Is this safe? (PTO shaft/rotary cutter)

[bill333]

I bought this used rotary cutter. I'm a bit of a newbie and know that I'm supposed to have some kind of shear protection, like a bolt, but don't know where to find it.

Here is a photo of my PTO shaft and how it is connect to the cutter. As you can see the shaft is welded to the yoke.

(seperately, I'm trying to figure out how to disconnect the shaft from the yoke so I can replace it with a longer shaft)

Am I missing something -- is there supposed to be a slip clutch or a shear pin? Or is the thing marked "what is this" the slip clutch?

I assume if I don't have either then this is not a good setup to run?

 

[aczlan]

On the removable clip question, your clips are on the inside of the yoke, about where my blue arrow is pointing.

The welding of the shaft and the yoke looks normal to me, there was at one time a guard that hooked into the groove on the end of the yoke near where it is welded to the shaft

As to the "what is this" thing I dont know, but if you pull the 4 bolts that hold the cross bracket halves together you should be able to take the whole thing off and that will make it MUCH easier to work on the yoke (trust me, I had to disassemble a similar yoke for our mower conditioner this summer). If it was me adding a longer shaft onto the yoke, I would take off the 4 bolts and take it into a shop and let them change out the shaft, it will be MUCH easier for you and to have the yoke rebuilt on our mo-co this summer only cost ~$30 (parts and labor).

Aaron Z

 

[bill333]

On the removable clip question, your clips are on the inside of the yoke, about where my blue arrow is pointing. View attachment 138288

The welding of the shaft and the yoke looks normal to me, there was at one time a guard that hooked into the groove on the end of the yoke near where it is welded to the shaft

As to the "what is this" thing I dont know, but if you pull the 4 bolts that hold the cross bracket halves together you should be able to take the whole thing off and that will make it MUCH easier to work on the yoke (trust me, I had to disassemble a similar yoke for our mower conditioner this summer). If it was me adding a longer shaft onto the yoke, I would take off the 4 bolts and take it into a shop and let them change out the shaft, it will be MUCH easier for you and to have the yoke rebuilt on our mo-co this summer only cost ~$30 (parts and labor).

Aaron Z

Thanks this is really helpful. I should have cleaned all that grease off the cross to find the clips.
As for lenthening the shaft, that is great advice about taking off the cross bracket (another poster told me that it is the slip clutch). But I can't imagine where I could find someone around here to put on a longer shaft...

 

[greg_g]

Inside clips, interesting concept - I've just never seen any. If you don't find them on yours, my guess is that you just hammer the cross out like any other U-joint. The "what is this" component looks like some kind of primitive slip clutch. Hard to tell from a photo if it's operable - or even salvageable. It would help to know up front what kind of RC this actually (make and model I mean)

As far as lengthening the shaft, you can get PTO driveline components (repair/replacement parts) at or through any farm supply store - or online from places like AgriSupply. But if that slip clutch is frozen - and if the rest of the RC can be considered worth the additional investment - you might want to consider buying a whole PTO drive line. If this is a 5 foot or smaller medium or light duty cutter, you can probably get by with the less expensive shear bolt type. If it's 6 foot or larger medium or heavy duty, I'd spring the extra bucks for the slip clutch version.

//greg//

 

[bill333]

Inside clips, interesting concept - I've just never seen any. If you don't find them on yours, my guess is that you just hammer the cross out like any other U-joint. The "what is this" component looks like some kind of primitive slip clutch. Hard to tell from a photo if it's operable - or even salvageable. It would help to know up front what kind of RC this actually (make and model I mean)

As far as lengthening the shaft, you can get PTO driveline components (repair/replacement parts) at or through any farm supply store - or online from places like AgriSupply. But if that slip clutch is frozen - and if the rest of the RC can be considered worth the additional investment - you might want to consider buying a whole PTO drive line. If this is a 5 foot or smaller medium or light duty cutter, you can probably get by with the less expensive shear bolt type. If it's 6 foot or larger medium or heavy duty, I'd spring the extra bucks for the slip clutch version.

//greg//

Dumb question -- how can I tell if the slip clutch is frozen?

And by a 'whole new PTO drive line" I assume you mean a new PTO shaft? I'd be willing to do that, except I haven't been able to find one that has a spline on one end and the yoke on the other.

It is a 5 ft medium duty Hardee cutter. I only paid $300 for it and if it is going to be a lot of work it might just be cheaper to buy another cutter.

 

[aczlan]

Thanks this is really helpful. I should have cleaned all that grease off the cross to find the clips.
As for lenthening the shaft, that is great advice about taking off the cross bracket (another poster told me that it is the slip clutch). But I can't imagine where I could find someone around here to put on a longer shaft...

