Over Running Couplers

AlanB · Jun 8, 2004

Given that you could make it slip with great force.. I would think is moot.. as that great force is probably what the shear pin is in the system to prevent.. I.E. the shear pin pops before the ORC functions incorrectlyand bypasses during a gross load exceding its designed capabilities...

I would also agree that a quick release one is the way to go.

Soundguy )

I guess I am belaboring the point now, but sometimes with this type of communication, it just does not get through. And sometimes, I do not tell enough of the story to make it clear.

Somewhere along the way, I bought a NH 1925 this year, after reading all the great information here, I found a reference where I should be running an over running coupler / clutch when using a bush hog to prevent back driving of my HST xmsn. (relevant post on the NH board) I asked several folks, the dealer I bought my tractor from and the NH dealer if I could just leave the ORC on when using my other PTO driven equipment and everyone said, all it would effect was driveline length and if the implement was spinning faster than the PTO.

I then bought the only type I had seen that pinned on.

So, after crawling around in the rain and in the dark installing this thing which while it sounds very straightforward and easy, caused much cussing and greif before I got it all lined up and finished off so the wife could use it the next morning.

Bush hog stuff went fine, then had to switch over and dig / drill some holes. Had been using the PHD no problem in the past.

The PHD would spin and start to dig, then it would stop, Thinking I had sheared a pin I lifted it and it started spinning again, up, down, up down, yep, you get the picture, the village idiot drilling holes. Pull the pin, (bolt actually) and look at it, scratch my head, wonder what is wrong, realize that I have added the ORC, oh it must be defective. Of course I do not have the tools with me to change it. Home we go, this job not getting done today. Get another ORC from my dealer explaining that this one is bad / defective and will not drive my PHD. Dealer agrees, sureley something must be wrong.

Install new one, test in yard, same results, then take the new one apart to see how it works, maybe it is backwards, spend an hour drawing circles in the air and looking at the rotation of my PTO trying to figure out if the darn thing is backwards or not. Go to rural King with snap ring pliers and dissasemble one of theirs and see if it is the same??? Go to TSC and do the same. Wander around on the web till I stumble in to the QD ones and realize that this is probably done becuase they do not work for driving all implements, if they did, why bother with a QD?

Go to my dealer, who thinks I am nuts and disassemble his, and another on the shelf from a different vendor, they are all the same.

Finally buy the QD one and mount it on the bush hog where I leave it because that is where I need it.

Soooooooooo, That is why I suggest buying the QD over running clutch.

And it never came close to shearing the shear bolt on the post hole digger when we were using it. And we probably shear 2 to 6 of them a day when we are using it heavy for planting.

Yep, I am bored and the wife is aggravated with me /forums/images/graemlins/smile.gif

Oh, and I do not care how things were designed to work, I just worry about what really happens.

DK35vince · Jun 8, 2004

I don't get it ?
I have been using an overrunning clutch for 2 1/2 years now.
I use it for all my implements (never take it off).
It has never slipped regardless of how hard I work it, or what implement I'm using. Including a post hole digger.
I also run a 6' brush mower, 6' finish mower, 5' tiller. No slip..

JerryG · Jun 8, 2004

Vince,
I am with you. I have never heard anything like this. I have worked on tractors that have had the same ORC on them for at least 30 years. Some of these tractors have been attached to every kind of implement and never a problem, nor was the OCR ever removed for any reason.

Inspector507 · Jun 9, 2004

The tiller PTO shaft is so short, that if the ORC stayed on, it would make the angle on the joints too great.

Soundguy · Jun 9, 2004

( use it for all my implements (never take it off).
It has never slipped regardless of how hard I work it, or what implement I'm using. Including a post hole digger.
)

I agree that I've never had my ORC slip in the drive position.. and as I posted.. a friedn had an orc nearly twist in half when his hog hit a stump.. go figure.

Another thing I'm wondering is why a HST trannied tractor needs an external ORC on the PTO... that HST will have independent pto.. and no direct driveline connection.. right?

( I know it is driven off the counter shaft.. but the acutal driveline should be isolated.. right? )

Soundguy

To20Chris · Jun 9, 2004

I ran a PHD with the ORC on, and it ran it no problem, no slipping. I'm not even sure how it could slip, as it seems to be just a ratchet? Wouldn't the mechanism have to be pretty much destroyed if it slipped in the forward direction?

