PTO shaft turns when PTO is off

PeterC

New member

Equipment
Current: M4060 HST-C. PAst:M9540 cab; M8200; L3600(?)
Jul 15, 2014
4
0
0
Walden, Vt
M9540, 2 speed PTO, 560 hrs. Problem: the PTO shaft turns even when the PTO is not engaged. When engine rpm exceeds 1500 the shaft stops but resumes turning as engine speed drops below 1000 rpm. Although there is not much force turning the shaft if there is enough to turn whatever you have attached (winch, post hole digger etc.). If you got caught up in it you could not get out. Very dangerous. Local dealer says he never heard of this.
Thanks in advance.
 

Tooljunkie

Active member
Lifetime Member

Equipment
L1501,home built carry all, mini plow blade.
May 13, 2014
4,150
24
38
58
Lac Du Bonnet, Manitoba,Canada
Quite a few ptos turn when not engaged. My little tractor spins. If i put a block of wood againt shaft, it stops quite easily. It wont drive anything.
So you had an implement connected and it was moving?
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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Sandpoint, ID
Tooljunkie,
Quite a few PTO's turn on older tractors, Newer tractors have a PTO brake to stop that from happening, and his model has one.

PeterC,
You have one of these problems, bad clutch pack that's leaking (not very likely), that should be more of a problem of Not engaging rather than sticking or floating.
Second would be a bad Clutch pack brake disk, that not stopping the clutch, visual inspection would be required, but that requires a complete teardown.

Third and most likely you either have a bad or bad adjustment on the PTO control valve that's allowing it to float or partially engage, a simple pressure test on the valve would show if that is the problem or not.
The fact that RPM's change the engagement lest me to be live that it could be a weak seal and when the pressure and flow get high enough it shuts off and when the pressure drops it engages.

Get it adjusted or fixed ASAP as if it's floating it will fry the brake then it will never stop like it should.

If it's not out of warranty the dealer should be fixing it, not giving you the lame excuse that he's never seen that, I've never seen a polar bear (in person) but I know they exist.
He should be NOW as it's a major safety hazard and should be covered under any area of a warranty!
 
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Tooljunkie

Active member
Lifetime Member

Equipment
L1501,home built carry all, mini plow blade.
May 13, 2014
4,150
24
38
58
Lac Du Bonnet, Manitoba,Canada
I should have realized it was a newer machine.
I do actually feel a little more educated now.
Thanks.
I would have to agree,if that pto is dragging on the brake for whatever reason,the longer it runs like that the more damage is being done.
 

PeterC

New member

Equipment
Current: M4060 HST-C. PAst:M9540 cab; M8200; L3600(?)
Jul 15, 2014
4
0
0
Walden, Vt
Thank you for your input. The unit is out of warranty (purchased used 12/12 w/269 hrs.) but perhaps Kubota would be willing to work with me on this. I'll be speaking w/the dealer shortly.
 

PeterC

New member

Equipment
Current: M4060 HST-C. PAst:M9540 cab; M8200; L3600(?)
Jul 15, 2014
4
0
0
Walden, Vt
Took the tractor to my local servicing dealer 7/21. Worst case scenario: they had to split the tractor and the clutch pack is damaged. Unit must have been worked pretty heavy as they had not seen one of these before. New one was ordered (replacement not rebuild) and I should have it back later this week. Est. cost $2500-$3000. Kubota agreed to cover 30% of the repair cost so that takes a little of the sting away.
Thanks again for your input.
 

lugbolt

Well-known member

Equipment
ZG127S-54
Oct 15, 2015
3,778
874
113
Mid, South, USA
Took the tractor to my local servicing dealer 7/21. Worst case scenario: they had to split the tractor and the clutch pack is damaged. Unit must have been worked pretty heavy as they had not seen one of these before. New one was ordered (replacement not rebuild) and I should have it back later this week. Est. cost $2500-$3000. Kubota agreed to cover 30% of the repair cost so that takes a little of the sting away.
Thanks again for your input.

