Lawn Mower Rattling – Expert’s Advice for a Smoother Cut in 2023

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Lawn mowers are a great tool to keep your lawn looking neat and tidy. However, if your lawnmower is making a rattling noise, it can be a sign of a problem. Lawn mower rattling can be caused by various factors, from loose bolts and nuts to damaged blades or a worn-out engine.

Sometimes, a simple fix such as tightening loose bolts or replacing a damaged blade can solve the problem. However, more severe issues, such as a worn-out engine may require professional assistance.

In this article, I will discuss the top reasons why your lawn mower may be rattling and provide solutions for each. By understanding the common causes of lawn mower rattling and taking the necessary steps to fix the problem, you can keep your lawn mower running smoothly and ensure a well-manicured lawn.

Top Reasons Why Your Lawn Mower Rattling

As a lawn mower owner, it can be frustrating when your machine starts to make a rattling noise. This noise can be caused by various reasons, and it’s important to identify the root cause of the problem to fix it.

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Top Reasons Why Your Lawn mower Mower Rattling

Loose or Damaged Blade Components

If you are experiencing a scraping or loud noise coming from the blade of your mower, it could indicate loose or damaged blade components. One way to address this issue is by seeking help and advice from a lawn care forum or small engine forum.

It is important to check the blade’s spindle, bearing, and assembly to determine if they are the source of the problem. If the noise persists, consider buying a new spindle for your push or riding mower.

In some cases, the noise could be caused by something as simple as a loose bolt or a clog in the mower’s system. Checking the idler, shaft, muffler, throttle, and PTO can help identify the issue.

If you cannot fix the problem yourself, taking your mower to a repair shop may be necessary. Remember to also check for any signs of rust or damage to other parts of the mower to ensure a better experience and prevent further complications. 

One of the most common reasons why your lawn mower is rattling is due to loose or damaged blade components. Over time, the blade and its components can become loose and start to vibrate, causing a rattling noise.

Inspecting the blade, blade adapter, and blade bolts for any signs of wear and tear is important. If any of these components are damaged or loose, they should be replaced immediately.

Engine Mount Issues 

Engine mount issues can cause a range of problems with a mower, such as excessive noise. One indicator of engine mount issues is a sudden increase in noise when the mower is started. Some users have reported experiencing this problem with John Deere mowers, particularly on the left side of the mower.

To fix this issue, check to see if the engine mount is worn or damaged, and if necessary, replace it with a new one. Another sign of engine mount issues is excessive vibration.

If the lawnmowers make excessive noise, but the vibration goes away when the engine is shut off, the engine mount may be the culprit. Checking and fixing engine mount issues on a mower is relatively easy.

However, it is important to remember that other factors, such as a damaged cylinder, faulty linkage, or a bent crankshaft, can also cause engine mount issues. Therefore, it is recommended that you thoroughly look over the mower and its components before jumping to conclusions. 

Another reason why your lawn mower is rattling could be due to engine mount issues. The engine mount is responsible for holding the engine in place, and if it becomes loose or damaged, it can cause the engine to vibrate and produce a rattling noise.

You can check the engine mount by inspecting the bolts and nuts that hold it in place. If any of these are loose, they should be tightened immediately.

Debris and Dirt Build-Up

Debris and dirt build-up can also cause your lawn mower to rattle. When debris and dirt accumulate on the blades, it can cause them to become unbalanced and vibrate, producing a rattling noise.

It’s important to clean your lawn mow. Engine mount issues can occur in various types of garden equipment, including push mowers.

One common problem is when the engine starts to spin or make a grinding or scraping noise.

This can happen if something goes wrong with the engine mounting or if the engine becomes dislodged from its proper position. In some cases, the noise may go away after a few minutes of use or after restarting the engine.

However, checking the engine mount for any signs of damage or wear is important. Other symptoms of engine mount issues may include excessive vibration or slop in the engine when trying to start or during operation.

If left unchecked, these issues can further damage the engine or other components and may even cause the mower to stall. Suppose you are experiencing engine mount problems with your garden equipment.

In that case, it is recommended to seek assistance from a dealer or a professional technician who can properly diagnose and repair the issue to prevent this from happening.

You can use a wire brush to remove any debris and dirt from the blades and underneath the deck.

Damaged or Loose Belts

It is important to address the issue promptly when it comes to damaged or loose belts in machinery such as lawnmowers or trimmers. One telltale sign of a damaged or loose belt is an unusual noise from the machine.

This noise may disappear once the machine is started, but investigating the cause is still important.

Damaged belts can result from various factors, such as wear and tear over time or hitting something while in use. Loose belts can often be tightened relatively easily by adjusting the tension.

