Lawnboy mower blade replacement. How to Change a Lawn Mower Blade

How to Change a Lawn Mower Blade

This article was co-authored by Grant Wallace. Grant Wallace is a Landscaper and Owner of Grantlanta Lawn in Atlanta, Georgia. With over seven years of experience, he specializes in lawn maintenance and landscape installation. In 2012, he earned his BA from the University of West Georgia. Grant has been profiled in Shoutout Atlanta, Canvas Rebel, and Voyage ATL.

This article has been viewed 387,277 times.

If you’re noticing missed patches in grass you know you mowed over, your mower just isn’t cutting it any more. Blades wear out with use and need to be changed occasionally to make your mower more efficient. You’ll keep your lawn healthier and you’ll need to mow less frequently with sharp, clean blades. Replacing them is an easy project that won’t take up much time, as long as you approach it correctly. See Step 1 for more information.

Inspecting and Removing Old Blades

• It’s also best to do this when there’s no gas in the mower. Wait until you use it all up to change the blade, or you might consider draining out the gas with syphon hose. Typically, self-syphon pumps are sold at any hardware or automotive parts store. This prevents gas spillage onto the mower body.

Unplug the spark plug. It’s best to stay on the safe side and prevent a short-out or electrical flare-up if any oil or gas should come in contact with the spark plug. It shouldn’t be a problem if you hold the mower properly, but it’s still best to be on the safe side. [2] X Research source

• Pay attention to the position of the blade as you’re removing it. You’ll mount the new one in the same orientation, usually with the sharp edge of the blade going counter-clockwise with the turning of the assembly. Again, this may not be true on all mowers, so pay attention to the way this blade is installed and install the new blade accordingly.

Installing New Blades

• Some mowers feature a bottom cap on which two shorter separate blades are attached, while some newer push mowers feature a single longer blade, that looks kind of like a ruler. Tilt the mower back to inspect the blade, or talk to someone at the hardware store about the type of blade appropriate for your brand of mower. You can also check in the owner’s manual, if you have it. [4] X Research source
• Alternatively, you can salvage the old blades and have them sharpened if they seem to be in decent condition. If the blades are worn out, with chips or chunks out of the metal, it’s probably wise to get a new set.
• Most blades are either specific or universal fit. Be sure you have the same length as the old blade before mounting the new one, and make sure the clearance from the lawn mower deck is the same. Tighten the new blade onto the bolts carefully, since it’ll likely be much sharper than the old one.
• It’s a good idea to wear thick mechanic gloves when doing the job, to keep your hands safe. It’s also advisable to use a small piece of wood to stop up the blade from turning while you reinstall it. You can jam a small piece of wood between the blade and the mower deck to keep things from turning. [6] X Research source

Check the blade for play. Be sure the blade is mounted correctly and has no wobble when you move it up and down, firmly. Remove any jacks or props used to hold mower in place and wait about 30-60 minutes for oil to return to motor to prevent issues or motor damage. Check the oil before use to ensure it is within the proper limits.

• After a quick inspection, you should be able to start up your mower and start cutting that grass much more efficiently with your new blades.

Expert QA

Grant Wallace is a Landscaper and Owner of Grantlanta Lawn in Atlanta, Georgia. With over seven years of experience, he specializes in lawn maintenance and landscape installation. In 2012, he earned his BA from the University of West Georgia. Grant has been profiled in Shoutout Atlanta, Canvas Rebel, and Voyage ATL.

Residential homeowners who only mow their grass a couple of times a month only need to sharpen their mower blades about once or twice a year. To check your blades manually, remove the spark plug from the mower and run your finger along the blade. If it feels dull or round, it likely needs to be sharpened.

Thanks! We’re glad this was helpful. Thank you for your feedback. As a small thank you, we’d like to offer you a 30 gift card (valid at GoNift.com). Use it to try out great new products and services nationwide without paying full price—wine, food delivery, clothing and more. Enjoy! Claim Your Gift If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even 1 helps us in our mission. Support wikiHow

It depends on the definition of stripped. Is it the head of the bolt or the threads? If it’s the head of the bolt it may be tricky, but an EZ out and a drill tap would get the job done, or a good pair of strong vice grips and a little heat from a propane torch should also assist with removing the bolt. If it’s stripped threads on the bolt then probably take the bolt to your local hardware store and get an exact copy of the bolt depending on the threads (if it’s coarse, fine or whatever). I am fairly certain it’s a 3/8 fine thread on lawnmower blades, though.

