Pros and cons of using an over run clutch/coupler on pto??

[5030]

Modern tractors with PTO brakes don’t give you the option of not destroying internal parts when you turn off the PTO…unless you buy aftermarket additions.
That should be totally unacceptable.

Sadly, that is the way it is. An over running coupler isn't all that expensive anyway and mist of my driven implements have one built into the driveline anyway. Only ones that don't are the bat wing and the 3 point shredder.

 

[jjeff]

Don't much care for that style (I believe it's a Weasler)... I prefer the the over the stub shaft lock on style with external grease fittings. Whatever you do, don't allow the cutter to freewheel the stub shaft (no over run coupler installed) because it will eat up the internal PTO brake. Reduce the PTO rpm gradually, don't just disengage the PTO at rated speed. which is something I do even with the over run coupler installed.

O never want to replace the driven pack or the brake plates. Both require a split and dissection of the gearbox.

Once the internal brake is shot, the PTO stub will rotate constantly whether the PTO is engaged or not. That occurs from the parasitic motion imparted to the PTO wet clutch.

Kubota designed the PTO brake to have a 1/4 rotational free turn to allow you to engage a driven implement easier.

Notice I have a replacement next to the one I jacked up probably install it tomorrow and yes unfortunately the pto brake on my old 4150 has long been worn to non working status. Surprisingly when the coupler is attached it does not freewheel with or without anything hooked up to it I'm pretty sure eventually I'll have to split that old tractor for various reasons it's now pushing 5k hrs, When the time comes I'm looking at it as another learning experience .

 

[JWR]

Yes, that’s a lesson that has come as a surprise for many, but once known, you can predict and control the outcome of turning off the PTO, or pushing in the clutch, without damage.
Modern tractors with PTO brakes don’t give you the option of not destroying internal parts when you turn off the PTO…unless you buy aftermarket additions.
That should be totally unacceptable.

I do not understand this conversation -- I use a MF 2660 which is a 2011 model & I would not call it ancient. Seems reasonably "modern" to me. There is no PTO brake to my knowledge and I have no idea why anyone would want one nor consider themselves 'modern' if they have one. So long as the PTO free-wheels when you take it out of gear and runs under power when engaged what else matters ? Why ? All tractors I have seen/driven since around 1970 work that way. The need for these "overrunning clutches" or shaft devices is that they allow the flywheel effect of attachments such as a bush hog to take place safely, not shove the tractor forward and not rip apart the PTO gears on the tractor if it is old and unprotected. I tore up a PTO gearbox on an old 1954 Massey Harris once using a bush hog and failed to realize the old MH PTO does not freewheel. What other issues are there?

 

[DK35vince]

I do not understand this conversation -- I use a MF 2660 which is a 2011 model & I would not call it ancient. Seems reasonably "modern" to me. There is no PTO brake to my knowledge and I have no idea why anyone would want one nor consider themselves 'modern' if they have one. So long as the PTO free-wheels when you take it out of gear and runs under power when engaged what else matters ? Why ? All tractors I have seen/driven since around 1970 work that way. The need for these "overrunning clutches" or shaft devices is that they allow the flywheel effect of attachments such as a bush hog to take place safely, not shove the tractor forward and not rip apart the PTO gears on the tractor if it is old and unprotected. I tore up a PTO gearbox on an old 1954 Massey Harris once using a bush hog and failed to realize the old MH PTO does not freewheel. What other issues are there?

Independant PTO have a clutch pack within the transmission.
Hydraulic Fluid running between the clutch plates can be enough to cause the PTO to turn without a PTO brake even with the PTO turned off.
That is why many/most independent PTO have a clutch brake
I have an overrun clutch on my tractor to save on that brake

 

[JWR]

Independant PTO have a clutch pack within the transmission.
Hydraulic Fluid running between the clutch plates can be enough to cause the PTO to turn without a PTO brake even with the PTO turned off.
That is why many/most independent PTO have a clutch brake
I have an overrun clutch on my tractor to save on that brake

I guess you know more about it than I do but I have never seen my PTO persist in turning after I put it out of gear (other than when some flywheel is involved like a bush hog) nor seen it suddenly stop turning when I put it out of gear (which would be evidence of a PTO brake.) So far, I conclude that whatever is going on is just fine with me and since I only put about 100hrs on it a year it will very likely outlast me anyway. Can't get excited about it.

 

[loggin]

I guess you know more about it than I do but I have never seen my PTO persist in turning after I put it out of gear (other than when some flywheel is involved like a bush hog) nor seen it suddenly stop turning when I put it out of gear (which would be evidence of a PTO brake.) So far, I conclude that whatever is going on is just fine with me and since I only put about 100hrs on it a year it will very likely outlast me anyway. Can't get excited about it.

I realize it's not your model of tractor exactly but here is a video that explains the hydraulic pto clutch engagement a little.

 

[loggin]

I found an overrun coupler here locally and will post some pictures when I have a chance.

 

[5030]

Kubota's are notorious for weak PTO clutch brakes, some models are worse than others. My M9's are among the worst. Just 2 plates for the PTO brake.

Always cognizant of that.

 

[jjeff]

Kubota's are notorious for weak PTO clutch brakes, some models are worse than others. My M9's are among the worst. Just 2 plates for the PTO brake.

Always cognizant of that.

I believe the L series of the 80s and early 90s aren't the most durable either in my experience my old 2850 had one previously installed not knowing much about them I almost removed it fortunately read up on them and left it. Pto brake still works on that old tractor I used that tractor for chopping and chipping before my 4150. so they do work to preserve the functionality of the pto brake like 5030 and other members say.

 

[loggin]

Here is a photo of the one I picked up. Supposed to be good for up to 70 hp. Have not had a chance to use and test it yet since mowing season is over in this neck of the woods. Hope it serves me well and does the trick.