How to Tell if Mower Deck Spindle is Bad

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Are you trying to mow your lawn evenly but can seem to get the desired results? Getting a smooth and even cut on your grass can never be possible without a well functioning mower deck spindle. 

A lawn mower uses revolving blades to shape the grass. Spindles are also crucial parts of your mower’s cutting deck. 

When they have issues, you will not achieve great results. Certain signs might be telling you that your mower deck spindle has issues. 

Related Article: How Often to Grease Mower Spindles

In this post, we are going to explore how to tell if the mower deck spindle is bad. Here we go.

Signs of a faulty mower deck spindle 

The following are common issues that you may face while using your mower deck spindle.

  • Uneven grass after cutting

If you cut your lawn and notice that the grass is uneven, then something might not be working well. The deck spindles work together with the pulleys to ensure that you get a smooth cut. 

If you are not achieving accurate cuts, then something might be wrong with the mower deck spindle.

  • Bent and broken parts

Does your spindle has broken or bent parts? This, too, can cause uneven spinning of blades. 

Sometimes the edges may stop spinning entirely if there are broken parts. With broken or bent parts, you won’t achieve smooth cuts on your lawn.

  • Squealing sounds

How to Tell if Mower Deck Spindle is Bad


Do you hear squealing noises while riding your tractor or mower? Please don’t ignore that as it may lead to more problems. 

Besides that, you may not achieve excellent results because something has gone amiss somewhere. Probably the spindles might be having issues that you need to resolve as soon as possible. 

They might be broken, or their bearings might be worn down. You can solve this by replacing the spindle bearings or the spindles by yourself.

  • Loud buzzing noise and vibration

Sometimes you may notice a buzzing sound and some vibrations while using your mower deck. This may stop for some time then come back a couple of minutes later. 

You need to note that the bearings have been sealed in the spindle. If you hear vibrations or buzzing sounds, the bearing in the spindle might be going wrong, and this may cause random vibrations.

  • Spindle failing to heat up

Does your spindle stay steady after a touch then starts getting heat after running for 30-40 minutes? If it fails to heat up immediately, then it might have lost preload. 

You might need to replace it.

Fixing the spindle

There are various ways of fixing these issues with the spindle of your mower deck. Here is what you need to do.

Separate the spindle from its mower deck


How to Tell if Mower Deck Spindle is Bad

– Put the mower on an even flat surface so that it can cool.

– Turn the brake off, then take away the key from the ignition and let the mower cool down so that you won’t burn yourself.

– Block the tires of the mower from rolling with by putting anything in front of its tires.

– Wear your gloves and lift the front of the mower. You can place a jack beneath the mower then raise it to access underneath the deck quickly. Consider the height of about 1 ft.

– Remove the cover of the spindle. Get the spindle cover from the top of the deck. Use a tool like torque bit to unfasten the cover and detach it. 

– Refer to the manual to find out the perfect fastener for this task.

– Take off the bolt above the spindle then remove the pulley. Find a rag and cover the blades beneath the mower deck. 

– Carefully hold them as you remove the bolt. Remember to hold the spindle and put it aside. Remove the pulley from the spindle. 

– You might want to keep track of the fasteners by putting them into a bowl so that you do not lose them.

-Separate the spindle from the blade. Three bolts are holding the spindle. You need to use the appropriate tool to remove them.

– If your mower has more than one spindle, repeat this process. Identify the direction that the spindle faces so that you may have an easy time during the reinstallation process.

Replace the spindle bearings

As mentioned earlier, your spindle might be bad due to issues with its bearings if the pulley wobbles. This is easy enough to replace.

– Separate the spindle assembly

– Remove each bearing and get matching replacement.

– Put the new bearings in place. Place the top bearings above the housing of the spindle and press it into its location using a rubber mallet.

– Use a socket or pipe in reconnecting the shaft to the spindle. Press the shaft of the spindle in the housing to rest beside the upper bearing’s inner race.

Installing the repaired or new spindle

After removing the spindle, check whether it is broken or bent. If it’s broken, you will need to replace the damaged parts.

– Connect the repaired or new spindle on the blade then tighten the nut that links them together.

– Return the spindle into the mower deck.

– Put back the bolt, belt, spindle cover, and the pulley. It would help if you first placed the pulley above the spindle. 

– This should be followed by placing the bolt above the pulley. Tighten the nut so that the pulley can be fixed in place. 

– Orient the belt to its original location by sliding it over the pulley. You can then replace the cover of the spindle and fasten it.

– Lower the mower.

After completing the repairs on the spindle, lower your mower down to the ground with the jack. Your mower deck will be ready to use by now.

Issues with the mower deck spindle can affect its normal functioning. It’s important to note any signs and find out if you can fix the problem.

If your mower deck is not cutting smoothly and evenly or is producing strange noises, you need to inspect its spindle. The good thing is that you can fix some issues easily by either repairing or replacing the spindle.


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