# PTO drive shaft length question



## TX MX5200 (May 12, 2020)

I have an undersized old Ford shredder at 5’ for my tractor, which is a Kubota MX5200 and I’ve not yet run this shredder on it. Recently got a quick hitch and just got it setup to attach to shredder and the PTO shaft is too short.

I expected this issue and planning to order a 61” shaft to replace the original, which looks to be around 52”ish.

my question is..is it good idea to also add a Clutch Over Run to pto also. I had one that was needed on the old Ford NAA…figured it may help with hookup so I don’t have to crawl into 3pt to hookup.


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## bmaverick (Feb 20, 2014)

TX MX5200 said:


> I have an undersized old Ford shredder at 5’ for my tractor, which is a Kubota MX5200 and I’ve not yet run this shredder on it. Recently got a quick hitch and just got it setup to attach to shredder and the PTO shaft is too short.
> 
> I expected this issue and planning to order a 61” shaft to replace the original, which looks to be around 52”ish.
> 
> my question is..is it good idea to also add a Clutch Over Run to pto also. I had one that was needed on the old Ford NAA…figured it may help with hookup so I don’t have to crawl into 3pt to hookup.


Does the Kubota have a built in overrun clutch within the PTO? Or is it a Gray Market machine and needs one externally? 

And depending on the machine for brand, import or era, not all PTO splines are the same size or number of splines. Search out what you would need as a coupler to proper modern standard spline and size in the industry. 

For Yanmars of the YM. F, FX era we can order overrun clutches with the proper spline to tractor and then to the modern standard to the implements. 

If your PTO shaft is a tad too short, a coupler would. It locks to the existing PTO spline shaft. And the implement locks to the coupler's spine shaft.


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## BigT (Sep 15, 2014)

Ideally, you would want your PTO shaft stroked out about half way when your tractor PTO is connected to the mower. 

If your Kubota tractor has live PTO (two stage clutch), you shouldn't need an overriding PTO clutch because you can stop the tractor with the drive clutch. Same thing with an independent PTO.


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## TX MX5200 (May 12, 2020)

It’s a Kubota…not gray market….I will look up the specs but it’s a 2014 MX model if that tells ya anything.

I’m not sure what is meant by “stroked out halfway way”. Hell, I’ve put 60 hours on it this past year and just realized I’ve never hit the pto switch. Only attachment I have with the need is the shredder. I’m kicking myself for not taking up the seller on his offer to sell me a 6’ new bush hog brand for 1,000. I don’t use shredder much and figured my old one would be fine and didn’t want to make another 10 hour round trip for it as it wouldnt fit on my trailer with the FEL, bucket, forks and box blade.


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## bmaverick (Feb 20, 2014)

TX MX5200 said:


> It’s a Kubota…not gray market….I will look up the specs but it’s a 2014 MX model if that tells ya anything.
> 
> I’m not sure what is meant by “stroked out halfway way”. Hell, I’ve put 60 hours on it this past year and just realized I’ve never hit the pto switch. Only attachment I have with the need is the shredder. I’m kicking myself for not taking up the seller on his offer to sell me a 6’ new bush hog brand for 1,000. I don’t use shredder much and figured my old one would be fine and didn’t want to make another 10 hour round trip for it as it wouldnt fit on my trailer with the FEL, bucket, forks and box blade.


There are over a few 10 thousand Kubota Gray Market machines here in the USA, that's why I asked.


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## TX MX5200 (May 12, 2020)

Well I assume it’s not gray market, but hell I don’t know now. It has Kubota written on it and is same as ones I’ve seen on lots…not sure I would know difference.
The PTO is listed as “independent” and pto clutch listed as wet clutch.


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## TX MX5200 (May 12, 2020)

All labels and tags on tractor are in English so unless they put the thousands of warning stickers all over it I guess it’s not grey market.


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## TX MX5200 (May 12, 2020)

I can deal with the longer drive shaft, but was thinking the clutch over run would make it easier to reach…didn’t want to put something on there that would mess up the PTO as it would move the wobble of the shaft farther back.


