How To Tell If The Spindle Is Bad On Riding Mower (6 Basic Signs)

During the process of mowing, you may encounter many different problems with the lawn mower. One of the most common problems you may encounter is a damaged lawn mower spindle. From there, it leads to a series of serious symptoms.

Some of the signs are strange noises, very loud creaking, shaking lawnmowers, uneven mowing, or engine difficulty moving. Turn off the engine and find out the cause of these symptoms as soon as possible. Because if you prolong the operation of the lawn mower in this condition, it will be seriously damaged. How to tell if the spindle is bad on riding a mower. Let’s find out the basic causes, signs, and how to fix this condition.

How To Tell If The Spindle Is Bad On Riding Mower (Definition And Signs)

The rotary shaft of the lawn mower is the part that helps transmit the power of the motor to the blade. It is a high-speed and high-torque process. A spindle has an internal assembly connected to a pulley and blade. Its outside connects to the deck of the lawn mower. Bearings are the part that separates the two parts.

Lawn mower rotating shafts are usually manufactured with materials with high strength and wear resistance. However, continuous use of the lawn mower, poor maintenance, or external influences will still affect the durability of the reel.

The rotation axis of the lawn mower when there is a problem will have six basic displays below. So, check for the signs below to spot the damage as soon as possible.

how to tell if spindle is bad on riding mower

Abnormalities In Observation

When the spindle has problems, you can observe abnormalities from the naked eye such as the lawn mower may be misaligned, or unbalanced, the belt moving abnormally up and down, the belt is overlapped or the knife net is not in the right position. The cause of these irregularities will lie in the bent bearings and shafts.

Strange Noise From Lawn Mower

One of the basic signs to warn of a bad lawn mower is a strange noise. Noise during lawn mower operation is a normal sound. However, if there is a roaring, creaking noise accompanied by an unpleasant smell, you should stop the engine and have it checked immediately.

The cause of the strange sound is a broken ring that causes the lawn mower’s rotating shaft to collide with the housing body. Therefore, the sound due to the friction of these two parts will be generated. It’s a sound made by two metal objects, and you can easily detect it.

Uneven Cuts In The Lawn

The lawn mower’s rotating shaft will continue to wear out due to collisions with other parts, making the lawn mower’s operation unstable. As a result, the position of the axis of rotation will be incorrect and not in the correct position in the housing body. From there, the spindle will be bent and the blade will not be in the right position. So, the cut on the lawn will be uneven because the blade is not fixed in one position.

The Belt Keeps Falling Off The Spindle

Because the axis of rotation is not at a constant and uniform angle, the belt will constantly fall off the pulley. In addition, the belt will also be damaged and not work properly. You will notice that the belt creaks or keeps falling off the pulley because the bearings are in the wrong position. Therefore, you should not attempt to use the lawn mower when the belt has fallen off the pulley because it will cause more serious damage to the spindle.

Lawn Mower Vibrates Abnormally

The lawn mower will vibrate during operation. However, the whole rotation of the lawn mower is shaken strongly, which is an abnormal phenomenon. Rotating shafts and bearings that are misaligned in the housing will cause them to have irregular gaps. From there, the movement of these two parts will not match and cause strong vibration. In addition, if the spindle is bent, the blade will also be deflected, thereby losing its balance. The movement of the blade will also create vibrations for the lawn mower.

Some Broken Parts Will Fall Out Of The Lawn Mower

When the spindle is worn and you do not pay attention to replacing or maintaining it, over time it will not be able to connect to some parts. The constant rubbing of metal against metal due to the lack of bearings will cause complete wear of the rotating shaft. In this case, the blade, pulley, or belt will fall out of the lawn mower.

How To Quickly Check The Spindle Of The Lawn Mower?

To quickly check if the lawn mower’s rotating shaft is damaged, you can follow some of the steps below.

  • Remove the belt from the pulley.
  • Check the operation of the rotating shaft when it is not connected to the bearings. Straight shaft, correct position, and rotation are all normal operations.
  • If it is working properly without strange noise then continue to check the housing of the spindle.
  • If the spindle has a strange noise, the rotation is uneven, or it is deflected from side to side, you need to have it serviced and replaced with a new one.

How To Prolong The Life Of The Spindle?

For any type of machine, maintenance is one of the most important factors in prolonging the life of the lawn mower. To ensure the lawn mower can work effectively for a long time, you need to pay attention to some of the ways to protect the rotary shaft below.

  • Proper maintenance periodically: First, you need to maintain the spindle at regular intervals or frequency of use. You should apply grease or lubricant regularly to avoid strong friction. Remove dirt, debris, or small materials from the pulley. Add lubricant and prevent foreign material from falling on the pulley to protect the inner shafts.
  • Do not wash the pulley when cleaning the lawn mower: You should not wash the pulley when cleaning the lawn mower because high-pressure water can penetrate the bearings and cause corrosion. From there, bearings and rotating shafts will corrode quickly.
  • Avoid solid objects while mowing: Any impact between the lawn mower and a hard object will cause the spindle and blade to be affected. They will be bent or not in place, which can lead to serious damage.


The rotary shaft of the lawn mower is one of the important parts of the lawn mower. If the spindle is damaged, other components such as bearings, pulleys, blades, or belts will also be affected. There are many causes for the shaft to fail such as lack of lubrication, damaged bearings, worn shafts, etc.

Some signs of a damaged crankshaft include strange noises, uneven lawn cuts, violent vibrations during operation, loose belts, and frequent falling off of the pulley. To limit the damage to the rotating shaft, you should check it regularly and maintain it periodically. Make sure lubricant is added continuously, removing dirt and solids from the pulley. From there, they will not be able to fall into the bearings.

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