How to Identify an Agricultural PTO Driveline - Royal Brass & Hose

An agricultural power take-off (PTO) driveline is a drive-shaft type device that connects a tractor to the farming implement it needs to operate. The connection provided by the driveline allows the implement to draw power directly from the tractor’s engine. Much like fluid hydraulic mechanisms, PTO drivelines will eventually break down from the rigors of daily farming projects and need to be replaced or repaired. When it is necessary to replace or repair a PTO driveline, it is important to choose the correct components applicable to the specific equipment in use. In order to choose the replacements correctly, you will need to know the answers to these four simple questions about your particular driveline:

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• What kind of equipment will the driveline be used on? (Identify by application)

• What are the individual driveline components?

• Is the driveline North American or Metric?

• What series is the driveline?

What kind of equipment will the driveline be used for? (Identify by application)

If you know which piece of equipment the driveline will be used for and want to replace the complete driveline, then identification is a quick two-step process:

Simply select the category of equipment and then choose the tube shape (see pictures below) and length for the driveline you want to replace.

If you need a replacement for a component of the driveline refer to the following identification process.

What are the Individual Driveline Components?

1.Tractor Yoke- The PTO assembly begins with this type of yoke.  It is connected to the tractor, and  used to attach the driveline.  There are two main types of tractor yokes.  The first type is a Spring-Lock, which uses a spring-loaded collar to attach and release the yoke.  The second type is a Quick Disconnect, which uses a push-pin mechanism for connectivity. 

The tractor yoke can also be designated as 6-spline, 20-spline, or 21-spline, representing how it matches to the connection on the tractor. This can be identified by counting the notches on the inside of the yoke collar.

If you want to learn more, please visit our website PTO Shaft Adapter.

2.  Cross and Bearing Kit- This is a u-joint that connects the yokes in the PTO assembly. The cross and bearing kit will either have a snap ring located internally in the bushing or located externally, meaning it can be found in the ears of the yoke.

3.Shaft Yoke- Using a cross and bearing kit, this connects the tractor yoke to the driveline shaft.

4.Shaft- The shaft is the metal rod at the core of the driveline providing its length and connecting the yoke attachments.

5.Tube- The shaft runs inside this metal cylinder adding reinforcement to the driveline

6.Tube Yoke- Attached to the end of the tube, this yoke connects the driveline to the implement using a second cross and bearing kit.

7.Implement Yoke- This connects the driveline to the machine or device being maneuvered by the tractor.

8.Guard- A hard plastic covering is placed around the driveline to prevent damage during operation.

Is the Driveline North American or Metric?

The simplest way to figure out whether a PTO is North American or metric is to determine the shape of the tubing and shafting. A PTO is domestic if the tubing/shafting is square, rectangle, hex or splined.  If the tubing/shafting is bell, lemon or star-shaped, then it is metric.  There are two types of metric drivelines: German style (Walterscheid brand) and Italian style (Bondioli & Pavesi).  The German style shafting/tubing has lemon and star profiles while the Italian has a bell-shaped design. 

What Series is the Driveline?

An accurate way to determine which series of PTO you have is to take two measurements of the cross and bearing kit on the tractor-end of the driveline. Using calipers, measure the outside diameters of the u-joint caps, which would be the same as measuring the inside holes of the yoke ears.

Second measure the u-joint end-to-end both ways. Match these measurements using a cross and bearing identification chart and the remaining PTO components needed or the complete driveline required can be determined with ease.

If you are looking for more details, kindly visit Pto Shaft.

Need to replace a driveline or component part?

Alright guys, with advice from a few members I replaced a broken gearbox with a new one. My mower now has a nice new 75hp gear box.

Here's the problem, my old slip clutch doesn't fit. The new gearbox has a 6 spline output that will connect to the Pto shaft. What do I need to connect the gearbox to the shaft? Do I just do a direct connect, or shear pin or a clutch? I would prefer not to buy a clutch because of cost. Any advice will be great. Pictures of the appropriate attachment part would be appreciated.

Thank you. A description or how it doesn't fit, or some pictures would do wonders. But just some thoughts...

-My clutch protected implements all have a splined shaft on the gearbox.
-Stuff made with shear bolt protection are just a round shaft with the shear bolt through it.
-Having splines on a shear design would prevent the PTO and gearbox shaft from spinning independently when the shear bolt should shear and won't provide any driveline protection.
-Having a splined shaft with no clutch would provide no driveline protection.
-Having a smooth shaft with shear bolt on a clutched shaft would offer two layers of driveline protection.

Did you upgrade the gearbox or use what was supposed to be the direct replacement? Upgrading the gearbox only transfers more shock and wear from the operation into the tractor's driveline and causes things farther up the line to wear and break, not really advisable. There are a wide variety of PTO adapters available and most Tractor Supply's, Rural Kings, etc have them on the shelf.

If you could post pictures of what you have it would be easier to point you in the right direction. I will attempt to add a photo of the mower. You can see that its a 6 spline input. In the background, on the mower deck is the old slip clutch. The slip clutch is too long and there is no way to secure it to the output shaft. Again, I am looking for an option or way to attach the pto shaft to the gearbox input shaft.

Thanks.

Here is a link to the gearbox. 75 HP Gearbox, Rotary Cutter Gearbox, Rotary Cutter Gearboxes | Agri Supply, 493

Here is a link to a shear bolt yoke. Is this what I need? PTO Shaft Torque Devices

That looks exactly like the shaft on all the rotary cutters I've seen. The piece laying on the far side of the deck doesn't look like any of the slip clutches I've seen, you may have some oddball shaft. We would need to see pictures of the clutch and shaft you have and where it attaches to the gearbox.

I think you may need a new PTO and slipclutch made for that gearbox. If available, any adapters you add will require shortening your existing shaft by an amount equal to the length of the installed adapter.