You might think that lawn mower blade replacement is a complicated affair, but it’s actually pretty simple to change a mower blade yourself. You don’t need any specialised equipment, nor does it require much DIY skill. It’s important to have seamless, sharp blades for optimal performance and to create clean cuts. This in turn prevents putting additional strain on the engine and also helps keep grass healthier. A dull or chipped blade will tear vegetation rather than neatly slicing it. When your grass has these ragged edges it’s more susceptible to picking up some sort of plant disease.
That’s why it’s so important to keep your lawn mower blades in good nick. And with JAK Max only a call away, you can get high-quality after-market replacement blades from some of the world’s most trusted manufacturers. We have an extensive dealer network across the country, run by specialists who understand the demands of lawn mower maintenance in Australia.
How Easy is Lawn Mower Blade Replacement?
With only a few tools and some basic steps, you can easily replace your own lawn mower blade. As with all DIY jobs, before you start, you need to prepare a few safety measures.
Safety Checklist:
- Put on safety gloves and some kind of proper eye protection (sports sunnies will work if they’re damage-resistant).
- Find the spark plug and disconnect it. This is to prevent your mower starting accidentally while you’re working.
- Drain the lawn mower of all fuel (you can leave the oil in).
- Tip the mower over so that the air filter and carburettor face upwards. This is to prevent oil spill or leftover fuel leaks.
Tools You’ll Need
You only need a few tools to change a mower blade:
- A block of wood or a clamp to stop the blades from rotating manually.
- A spanner or socket wrench to loosen the blade bolt.
Optional: If you’re a more serious DIY person and you have them, you can use a blade balancer and torque wrench to get a more precision fit. They’re not necessary though.
How to Replace a Lawn Mower Blade: Step by Step
1. Prepare Your Mower
The main thing to worry about is making sure that the engine doesn’t accidentally start while you’re changing a blade. You can imagine the perils of this. To prevent it, disconnect the spark plug wire. Then brush away any built-up vegetation or debris around the entire blade area. Once that’s done, tip the mower on its side, making sure that the carburettor and oil filter are pointing upwards.
2. Remove the Blade
You’ll need something to stabilise the blades so that they don’t rotate while you’re working. This isn’t dangerous as it’s your hands that will cause the movement, but it can be really frustrating. To solve the problem, wedge the blades in place with a block of wood, and then loosen the blade bolt using your socket wrench or spanner.
You can also get a purpose-built blade removal tool from JAK Max. It’s designed to secure the mower deck and the blade to prevent any movement and allow you to remove it safely
Which way do you turn the bolt to remove a lawn mower blade?
Most lawnmower bolt threads are standard – in other words, you turn them counterclockwise (to the left). However, some models have the opposite mower blade bolt direction. Check your user manual beforehand.
Are lawn mower blades reverse thread?
As we said above, most lawn mowers have the same mower blade direction, but some manufacturers use reverse thread mower blades. The reason is to prevent accidental loosening while you’re using your mower.
3. Inspect the Blade
A cracked or damage blade won’t only make a mess of your lawn – it can also be dangerous to use your mower in this condition, in case a piece of the blade flies off at high speed. Carefully inspect the blade you want to replace for any cracks, bends or dents. If the blade isn’t cutting properly, but it’s still intact, you might only need to sharpen it rather than replace it.
How to tell if mower blades are on backwards?
If the blades are on backwards, their cutting edges will face in the opposite direction to the cutting rotation. You’ll effectively be trying to cut with the blunt edges. If you notice that the grass cutting properly, or if the blade is hitting the ground as well as the grass, there’s a good chance that it’s installed backwards.
4. Fit a New Blade
Following your manual, fit the blade into its bolt slot. Double check that the blade is facing in the right direction. Then tighten the bolt to secure it safely.
5. Torque the Bolts Securely
You shouldn’t have a problem tightening the blade bolt with a spanner or socket wrench, but if you have a torque wrench that’s even better. Use it to give the bolt a final tightening according to the spec recommended in the manual. If the bolt isn’t tight enough, the blade can rattle, and if it’s too tight you can damage the blade.
6. Test Run and Safety Check
Now you’re ready to test the installation. Reconnect the spark plug wire and start the engine. Check for unusual vibrations, and make sure that the blade spins freely and uniformly.
Which Way Do You Tip a Lawn Mower When Changing Blades?
