Is this safe? (PTO shaft/rotary cutter)

[dex3361]

As others have said take it apart and clean it up. That Clutch looks like one I had on an old Ford 5 foot mower a few years back. I think the clutch adjustment is between the yoke and the clutch disc and pressure plate adjusted with a large hex nut or spanner nut. If I am not mistaken it has a bellville spring for pressure. I usually mark the clutch disc and pressure plate and yoke and start with the cluch very loose cut a few seconds with the intent of making it slip. Remark for alignment tighten it a little cut a few seconds check the alignments of marks proceed until it doesnt slip on the heaviest stuff that your rotary can safely cut. It has worked for me and it protects the tractor from damage. More detailed pictures would help on whether that is how it is adjusted or not.

 

[greg_g]

The cutter is a Hardee E60.

Too bad we didn't know that up front. What you're looking for is likely here: Hardee and the slip clutch is probably similar to the repair guide page 7. If true, it uses compression springs - not a Belleville.

//greg//

 

[bill333]

As others have said take it apart and clean it up. That Clutch looks like one I had on an old Ford 5 foot mower a few years back. I think the clutch adjustment is between the yoke and the clutch disc and pressure plate adjusted with a large hex nut or spanner nut. If I am not mistaken it has a bellville spring for pressure. I usually mark the clutch disc and pressure plate and yoke and start with the cluch very loose cut a few seconds with the intent of making it slip. Remark for alignment tighten it a little cut a few seconds check the alignments of marks proceed until it doesnt slip on the heaviest stuff that your rotary can safely cut. It has worked for me and it protects the tractor from damage. More detailed pictures would help on whether that is how it is adjusted or not.

Thanks.This is one of those situations though, that while I understand every word in your post, I'm not sure what it all means! (Not that I'm criticizing your helpful suggestion, just that I"m an idiot. This must be what it feels like when I"m explaining net present value and cash flow to one of my clients).

I just don't have a sense for what "slipping" looks like/feels like.

I did manage to get a hold of someone at Hardee. He told me the following:

1. most of the cutters they sell don't come with either shear bolts or slip clutches. (Although I noticed on their web page that shear bolts come standard with many of the mowers). I asked him if this meant that people added them later and he said no, they run them without either, and he has been himself for years. (not suggesting this is correct, just that this is what he said).

He agrees with both Greg and Soundguy that there is a good chance it is frozen. To adjust it/unfreeze it (?) he said I should do the following :

1. remove the 4 bolts on the flange which holds the clutch in place.

2. remove the e clip on the front.

3. loosen the large nut on the back . He said the nut holds everything in place.

4. Retighten.

He didn't say anything about mowing first, or how much to retighten, but he might have just figured I understood that was needed.

p.s. he said if it were his he would just go ahead and mow with it as is!

 

[tommu56]

Here is a good link on replacing the ujoint
I had to replaced a axle one last weekend and after hammering and trying to press it o it with a vise and sockets for hours I had to take it to a shop the guy had it apart in 5 minuets using this method I haven't ever seen before.

JeepWire - Changing Axle Shaft U-Joints


it removes one cap at a time.

tom

 

[bill333]

Too bad we didn't know that up front. What you're looking for is likely here: Hardee and the slip clutch is probably similar to the repair guide page 7. If true, it uses compression springs - not a Belleville.

//greg//

Sorry, I thought I had mentioned the make (but not the model number) earlier.

I looked at that repair guide. The cutter looks similar but the slip clutch is different. The one in the guide looks like the ones I've seen at TSC; it just slips over the spline. Mine has some kind of bolt arrangement, although it might have splines and I can't see them. I don't really understand where the springs are and what they do.

I"m going to try to go to a place that sells rotary cutters (which is unfortunately an hour away) and see if I can get a salesman to explain to me how it all works so that I'm not wasting everyone's time with these stupid questions!

 

[MarkV]

Bill your slip clutch looks different than mine and may be an older style that not many of us are familiar with. Don't give up, someone usually will run across a thread like this and know all about it.

In general a slip clutch is used to protect the tractor if the mower were to hit an immovable object. As the name implies the clutch is suppose to slip so the tractor does not have to absorb the sudden impact. Slip clutches have a cluster of metal disks that are spring loaded. The springs are tightened to a point where there is enough friction between the disks to allow for normal operation. When you exceed the amount of friction for normal operation, like hitting that immovable object, the disks will slip against each other to protect the tractor from the impact. A shear bolt serves the same function of protection by breaking a bolt, that has to be replaced, as the slip clutch does by slipping.

Where slip clutches have a problem is when they are left in the elements and the disks rust together. They then lose their ability to slip and protect the drive line. Annual maintenance for many of us is to loosen the springs until the clutch will slip, then retighten to normal operating tension. That way any rust is broken free and we know the clutch will work if needed.