Thanks! We’re glad this was helpful. Thank you for your feedback. As a small thank you, we’d like to offer you a 30 gift card (valid at GoNift.com). Use it to try out great new products and services nationwide without paying full price—wine, food delivery, clothing and more. Enjoy! Claim Your Gift If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even 1 helps us in our mission. Support wikiHow

The sharp edge of the blade should be installed facing the grass. If the blades have tabs to fit into the housing, then go ahead and fit the tabs into the housing around the shaft. Always wear gloves though (preferably leather).

Thanks! We’re glad this was helpful. Thank you for your feedback. As a small thank you, we’d like to offer you a 30 gift card (valid at GoNift.com). Use it to try out great new products and services nationwide without paying full price—wine, food delivery, clothing and more. Enjoy! Claim Your Gift If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even 1 helps us in our mission. Support wikiHow

How to Change a Lawn Mower Blade

This article was co-authored by Grant Wallace. Grant Wallace is a Landscaper and Owner of Grantlanta Lawn in Atlanta, Georgia. With over seven years of experience, he specializes in lawn maintenance and landscape installation. In 2012, he earned his BA from the University of West Georgia. Grant has been profiled in Shoutout Atlanta, Canvas Rebel, and Voyage ATL.

This article has been viewed 387,277 times.

If you’re noticing missed patches in grass you know you mowed over, your mower just isn’t cutting it any more. Blades wear out with use and need to be changed occasionally to make your mower more efficient. You’ll keep your lawn healthier and you’ll need to mow less frequently with sharp, clean blades. Replacing them is an easy project that won’t take up much time, as long as you approach it correctly. See Step 1 for more information.

Inspecting and Removing Old Blades

• It’s also best to do this when there’s no gas in the mower. Wait until you use it all up to change the blade, or you might consider draining out the gas with syphon hose. Typically, self-syphon pumps are sold at any hardware or automotive parts store. This prevents gas spillage onto the mower body.

Unplug the spark plug. It’s best to stay on the safe side and prevent a short-out or electrical flare-up if any oil or gas should come in contact with the spark plug. It shouldn’t be a problem if you hold the mower properly, but it’s still best to be on the safe side. [2] X Research source

• Pay attention to the position of the blade as you’re removing it. You’ll mount the new one in the same orientation, usually with the sharp edge of the blade going counter-clockwise with the turning of the assembly. Again, this may not be true on all mowers, so pay attention to the way this blade is installed and install the new blade accordingly.

Installing New Blades

• Some mowers feature a bottom cap on which two shorter separate blades are attached, while some newer push mowers feature a single longer blade, that looks kind of like a ruler. Tilt the mower back to inspect the blade, or talk to someone at the hardware store about the type of blade appropriate for your brand of mower. You can also check in the owner’s manual, if you have it. [4] X Research source
• Alternatively, you can salvage the old blades and have them sharpened if they seem to be in decent condition. If the blades are worn out, with chips or chunks out of the metal, it’s probably wise to get a new set.
• Most blades are either specific or universal fit. Be sure you have the same length as the old blade before mounting the new one, and make sure the clearance from the lawn mower deck is the same. Tighten the new blade onto the bolts carefully, since it’ll likely be much sharper than the old one.
• It’s a good idea to wear thick mechanic gloves when doing the job, to keep your hands safe. It’s also advisable to use a small piece of wood to stop up the blade from turning while you reinstall it. You can jam a small piece of wood between the blade and the mower deck to keep things from turning. [6] X Research source

Check the blade for play. Be sure the blade is mounted correctly and has no wobble when you move it up and down, firmly. Remove any jacks or props used to hold mower in place and wait about 30-60 minutes for oil to return to motor to prevent issues or motor damage. Check the oil before use to ensure it is within the proper limits.

• After a quick inspection, you should be able to start up your mower and start cutting that grass much more efficiently with your new blades.