Besides giving you easier access to change a mower blade, the reason to tip your mower is to stop fuel or oil leaking out. If these get into areas of the engine that they shouldn’t be, it can cause hard starting, a smoking exhaust or even damage the engine. That’s why you tip your mower so that both the fuel-filled carburettor and the oil filter face skywards.
Should I Sharpen or Replace My Mower Blade?
Is it better to sharpen a lawn mower blade or buy a new one?
If the blade just has a dull edge but doesn’t show any signs of damage, you can just sharpen it to get it cutting efficiently again. However, if you see that the edge is chipped or has a warp. then you should replace it. Sharpening won’t solve the problem. The same is true if the blade has a crack or has been worn a little thin. Replacing blades in this condition is always the safer option. JAK Max stocks a wide range of lawn mower bar blades for many different makes, including our new XHT-Eco range that gives you reliability at affordable prices.
How Often Should I Change My Lawn Mower Blade?
As a rule of thumb, it’s recommended that you replace a blade once a year during the mowing season. Most blades are designed to last for about 100 hours, so use that as the other marker for when you should replace yours.
This is the standard recommendation, but if you use your mower more often than average, or if you have mixed ground conditions in your garden, your blades might not last as long. This is especially true if you mow across gravel areas or sandy soil. Check your blades regularly to make sure that they’re not dulling or picking up other kinds of damage.
Pro Tips for Lawn Mower Blade Replacement
If you’re the type of person who likes to do everything very precisely, here are some more advanced tips on how to replace a lawn mower blade.
Blade direction marker: Before you start, use a sticker or a marker pen to indicate the correct direction in which to fit the blade so that you don’t forget. Then make sure that the sharper cutting edge faces in the same direction of the blade’s rotation when it comes to fitting it.
Blade balancing: If a blade is unbalanced it can vibrate, causing it to cut inefficiently and put wear and tear on your mower. You can use a blade balancer to prevent this.
Need a New Blade? JAK Max can help
JAK Max is one of Australia’s most trusted suppliers of after-market lawn mower blades. Professionals and DIYers alike rely on us to provide premium products and parts. We’ll make sure that your mower cuts cleanly and lasts as long as possible. Our experts can also advise you on the most suitable blade for your mower model and show you how to replace it. We can also give you plenty of tips on lawn mower maintenance.
Changing a lawn mower blade won’t take long and it’s dead easy. The payoff will be a crisply cut and healthier lawn. You’ll also prolong the lifespan of your mower by eliminating extra stress on the motor. When you need lawn mower blade replacement anywhere in Australia you can trust JAK Max for top-quality and expertise.
How to Replace a Lawn Mower Blade FAQs
Is it easy to replace a lawn mower blade?
It’s easier to change a mower blade than you might think. You just need to take a few basic safety measures and use easily available tools. Using this guide, anyone can replace a lawn mower blade, even if you don’t have the knack for DIY.
Which way do you turn the bolt to remove a lawn mower blade?
The mower blade direction on most models is the same. You remove the blade by turning the fastening bolt counterclockwise. However, some manufacturers use bolts with opposite threads. In this case unscrew the bolt in a clockwise direction. Check your manual for this.
Are lawn mower blades reverse thread?
Yes, some are. Some manufacturers use a reverse thread mower blade to stop the bolt from loosening as the blade rotates in the same direction as the thread. Check your user manual or look for the directional arrow on the bolt that some suppliers provide.
Is it better to sharpen a lawn mower blade or buy a new one?
That depends on the condition of the blade. You can’t carry on using one that is bent, chipped, cracked or worn down. It won’t cut properly, and there’s a good chance of over-stressing your mower’s engine. In this case you should definitely replace it. If it’s otherwise fine but the edge is dull, sharpening should be all you need.
How often should I change the blade on my lawn mower?
It’s best to change a mower blade once per 100 hours of use. To make it easier to keep track, change it at least once per mowing season. Rougher ground conditions, like lawns that contain small stones, may require you to change yours more often.
How to tell if mower blades are on backwards?
The easiest way is to look at your manual for the correct mower blade direction and then check that your blade is facing the right way, by seeing which side the cutting edge is on. The cutting edge should always face in the same direction as the blade rotation.
Which way do you tip a lawn mower when changing blades?
It doesn’t matter which way you tip your lawn mower to change blades, as long as the oil filter and carburettor are facing upwards.