However, if the belt has sustained significant damage or has completely broken, it will need to be replaced.

It is also important to check the condition of the bushing that holds the belt in place, as a worn or damaged bushing can cause the belt to slip or come off entirely.

Regular maintenance and inspection can help prevent belt issues, but if they do occur, it’s best to address them promptly to ensure optimal performance and safety. 

Damaged or loose belts can also cause your lawn mower to rattle. Belts that are worn or damaged can produce a rattling noise when they come into contact with other parts of the machine. Inspecting the belts regularly and replacing them if they are damaged or loose is important. Tightening loose belts can also help reduce the rattling noise.

Bent Crankshaft 

When I started my lawn mower, I noticed a strange noise from the engine. It went away after a few minutes of running, so I thought nothing of it.

However, the next time I tried to start the mower, it wouldn’t start at all. Confused, I checked the gas and pulled the starter rope multiple times, but still no luck.

Frustrated, I decided to do some research online. I came across an older thread on a lawnmower forum that discussed similar issues. I may have a bent crankshaft.

The forum members suggested that a bent crankshaft could cause excessive noise and eventually lead to a mower not starting.

They recommended checking the oil and inspecting the shaft for any visible signs of damage. They also mentioned that a bent crankshaft is a complex fix and may require professional assistance. I realized I should have paid attention to the strange noise earlier and immediately acted.

Now, I would have to take my mower to a repair shop for further inspection and get ready to spend some money on repairs. 

A bent crankshaft can cause your lawn mower to produce a rattling noise. The crankshaft is responsible for converting the reciprocating motion of the piston into rotational motion. When the crankshaft becomes bent, it can cause the engine to vibrate and produce a rattling noise.

If you suspect that the crankshaft is bent, it’s important to take your lawn mower to a professional for repair.

By finding out the root cause of the rattling noise, you can take the necessary steps to fix your lawn mower and prevent further damage. It’s important to look over your lawn mower regularly and address any issues as soon as they arise to keep your machine running smoothly.

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Common Causes of Your Lawn Mower Makes a Loud Clanking Sound

As a lawn mower owner, you may have experienced a loud clanking sound coming from your machine. This sound can be alarming and may indicate a problem with your mower.

I will discuss the most common causes of a loud clanking sound in your lawn mower.

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Common Causes of Your Lawn Mower Makes a Loud Clanking Sound

Engine Problems 

Engine problems can be a common issue that many people face with their machines. One of the main indicators of engine problems is when strange noises start to emanate from the motor.

For example, if you notice that your lawn mower started making unusual sounds while in operation, it may be a sign of an engine problem. It is important to address this issue as soon as possible so that there is no more damage to the machine.

In some cases, these noises may disappear on their own, but it is always best to investigate the root cause of the problem. Another factor to consider is the type of gasoline being used.

Using low-quality fuel or an improper fuel-oil mixture can cause engine problems. Additionally, the horsepower of the engine may also be a contributing factor.

If the motor is not powerful enough to handle the workload, it may struggle and make strange noises. Always be sure to check under the hood regularly and address any engine problems promptly to ensure the longevity of your machine. 

One of the most common causes of a loud clanking sound in your lawn mower is engine problems. If you hear a knocking sound coming from your engine, it could be due to low oil levels, a damaged blade, a broken blade adapter, a damaged belt, or an obstruction in the deck.

You can check the engine oil level and add oil if necessary. If the blade is damaged or broken, replace it with a new one. Also, check the blade adapter and belt for any damage or wear and replace them if necessary. If there is an obstruction in the deck, remove it carefully.

Loose Parts 

Loose Parts play is an open-ended, creative, and child-directed play that involves using a variety of materials and objects that can be freely moved, combined, and manipulated.

When engaged in loose parts play, children explore and experiment with materials such as pebbles, sticks, fabric scraps, and other loose items, allowing their imagination to run wild.

This type of play encourages problem-solving skills, social interaction, and cognitive development. Loose-part play also provides sensory experiences as children touch, feel, and manipulate different textures and materials.

Furthermore, loose-part play promotes physical activity and keeps children engaged for longer periods. The noise went away from the play area as children were focused on their imaginative play.

It is important to ensure a safe play environment with age-appropriate loose parts and always supervise younger children to minimize choking hazards.

Overall, loose-part play is a valuable and enriching play experience that allows children to use their creativity and imagination in a way that traditional toys may not offer. 

Loose parts are another common cause of a loud clanking sound in your lawn mower. Loose parts can include the blade, blade adapter, belt, and engine mounts.

Check all these parts to ensure they are secure and tightened properly. If any of these parts are loose, tighten them immediately to prevent further damage to your mower.