Expert QA

Grant Wallace is a Landscaper and Owner of Grantlanta Lawn in Atlanta, Georgia. With over seven years of experience, he specializes in lawn maintenance and landscape installation. In 2012, he earned his BA from the University of West Georgia. Grant has been profiled in Shoutout Atlanta, Canvas Rebel, and Voyage ATL.

Residential homeowners who only mow their grass a couple of times a month only need to sharpen their mower blades about once or twice a year. To check your blades manually, remove the spark plug from the mower and run your finger along the blade. If it feels dull or round, it likely needs to be sharpened.

Thanks! We’re glad this was helpful. Thank you for your feedback. As a small thank you, we’d like to offer you a 30 gift card (valid at GoNift.com). Use it to try out great new products and services nationwide without paying full price—wine, food delivery, clothing and more. Enjoy! Claim Your Gift If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even 1 helps us in our mission. Support wikiHow

It depends on the definition of stripped. Is it the head of the bolt or the threads? If it’s the head of the bolt it may be tricky, but an EZ out and a drill tap would get the job done, or a good pair of strong vice grips and a little heat from a propane torch should also assist with removing the bolt. If it’s stripped threads on the bolt then probably take the bolt to your local hardware store and get an exact copy of the bolt depending on the threads (if it’s coarse, fine or whatever). I am fairly certain it’s a 3/8 fine thread on lawnmower blades, though.

Thanks! We’re glad this was helpful. Thank you for your feedback. As a small thank you, we’d like to offer you a 30 gift card (valid at GoNift.com). Use it to try out great new products and services nationwide without paying full price—wine, food delivery, clothing and more. Enjoy! Claim Your Gift If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even 1 helps us in our mission. Support wikiHow

The sharp edge of the blade should be installed facing the grass. If the blades have tabs to fit into the housing, then go ahead and fit the tabs into the housing around the shaft. Always wear gloves though (preferably leather).

Thanks! We’re glad this was helpful. Thank you for your feedback. As a small thank you, we’d like to offer you a 30 gift card (valid at GoNift.com). Use it to try out great new products and services nationwide without paying full price—wine, food delivery, clothing and more. Enjoy! Claim Your Gift If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even 1 helps us in our mission. Support wikiHow

How to Replace a Lawn Mower Blade

About: We are the ULTIMATE in supplying you with replacement parts from over 60 name brands, and creating award winning How To Articles and Repair Videos. eReplacementParts.com is #1 when it comes to figuring out e… About toolrepair »

Lawn mower blades must be replaced after so many hours of cutting, and the steps in this instructable explain how to perform this simple parts replacement.

Broken, dull, damaged, and mismatched mower blades can cause a number of easily-noticed symptoms.

Damaged mower blades can cause excessive vibration in the mower, while dull mower blades usually get noticed by the ugly, irregular patterns they make in the lawn.

Mower blades can be sharpened several times to extend their life and ensure that your grass gets a healthy cut, but they can only be filed so many times before a blade replacement is necessary.

If you need to replace a lawn mower blade, you can do so at eReplacementParts.com

Homeowners can save themselves quite a bit of money performing simple repairs like this one. New mower blades tend to be reasonably priced, and mower blade replacements usually only require the use of a wrench.

For information about matching a replacement mower blade to your mower, please read the article, Lawn Mower Blade Measurements and Types.

Steps to Replace a Lawn Mower Blade

Mower blade mounting designs vary, but the basic steps are usually the same. Most mowers have use a very simple blade mounting design like the mower we use below as an example.

Step 1: Set the Mower on Its Side

Always set the mower on the side that does not have a carburetor so that the mower’s fuel does not leak out.

Make sure the gas and oil caps are screwed on tightly before tipping the mower.

Step 2: Remove the Fasteners Holding the Mower Blade On

This just means removing one nut on our example mower, and this is usually the case for most mower models.

Use one hand to steady the blade when first loosening the nut.

Step 4: Install the New Blade

Most mower designs will not allow the mower blade to be installed with the wrong side down.

Our example mower blade and its retaining plate are shaped so that the blade can only be installed in the correct position

It is possible to incorrectly install mower blades on some mowers. And it’s always possible to install a blade too loosely.

Vibration and poor lawn cutting will quickly make a poor mower blade installation noticeable. A quick adjustment is all it takes to get back to work in the event of an incorrect installation.

