Sometimes your lawn mower blade just needs to be replaced. Sharpening can keep you going for a little while, but the metal itself will eventually wear out and get too thin from repeated sharpening.
When it’s time to replace your blade, you need to know how to remove your current lawn mower blade first.
The process is relatively simple and can be done at home with a minimum of tools. Some professionals might offer a blade change service for a fee, but this is so easy I don’t think it’s worth paying for unless you have a large riding lawn mower.
I’ll cover riding lawn mowers too, just in case you have the equipment needed to make that change.
In this guide you’ll learn:
- How to tell when your lawn mower’s blade needs to be replaced
- How to replace 3 kinds of lawn mower blades
- And much more!
What Are the Reasons You Need To Remove Your Lawn Mower Blade?
Lawn mower blades tend to be pretty durable and long lasting tools, especially when you know how to sharpen them. But, they do eventually wear out and need replacement. A poorly mowed lawn is only the least of your problems when you have a lawn mower blade that needs to be replaced.
That doesn’t mean that a bad mowing job isn’t a big problem, though. Uneven, ragged, mowing can seriously stress your lawn and made it difficult to keep your grass healthy.
Removing your lawn mower blade is the first step to replace it, so it’s an important skill to have.
Of course, replacing your lawn mower’s blade isn’t the only time you might need to remove the blade. For instance, if you have blades for different uses, you might need to switch between them in the middle of the season. Or, your blade might need some maintenance like a sharpening session or a thorough cleaning.
Some people will remove lawn mower blades to help winterize their mowers. I don’t think that’s particularly necessary unless you live somewhere with high humidity and rust risk in the winter. But, it can sometimes make storage easier or give you an opportunity to do some maintenance on the blade during the off season.
How To Tell When It’s Time To Replace Your Lawn Mower Blade?
Knowing that you might need to replace your lawn mower’s blade won’t do you any good if you can’t tell when it’s time for a replacement. Here are a few signs to look for that it’s time to replace your blade:
Your Lawn Mower Blade has Bent or Twisted
Despite being relatively simple tools, lawn mower blades are still optimized to provide good cutting power. Any sign that your blade has started bending or twisting means, at a minimum, that your blade isn’t performing the way it should any longer.
At worst, your blade could be starting to damage your lawn mower itself, or may start damaging your lawn mower soon.
As soon as you notice signs of bending or twisting in your lawn mower’s blade, it’s time for a new one.
Nicks and Gouges Make It Difficult to Sharpen
Re-sharpening your lawn mower’s blade can extend the life quite a bit, but sometimes the surface scratches on your blade are too deep to work around. Scratches are a normal part of any used lawn mower blade. Grass, gravel, rocks, and even small clumps of dirt can all cause scratches over time.
Usually small surface scratches are no problem. You can buff them out while sharpening, and many scratches won’t be anywhere that affects the function of the blade.
However, if you’re starting to get deeper scratches and gouges, more than about 2-3mm deep, it may be time to consider replacement. That’s because deeper scratches and gouges can cause weak points in the blade. The last thing you want is your lawn mower blade cracking while you’re using it.
Read More: >> How To Mow Your Lawn Like A Professional
In a worse case scenario a deep gash could crack and eventually break free entirely. If you’re lucky, a broken blade will damage your lawn mower. If you’re not lucky the blade could fly free of the mower and cause damage to you, or the people, plants, and buildings around you.
It Isn’t Holding An Edge
This is less common, but some blades will lose their ability to hold an edge over time. Usually this happens with blades where only the original cutting edge was fully hardened, and problems with hardening can happen with any manufacturer and model.
Over time these blades just won’t take or hold an effective cutting edge, losing their ability to cut grass at the same time. If you’re having to sharpen your lawn mower’s blade more and more often it’s probably time to remove the blade and replace it.
It’s Not Performing Well
The last reason is both the most common, and the simplest. You might need to remove and replace your blade simply because it doesn’t seem to be working as well anymore. Sharpening may be an option at this phase, but it depends on the blade and owner. Lawn mower blades are usually pretty affordable, so I know plenty of people who don’t bother sharpening their blades when they’ve started to go dull.
If you’re getting uneven clumps of grass after mowing, chances are you either need to sharpen your blade, or replace it.
How To Remove Your Push Lawn Mower Blade
To start with, let’s talk about one of the most common kinds of lawn mower—the motorized push behind lawn mower. Chances are, if you have a suburban-sized lawn, this is the kind of lawn mower you use.
Read More: >> The Best Lawn Mower Blades For Thick Grass
Step 1: Get Your Lawn Mower Ready
The first step to remove your lawn mower’s blade is to get it ready to be tilted or flipped over. For gas-powered lawn mowers that means you should drain the gas tank (if possible) and remove the spark plug.
Remove the battery from battery powered lawn mowers.
Unplug electric corded lawn mowers.
This prep helps prevent accidents and can also help your lawn mower last longer in the case of gas-powered mowers.
Once the power source is safe, either tilt your lawn mower up so you can access the blade, or consider flipping it entirely on it’s back. I like to place a tarp under the lawn mower to help prevent scratches on the outer casing.
Step 2: Remove Fasteners
Your lawn mower’s blade should be held on by 1 to 3 bolts in the center of the blade. It’s unlikely that you’ll be able to loosen these bolts with your hands, so you’ll need a wrench, or in some cases a screwdriver, to get them free.