I do wonder if you got ahold of the wrong person at Hardee. I don't think I have ever heard of a rotary mower that did not have a shear bolt or a slip clutch. I know I would not buy one that didn't.

MarkV

 

[dex3361]

Too bad we didn't know that up front. What you're looking for is likely here: Hardee and the slip clutch is probably similar to the repair guide page 7. If true, it uses compression springs - not a Belleville.

//greg//

I cant find the repair guide that you are talking about could you link it?
I think that the item bill333 has marked with the "what is this" is the slip clutch. I also think that it has a bellville spring because from the looks of it it is to thin for coil type springs. But of course I have been wrong before and I am sure I will be wrong again.

 

[aczlan]

I cant find the repair guide that you are talking about could you link it?

Try this: http://www.hardeebyevh.com/images/shopcart/items/31.pdf

I think that the item bill333 has marked with the "what is this" is the slip clutch. I also think that it has a bellville spring because from the looks of it it is to thin for coil type springs. But of course I have been wrong before and I am sure I will be wrong again.

I agree that it is a slip clutch and it could be a Bellville spring slip clutch (at least if a Bellville spring looks like a flatwasher that has been bent so that it is sort of funnel shaped). If that is the case, the clutch is very different from the one the the linked manual.

Aaron Z

 

[dex3361]

Thanks.This is one of those situations though, that while I understand every word in your post, I'm not sure what it all means! (Not that I'm criticizing your helpful suggestion, just that I"m an idiot. This must be what it feels like when I"m explaining net present value and cash flow to one of my clients).

I just don't have a sense for what "slipping" looks like/feels like.

I did manage to get a hold of someone at Hardee. He told me the following:

1. most of the cutters they sell don't come with either shear bolts or slip clutches. (Although I noticed on their web page that shear bolts come standard with many of the mowers). I asked him if this meant that people added them later and he said no, they run them without either, and he has been himself for years. (not suggesting this is correct, just that this is what he said).

He agrees with both Greg and Soundguy that there is a good chance it is frozen. To adjust it/unfreeze it (?) he said I should do the following :

1. remove the 4 bolts on the flange which holds the clutch in place.

2. remove the e clip on the front.

3. loosen the large nut on the back . He said the nut holds everything in place.

4. Retighten.

He didn't say anything about mowing first, or how much to retighten, but he might have just figured I understood that was needed.

p.s. he said if it were his he would just go ahead and mow with it as is!

Bill 333
See if these pdf attachments help cause a picture is worth athousand words. Look in the Hardee manual on pages 3 and 4 it has a clutch adjustment procedure. the other pdf is a good example of the type of clutch that you have.

 

[Soundguy]

I'd like to add that running any driveline without the protection of a slip clutch or shear pin / bolt is just asking for pto or transmission problems. these units that suposedly don't have a clutch or shear pin..if their if your gearbox has a smooth shaft .. I'd use a grade 2 bolt in it.. notheing harder.. if it's a splined connection on both sides.. then clutch for sure..

soundguy

 

[greg_g]

Bill 333
See if these pdf attachments help cause a picture is worth athousand words. Look in the Hardee manual on pages 3 and 4 it has a clutch adjustment procedure. the other pdf is a good example of the type of clutch that you have.

Good find, the ones I pointed too didn't include the "older models" section. It also tilts the scale towards Belleville (vs compression) style. Hopefully this will save Bill that next fact-finding road trip.

//greg//

 

[dex3361]

I'd like to add that running any driveline without the protection of a slip clutch or shear pin / bolt is just asking for pto or transmission problems. these units that suposedly don't have a clutch or shear pin..if their if your gearbox has a smooth shaft .. I'd use a grade 2 bolt in it.. notheing harder.. if it's a splined connection on both sides.. then clutch for sure..

soundguy

DITTO

 

[SPYDERLK]

There is a clutch on the pto driveline in the tractor. My experience with serious heavy duty use of a bushog over a 40 year period on 2 different tractors is that this internal clutch ptotects the tractor side effectively. At a guess id estimate this clutch is designed to slip at about 3 times the steady state torque that the tractor engine can apply and that this slippage point is within the safe region for all internal drive line components. I adjust my 5' bushog slip clutch by dropping the bushog onto a pile of loose dirt at full rated rpm. With a 35 to 45HP tractor it should bog the tractor very quickly. You have to act quickly to keep from stalling. Next, I disengage the PTO drive and drop the BH in the dirt to stop it - then quickly feel the slip clutch for heat. If there is none it hasnt slipped - loosen and repeat. If it is hot it has slipped a lot [and you may have noticed that the tractor didnt bog]. In this case the clutch is too loose and must be tightened or it will burn up quickly in heavy steady state cutting like thick grass. This is why sneaking up on a correct setting can be counterproductive. The mating of a 5' or 6' bushog to a tractor in the 40 HP range forms a robust system that does not require coddling. However, if the bh is light duty or this size is being run by a 70 hp tractor then one end of the system is comparatively weak. You could not set the slip clutch as I do because, even with the compliance of soft dirt a quick bog or stall may transmit a transient amt of torque associated with ~3x70 HP. Heavy Duty 5 and 6 foot bushog gearboxes rate at around 100HP. If the slip clutch is frozen you will probably twist the telescoping pto shaft or else damage the bh gearbox. This is not necessarily too much tractor, but the situation demands a tighter balance to keep from burning up the clutch or damaging the implement when you encounter a situation that requires its full capability.
larry