Step 5: Conclusion

The surprising thing about this repair might be how easy it is, especially since many lawn mower owners do not take the opportunity to save money on tool repairs by doing them at home.

If your mower blade is dull, damaged, or heavily worn, visit our eReplacementParts.com Lawn Mower Blades page to start your search for a compatible match and get started with this fast and easy repair.

Be the First to Share

Did you make this project? Share it with us!

Make It Bridge

Metal Contest

Комментарии и мнения владельцев

GOOD GOD, PEOPLE ! DISCONNECT THE SPARK PLUG BEFORE DOING ANYTHING.

my apologies for shouting, but to avoid any of you being called lefty your attention was required

See this video for a safer way! http://www.searspartsdirect.com/article/how-to-replace-a-lawn-mower-blade-video.html

This is the worst Instructables. First not disconnecting the spark plug. Second not having gas tank emptied to prevent gasoline spill. Third block the blade from rotating!

Doe it make any difference how the blade is installed compared to piston position? For ease of starting and engine balance.

If you’ve never done this task before, this is NOT the Instructable to follow. You’re much better off following drezac’s instructions in his Комментарии и мнения владельцев below. Otherwise, you’re liable to get some bruises or cuts or worse.

Besides not mentioning the horrific safety item of not removing the spark plug wire first to avoid an accidental starting of the lawnmower with your hands around the blade, just look at that photo with the bare hands holding the blade between one’s fingertips. That’s just asking for trouble. Also, note the hand on the ratchet wrench. nobody holds a ratchet wrench like that in a situation when a good amount of force must be applied.

BTW, with the underside of a mower that dirty with crusted-on grass and gunk, you just know that that mower blade hasn’t been serviced in a long while and is not going to come off with a few simple turns of the ratchet.

Also, check out that last photo. NOW the guy is going to put on a protective glove. (Maybe the glove in this photo is necessary to hide the fingers lost in the execution of the previous Instructable steps. )

Mower Blades (165 items found)

Lawn mowers can go the distance for you, but only when given the proper maintenance. When your mower blades are damaged, chipped or dull, they can cause serious damage to your lawn mower and create irregular cuts across your beautiful lawn. Dull mower blades shred grass instead of cutting it, making the texture of your lawn jagged and leaving it vulnerable to disease and discoloration.

So, if you notice that the cuts your lawn mower makes are less precise lately, the culprit is probably your mower blades. When trying to work with the blades you already have, you can carefully sharpen them yourself. Watch our video on how to sharpen lawn mower blades for an expert tutorial, complete with step-by-step instructions on properly removing your lawn mower attachments and safely sharpening the blades with a bench grinder or a rotary sharpening tool.

Additionally, many of our locations offer blade sharpening services. Check your local Ace store before buying a lawn mower replacement blade to see if sharpening is a better option

When to Get Replacement Mower Blades

If you still feel like your lawn mower isn’t performing to its full potential or you want to skip the whole sharpening process, swap out your old, worn blades with sharp new ones. We carry a wide selection of lawn mower blades to fit any size mower, from the smallest, cordless electric model to the largest, gas riding mower.

Choosing Lawn Mower Blades

Browse our selection of lawn mower replacement blades by brand or model compatibility, or shop for universal sizes to find the best fit for your mower. We carry all types from the very basic to highly crafted and streamlined mower blades to cater to your lawn maintenance needs.

Ultimately, the type of lawn mower blade replacements you need will depend on the kind of mower and lawn you have, as well as what you want to do with your yard clippings. We recommend you read and review your owner’s manual to understand the manufactures recommendations. You can purchase a single lawn mower blade or sets of two or three replacement blades for riding mowers, walk-behind mowers and lawn tractors. Choose from regular mower blades that either discharge or bag the clippings and 3-in-1 mulching blades with the capacity to shred grass and leave behind a fine mulch instead.

Buy Your Mower Blades at Ace

Find everything from your standard blade replacements to mulching lawn mower blades at Ace. We stock name brand products, including those by MaxPower, Craftsman, EGO, our own Ace brand and more. Our team of experts is here to help you find the right fit for your lawn mower and anything else you may need, like lawn mower parts and replacement mower tires.