Blade Issues 

Blade issues can be quite frustrating for individuals who rely on their blades for various tasks. One common issue that arises is when the blades do not lower properly.

This can be due to a malfunction in the lifting mechanism or simply because the blades are dull and unable to penetrate the surface effectively.

Another issue that may occur is when the blades need to spin properly. If the blades are spinning at the desired speed, it can improve the tool’s performance and make it easier to cut through materials.

Additionally, sometimes, the blades may still lack sharpness even after sharpening them.

This can be a frustrating situation as one would expect the blades to be fully functional and sharp after sharpening. To avoid these blade issues, it is vital to ensure that the machine is in good working condition and that the blades are regularly maintained and replaced when necessary. 

Blade issues can also cause a loud clanking sound in your lawn mower. If the blade is dull or damaged, it can cause a loud noise when cutting the grass. To fix this issue, sharpen or replace the blade.

Also, check the cutting deck for any debris or buildup, as this can cause the blade to become unbalanced and create a loud noise.

A loud clanking sound in your lawn mower can be caused by engine problems, loose parts, or blade issues. By checking these common causes and fixing any issues that you find, you can prevent further damage to your mower and ensure that it runs smoothly and quietly.

Diagnosing Rattling Sounds

As a lawn mower owner, it’s important to be able to diagnose rattling sounds coming from your machine. These sounds can indicate a variety of problems, some minor and others requiring immediate attention.

I’ll cover two methods for diagnosing rattling sounds: visual inspection and sound identification.

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Diagnosing Rattling Sounds

Visual Inspection

The first step in diagnosing rattling sounds is to perform a visual inspection of your lawn mower. Start by turning off the engine and removing the spark plug wire. Then, inspect the mower for any loose or damaged parts. Here are some areas to pay attention to:

  • Blade: Check for any signs of damage or looseness. A damaged or loose blade can cause rattling sounds.
  • Deck: Inspect the deck for any cracks, dents, or other damage. A damaged deck can cause rattling sounds.
  • Bolts and Nuts: Check all bolts and nuts to ensure they are tight and secure. Loose bolts and nuts can cause rattling sounds.

If you happen to notice any issues during your visual inspection, please take note of them and address them as soon as possible.

Sound Identification

If you cannot identify the source of the rattling sound through a visual inspection, the next step is to identify the sound itself. This can help you pinpoint the source of the problem. Here are some common rattling sounds and what they might indicate:

  • High-pitched squeaking: This could be caused by a loose belt or worn-out pulley.
  • Grinding or metal-on-metal sound: This could indicate a damaged blade or other metal part.
  • Rattling or shaking: This could be caused by loose or damaged parts, such as a loose blade or deck.

Once you’ve identified the sound, you can use this information to perform a more targeted visual inspection and address the issue.

Diagnosing rattling sounds coming from your lawn mower requires a combination of visual inspection and sound identification. By following these steps, you can identify the source of the problem and take appropriate action to address it.

Fixing a “clanking noise” and some vibration Lawn Mower

If your lawn mower is making a “clanking noise” and some vibration, there are a few things you can do to fix it. Here are some possible solutions:

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Fixing a Clanking noise and some vibration Lawn Mower

Tightening Loose Parts

One common cause of a rattling lawn mower is loose parts. Check all the nuts, bolts, and screws on the mower and tighten any that are loose. I would also like you to check the blade and make sure it is properly tightened. If the blade is loose, it can cause a lot of vibration and noise.

Engine Repair

If tightening the loose parts doesn’t fix the problem, the issue may be with the engine. A common cause of engine noise is a blown rod. You can diagnose a blown rod by removing the spark plug and turning the blade by hand.

If the blade is difficult to turn or makes a clanking noise, it’s likely a blown rod. In this case, you’ll need to take the mower to a professional for engine repair.

Blade Replacement

If the blade is damaged, it can cause a lot of vibration and noise. Check the blade for any nicks, dents, or other damage. If the blade is damaged, it will need to be replaced. You can replace the blade yourself or take the mower to a professional for blade replacement.

A rattling lawn mower can be caused by loose parts, engine issues, or a damaged blade. Check for loose parts and tighten them as necessary. If that doesn’t fix the problem, diagnose the engine and take it to a professional for repair if necessary.

Finally, check the blade for damage and replace it if needed.

Preventing Future Rattling Noise

As a lawn mower owner, I know how frustrating it can be when your machine starts to make strange noises. Here are some tips to prevent future rattling noise:

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Preventing Future Rattling Noise

Regular Maintenance

One of the most important things you can do to prevent rattling noise is to perform regular maintenance on your lawn mower. This includes:

  • Checking and tightening all bolts, nuts, and screws regularly.
  • Cleaning the mower deck and blades after each use to prevent the buildup of debris and dirt.
  • Lubricating all moving parts, including the engine, wheels, and blades.
  • Replacing worn or damaged parts promptly.

