Downside to PTO overrun coupler?

[JCCinOhio]

Other than maybe having to shorten the PTO shaft, and the safety concern of the implement drifting to a stop are there any other negatives to using an overrun coupler?

Would be on a JD2305 sub-compact. I'd like to put as little stress on my tractor tranny as possible, and the rotary cutter I just got makes a big THUMP when turned off. Any reason I shouldn't go with an overrun coupler?

Thanks

 

[Jerry/MT]

Other than maybe having to shorten the PTO shaft, and the safety concern of the implement drifting to a stop are there any other negatives to using an overrun coupler?

Would be on a JD2305 sub-compact. I'd like to put as little stress on my tractor tranny as possible, and the rotary cutter I just got makes a big THUMP when turned off. Any reason I shouldn't go with an overrun coupler?

Thanks

That big thump may be caused by the internal clutch on the pto shaft stopping the shaft and causing the rotary cutter blades to fold under the stump jumper.

I use an over-running clutch on my tractor when I have a rotary cutter on it and have for 10 years. I do it to save wear and tear on the pto clutch mechanism that's buried in the tranny/rear axle housing so I won't have to do a repair on it. I can see no down side to using it to protect the pto clutch.

 

[California]

Other than maybe having to shorten the PTO shaft, ..

A quick hitch moves the implement back. This may be a way to avoid shortening the driveline.

The overrun coupler adds significant safety. Highly recommended.

The only downside I can think of, and its harmless, is the units built integrally inside the US-version YM Yanmars is noisy, probably alarming to anyone nearby as the mower winds down. Sounds like nasty gear grinding. I generally reach down and disengage the PTO lever to make the racket cease.

 

[JCCinOhio]

That big thump may be caused by the internal clutch on the pto shaft stopping the shaft and causing the rotary cutter blades to fold under the stump jumper.

Yes, I believe it's partly that.. and partly that there is about 5-10 degrees of slop in the bolt hole that holds the slip clutch onto the gear box input shaft. Not sure if that is designed that way or if it's because I bought a used rotary cutter. But that also rotates that extra 5-10 degrees when the PTO is cut off and then abruptly stops.

 

[ovrszd]

I always idle the engine before disengaging PTO. Even when using the MMM on my JD2210.

 

[LouNY]

Other than maybe having to shorten the PTO shaft, and the safety concern of the implement drifting to a stop are there any other negatives to using an overrun coupler?

Would be on a JD2305 sub-compact. I'd like to put as little stress on my tractor tranny as possible, and the rotary cutter I just got makes a big THUMP when turned off. Any reason I shouldn't go with an overrun coupler?

Thanks

Nope, No reasons not to use one.

There are people that will say you shouldn't as your implement will not rapidly stop turning.
So it would be possible to shut off the pto get off the tractor and get back and stick your arm or a foot
up into a rotating implement.
I can attest to the impatience of people that have plugged up a cutting unit, or broken a shear bolt.
Being in a hurry to get it replaced and get back to work, it can seem like a long time for some high inertia
items to stop rotating.
Those people that don't wait usually don't do the same boneheaded mistake again. But they are also
the reasons for seat interlocks and lawn mowers having blade brakes.

 

[ovrszd]

Nope, No reasons not to use one.

There are people that will say you shouldn't as your implement will not rapidly stop turning.
So it would be possible to shut off the pto get off the tractor and get back and stick your arm or a foot
up into a rotating implement.
I can attest to the impatience of people that have plugged up a cutting unit, or broken a shear bolt.
Being in a hurry to get it replaced and get back to work, it can seem like a long time for some high inertia
items to stop rotating.
Those people that don't wait usually don't do the same boneheaded mistake again. But they are also
the reasons for seat interlocks and lawn mowers having blade brakes.

Even throttling down to idle before disengaging the PTO on my Kubota doesn't cause my 15ft batwing to stop turning quickly. It's easy for me to get off the tractor and approach the cutter when it's still spinning.

I not only respect a spinning PTO shaft, I fear it. I mentally promote that fear. Improves my odds of not hurting myself thru neglect.

 

[LouNY]

I also have a very healthy respect for PTO shafts.

I can't count the number of times I've stood and waited the several seconds (which seem like minutes) for all motion
to stop before replacing a shear bolt on a forage chopper and similar implements. All the while knowing that you are the one holding
up the operation.

Or the immense fun of standing between two tractors with running PTO's one on a self unloading wagon to operate the
controls for the beaters the feed conveyor (discharge) and the apron speed, with the other tractor on a forage blower at full pto speed
to blow the silage up in the silo. Then all of a sudden a big slug gets by you into the blower and the blower tractor starts bogging down and you know it's going to plug the blower pipe before you can clutch the blower table or stop the pto on the blower so it's not packed tighter then heck for 20-70 feet of pipe, which is going to take an hour to unplug which means shutting the whole operation down, two to four more men and tractors.
Talk about working in close proximity to potential hazardous conditions, and having to maintain safe operation.

 

[ovrszd]

I also have a very healthy respect for PTO shafts.

I can't count the number of times I've stood and waited the several seconds (which seem like minutes) for all motion
to stop before replacing a shear bolt on a forage chopper and similar implements. All the while knowing that you are the one holding
up the operation.

Or the immense fun of standing between two tractors with running PTO's one on a self unloading wagon to operate the
controls for the beaters the feed conveyor (discharge) and the apron speed, with the other tractor on a forage blower at full pto speed
to blow the silage up in the silo. Then all of a sudden a big slug gets by you into the blower and the blower tractor starts bogging down and you know it's going to plug the blower pipe before you can clutch the blower table or stop the pto on the blower so it's not packed tighter then heck for 20-70 feet of pipe, which is going to take an hour to unplug which means shutting the whole operation down, two to four more men and tractors.
Talk about working in close proximity to potential hazardous conditions, and having to maintain safe operation.

The older I get the more nervous I become in situations like you described. And a sileage operation is seasonal. Not something you do every day. So when you start this Fall you have to relearn and reinforce your internal warnings about the danger you are in. If one of those spinning PTO shafts get ahold of you it'll beat you to death in a couple seconds and the tractor won't even change rpms.......

 

[airbiscuit]

The older I get the more nervous I become in situations like you described. And a sileage operation is seasonal. Not something you do every day. So when you start this Fall you have to relearn and reinforce your internal warnings about the danger you are in. If one of those spinning PTO shafts get ahold of you it'll beat you to death in a couple seconds and the tractor won't even change rpms.......

Our neighbor was combining, and somehow his shirtsleeve got caught in the PTO. It ripped every bit of his clothing off. He was naked as a newborn and black and blue from head to foot. He was very lucky. You usually don't get a second chance with a PTO encounter.

He had a Cockshutt tractor, and I swear that was the smoothest running tractor I ever saw.