3PT PTO shaft questions | OrangeTractorTalks - Everything Kubota

23 Jun.,2025

 

3PT PTO shaft questions | OrangeTractorTalks - Everything Kubota

Hi all, I just ordered the Pat's Easy Hitch for my BX25, it'll arrive in a few days. I know I'm going to have to check and make sure the PTO shaft will be long enough since I'll gain 3 to 4 inches on the lift arms. Soooo here's my confusion...
I bought a used Howes 4' Bush Hog a few years ago, the square PTO shaft was too long to fit so a friend came over to look at things and determined the shaft had to be cut. We cut down but only cut the solid bar, it then fit (but viabrates pretty good and REALLY viabrates when I lift it too high). After reading about the 3 to 4 inch gain on the lift arms I'm going to have to measure things out and make sure this shaft will work. I considered getting a 4 inch extender but then read they can be bad due to questionable quality and increased side loading on the tractor's PTO. Then I figured I waited a long time before buying this tractor and don't want to ruin it over something like a PTO shaft so I started looking at just buying a new one. I see there are Series 1 and Series 4, I think I need the 4 but not sure. Any input or guidance would be deeply appreciated. BTW, I'm currently deer hunting until Sunday so my responses will be sporadic at best. Thanks in advance!
When cutting any PTO shaft to length, you always cut equal lengths from both the male and female ends.

Just get yourself a 6 spline PTO shaft extension. Lots cheaper. TSC has them in their stores. Vibration is usally caused by to acute of an angle between the shafting and the 'U' joints and keep the overlapping shafting well greased.
I'm sorry but that's got to be the worst advice I've ever seen posted on here!.

He's already got a compromised PTO shaft (by your account and his), and you want him to exaggerate the issue by adding a PTO extension!

Great way to trash the bearings and PTO drive!

Go buy a new PTO shaft and cut the same amount off both sides, and also make sure the shield clears too.
Static check length (with it not hooked to the PTO on the tractor) in the up, down, and middle of the three point movement.
I'm sorry but that's got to be the worst advice I've ever seen posted on here!.

He's already got a compromised PTO shaft (by your account and his), and you want him to exaggerate the issue by adding a PTO extension!

Great way to trash the bearings and PTO drive!

Go buy a new PTO shaft and cut the same amount off both sides, and also make sure the shield clears too.
Static check length (with it not hooked to the PTO on the tractor) in the up, down, and middle of the three point movement.
Huh???

How is it compromised (other than by cutting only one side of the slip link instead of both).... Vibration is usually cause by angular misalignment and lack of lubrication on the overlapping sections.

Guess your idea of a compromised drive and mine are 2 different things and the driveline should be Series 4.

Far as adding a PTO extender, if the Pats easy change adds a couple inches to the mounting point and the PTO shaft don't bottom now, adding an extender will not impact the output shaft one way or another and if it does (or you think it does), please post it. Been doing that for years.
Huh???

How is it compromised (other than by cutting only one side of the slip link instead of both).... Vibration is usually cause by angular misalignment and lack of lubrication on the overlapping sections.

Guess your idea of a compromised drive and mine are 2 different things and the driveline should be Series 4.

Far as adding a PTO extender, if the Pats easy change adds a couple inches to the mounting point and the PTO shaft don't bottom now, adding an extender will not impact the output shaft one way or another and if it does (or you think it does), please post it. Been doing that for years.

By only cutting one side of the PTO shaft you don’t gain (shorten) anything. The PTO shaft will still be the same length and bottom out risking damage to the tractor and if not the implement. His vibration is most likely come after the shaft was only cut on one end which didn’t change anything and now he has sprung his yokes. The U-joint caps may now be loose inside the yokes or bent ears causing the vibration. The shafts on either side of a u-joint rotate at the same speed only when the shafts are exactly aligned with each other. As soon as the shafts are at an angle, the driven shaft will speed up and slow down once per revolution. The greater the angle, the greater the speed fluctuation. The greater the fluctuation, the greater the vibration.

When two u-joints are used in a drive-train of 3 shafts, the effect is cancelled out PROVIDED the two u-joints are in phase (ie: yokes oriented identically) AND the axis of the final (3rd) shaft is parallel to the axis of the driving shaft so as to evenly distribute the angles between the joints.

The top link may need to be adjusted to change the implement angle so the shaft is parallel to the tractor's PTO shaft. Bear in mind that the angle will probably change when the 3PH is raised unless the distance between the centerline of the top link pivot and the centerline of the lower arm pivots are exactly the same on the tractor and the implement.

Many tractors have multiple mounting holes for the top link, so you can choose the closest match to the implement's dimensions. Some implement's also have more than one mounting location for either the top link or the bottom pins.

