PTO won't shut off

[Dennis.D]

I have a Gr L6060 with an electric engaging PTO. Every once in a while when I push the button to disengage the pro it won't stop the PTO. I turn the switch on and off several times still won't shut down. It seems the when I slow the engine to an idle it will eventually stop turning the PTO. It has happened with the Harley power rake, bush hog, wood chipper and finish mower. So it doesn't seem to be a single attachment. There is no load on the implement when it happens because I'm done using it when I hit the button to disengage. Then it will work fine for several uses. I'm thinking maybe a bad switch but, its hard to test because it works more than it doesn't. Anyone had a similar issue and found a fix?

 

[Roadworthy]

I don't know your tractor but try depressing the clutch before attempting to engage or disengage the PTO. That should remove any load so it can drop out or be more easily engaged.

 

[Dennis.D]

No clutch, it's hydro. I have turned the RPM's up then down thinking it was somehow under load. That didn't help.

 

[woodman55]

Next time, check your dash. In one window it shows the pto rpm and if it is on or off. The on/off part should tell you whether the switch is sticking or not.

 

[Dennis.D]

Ok, the PTO wouldn't shut off again the other day. I was using my Harley power rake and when I was done I pushed the PTO switch down and the rake kept turning. I turned the switch on and off several times with the same results. I did look at the dash and the tractor thought the PTO was off and read 0 RPM. But it was turning at idle speed. I shut the tractor off and restarted and the PTO was off and not turning. It sounds to me like the solenoid that engages the PTO might be sticking in the on position. Anyone had any similar issue or thoughts on this? I could take it to Kubota, but it might not do it for another month.

 

[SDT]

Ok, the PTO wouldn't shut off again the other day. I was using my Harley power rake and when I was done I pushed the PTO switch down and the rake kept turning. I turned the switch on and off several times with the same results. I did look at the dash and the tractor thought the PTO was off and read 0 RPM. But it was turning at idle speed. I shut the tractor off and restarted and the PTO was off and not turning. It sounds to me like the solenoid that engages the PTO might be sticking in the on position. Anyone had any similar issue or thoughts on this? I could take it to Kubota, but it might not do it for another month.

Don't waste time and money taking to the dealer until it fails hard.

Very difficult to find intermittent problems but time attempting to do so is not free.

 

[Dennis.D]

I hear ya. That's why I haven't taken it to them, because the chances of it acting up while they have it are pretty slim.

 

[DustyRusty]

Electrical work isn't difficult once you understand the circuit. Think of the positive wire as hot water, and the negative as cold water, and never should they be joined together, but can work together when something is attached to them i.e. your PTO clutch. The first and easiest thing to do is to test the switch using an ohm meter. connect each wire of the ohm meter to each side of the switch, and see if it reacts when you push the switch. Do not do this when there is power going to the switch. From your description, it is most likely an intermittent switch. I don't know what your switch looks like, but they are fairly universal. If you can remove the switch from the machine, it will make testing a lot easier. I have no idea how the PTO clutch is wired, and if you interrupt the power to shut it off or interrupt the ground wire to shut it off. This is when you will need a schematic of the wiring of the unit. Check the switch and report back.

 

[woodman55]

Ok, the PTO wouldn't shut off again the other day. I was using my Harley power rake and when I was done I pushed the PTO switch down and the rake kept turning. I turned the switch on and off several times with the same results. I did look at the dash and the tractor thought the PTO was off and read 0 RPM. But it was turning at idle speed. I shut the tractor off and restarted and the PTO was off and not turning. It sounds to me like the solenoid that engages the PTO might be sticking in the on position. Anyone had any similar issue or thoughts on this? I could take it to Kubota, but it might not do it for another month.

The service manual does show a plug you can take out to check the pressure, it should be 363 to 413 psi. I tried to paste a picture of the service manual, but could not get it figured out. The valve/solenoid is just to the rear of the trans filters. According to the manual it is a 1/8 pipe plug. It looks like you need to remove the assembly to get to the solenoid. Go into kubota online parts, and you can see it.

 

[woodman55]

Parts Finder | Kubota Canada This should take you to it.

 

[Fedup]

I think if it were me doing this I would look for the PTO valve. There should be a harness connector on (or darn close to) it you can unplug or disconnect. Next time it acts up I would let it run, get down and disconnect said plug. If the PTO doesn't stop, the problem is not electrical. No need to worry about "ohming" this that or the other.

 

[bucktail]

Maybe it is turning off and the momentum is keeping it turning.

 

[GreensvilleJay]

curious ,so...I looked up online....
the PTO valve assy is $470, just the solenoid is $170..

A simple ,easy electrical test is to remove the connector and put a test lamp or DVM in it's place. Now just turn on/off PTO ( don't need engine running ?) and the light should come on/off as the switch is used. If it does then NOT an 'electrical' problem. Odds are it's fine.....

