PTO overruning harmful?

[DiskDoctr]

I've always had an overrunning PTO clutch/coupler on my PTO's on all our farm tractors...forever. I put one on my 2004 3510 when it was new and now it is shot.

It wobbles way too much for my new-to-me brushhog (well used by PO), so I've removed it.

My local TSC didn't have one, so I ran it about 1/2 hour (first time) today without an overruning or slip clutch in the drive line. No problems, but I have a question.

This is a live PTO tractor, so I don't have to worry about the inertia of the brushhog blades pushing the tractor like our Ferguson, but I am worried that having the PTO disengaged (turned off) and the brushhog having momentum and forcing the PTO to turn.

Will it harm the PTO driveline or anything by not having an overrunning coupler and it turning the tractor's PTO at an initial high speed, then decreasing as it slows?

This BH does not have a slip clutch. I don't want to destroy it. We mow fields and stuff. I've had a previous mower stop dead as it hits a stump or gets tangled in multiflora rose or a hidden piece of barbed wire

So I am considering adding a slip clutch, but don't want both a slip clutch and overrun coupler in the same driveline. (This would be one of the addon slip clutches, not built into the drive shaft)

If they weren't so $$, I'd likely add a driveshaft with an in-built slip clutch and add the overrunning coupler, but I have to make a choice.

Thoughts and opinions?

Thanks!

- JC

 

[Mark @ Everlast]

As long as the brush cutter is properly sized for the tractor, your pto should suffer no harm. The overunning clutch is only for "dead" pto tractors. Absolutely no need for an overunning clutch on a live pto tractor.

But to keep a overunning clutch in top notch shape, it should be greased and serviced every 5-8 hours of operation.

A slip clutch isn't necessary if the cutter isn't equipped with one, as long as the proper grade shear bolt is always used...depending upon the model, it is usually a grade 2 bolt with no marks on the head. A few cutters specify a grade 5, but its pushing it in my opinion