The Fordson Tractor Pages Forum

I was scanning parts, and not knowing much about accessories, can someone tell me what the pto overrun clutch is used for?

Brian
They are used on tractors that do not have live drive.
When using an implement such as a topper, when you put the clutch in to say, stop at the end of the paddock, the momentum of the rotating topper will continue to drive the tractor forward even though the clutch in pushed in.
The over-run clutch attaches to the pto of the tractor. It is basically a ratchet that will drive in one direction but free-wheel in the other direction. (It is very unnerving when a topper pushes you into a gate or tree.)
The cost of an over-run clutch is worth very every dollar. Once you have one, you won't go back to not using one.
Kiwi Kev

Can anyone recommend a particular supplier/make for a Dexta?

Or are they all much the same?

I need to go topping!

thanks for info Kiwi Kev, what effect would it have on a sickle/fingerbar mower?

Brian
I don't see why there would be any problem with using an over-run clutch on a sickle bar mower.
Whether you would need one (as a sickle bar mower won't have the same inertia as a topper/flail mower/rotary hoe etc etc) is up to you, but using one on the sickle won't have any adverse effects.
You may need to shorten the implement drive shaft to allow for the length of the OR clutch, but as I've said, once you have used one, you won't want to not use one.
Kiwi Kev

Kiwi Kev wrote:Brian
I don't see why there would be any problem with using an over-run clutch on a sickle bar mower.
Whether you would need one (as a sickle bar mower won't have the same inertia as a topper/flail mower/rotary hoe etc etc) is up to you, but using one on the sickle won't have any adverse effects.
You may need to shorten the implement drive shaft to allow for the length of the OR clutch, but as I've said, once you have used one, you won't want to not use one.
Kiwi Kev

I believe some are easily removable and some can be fixed to the pto shaft with a roll pin.

Which type do you recommend?

I have one on my Teagle topper. It was an option when I bought the topper.

This one is integral to the PTO shaft so you would hardly know it was there to look at it and it works a treat!

It certainly makes tiopping a joy, It's not a nice feeling when you are heading towards a fence or gate and can't stop when you haven't got one !!!


I have been told to keep over-run clutches well greased up to extend their life.

Chris Ivin wrote:This one is integral to the PTO shaft so you would hardly know it was there to look at it and it works a treat!

Chris,
Is that integral with the tractor PTO shaft, or built into the shaft to the topper? So it's not something you bought separately?

They can be bought separately as an individual item.
They can be fitted to the tractor pto shaft spline, or to the topper gearbox input shaft spline.
They can be bought with a quick release style for ease of removal from pto spline or with a roll pin/bolt type of attachment method. They can even be part of the universal joint yoke of the actual drive shaft.
In Chris's case, his topper supplier value added an over run clutch onto the topper, which obviously has the over run clutch fitted to the topper.
If you only have 1 tractor and 1 pto driven implement, then it doesn't matter if it is fitted to the tractor end or the implement end. If you have 1 tractor and say 3 pto driven implements, then you may wish to have the over run clutch fitted to the tractor so it can be used with all the different implements (or just have 3 over run clutches)
Kiwi Kev

Kev,

Thanks for the clarification.

As usual quite a few choices!

As Kev speculated, my over-run clutch is built into the tractor end yoke of the implement PTO shaft. .http://www.malpasonline.co.uk/itm/Type- ... ih81I.dpbs
It suit me just fine as this is the only implement I really need an over-run clutch for.

I've taken my PTO shaft to my local ag mech who will fit one to the shaft.

Thanks for the help.