This is an older post, but a note worth mentioning. This is a common "issue" with the 8540 and 9540, and possibly others. It is usually caused by turning off a high-inertia implement, such as a bush hog where when the power is removed from the PTO, the blades keep turning due to their weight. Generally, when the PTO is turned off, the PTO clutch is disengaged but at the same time the PTO brake is engaged. The brake plate has one tab on it which kind of rubs against a lug that is part of the PTO clutch holder. After repeated use, the tab (which is harder than the cast iron holder) will wear, and at some point will wear both the brake plate tab and the cast iron pto clutch holder. Kubota knew about the problem many years ago. It wasn't a huge issue so long as the implement was turned off at idle speed only. Once the part is out of the tractor, you will see it, and it's obvious what's going on with it.

There is a way to check the clutch without splitting the tractor. Have to remove the hydraulic pump, right side of the tractor's transmission, and behind it is the PTO clutch assembly. You can feel around in there, the back side of it (engine OFF of course), and if the PTO brake plate tab is razor sharp or missing, it's likely worn off, at which point the tractor will have to be split to repair it.

The original parts are superceded to the new style clutch assembly which is the same clutch as the M9960 and M8560 PTO clutch. It is of a much better design. Instead of using the PTO clutch holder's cast iron "lug" (which was cast into the holder itself), it now uses a steel pin. The steel pin is much harder and tougher than the iron. Also the entire clutch assembly is MUCH improved over the old setup. Everything about it is improved. It costs quite a bit more than the original (don't have the numbers right off hand) but it should last a LOT longer than the original. If the tractor is going to be down for a little while, and the owner has enough to spend on it, it's highly advisable to install the new style clutch assembly rather than trying to piece the old one together.

I've done a couple of them. They are fun. Heavy, time consuming, but honestly not a hard job. Oh and expensive but it's an expensive tractor, and still better to repair than to fight with the new Tier 4+ stuff.
 

John Corey

New member

Equipment
Kubota Sunshine L1-22DT
Oct 30, 2015
46
0
0
Gold Coast Australia
Tooljunkie,
Quite a few PTO's turn on older tractors, Newer tractors have a PTO brake to stop that from happening, and his model has one.

PeterC,
You have one of these problems, bad clutch pack that's leaking (not very likely), that should be more of a problem of Not engaging rather than sticking or floating.
Second would be a bad Clutch pack brake disk, that not stopping the clutch, visual inspection would be required, but that requires a complete teardown.

Third and most likely you either have a bad or bad adjustment on the PTO control valve that's allowing it to float or partially engage, a simple pressure test on the valve would show if that is the problem or not.
The fact that RPM's change the engagement lest me to be live that it could be a weak seal and when the pressure and flow get high enough it shuts off and when the pressure drops it engages.

Get it adjusted or fixed ASAP as if it's floating it will fry the brake then it will never stop like it should.

If it's not out of warranty the dealer should be fixing it, not giving you the lame excuse that he's never seen that, I've never seen a polar bear (in person) but I know they exist.
He should be NOW as it's a major safety hazard and should be covered under any area of a warranty!
Hi Wolfman. Just came across this thread as I'm having the same prob with my PTO shaft. I notice your comment about older tractors do spin. I assume you are saying that they were supposed to spin as they did not come with a PTO brake? Mine is a L1-22DT and I just disengaged the slasher (bush hog) for the first time since I bought it a month ago. Can't say for certain but it's mid 80s I think. Even though the PTO is in neutral, the shaft won't stop spinning. I can stop it with my hand but when I release it, it starts again. Do you think this is normal and I have nothing to worry about? I should add that when I engage the clutch the shaft stops spinning.
 
Last edited:

North Idaho Wolfman

Moderator
Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
23,141
1,234
113
Sandpoint, ID
JC,
Yes that spinning is normal, it's just being turned by fluid transfer in the and over the gears, hence why you can stop it with your hand and with pushing in the clutch pedal.
And it will not cause any issues. ;)

Oh major word of caution to others that have a fluid spinning PTO, DO NOT try and stop it with a gloved hand as if it is truly not disconnected and is under power it will remove your hand/arm in a split second, and it's not pretty! :eek::(
I recommend using a piece of wood and just rub the shaft to see if you can stop it, if you can't, it's under power and you either have not disengaged the PTO or there is a problem with it!;)