 

[Soundguy]

slipping the pto side of a 2 stage clutch in my tractor is not my idea of a good time.

slipping the main clutch on a non live, single stage clutch machine is not my idea of a good time.

power slipping the wet clutchpack of my independent pto machine is not my idea of a good time.

I'd much rather replace a 50 cent shear pin.. or a 100$ slide on external slip clutch than SPLIT my tractor to replace the main or pto clutch. BTDT.. on independent pto clutchpack on a couple jd before... it's a no-fun job and a tad spendy.

the pto clutch internal to the tractor is there to get the driveline moving.. it shouldn't be the front line of protection especially when there are provisions for that externally.

kinda like saying your car doesn't need brakes as long as it has good seatbelts and airbags.

a quite ridiculous notion really

soundguy

 

[SPYDERLK]

slipping the pto side of a 2 stage clutch in my tractor is not my idea of a good time.

the pto clutch internal to the tractor is there to get the driveline moving.. it shouldn't be the front line of protection especially when there are provisions for that externally.

kinda like saying your car doesn't need brakes as long as it has good seatbelts and airbags.

a quite ridiculous notion really

soundguy

Yes. Agreed for the inaccurate comparison and exaggerative notion of your post. I didnt call it a good time, nor did I recommend it. The fact that the clutch is there and is sized for the tractor makes it able to protect the tractor by slipping on a catastrophic overload. That this clutch is exercised regularly and is housed is a stable internal environment favor its stability of action. This in no way means you should not use an external protective device to prevent it seeing such overload - just that malfunction of the external device is not a death knell to a well designed pto system.
larry

 

[bill333]

Bill 333
See if these pdf attachments help cause a picture is worth athousand words. Look in the Hardee manual on pages 3 and 4 it has a clutch adjustment procedure. the other pdf is a good example of the type of clutch that you have.

I think you found it! Mine looks like the 2 plate model.
From the directions it looks like I just loosen the large nut (8) I think?

I didn't know if I had to loosen the 4 bolts that hold the yoke attachment to the drive plate. (I'm hoping not, as these are rusted and bent)

 

[bill333]

I'd like to add that running any driveline without the protection of a slip clutch or shear pin / bolt is just asking for pto or transmission problems. these units that suposedly don't have a clutch or shear pin..if their if your gearbox has a smooth shaft .. I'd use a grade 2 bolt in it.. notheing harder.. if it's a splined connection on both sides.. then clutch for sure..

soundguy

I understand -- this is why I stopped using the cutter as soon as I came across the information in this forum. (I had used it before I knew better). So right now I'm trying to understand all this (thanks to all for their patient explanations) before I attack by foot high pasture grass.

 

[bill333]

In general a slip clutch is used to protect the tractor if the mower were to hit an immovable object. As the name implies the clutch is suppose to slip so the tractor does not have to absorb the sudden impact. Slip clutches have a cluster of metal disks that are spring loaded. The springs are tightened to a point where there is enough friction between the disks to allow for normal operation. When you exceed the amount of friction for normal operation, like hitting that immovable object, the disks will slip against each other to protect the tractor from the impact.

MarkV

MarkV: This description really helped me understand how it works. Kind of like if a car was driven by a connection between the brakes and the transmission, and the disks where left "on" (slightly rubbing). Weird analogy but it helps me.

I took another look at mine up close, if the amount of rust around the edges is any indication, I'm sure it is seized up. I'm a little confused about the springs, they seem awfully narrow (i.e. there doesn't seem much room for much of a spring) but I guess that is how it looks when fully compressed.

I'll try to attack that nut tomorrow and see if I can loosen it up.

 

[greg_g]

I'm a little confused about the springs, they seem awfully narrow (i.e. there doesn't seem much room for much of a spring) but I guess that is how it looks when fully compressed.

Well, they're still technically compression springs, just not in coil form. Imagine them as very large washers made of spring steel, washers that bend when you push on them - then spring back when you let go. In the case of your slip clutch, they maintain equal circumferential tension on a round pressure plate - which keeps a round friction disc stationary - until feedback force from the mower becomes greater than the tensioning force of the spring. Then the friction disc slips against the pressure plate, because there's more force working against it - than it's tensioned to maintain.

//greg//

 

[bill333]

By george, I think I got it!
Thanks for the explanation, now I can picture it.