Overrunning PTO Coupler

I have a Farmall H that I am going to be using a 5' pull behind rotory mower. "No live PTO".... Is it a wise thing to get a overrunning pto coupler for this tractor. I don't need to tear the transmission out with a mower deck if I hit something like a rock of big limb on the ground.

Just wondering your thoughts on this

Thanks
Steve

The overunning PTO coupler is to prevent the blades from pushing the tractor after you push in the clutch. Damage to the mower or PTO is prevented by a shear pin.

We learned rite off to either kick the pto out of gear or kick the tranny into neutral as we didnt have the over running pto thingys.

i use an i-h model 27 rotary mower behind my h, it does not have an over running coupler. no problems, just anticipate when getting in to a tight spot, idle down and push the clutch in. maybe some day i will spring for an orc for that tractor.

An overrun coupler isn't going to do too much if you hit something with the mower. That's not what they're for.

The purpose for it is that if you don't have live pto - if you were to push and hold the clutch in on your tractor, you'd obviously not be driven forward by the engine. But if you were to grab the pto output shaft and start turning it - that would drive the transmission just as if the engine were turning it. Meaning you would move forward.

When you're running equipment that has some flywheel effect, like a mower, the blades keep spinning when you push the clutch on your tractor - say to stop.

With the blades spinning, the pto shaft is spinning - which means the momentum of the mower blades is now powering you forward as if you never pushed the clutch in.

Granted, the effect doesn't last too long as the momentum is quickly used up, but when you're expecting to stop,and you keep rolling, it can get real dangerous real fast. Especially if you're stopping for an emergency - like a dog runs in front of you.

So I'd say yes, for a rotary mower I'd use an overrun coupler. For something like a sickle bar mower, they don't have much momentum, so an overrun coupler isn't needed.

You can find fairly inexpensive ones that would be cheap insurance.

To possibly avoid damage to the mower, you will need a slip clutch. To avoid the mower from pushing the tractor into a tree or fence etc... you need an overrun. The mower does not have a slip clutch on it? overrun coupler is a MUST without live pto IMHO

I would highly suggest investing in over running clutch.

When growing up,had neighbor that was mowing with tractor WITHOUT overrunning clutch. He got in a tight spot and ended up getting pushed into some brush and rolling over the tractor. He was pinned under the tractor and died from the rollover and fire from the gas tank leaking.

Less than fantastic brakes and inertia from the mower"s drive line driving the transmission could be a dangerous combination.

BMD

I agree. An over-running clutch is cheap insurance against getting into trouble. I found that even a 4' mower can push a tractor (a Deere M in my case) with surprising force and a 5-footer would be even worse. It makes back and forth work a lot easier too since the mower never has to stop turning when shifting. Needless to say an ORC was added shortly after I got the mower.

Check first to see if your mower has an over-running clutch built in. If it does not have one, the $50 for one at a farm store is a good investment.

Looks as if I will be out tomorrow trying to find one. I want to be safe and you guys have answered my questions.

With great respect I thank you all

Steve

Works great. Well worth the money. Be sure and check them out some aren"t very strong. I have on that has warped bad and hasn"t been used a lot.
Store where I bought it has changed styles and they seem a lot stronger.

Sounds VERY familiar. We did the same for years.
Disengaging the clutch,
pulling back on the throttle,
shifting the gear shift lever into neutral,
and applying the brakes
was all done simultaneously when stopping was called for. My father made sure we mastered this technique ;-)

If you're inexperienced at using a tractor without LPTO I would defenitely recomend using one as you can get into trouble in a hurry without one. If you are an experienced operator I'd still recomend using one. Just speaking as someone who grew up back before most tractors had LPTO.

(quoted from post at 08:08:20 07/28/11) Sounds VERY familiar. We did the same for years.
Disengaging the clutch,
pulling back on the throttle,
shifting the gear shift lever into neutral,
and applying the brakes
was all done simultaneously when stopping was called for. My father made sure we mastered this technique ;-)

Click to expand...

Problem with that is with something unexpected happening, like hitting a yellow jacket nest, getting stung by many angry critters and trying to stop all at the same time. Or getting swatted in the face with a tree branch that knocks yer glasses off! You instinctively go for the clutch and brake but with the location on some in not most of the older tractors of the PTO control could be a problem. I have 2 tractors that could have a better (easyer to reach quickly) location for the PTO lever, my M and my Ford 8N. Get an ORC!

Rick

One thing to keep in mind is that you might have to shorten your mower's driveline when you add the ORC; I had to trim several inches off of mine. You sure don't want the telescoping shaft to bottom out when the back of the mower rides up over a berm. On the other hand, don't trim off more than what is necessary or you could have insufficient overlap when it gets fully extended. You'll just have to take a look at your setup to see what (if anything) needs to be done.

I bought an 8n ford one time that had the pto bearing housing broken to pieces by a driveline being too long after the po installed an orc.

Rick. You are right in saying get an ORC. It is more fail safe than the operator-under-stress.
Two notes:
1) We cannot adjust history. I saw the first ORC long after live PTO was introduced, in other words, the ORC's introduction came at a time it was not so important anymore.
2) To avoid being pushed forward by the mower's inertia after disengaging the clutch, it is sufficient to either shift the transmission into neutral or to shift the PTO control into neutral. I agree that not all PTO levers are "ergonomically positioned" but transmission shift levers are.
Thanks, Hendrik