Since it does engage, the actual 'solenoid'... ($170) probably works fine, though it may be 'dirty' or 'sticky', possibly due to thick oil buildup ? I'd remove the assy, tear apart, clean using spray brake cleaner, dry off, repeat 3x, then reinstall and see what happens.

I've had similar fluid solenoids act that way (gas anti-dieseling on Kohlers were bad..) Simple remove/clean/reinstall would fix them...

 

[dvcochran]

Ok, the PTO wouldn't shut off again the other day. I was using my Harley power rake and when I was done I pushed the PTO switch down and the rake kept turning. I turned the switch on and off several times with the same results. I did look at the dash and the tractor thought the PTO was off and read 0 RPM. But it was turning at idle speed. I shut the tractor off and restarted and the PTO was off and not turning. It sounds to me like the solenoid that engages the PTO might be sticking in the on position. Anyone had any similar issue or thoughts on this? I could take it to Kubota, but it might not do it for another month.

Knowing the solenoid wiring would be important but I would nearer think the switch to be the culprit. However, if you turn the machine off and it does restart, that would seem to factor out the switch, to some degree. Could be using a different set of contacts and still be bad.
There is also a chance that the PTO disc is sticking when it gets hot and opens up when things cool down.
I would start by finding the wiring diagram.

 

[Dennis.D]

Thanks for the reply's. I was assuming the switch worked, because the instrument cluster is reporting the PTO as on and off with the switch, even when the PTO is actually still turning under power. I need to get a wiring diagram and find the plug for the PTO solenoid. Hopefully it's in a spot where I can unplug the solenoid next time w/o having to shut off tractor. If not I may be able to wire in a small test lamp that will go on when power is sent to PTO. If the light goes out and PTO is still under power I will know the problem is in the solenoid not electrical.

 

[GreensvilleJay]

This is another case where the wiring diagram is crucial to see.
One wiring way is the PTO switch supplies power to both the light and the solenoid. Simple, basic, reliable, easy ...old skool. In this case since switch and light work, the solenoid IS getting power, but 'mechanically' failing

The other way is the switch sends a signal to a 'computer' that then controls the panel light and the solenoid (maybe through an external relay...). In this case it could be the 'computer' OR the solenoid.

I don't see why the engine needs to be running, so have a helper turn the switch on /off while you're at the solenoid connector.DVM blk lead to ground( anywhere), red lead on the pin in the connector. cycle the switch several times,say once per second . NOT fast as DVMs are slow readers. A 12v test light probably is easier to use. LED 'offroad' lights are great for this,just don't point at yourself !

 

[woodman55]

Thanks for the reply's. I was assuming the switch worked, because the instrument cluster is reporting the PTO as on and off with the switch, even when the PTO is actually still turning under power. I need to get a wiring diagram and find the plug for the PTO solenoid. Hopefully it's in a spot where I can unplug the solenoid next time w/o having to shut off tractor. If not I may be able to wire in a small test lamp that will go on when power is sent to PTO. If the light goes out and PTO is still under power I will know the problem is in the solenoid not electrical.

I looked in my schematic and it looks like the switch has two wires, a common power and a wire to the ecu. The solenoid has one wire that goes to the ecu, but to a different plug.

I am inclined to think the solenoid is sticking once in a while. If it was an electrical error you would be getting a code of some type.

something else you could do is connect a gauge to that 1/8 plug hole and mount it where you can see it, so the next time it happens you can see if there is still pressure.

 

[Dennis.D]

I looked in my schematic and it looks like the switch has two wires, a common power and a wire to the ecu. The solenoid has one wire that goes to the ecu, but to a different plug.

I am inclined to think the solenoid is sticking once in a while. If it was an electrical error you would be getting a code of some type.

something else you could do is connect a gauge to that 1/8 plug hole and mount it where you can see it, so the next time it happens you can see if there is still pressure.

Looking at some of the posts here. It looks like the solenoid is actually just turning the oil presure on and off to the hydraulic clutch. Is that correct?

 

[TheOldHokie]

Ok, the PTO wouldn't shut off again the other day. I was using my Harley power rake and when I was done I pushed the PTO switch down and the rake kept turning. I turned the switch on and off several times with the same results. I did look at the dash and the tractor thought the PTO was off and read 0 RPM. But it was turning at idle speed. I shut the tractor off and restarted and the PTO was off and not turning. It sounds to me like the solenoid that engages the PTO might be sticking in the on position. Anyone had any similar issue or thoughts on this? I could take it to Kubota, but it might not do it for another month.

Is it just truning from the viscous oil drag? Does it stop when the rotating implement is lightly touched?

Dan

 

[Dennis.D]

Is it just truning from the oil drag? Does it stop when the rotating implement is lightly touched?

Dan

No I actually put the roller on the ground just to be sure. It kept on turning the dirt up, definitely under power.