Over Running Couplers

[AlanB]

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 )</font>

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]

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]

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]

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

 

[Soundguy]

</font><font color="blue" class="small">( 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.
)</font>

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]

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]

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]

</font><font color="blueclass=small">( 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?
)</font>

No need to be rude to have a simple conversation.

</font><font color="blueclass=small">( 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 )</font>

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.

</font><font color="blueclass=small">( 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 )</font>

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

</font><font color="blueclass=small">( how did his ORC (Almost) twist in half? It should have been upstream from an Slip clutch or shear bolt? )</font>

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]

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]

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.