings.


15.  Where Are Slewing Bearings Mounted On Excavators?


Slewing bearings are mounted on the excavator’s undercarriage. They connect the undercarriage and the upper carriage.

When mounting them, remember to follow the correct installation procedures to prevent premature slewing bearing failure. You can contact us in case you are in any decisional doubt.


16.  What Are the Different Types of Slewing Bearings?


Now, there are different types of slewing bearings in the market today. Their primary differences lie within their functionalities.

Check them out:

1. Ball Bearing Slewing Rings

These types of slewing rings are ideal for low to medium loads. They are mostly made out of steel or brass metals. Ball-bearing slewing rings have polymer spaces installed between their rolling elements.

You can acquire quality ball-bearing slewing rings from KS today. Contact us for more information.

2. Roller Bearing Slewing Rings

This type of slewing bearings is ideal for medium to high loads. They have one radial and two axial raceways.

3. Combined Roller and Ball Bearing Rings

Its design is most suitable for high axial loads. It has both roller and ball-bearing rings.

4. Tapered Roller Slewing Bearings Rings

This type of slewing bearings is ideal for both radial and axial loads. They can support high loads.


17.  What Are the Steps To Follow When Selecting A Slewing Bearing?


You need to select the correct slewing bearing for your machine to work effectively and efficiently. Slewing bearing selection significantly affects how your machine performs, as well as its lifespan.

Now, selecting the correct slewing bearing can be intimidating. It can be intimidating if you are not so technically knowledgeable or if there are economic challenges.

KS can provide you with all the knowledge you require when selecting the appropriate slewing bearing. Our slewing bearings are manufactured to meet OEM standards. They will offer you long service life.


Scroll to Top

Get a Quick Quote!


    Get a Quick Quote!