You can get a new yoke/shaft (male shaft and half of the yoke) at tractor supply or a similar store. However if you have never taken apart a yoke before I would not recommend it unless you are very good with tools, it has to be put back in just so or it will bind and removing the center takes some creativity with a vise as the inside clip retainers are a PITA to get loose. If you pull the 4 bolts and take it into a decent dealer they should be able to get you the parts you need, and put it together. I would guess that it will run you $60-100 for the shaft (depending on the length and style) and $20-30 for the center of the yoke.

If you don't have a good tractor dealer nearby, you can pull the 4 bolts, take the assembly into tractor supply, have then set you up with a shaft and take the whole thing to a truck repair shop, they will be able to press out the old center and in a new one with your new shaft pretty quickly. You may need to have them take it apart first so that you can get the measurements as to the yoke size and then take them the new shaft.

Where (roughly) are you located?

Aaron Z

 

[aczlan]

You may also be able to remove the whole assembly after removing the 4 bolts and put in a whole new PTO shaft.

Pull the bolts and post some pictures of how it looks.

Aaron Z

 

[greg_g]

Dumb question -- how can I tell if the slip clutch is frozen?

It won't slip. When you get into the rough stuff - wet grass especially - or hit an unseen rock or tree stump - the clutch is suppose to slip before the shock travels all the way up the driveline and breaks something inside the tractor transmission. You need to disassemble/clean/adjust/reassemble - and hope for the best. If it won't come apart, it likely won't slip either.

I mentioned the online AgriSupply as a source. I guess you didn't look. So start here - PTO SHAFTS/ACCESSORIES - Agri Supply - and familiarize yourself with the repair and replacement options.

//greg//

 

[bjr]

Yeah, pull things apart. Get a cheap set like (Harbor Freight sells) digital calipers so's you can measure the yoke cap/bearing bore and the inside the yoke ear to ear distance and 'bout the length to the tractor pto shaft when it's hook up to the mower so you know the median length of the driveline. Call Agri-Supply and tell them what you're doing, they'll probably ask for some of those measurements. Go back with regular six spline 1-3/8" for the tractor end (I'm thinkin' small utility tractor here) and probably smooth bore (you know the size of shaft by now) with bolt hole for shear bolt. Get the low hardness bolts (no marks on the head) to use for shear bolts. The slip clutchs are nice but kinda spendy. The new 5' Bush Hog I bought had shear bolts in it right from the factory. Oh yeah check the grease or oil in the gear head and grease the pto joints. It probably wouldn't hurt to roll the thing up on one side so's you can check things out underneath that something isn't about come apart and the blades swing freely and maybe touch the blades up with a 4" angle grinder (again Harbor Freight tool). I think you'll be happy with the results. Field mowers generally get beat up pretty much so, having new dent free mower isn't the fad. Narly patched up with different paint schemes gives you the Rambo look, much more desireable. Go spend the saved money on the significant other a nice dinner. bjr

 

[bill333]

It won't slip. When you get into the rough stuff - wet grass especially - or hit an unseen rock or tree stump - the clutch is suppose to slip before the shock travels all the way up the driveline and breaks something inside the tractor transmission. You need to disassemble/clean/adjust/reassemble - and hope for the best. If it won't come apart, it likely won't slip either.

I mentioned the online AgriSupply as a source. I guess you didn't look. So start here - PTO SHAFTS/ACCESSORIES - Agri Supply - and familiarize yourself with the repair and replacement options.

//greg//

Sorry, I should have been much clearer in my question. What I meant to ask is, Is there any way to tell if the slip clutch is working without finding out the hard way that it isn't? In other words without running the tractor?

I know the cutter works, I've used it -- but I stopped after reading this forum and wondering if I was in danger of ruining the tractor.

As for agrisupply, I did look at that carefully actually before posting anything. But the descriptions of the products are really only useful if you know the terminology. For example, this the agrisupply description of a PTO assembly:

"8651054 TX1 1110 1-3/8 SPL X 1-1/4R-3/8".

That doesn't help me very much. I can't tell if it is 6 splines or 21. I'm guessing that one end is splined but I don't know what the other end is, or if that other end (Round?) is what I have on my tractor. The photos posted are generic.

I also went to my local tractor supply with detailed pics and measurements. But it is staffed mostly with high school kids, they know less about this than I do, so that doesn't help. They keep very little in stock (good supply of yokes though!) so I can't even find something on the shelves or in the book that looks like what I have.