How To Remove A Lawn Mower Blade: Easy and Effective Ways

How To Remove A Lawn Mower Blade

The blades on lawn mowers wear out over time, making it difficult to make the perfect cut. Getting lawn mower blades replaced by a professional can be expensive, but you can save money by doing it yourself. Pick up the necessary lawn mower supplies and follow these steps to replace a lawn mower blade.

The best thing to do when your lawn mower blade wears out is to replace it. You only pay $15-$35 a pop and you will get a nice cut on your lawn all season long. The following are red flags that you should replace your blade as soon as possible:

  •  It is not clean and/or uneven.
  • The lawn mower blade vibrates too much.
  •  There are many damages to the blade (bent, scratched, rusted, etc.).
  •  The blade is more than two years old.

When you notice one or more of these things, you should change your lawn mower blade right away.

What to look for when buying a replacement lawn mower blade

The first thing you should do is to buy a replacement blade. However, how do you know which blade to get for your mower? Look in the manual for information about the blade for your mower. You should specifically look for:

The OEM number: It is the blade’s number assigned by the manufacturer. You can use this number to quickly locate the blade you need.

Model name and number: If you are unable to find the OEM number, use the model name and number instead.

Length and center hole design: To find a product that works with your lawn mower without knowing the OEM number or model, measure the blade length (measured diagonally) and center hole design (circle size, rounded rectangle, H-pattern, Y-pattern, or 5-point, 6-point, or 7-point star)..

How To Remove A Lawn Mower Blade and replace it?

Once you have acquired the right blade for your mower, have it close at hand for installation. Here are the things you’ll need if you want to replace a lawn mower blade.

Parts

 The new lawn mower blade 

Tools

  • Wrenches or ratchets
  • A vice grip, a clamp, or a block of wood 
  • Two Ziploc bags
  • Some gloves

1. Make sure you have the appropriate operator’s manual for your model

If your lawn mower’s manual doesn’t specify anything about your model, you should consult it before replacing a lawn mower blade. Make sure you follow the instructions for replacing a blade for your particular mower model.

2. Remove the spark plug wire

You should not start the lawn mower while repairing it. Ultimately, manually turning the blade is essentially the same motion the machine performs to power up. As most lawn mowers run on gas, you will need to remove the spark plug wire for safety.

It can be found in the front of the mower. It resembles a little black boot. Make sure you wear work gloves and disconnect the wire. Using a Ziplock bag, you can ensure it does not make contact and start the mower. This will provide an extra layer of protection. 

3. Ensure no fuel leaks

As you replace the blade, make sure your lawn mower doesn’t leak fuel. You can take a few steps to address this problem. You can run down the gas before replacing the blade, so there is no problem. You can also remove the fuel tank cap, place a Ziplock bag over the opening, and then screw the cap back on.

This will prevent fuel from leaking while you maintain the mower. You can also protect your driveway from leaks by placing a mat under your mower.

4. Position the mower correctly.

When the mower is securely fastened, you should turn it so the air filter is facing up. It’s usually the side from which grass blows out. It is usually the right side (when you are standing behind the mower). As you change the lawn mower blade, you can protect the air filter by tipping it on its right side.

5. Lock the blade in place

To avoid cutting yourself, you must lock the blade in place so it does not spin while you remove it. Using vice grips or C-clamps you can secure this to the side of the mower so that the blade can’t turn when it’s loosened. Another solution is to wedge a block of wood in the undercarriage of the mower so that it cannot move.

6. Loosen the bolt and washer

You will need a wrench or ratchet to loosen the bolt holding the blade in place. In general, for loosening it, you should turn it left or counterclockwise. 

After loosening the bolt enough, remove the washer and bolt that retain the blade. Are the bolts and/or washers on your mower rusted? Find the lawn mower parts you need on Appliance Parts Pros.

7. Write down the blade’s right side up

Take note of which side of the lawn mower blade is facing upwards before you remove it. Mixing up the sides and replacing the blade upside-down is easy.

A tip: Take a picture of the blade prior to removing it so that you can compare it if you get confused. You can now replace the blade once you have taken out the old one. 

8. Replace the blade correctly.

As you took the photo in the previous step, pick up your new lawn mower replacement blade and position it accordingly. It is important that the center hole of the blade line up with the wings facing the same way as the old blade.

9. Tighten the blade to the correct torque

You need to replace the washer and the bolt. After the bolt has been twisted by hand, pick up your wrench and finish tightening. If you have a torque wrench, that would be even better. The blade can be tightened according to the operator’s manual. Either way, tighten the blade so that it won’t spin off anytime soon.

10. Restore your mower to its original state

Congratulations! You’ve replaced your lawnmower blade successfully! Here’s how to put the lawn mower back to its original state:

  • Return your mower to its upright position.
  • Take the Ziplock bag out of the fuel tank and replace it.
  • Remove the Ziplock bag from the spark plug and attach it again.
  • Time to get moving! Your lawn mower is now ready for a clean cut all season long.

Maintain your lawn mower annually

The maintenance of your lawn mower goes beyond just replacing the blades. For instance, you should perform the following every year:

 

  • Change the oil
  • Clean the air filter
  • Replace the spark plug
  • Fog the engine
  • Wash the lawn mower (especially the undercarriage)

 

In order to maintain your lawn mower correctly, you may need some lawn mower parts.

Lawn mower blade FAQs

What is the recommended frequency of lawn mower blade replacement?

Generally, you should replace the lawn mower blade every two to three years. If you want the best cut, change the blade every season. 

Which way does the bolt need to be turned to remove the mower blade?

To remove a lawn mower blade, turn the bolt to the left or counterclockwise. Be sure to lock the blade in place with a vice grip, C-clamp or block of wood before attempting to remove it.

What side of the lawn mower blade is up?

  • It would be prudent to take note of the right side up when you remove your old blade. For those who forgot to follow these steps, here are a few clues:
  • A sticker or stamp may have been added by the manufacturer to indicate which side should be up.
  • Mower blades with cutting edges should be facing grass; those with dull edges should face the mower.
  • Ideally, the wings or taper of the mower should face up towards the underside.
  • Having trouble tightening the blade after you tighten it could indicate that it is upside-down.

After you’ve installed the blade correctly, you might add a sticker of your own to make recognizing the correct side easier in the future.

What is the best method for removing a lawn mower blade that is stuck?

Lawn mower blades that get stuck usually have overtightened bolts. To remove them, you’ll need some extra leverage. You can make the bolt loosen faster by using a ratchet or breaker bar.

Is it a good idea to sharpen your own lawn mower blade?

Most DIY repairmen don’t think it’s worth their time to sharpen their own lawn mower blades. Blades today can be difficult to sharpen because of their complex shapes and inset cuts. In most situations, it’s better to buy new blades unless you’re a professional with the correct tools.

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