I did have a probelm with the ORC on my TO20 with the PHD digger on though - on about the third hole it dropped down very fast (too much RPM), and at the bottom I chickened out and pushed in the clutch (no live PTO, no separate hydraulics, very slow lift response time). I could not get it to spin up again without stalling the tractor. Then I discovered that the PTO shaft was too long and was bound up good and tight (due to the extra length of the ORC mostly) - I could not release it, or get any of the pins on the 3ph out! /forums/images/graemlins/shocked.gif My Dad I & scratched our heads for a while & figured there was nothing left but to dig out the 3' bit. After a couple of starts at digging, I figured there had to be a better way - and there was! I got a jack and a block of wood & jacked the front of the tractor up until the PTO shaft unloaded, and then I could unhitch the PHD. Then I put a bar in the U-joints and turned it backwards by hand until it unscrewed from the ground. Needlees to say, I replaced the ORC with a fixed adaptor (TO20 is not standard size PTO splines), and adjusted the shaft length. I have used the manual unscrew method sevaral more times since, when the PHD gets bound up at the bottom & breaks the pin.

I'm sure the Kioti would have made that job a lot easier!

AlanB · Jun 9, 2004

I guess I must just be full of crap then, but what the heck,

Be careful wrestling in the mud with a pig, after a while, you realize the pig likes it.

So, Lets See.

Go find New Holland Assit bulletin #443 that says class II boomers (which when I called and spoke with Tech services NH also applied to my 1925) Do I need to provide thier phone # to prove it?

It was referenced here on TBN on the NH forums as I said

link

Anyway, as I also said, I thought it would be like a ratchet, however, the ones I have seen, are not. I am sure there are other makes I have not seen, but if you look at the attatchment that soundguy posted you will see that it is actually ramped in both directions, and there is room for the locking pawls to collapse inside against the springs.

Ratchets, as a general statement, have a positive lock in where they cannot slip in the driven direction, increased torque increases the bite of the pawl, until something gives. Or said another way, the angles are different than in the ORC's that I have seen.

But hey, whatever, anyone that is interested can come by the house with a video camera and I will hook it up and run it for them.

And Soundman, how did his ORC (Almost) twist in half? It should have been upstream from an Slip clutch or shear bolt?

Soundguy · Jun 9, 2004

( which when I called and spoke with Tech services NH also applied to my 1925) Do I need to provide thier phone # to prove it?
)

No need to be rude to have a simple conversation.

( Go find New Holland Assit bulletin #443 that says class II boomers (which when I called and spoke with Tech services NH also applied to my 1925) It was referenced here on TBN on the NH forums as I said
link )

That bulletin, taken with the rest of the posts in that section show that the orc is necescary.. due to a DEFECT .. and should not be considdered regular operation. The ORC was a bandaid around the real problem.. which was probably a bearing seized on the tranny countershaft which drove the pot and in that case.. allowed the pto to backfeed the tractor drive train. In normal situations ( correctly functioning machine ).. that wouldn't happen. I believe the answer came down that the unit had been run low on oil allowing either the bearing or aft gear to sieze to the shaft.
This proves nothing.. except NH wanted to bandaid a problem rather than fix it.. whether it is a manufacturing/design problem.. or a user defect doesn't affect the situation any.

( but if you look at the attatchment that soundguy posted you will see that it is actually ramped in both directions, and there is room for the locking pawls to collapse inside against the springs )

Under tremendous load.. yes.not normal operation.... we already covered that.

( how did his ORC (Almost) twist in half? It should have been upstream from an Slip clutch or shear bolt? )

He was running it with no slip clutch and it had a hardened bolt for the shear bolt ( previous owner ). He was told by the previous owner, when he bought the mower and the tractor, that the ORC WAS designed to slip and protect the mower.. obviously it didnt... /forums/images/graemlins/confused.gif the ORC didn't ratched forwad, and instead put a half inch twist in the spline.. and stalled the tractor as the mower stopped on a huge shock load to the drivetrain.

As soon as I get his pic.. I'll post it...

Soundguy

To20Chris · Jun 9, 2004

Your conclusion was that the ORC must be slipping because the PHD stalled, and the motor did not, and you verified that by trying another ORC which worked the same. But what if the ORC was not what was slipping? With the ORC on, could you actually see the PTO shaft fromthe tractor spining? I can't imagine what would slip in the tractor PTO drive, other than the PTO clutch, but I am not afmiliar with your particular tractor either. Again, I've run the same TSC PHD digger through the ORC that's been on my tractor for about 25yrs, and I broke many shear pins through the ORC - it never slipped. Another possibility is that they are made differently now, with the most likely difference being that they are now made out of lousey materials and with poor tolerances

AlanB · Jun 9, 2004

And then I verified it by removing the ORC from the system and it all works fine. Which led me to the conclusion that the ORC was the problem.

As I stated, it worked fine prior to installation of the ORC, I installed the ORC, it then did not work, I changed the ORC believeing it to be defective, it did the same thing. (recognizing that this ORC was the same manufacturer)

We then took the ORC off and my PHD again works.