Try to only use tools the right size and shape from the bolt to prevent stripping them or changing the shape. Most lawn mower blade fasteners can be replaced, but some are a non-standard size or length and can be hard to find.
Once the fasters are loose, put them in a small bag or a pocket to keep them safe.
Step 3: Lift the Blade Off
With the fasteners gone your blade should lift free of the lawn mower. I recommend having a can of WD-40, or a rag and some water, in case the blade is stuck in place. Gently work the blade free until it’s completely loose.
Remember, don’t use too much force at this phase or you’ll risk breaking either the blade or it’s attachment points.
How To Remove Your Riding Lawn Mower Blade
Step 1: Park Your Riding Lawn Mower
First you’ll need to drive your riding lawn mower into a garage, barn, or other sheltered area and park it. You don’t want anything to move while you’re working, so go ahead and use the brake systems and other lock settings to keep the lawn mower as immobile as possible.
Step 2: Lift The Lawn Mower So You Have Work Space
The next step is getting the lawn mower lifted enough that you can get your tools underneath and have room to work. Some people drive up a ramp onto a special maintenance frame to get access, while others lift the lawn mower onto wooden blocks.
I personally recommend using a riding lawn mower and tractor lift since it’s the safest and most secure option. However, those lifts can be relatively expensive equipment so not everyone uses them.
Whatever method you choose, check to make sure the lawn mower is secure and unlikely to fall. Think about this the same way you would think about lifting a car and working under it, the risks are very similar.
Step 3: Match The Bolt To The Appropriate Wrench
The larger, tighter bolts of a riding lawn mower’s blade generally need a wrench to remove. I recommend checking to make sure you have the right size, or setting the width of an adjustable wrench, before you start to get to work.
The wrench is a good fit if it’s wide enough to reach all the way around the bolt without any wiggle room. The more space between the sides of the bolt and the wrench, the more likely you’ll accidentally curve the corners of the bolt when you remove it.
Step 4: Remove the Fastener
Most riding lawn mower blades only have a single attachment bolt, but some do have more than one. Use the wrench to remove each bolt, until the blade is free.
I don’t recommend using a breaking bar unless absolutely necessary in this process. A small amount of WD-40 should be enough to loosen particularly stubborn bolts. Alternatively you can use a rubber mallet on the end of the wrench to provide some more force without risking damaging the bolts.
Step 2: Remove the Blade
Slowly and gently remove the blade if it didn’t come free on it’s own after you’ve removed the fasteners. Once the blade is free I recommend taking a moment to clean the area and remove any rust or corrosion that could make reattaching or removing the blade more difficult in the future.
How To Remove Your Reel Lawn Mower Blade
Reel lawn mowers are a little different, if you need to replace or repair the blades you’re not going to remove them from the lawn mower. Instead, your best option is to remove the other components of your reel mower and then replace them after sharpening or repairing the blade.
In some cases, you might replace the whole reel blade and then reattach the other components to the new blade.
Step 1: Remove the Drive Wheels
First, lay your reel mower on a flat space where it’s relatively stable. Your drive wheels are on either side of the blade, usually covered by a plastic hub cap. You can use a screwdriver to remove the hub caps without damaging them. Set the hub caps aside.
There is a clip holding both wheels to the axel. Use the same screwdriver to pull the clip loose. Set aside.
Next is a pinion gear. This can be removed by turning it counterclockwise until it comes free. You should be able to turn the gear with your hands.
There’s one more clip you’ll need to remove, also on the axel. Pull this away from the assembly plate. While you can dissasemble the assembly plate as well, it isn’t necessary and can cause irreparable damage to your lawn mower, so I don’t recommend it. Instead you’ll work around it to get this pin free.
Once the last pin is out you should be able to remove the blade from that side. Repeat on the other drive wheel.
Step 2: Remove the Rear Wheels
Most lawn reel mowers have a set of rear wheels for added stability. Some will also have a set of front wheels, but the removal process is the same for both.
All you need to do here is unbolt the wheels from the main assembly with a wrench. Try to make sure the wrench fits securely before you start to help avoid damaging the bolts.
Step 3: Remove the Mower Handle
Most reel mower handles are held on with a small pin near the bottom of the handle. Use a screwdriver to help remove the pin, and push the lawn mower handle toward the bottom to help remove some pressure from the pin.
Once the pin is free, the handle should be easy to remove. If it sticks, clean off the bottom of the handle and grease it with some mineral oil or WD-40 to help prevent further corrosion and make future maintenance easier.
Once the handle is removed you should be left with the blade and the assembly plate. Removing the blade is simple at this point, or you can sharpen the blade still attached to the assembly plate.
My Final Thoughts On Removing Your Lawn Mower Blade
Removing your lawn mower blade might not be fun or exciting, but it is an important skill to have. This guide should cover just about any standard lawn mower in the United States, but it’s also a good idea to check your users manual if you have it.
Remember that not all maintenance means you have to remove the blade. You can even sharpen some blades without taking them off of the lawn mower. I’ve written a guide to sharpening blades without removing them, but it does work best for blades with a simpler design.
As always, if you’re concerned that you can’t safely perform maintenance on your lawn mower yourself you should take it to a professional instead. No amount of savings is worth taking unnecessary risks to maintain your lawn mower.
With that in mind, happy mowing, and may your lawn mower never need more than basic maintenance!