Lawn Mower Blade Spins Freely: Maintaining a Blade

A lawn mower is a handy homestead tool that utilizes revolving blades to cut grass. As such, the blades of your mower must be sharp, in good shape, and secured in place to cut grass effectively, neatly, and evenly.  Normally, lawn mower blades are connected directly or indirectly via belts or other mechanisms to the engine. If you notice that your lawn mower blade is spinning freely (without cutting grass), then this is an indicator that there is a problem.

Lawnmower blades normally should not spin freely, so you need to look into what is causing your mower blade to spin. The causes can vary greatly, depending on whether you have a push or ride-on mower.

If your lawn mower has recently started producing a rattling sound and its blades are spinning freely, it is important to identify the root problem and address it before it worsens. In this post, you will find potential reasons why your lawn mower blade is spinning freely, along with feasible solutions.


Why is your lawn mower blade spinning freely?

Lawn mower blade spins freely

If you own a lawn mower, it is imperative to gain insight into how the components of your mower operate. Understanding how each component works will make it easier for you to find problems and fix them whenever they show up.

Lawn mower blades are an essential component of any lawn mower. To cut grass evenly and neatly, they must be securely attached so that they don’t move freely. However, how tight your lawn mower blade should be will depend on the type of mower you have. 

On the other hand, a loose mower blade is a recipe for an accident. Besides causing your mowing machine to operate inefficiently, a mower blade that’s spinning freely can easily come off during mowing, posing a serious safety hazard. Here are possible reasons for a mower blade to spin freely, depending on the type of mower you have. 

1. Push mowers

Push mowers usually have an internal combustion engine that relies on compression to transfer energy. As such, the principle of compression is critical to the functioning of your lawnmower. If the blade of your push lawn mower is spinning freely, low engine compression is most likely to be the culprit. This is because their blades are usually connected to the engine by an axle.

Lack of compression often results from leaks in one or more of your mower cylinders. While there are many causes of compression loss, the most common is normal engine wear and tear. However, you may want to check just to ensure that the engine problems are not a result of another issue.

2. Riding mowers (Tractors)

Unlike push lawn mowers whose blades are directly connected to the engine by an axle, riding mower blades are normally powered by a belt connected to the engine. As such, if the blades spin freely, a faulty or missing belt is likely to be the cause.

Over time, the belt that brings the engine power to your mower blades can break or wear out to a point where it is loose and can’t turn the blades. If you notice your lawn mower blade is turning freely, check if the belt is in good condition.


Fixing loose blades in push lawn mowers

Lawn mower blade spins freely

Lawn mower blades are meant to be secured properly and should never spin freely, except ONLY when the mower has a clutch. If your push lawn mower blade is spinning freely, follow these steps to fix it:

  1. Empty the gas tank. You can use a hand siphon.
  2. Turn your mower over.
  3. Inspect your lawn for things that may cause the blade to spin freely. Possible causes include compression loss, the blade not being centered, the bolt not being tight enough, and deformations.
  4. Place a wedge between the blade and deck to stop the blades from spinning.
  5. Fix the problem. If you have compression loss, the best solution is to replace the leaking component — piston, piston ring, valve, or head gasket. Most of the other issues require tightening. 
  6. Turn the mower to its wheels.

Fixing loose blades in riding lawn mowers

When it comes to fixing loose riding mower blades, the most important thing is to identify whatever causes your mower blade to spin freely. Follow these steps to fix your riding lawn mower.

  1. Park your mower on flat ground and away from obstacles
  2. Raise the deck to the highest position and turn it off.
  3. Inspect your lawn mower. A torn or worn-out belt is likely to be the problem. If the belt that drives the lawn mower blade is in good shape, check if the bolts are tight.
  4. If your lawn mower belt is too old, missing, or worn out, replace it with a new one. You may also want to tighten the bolts.

Once you have fixed your lawn mower, keep it in a safe place. Lawn mower components can be hurt by inclement weather, so it is best to keep your lawn mower in the garage or garden shed.


Conclusion

It can be annoying to have your lawnmower blade spinning freely. No matter the cause, you should consider fixing it immediately. Hopefully, this post will help you fix your loose lawn mower blade.