Just a thought, but if your ORC is 25 years old, when was the last time it was disassembled and greased?

I realize that there are grease fittings on the ORC (more than Likely) but I believe that you will find that the grease put in through those fittings has a very hard time going down and lubricating the actual pawls of the mechanism.

AlanB · Jun 9, 2004

SG said "No need to be rude to have a simple conversation."

AB said I did not feel I was being rude, you seem to question every response I make as though it is untrue, so I offered to provide further verification and authentication so that I do not appear to be one of those guys that types away on the computer without actually doing what I am referring too.

AB originally said ( Go find New Holland Assit bulletin #443 that says class II boomers (which when I called and spoke with Tech services NH also applied to my 1925) It was referenced here on TBN on the NH forums as I said
http://www.tractorbynet.com/forums/showflat.php/.../353673/ )

SG replied with "That bulletin, taken with the rest of the posts in that section show that the orc is necescary.. due to a DEFECT .. and should not be considdered regular operation. The ORC was a bandaid around the real problem.. which was probably a bearing seized on the tranny countershaft which drove the pot and in that case.. allowed the pto to backfeed the tractor drive train. In normal situations ( correctly functioning machine ).. that wouldn't happen. I believe the answer came down that the unit had been run low on oil allowing either the bearing or aft gear to sieze to the shaft.
This proves nothing.. except NH wanted to bandaid a problem rather than fix it.. whether it is a manufacturing/design problem.. or a user defect doesn't affect the situation any."

AB said I think you should re- read the post, and the NH assist bulletin. If it was for a "failure" then they would just do it on that machine, not take the time to do an assist bulletin and reccomend it across the board. Why would they reccomend to do it all on class II boomers?

SG said "He was running it with no slip clutch and it had a hardened bolt for the shear bolt ( previous owner ). He was told by the previous owner, when he bought the mower and the tractor, that the ORC WAS designed to slip and protect the mower.. obviously it didnt... /forums/images/graemlins/confused.gif the ORC didn't ratched forwad, and instead put a half inch twist in the spline.. and stalled the tractor as the mower stopped on a huge shock load to the drivetrain."

AB said Would you pull apart his ORC and see what kind of condition it is in internally? Or would you send it too me so that I could? I would be willing to cover shipping costs.

I do not know, but I would be willing to bet, that it is siezed inside.

I know this is not edited as nicely as I would like, but I am trying to figure out the color / instant markup thing and not being too sucsessful

normde2001 · Jun 9, 2004

AlanB, it would sure be a lot easier to read and understand your posts if you would put your quotes in quotation marks. /forums/images/graemlins/confused.gif

AlanB · Jun 9, 2004

Sorry. Let me figure it out.

To20Chris · Jun 9, 2004

I grease it every couple of months, and it usually squirts out all over, so I think it's getting in there pretty good. Also, it's 25yrs old and still works fine, so I'm betting it gets greased pretty effectively. I'm thinking there is something peculiar about the particular deisgn / batch / whatever ORC you were using. As I mentioned before, I've seen all sorts of common items that had been perfected years ago and are now outsourced - and now they no longer work at all. I buy lots of stuff at TSC too, but it isn''t because of the high quality! /forums/images/graemlins/grin.gif A couple of years ago I went to get finnishing brads at Home Depot - there were heads on most of the nails (not always centered though), but the "pointy" end was usually a bigger blob than the head! Every box in every size was the same junk. That incident with the PHD digger was a bit hard on the old ORC, but I'm betting if I went and got another that it wouldn't last 25yrs!

Soundguy · Jun 9, 2004

( I did not feel I was being rude, you seem to question every response I make as though it is untrue )

Sorry... not intended to make you feel that way. I'm just as interested in getting to the bottom of this as you.. no matter whatt the outcome... I'm just one of those skeptical/questioning..hands on engineer people. I look at everything with that 'squinty' eye look until I can directly see what is going on.

( If it was for a "failure" then they would just do it on that machine, not take the time to do an assist bulletin and reccomend it across the board. Why would they reccomend to do it all on class II boomers? )

Though I have no evidence to support this.. My guess would be a CYA type maneuver. Given that this defect may show up as a common occourance.. even if it is user fault.. the failure is probably very re-creatable.. in that it fails often as a result of the low oil. For them it looks like a liability shield. Recomending an external ORC makes so that if thier internals fail.. there is still a safety margin on the equipment.

Course this is all speculation.. and I doubt NH would fess up either way..

I've got an email out to the eng. dept at speeco right now.. and am awaiting a reply. I've cc'ed them the basics of our group discussion, and when I get a reply.. I'll post it here.

