Should PTO Clutch Spin Freely? How To Test PTO Clutch?

Have you noticed your PTO clutch spinning freely when you engage the clutch? PTO clutch is a power transmission component which allows power to travel to the blades while operating a mower. Many users of these PTO clutches have the same questions regarding its spinning conventions. Should PTO clutch spin freely?

Yes, the PTO clutch should spin freely while engaging the clutch. Only insufficient voltage, damaged solenoid, inadequate lubrication and dirt causing clutch slippage can prevent the clutch from spinning freely. 

Now, let’s take a deeper look into how a PTO clutch works and why it should spin freely. In this guide, we will also incorporate the circumstances where the PTO clutch refrains from spinning and provide solutions to them. 

What Is a PTO Clutch and How Does It Work?

The full form of PTO is Power Take Off. PTO clutch provides a mechanical separation between the power and a piece of equipment. 

The power created in this case is from gas, diesel engine or electric motors. This power is then redirected to the piece of equipment which is unable to produce to their own power. 

The PTO clutch can be accessed and engaged with the help of a switch or lever. It then transfers the power from the engine or motor to the blades of a mower, for instance. You can complete this power transfer both manually or electrically.

Once engaged, the lower plate moves up to the upper plate and attaches to the flywheel in the middle. 

As a result, the flywheel and the clutch both spin freely. They stop spinning once the PTO clutch is disengaged and moved away from the middle. 

Read also: 6 Common Toro PTO Clutch Problems [With Troubleshooting]

Should PTO Clutch Spin Freely?

The PTO clutch should spin freely when they are engaged. Once you engage the PTO clutch, one of the plates inside it comes in contact with the flywheel. 

It spins along with the flywheel at that moment. In these circumstances, you should be able to spin the clutch freely with your fingertips. It can also rotate freely without any outside help. 

In case of electric PTO clutches, they have a belt that drags the clutch back only when the clutch is disengaged. 

In these types of clutches, if the clutch is disengaged, the belt will stop it from spinning freely. However, when the sides of the brake are worn, the clutch spins freely once again. 

4 reasons Why Your PTO Clutch May Not Spin Freely

The PTO clutch might not spin freely when there are some kind of problems in the clutch itself. It has a tendency to run into some common PTO clutch troubles (YouTube vide link). 

If you can troubleshoot and diagnose these issues, you can get rid of the problem of the PTO clutch not spinning freely.  The problems that can lead to the PTO clutch to not spin freely are: 

1. The PTO doesn’t get enough voltage

If the clutch does not receive sufficient power, it can’t engage properly. As a result, it won’t spin either. The PTO clutch needs to receive a constant voltage of 12-14 volts of power. 

Any lower than this, the power won’t be enough to engage the clutch freely. Check out the PTO clutch battery and measure the voltage at the wiring terminals. 

Inspect the wiring connection between the grounding wire and the battery terminals to locate interruption. Look out for any kind of tears or damages in the wires to repair and reestablish the connection. 

2. PTO Solenoid Is Bad

The PTO solenoid is the component which controls the electromagnetic clutch engagement of the PTO clutch. 

Sometimes, due to the fault in the solenoid, it can’t receive the power provided to the clutch. Additionally, the solenoid itself might be defective which leads to the PTO clutch not spinning at all.

A bad solenoid can’t be overcooked if you want the PTO clutch to work smoothly. Replacing the damaged solenoid is the only fix when it comes to this. Take the clutch to a repair shop to install a new solenoid professionally.

READ: Check out why Mower/Tractor Engine Dies When PTO Is Engaged

3. Lack of Proper Lubrication

Without proper lubrication, the PTO clutch can’t operate fully. You can hear whirring and grinding noises while engaging the clutch. 

The gears inside tend to grind against each other trying to spin. Lack of lubrication doesn’t allow the clutch to rotate freely without any obstruction.

To ensure that the PTO clutch is properly lubricated, make sure to look out for vibrations. 

If you notice any unusual noise coming from the clutch, that would be your sign to oil the components of the clutch. Remember to choose a suitable enough lubricant for the job.

4. Clutch Slipping

PTO clutch can fail to spin due to clutch slippage or damage. This slippage occurs when there is something lodged inside the clutch. 

The clutch components could be contaminated with stray pieces of material at any given time. 

As a result, the gears get stuck and so the PTO clutch refuses to spin. Thoroughly inspect the clutch surfaces of the rotor, armature, and brake. 

Clean all surfaces properly and look for any residual buildup or product inside the components. Examine the deck for grass buildup and clean it if necessary. 

Read also: Electric PTO Clutch Troubleshooting Guide 

how to test pto clutch Properly?

Depending on what model and type of PTO clutch you own, there could be differences in the process of testing. 

In order to know whether or not your PTO clutch is engaging properly, you need to conduct a thorough PTO clutch test. 

Test The Battery Voltage

To test a PTO clutch voltage with the help of a multimeter-

• Turn the engine off and use jack stands to access the clutch driving assembly. 
• Remove the wiring harness from the transmission box and get the battery isolated. 
• Connect the positive end of the multimeter on the red terminal of the battery.
• Attach the negative end of the multimeter on the engine power source. 
• Check the voltage output of the battery in the multimeter. If the voltage is 12.5 or below it, the battery doesn’t have sufficient power.
• Charge the battery. 

Test The Ohms

In order to check if the PTO clutch is operating within the predicted ohm range, follow these steps:

• Set the multimeter to resistance setting to check ohms.
• Turn the engine off and use jack stands to access the clutch driving assembly. 
• Remove the wiring harness from the transmission box and get the battery isolated.
• Place each end of the multimeter to two different sides of the PTO wires.
• Get the resistance reading from the multimeter.
• The range of resistance for the PTO clutch is 2-5 ohms. If the reading provides an ohm between this range, the PTO clutch is working fine. Any reading above or below this means that the PTO clutch is facing some problems while engaging. 

When to Have Your PTO Clutch Serviced?

It is recommended to service your PTO clutch at least once every year. Moreover, servicing it before the working season is also good practice for the health of the PTO clutch. 

Make sure to service the clutch 1 to 2 months before the working season. Apart from this routine servicing, look out for any signs of trouble within the PTO clutch. 

If you notice any of these symptoms, take the clutch for a servicing right away for the best results.

• Grinding, whining or whirring noise coming from the clutch when it is engaged.
• PTO clutch vibrates more than usual 
• Sudden lack of power after the engagement of the PTO clutch
• The PTO takes longer than usual in order to fully engage. 
• Clutch emanates excessive heat for no reason.
• Small fluid leaks in the clutch system.  

Mower PTO Clutch Spin related (FAQs)

Putting aside our core question, it is safe to say, you might still have a lot of questions regarding your PTO clutch. As a new user of this clutch, these answers below might help you a lot.

Conclusion – Should PTO Clutch Spin Freely?

Next time you see your PTO clutch spinning freely, don’t be worried at all! It is normal for the PTO clutch to be spinning even when the engine is not running. 

It usually spins freely to reduce friction and minimize power loss. This ends up improving the overall performance of the clutch. While testing the clutch spin, be especially careful around the clutch and its blades. 

As the rotating clutch could get caught anywhere and cause accidents. If you’re not familiar with the clutch components, take it to a repair shop for a safe fix every time.