By following these maintenance tips, you can keep your mower in good working condition and avoid rattling noise caused by loose or damaged parts.

Proper Usage

Another key factor in preventing rattling noise is proper lawn mower usage. Here are some tips to keep in mind:

  • Avoid hitting rocks, stumps, or other obstacles while mowing, as this can damage the blades and other parts of the mower.
  • Use the mower on a flat, even terrain to prevent excessive vibration that can loosen bolts and nuts.
  • Follow the manufacturer’s guidelines for oil changes, filter replacements, and other maintenance tasks to keep your mower running smoothly.

By using your lawn mower properly and following the manufacturer’s guidelines, you can prevent rattling noise and extend the life of your machine.

Remember, regular maintenance and proper usage are key to preventing rattling noise in your lawn mower. By taking these steps, you can keep your machine running smoothly and enjoy a well-manicured lawn all season long.

Frequently Asked Questions

What are the possible causes of a noisy mower?

When your lawn mower is running and you hear a rattling noise, it’s essential to consider several possible causes. These may include issues with the fasteners, flywheel, or lawnmower blades. To pinpoint the problem accurately, refer to your owner’s manual for knowledge to support the diagnosis process.

Can a lawn mower’s deck height affect rattling noises?

The deck height of a lawn mower can indeed affect rattling noises. If the deck is set too low, it can cause the mower to make loud and unsettling noises as it cuts through the grass. You’ll hear the blades hitting rocks or other obstacles in the lawn, causing a loud clicking sound.

Additionally, if the deck is not properly adjusted, it can cause the mower to vibrate and create rattling noises.

This can be exacerbated if the mower is old and the oil needs changing, or if the blades are not properly balanced. Overall, the deck height is an important factor in determining the level of noise a lawnmower makes a loud.

What steps should I take if I hear a loud ‘clunk’ while running the mower?

If you hear a loud ‘clunk’ while running the mower, there are several steps you should take. First, turn off the mower engine and check for any visible damage to the mower’s cutting blades.

Next, check the bearings and idler pulley for any signs of wear or damage. Remove the belt and increase the tension, as it may have become loose over time. Also, check for grass clippings or debris that may be causing the metal to resonate.

Finally, consider replacing the bearings or idler pulley, as worn out bearings since could be causing the clunking noise while the mower is running.

How can I diagnose the source of the rattling noise in my lawn mower?

Diagnosing the source of the rattling noise in your lawnmower involves a systematic approach. Start by turn off the mower and inspect the blades, engine, and other components for any signs of wear, damage, or loose parts. Check the air filter, oil level, and any visible debris. If the issue persists, it’s recommended to consult a professional for further troubleshooting.

Can using old engine oil lead to a rattling noise in the lawn mower?

Using old oil in a lawn mower can lead to a rattling or clicking noise. When the engine’s lubrication is compromised, the metal components can rub together and create a loud, annoying sound.

If you’re like me and prefer a quiet, smooth operation, it’s best to use new oil and regularly replace it to avoid common noises.

Additionally, disconnecting the spark plug and turning the mower’s blades by hand can help diagnose the origin of the noise and prevent major issues like replacing a crankshaft.

Always wear hearing protection when working with a reel mower, as the loud combustion and rattle can cause damage to your ears. 


In conclusion, there are several reasons why your lawn mower may be rattling. Loose or damaged blade components, engine mount issues, bent crankshaft, debris and dirt build-up, damaged or loose belts, and loose handles or controls are common causes of rattling.

It is important to address these issues promptly to prevent further damage to your lawn mower.

Regular maintenance and cleaning can help prevent some of these issues from occurring. Clean your lawn mower after each use, and check for loose bolts and nuts. If you notice any unusual sounds or vibrations, immediately stop using your lawn mower and inspect it for damage.

If you need help fixing the issue, it is best to consult a professional. They can diagnose the problem and provide the necessary repairs. Remember always to prioritize safety when working with lawn mowers.

By taking care of your lawn mower and addressing any issues promptly, you can make sure that it runs smoothly and efficiently for years to come.

Hopefully through this article from J & R Tractor, everyone can easily take better care of their garden.

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Hello there! I'm Jim Marl, and I have a wealth of experience in the world of tractors and gardening. For many years, I have been working with these machines and plants, learning everything there is to know about their care and maintenance. Whether you need help with your tractor or want advice on how to keep your garden thriving, I'm here to share my knowledge and expertise with you. Let's get started!

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