Soundguy

rambler · Jun 9, 2004

( Sorry. Let me figure it out. )

Alan, I had a hard time figuring out the whole need for an over running coupler back in the NH form when that was a new subject. I stayed out of the conversation as I had nothing to offer, but it made no sense at all to me. It sure sounded like the tractor broke, and the cheapest thing for the company/dealer to do was use an orc. Did not, and still does not, make sense to me. But I just can't get a good handle on what the deal is with that. Shook my head on that whole thread.

May I ask what size post hole digger you are using? I have used a 12" in my clay soils - I have rocks too. Worked fine with my b-i-l's 15 hp compact. Really, they don't draw all that much raw power. I can't imagine stressing an ORC with a post hole digger.

On the other hand, I used my 55hp tractor with a cheap ORC from bankrupt Quality chain. I was running a 9' mower condioner. (To make this story longer, my tractor had live pto, but the collar pto yoke would not fit, so had to use the OCR just as a way to couple the moco to the tractor. Normally I use an 85 hp tractor on the moco, 50 hp is very light weight & I had to drive slow.)

So anyhow, a good share of the hp was put into that ORC. It did not slip, not ever. This was several hours of cutting time, no breaks. Full power, full throttle. I actually wore the roll pin out, but it got my alfalfa cut when I needed it.

Anyhow, normal ORC's don't slip in the opposite direction. Not the one's I've ever seen. Mine took 50 hp on a difficult load, no problem, no slippage.

Now, it isn't that I don't believe you. You are just bringing up some points that are difficult to comprehend. I've worked on this farm for 35+ years, do my own mechanical work on tractors, planter, combines. I've run into all kinds of weird deals, & I'm certainly open to things working differently than I would expect them to -heck that happens all the time! /forums/images/graemlins/smile.gif

But I've never ever heard of an OCR 'slipping' in the forward direction, and have not experienced it myself under some trying conditions.

I find your experience extraordinary, & puzzling.

I hope you don't take offense at my posting. You just have some experiences that are outside what I have experienced.

--->Paul

AlanB · Jun 9, 2004

No offense taken

We use a 12" auger in clay / rocky soil, but it was stopping well short of doing any real "digging"

As to the need of the ORC on the boomers, CYA or whatever for NH, at some point, I figure if they reccomend it, I ought to do it. I am making the assumption, maybe incorrectly, that they took the time for the driveline engineer to look at it, evaluate the problem, come up with an answer, and put it out as an assist bulletin. I could be wrong, but I doubt they do that lightly.

I need to go out now and hook up the PHD and the quick connect ORC and see what that does. Maybe I got 2 "bad" ones out of the same batch???? But honestly, from closely looking at their guts trying to figure out what was happening, it does not take that much for the ones I have seen to slip.

I do not know what a Mower conditioner is, my thoughts revolve around the BH that I run.
I do not think a bush hog, of any size really, is a heavy torque load, my thoughts are that a BH is acting like a huge flywheel back there and you are providing enough drive to keep it spinning, the High torque loads it experiences are overcome by it's flywheel effect.

I am probably coming across wrong, I do not mind being questioned, but it just seems to come back to me, NO, that could not happen.

Sooo, turning it around. Lets say they never slip, they are a positive lock.

Why would you need a QD if you never need take it off?

(short driveline on Tiller noted exception)

Soundguy · Jun 9, 2004

My take is that the pin on ones are 30 bucks less than the qd ones.. that seems like two different market targets... Aside from the ease of removal as well.

Some of us have a pto housing that is of a wrong size to accept the push button or collar lock models.. and the roll pin is the only way to go.. ( for instance.. on my old ford.. etc )

Soundguy

AlanB · Jun 9, 2004

I guess I am totally missing my target.

My point is, most all of us (there are always exceptions) would buy the cheaper pin on version, if it worked in all circumstances, and leave it in place.

I know that is what I intended.

I am attempting to draw an inference to the fact if they go through great pains and added expense and retooling and different molds for the casting etc, there is a benefit too it.

Maybe not, maybe folks just want to be able to take it off easy.

Interested to hear what speeco says.

Also thought about grabbing my QD one and taking it apart to see what it looks like.

Also thought that I would go grab one that I say slips, put it in a vice with a torque wrench and see what it takes to break it loose, I think I can do it with a standard ft. Lb wrench, maybe not, but I would be interested.

Rambler, next time you are by your tractor, would you do me the favor of reaching down and spinning your ORC in the over run direction and verifying that you can spin it with your hand please? Thanks.

woodlot · Jun 10, 2004

Sorry to chime in as I usually do not post. Alan has said quite a few times to grease the ORC good, not just through the zerk. I just got to thinking that too much grease may lead to a problem. If excess grease was present ABOVE the "clutch dogs" it may prevent them from fully engaging and lead to a slipping problem. Just A thought.