Blades continue spinning when PTO button is pressed

[BenLee]

Hello, I have a Cub Cadet ZT1 54 and just recently started having an issue with the blades continuing to spin after the PTO button is pressed. At first it seemed that you could hear the blades slowly winding down, especially if there was resistance against the blades, like grass...but now the blades are continuing to spin indefinitely after the PTO button is pressed.

The mower is still able to start, and the blades do no spin upon starting up, but will immediately start spinning as soon as the PTO button is pulled, but the only way to stop the blades now is to shut off the mower.

I back-probed the wires on the PTO clutch and applied direct battery voltage and did hear the clutch engaging, but it was not as loud as I thought it would be, so I am not sure if it could be just partially seized or not...but it definitely did respond when applying 12 volts directly to it.

I would have thought the clutch was seized, but then the blades would engage immediately at start-up, which they do not.

I was going to go ahead and order a new PTO switch, but I wanted check here first since I have a feeling the switch may not be the issue.
Thanks for your input!

 

[Rivets]

Before ordering any parts I would be checking to see if the deck belt is in good condition. If there is not enough tension on the belt or it is worn, it will allow the blades to spin due to a loss of resistance on the spindle pulleys.

 

[ILENGINE]

If you do not have battery voltage at the pto after shutting off the blades then I would doubt the pto switch. What I would consider is the bottom bearing on the pto clutch is seizing when hot keeping the blades engaged and then releasing after cooling.

 

[BenLee]

If you do not have battery voltage at the pto after shutting off the blades then I would doubt the pto switch. What I would consider is the bottom bearing on the pto clutch is seizing when hot keeping the blades engaged and then releasing after cooling.

Thanks for your response! Just to be clear, the blades remain dis-engaged even if I immediately re-start the engine with the engine still warm, and they will not begin spinning until I pull up the PTO switch to turn them on.

As far as having battery voltage at the PTO after shutting the blades off, how would I go about checking that? Can I check for battery voltage at the PTO without the engine running?

 

[StarTech]

Personally I would lay odds on the PTO itself failing.

But a test turn PTO on and then off. While the blades are still turning pull both lap bars into full reverse. This will disconnect the PTO electrical signal and if if is the PTO switch the blades will stop until you release the laps from full reverse. Actually PTO should stay disenegaged until the PTO switch is cycled.

 

[BenLee]

Before ordering any parts I would be checking to see if the deck belt is in good condition. If there is not enough tension on the belt or it is worn, it will allow the blades to spin due to a loss of resistance on the spindle pulleys.

Thanks, I will definitely check that, because the belt does seem a little floppy. Maybe a pully or spring could be sticking also?

 

[BenLee]

UPDATE: so the clutch is definitely seized, since the blades are now spinning immediately after starting the mower and will not stop spinning unless the mower is shut off, so the problem got progressively worse until the point it is at now.

I replaced the PTO switch and that did not fix it, so I disconnected the wires to the clutch and it still spins when the mower is running. I also probed the pins on the clutch and the resistance is reading normal at 3.5 ohms, so there does not seem to be an issue with the coils of the clutch.

Would that mean that there is either a bearing issue inside the clutch, or the plates in the clutch are stuck together somehow?

Is there any way to take the clutch apart to repair it? I really can't afford a $400 clutch.
Thanks!

 

[ILENGINE]

Most clutches don't come apart easily and the bearings will not be replaceable in that clutch. Normally not a standard size bearing even though the number on the bearing seal will make it look like it is. Most techs are now replacing the OEM failed clutches with the Xtremeope clutches. Which tend to run cheaper than OEM but are still not cheap by any means.

 

[StarTech]

Yes the lower bearing is seized.

Xtreme X0726 $265 Amazon. or you could try the OX Clutch which is $240 plus shipping.

Just remember to follow the enclosed instructions.

 

[BenLee]

I changed out the clutch with a replacement from Amazon and that fixed the issue. I ordered pretty much the least expensive one that I could find that was an exact match, which was only $150, and it actually has Warner (the OEM brand) stamped on the outside.

The thing that has me confused is that when I got the original clutch off, and then held each one and turned it manually in my hands, and turned the bearing, both clutches turned the same and felt almost exactly the same...so I'm not sure why the old one was not working properly, but maybe it is an internal seizing that I'm not able to see or feel from the outside.