If the distances match, then the implement will rise straight up. If the tractor end is shorter, the implement will rise in an upwards arc. If the tractor end is taller, the implement will point downward when raised. In either of the latter two cases, the axis of the shafts will not be parallel and vibration will occur. Back in my tree stand (the only place this works out here). I bought the mower used so I'm not sure what the previous owner did but there was much more square bar than sleeve on the shaft. I never did check phasing so there's that possibility. The shaft has no protective guards whatsoever so I'm thinking when I raise the mower deck maybe the square shaft it hitting the deck which would make sense. I'll have to check all this out when I get home.
By only cutting one side of the PTO shaft you don’t gain (shorten) anything. The PTO shaft will still be the same length and bottom out risking damage to the tractor and if not the implement. His vibration is most likely come after the shaft was only cut on one end which didn’t change anything and now he has sprung his yokes. The U-joint caps may now be loose inside the yokes or bent ears causing the vibration.
What I said, always cut both the male and female ends equally.


"When cutting any PTO shaft to length, you always cut equal lengths from both the male and female ends."
I bought the mower used so I'm not sure what the previous owner did but there was much more square bar than sleeve on the shaft.
That sounds like your buddy corrected a mistake made by the previous owner, by making the inner and outer sections the same length. That's good then. However, it is possible that the previous owner damaged (bent) the shaft by running it in that condition. I would carefully rotate the shaft by hand with some sort of index around the centre point to check for runnout.

If that is the case, extending the shaft will only make things worse. At the least, it will cause premature bearing failure at the tractor PTO, the implement gear box, or both. At worst, it could cause catastrophic failure of the driveshaft assembly with subsequent damage to equipment and people.
Buy a new shaft with a shield!
I'm pretty sure that'll be getting a new series 4 PTO shaft for it, I'll do the measurements Sunday when I get home. I waited a long time to own a tractor and kick myself in the butt for waiting so long everytime I think about it, I don't want to screw it up over a something so simple. The prices seem all over the graph from under $100 to hundreds of dollars, maybe I'm missing something. I do enjoy learning and working on it...its in WAY better condition than when I first bought it! That will probably be what I'll get although I'm about to go out look what I have, take some measurements and see what I need. I do have a bunch of stuff from purchases of used equipment and now that I did a crash course on PTOs while in my tree stand for a few days I'll be able more intelligently able to decide what I need. The cheap part of me says maybe simply installing the clutch on the old cut down shaft would gain a few inches and I do have some shielding laying around. I'll see, but that shaft/clutch assembly you mentioned will most likely be the ticket. When I looked it up its reads $111 and change, who knows but thanks for pointing me in that direction! BTW, Pat's Easy Change was supposed to be delivered yesterday but it appears to be in Baltimore's FedEx Package Purgatory...I had 1 of the 4 wheels for my pickup truck there for 3 weeks until I personally went to the distribution warehouse and recovered it along with some other undelivered packages...I don't know about other parts of the country but FedEx Baltimore has a BAD reputation that they strive to maintain!

Triangular PTO Shaft Tubing Questions - TractorByNet

I bought a used finish mower with too short of a PTO shaft. There was not enough overlap and the inner tube stretched the outer and today it failed when the outer tube split. The inner tube is badly worn and deformed as well, and can't be reused.

All the other PTO shafts I have are even shorter, or too much too long to borrow to get me back mowing. So I must get both inner and outer tubes to effect the repair. I see online places selling the tubing, either as 36 inch sets, or single inner or outer at 59 inches, sold separately. They are classed with numbers that have no meaning for me, but I assume these have to do with wall thickness and overall outside and inside dimensions. Is there a good reference page about this tubing anywhere?

The places I found were on the East Coast I am on the Pacific Northwest Coast. I am hoping to find an outlet for the tubing closer to home to do this simple repair. Any help out there? Thanks for looking. You have the Euro style of shafting.

You'll need to determine the size you have in order to get the proper series of replacement shafting. Some of the various series use one size for an inner and the same size for an outer on the next step down and vise versa.

Agri Supply is one of a handful of vendors who carry the individual bits for these shafts online. You might find it locally, but you might also pay dearly for that option. ASC is actually quite good about reasonable prices and shipping fees. When I built my series 7 PTO shaft, there was another outfit that had slightly better prices, but their online store was brutal to navigate. Rather than having orders from two different vendors, I put all my eggs in one basket and that proved to be easier for me to keep track of rather than saving about 1% on the whole assembly when it was all said and done.

Here's a chart with dimensions: EUROCARDAN Standard Series Thanks Jim.

That chart should help me at least find out what I have here. Tough to read some of the dimensions on the gif on my monitor but I think I can make enough of them out. I have a metric dial caliper around here somewhere.

So, I guess I will just have to wait for a cross-country delivery, as it seems that is where the domestic suppliers be.

I noticed that one place was willing to part with the roll pins for a measly five bucks each (plus postage and handling, of course). Should be able to find those at the auto parts store, eh?

I'll post the chart here for the next guy:

I could not find the tubing at Tractor Supply's web page, just complete PTO shafts. Since the rest of my broken drive is good, I would rather repair it, since it's as simple as driving out two roll pins and cutting the new tubing to length. No desire to put two good U-joints and quick connects on the shelf.

I found 36 inch sets (inners and outers) for series 4 & 6 from someone called Georgia Equipment on Ebay (series 4 is $35 & 6 is $45 -- $40 to ship and ten days out).

Agri Supply sells the 59 inch individual inners and outers. Looking at $140 for series 6, with eight to ten days to ship and get way more length than I need. No quote on shipping cost.

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