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## BinVa (Sep 21, 2020)

You could add the overrun clutch but it is not necessary on your independent PTO tractor… you may be able to replace only a half shaft on your cutter depending on where it was cut to length. B.


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## SidecarFlip (Mar 25, 2021)

If it was mine, I'd add an over running clutch (ratchet clutch) to the output end of the pto stub as a matter of clutch brake longevity because Kubota's have notoriously weak clutch brakes on the wet pack and you don't want to fry it. Over running clutches are inexpensive and add little length to the overall drive line. Moat of my hay tool shave built in over running clutches but as a rule shreddetrs / choppers / brush hogs don't.


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## TX MX5200 (May 12, 2020)

SidecarFlip said:


> If it was mine, I'd add an over running clutch (ratchet clutch) to the output end of the pto stub as a matter of clutch brake longevity because Kubota's have notoriously weak clutch brakes on the wet pack and you don't want to fry it. Over running clutches are inexpensive and add little length to the overall drive line. Moat of my hay tool shave built in over running clutches but as a rule shreddetrs / choppers / brush hogs don't.


That’s what I will do and will get the quick attach with spring pin one so there’s no banging expansion pins. I was thinking having it would be a second level of protection but didn’t want to add something that would mess the PTO up.

I will be getting a new drive shaft also…it may make the length with the added clutch, but will be too close to end for comfort once it’s all the way lowered.


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## SidecarFlip (Mar 25, 2021)

Shredders are notorious for freewheeling the pto after you dis engage it or chop the throttle and that is hell on a clutch brake on any tractor. Mine 'sings' when I run my batwing all time and chop the throttle or dis engage it. Sure you can idle them down slowly, but the one time you forget, could be the end of the clutch brake. I think mine adds maybe 4" to the length of the pto stub which in reality isn't much. I didn't even have to cut the pto shaft on the batwing to fit it.


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## thedukes (Jan 9, 2022)

Over run clutch is a win
Gives you PTO brake insurance== No wear on pto brake
and
if running a quick hitch/I match...gives you 5" of driveline length


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## SidecarFlip (Mar 25, 2021)

thedukes said:


> if running a quick hitch/I match...gives you 5" of driveline length


That depends entirely on the size of the over running clutch (which really isn't a 'clutch') in the true sense of the word but rather a one way ratchet. I locks when turning in the direction of the pto and ratchets when the pto is disengaged but the driveline is still rotating. Like I said, most of my 'freewheeling' implements like my disc bine have a built in over running clutch and so did my square bailer but implements like brush hogs don't (they should but they don't). I run a heavy duty (up to 130 pto horsepower one). Most of them are only good for about 65 pto transmitted horsepower.

really a simple mechanism too. It has an outer drum which is welded to the output stub on the brake itself, with an internal pawl type ratchet that is mated to the pto stub of the tractor and retained with a large internal circlip. They all have grease fittings to keep the ratchet mechanism lubricated (so do the ones on my equipped implements as well. A shot of grease every so often, keeps them working well.

Kubota's especially are notorious for weak clutch brakes and especially mine. Kubota had a recall on my M's, way back when to upgrade the brake pack. Of course I'm way out of warranty so it's kind of moot and the only way to upgrade the pack is to split the tractor. Of course, the easy answer to keep it from failing is an over running clutch. Agri-Supply sells them and so does TSC in their stores.

What happens is when the brake fails, there is nothing to lock the pto stub from turning and because it's a wet clutch pack it will constantly turn from internal drag. Easy to check the brake. All you have to do is grab the stub (with the tractor engine off and the pto disengaged) and if the shaft only rotates about half a turn and stops, the brake is good. If the shaft can be rotated more than half way with no resistance, the brake has failed. It's designed so it's locked when there is no pressure on the pack. Once you apply hydraulic pressure, the pack locks and the brake unlocks.

You can always tell when it 'doing it's job' because you'll hear it ratchet and the implement driveline will keep rotating (freewheeling) when the pto is disengaged.

Far as I'm concerned it's good insurance you never destroy the clutch brake. When not needed, I keep it in the tool box on the tractor. Not overly expensive either. I believe you can buy one for under 75 bucks.


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