PTO shaft slip clutch??

Just bought a bush hog and the PTO shaft has a slip type clutch at the gear box. Never had anything with this set up. Is there any adjustment, has bolts around it with springs. I'm guessing it should still be attached with a shear bolt.

Hi Eman85

Slip clutch should have all bolts tightened the same count threads or measure as you can. In theory these should be checked to see they will slip each season (loosen then retention to correct setting) yes I don't generally do that. I am coming at this more from hay equipment but concepts are the same. You will know when it slips as they really scream. For my baler the slip clutch should be just warm after use. The big thing is you won't it to slip or shear the bolt instead of damaging other parts like tractor PTO shafts etc. Clutch plates can be replaced as they wear.

Or with a bush hog, to stop it's inertia to keep pushing you on, into something, after you have stepped on the clutch to stop from hitting what ever.

Pat

(quoted from post at 06:32:05 10/11/18)
Or with a bush hog, to stop it's inertia to keep pushing you on, into something, after you have stepped on the clutch to stop from hitting what ever.

Pat

Click to expand...

No, a slip clutch is not designed to do that. You are thinking of an Over Running Clutch (ORC) which is completely different from a slip clutch. A slip clutch slips when the resistance at the implement becomes higher than a certain amount. An ORC is a ratchet that will never slip in the normal power deliver rotational direction and only slips when the implement tries to impart its energy back into the tractor in the opposite rotational direction.

Assuming your spring tension is set correctly, per manual instructions, measure the distance from the end of the threaded shaft to the surface of the
nut holding pressure against the spring (which amounts to counting the threads but easier).

Disassemble the clutch and clean up the surfaces, or if it appears that there may not be very much rust, back off the pressure on the springs maybe 10
full turns of the nut. Connect the mower and go out and attempt to mow tall grass forcing the clutch to slip and let it do that for a time so as to grind
off the rust that developed on the steel plates which would impede proper operation. Once cleaned up put the 10 turns (or however many you undid)
back and go back out and mow with it.

Obviously if you did the full disassembly, just put it back where it was.

On either if it slips under heavy "legitimate" loads, not whacks, (due to springs getting weak over time) then tighten them until it just quits slipping.

(quoted from post at 08:42:58 10/11/18) Assuming your spring tension is set correctly, per manual instructions, measure the distance from the end of the threaded shaft to the surface of the
nut holding pressure against the spring (which amounts to counting the threads but easier).

Disassemble the clutch and clean up the surfaces, or if it appears that there may not be very much rust, back off the pressure on the springs maybe 10
full turns of the nut. Connect the mower and go out and attempt to mow tall grass forcing the clutch to slip and let it do that for a time so as to grind
off the rust that developed on the steel plates which would impede proper operation. Once cleaned up put the 10 turns (or however many you undid)
back and go back out and mow with it.

Obviously if you did the full disassembly, just put it back where it was.

On either if it slips under heavy "legitimate" loads, not whacks, (due to springs getting weak over time) then tighten them until it just quits slipping.

Click to expand...

Factory recommendations.... BUT.. what I find is... that if I back off the nuts, spin the shaft, so make sure the plates are loose and then tighten the nuts per the factory instructions, the slip clutch then will continue to spin and burn up the clutch plates. I tighten them more and they still slip... Tighten them more and they still slip under normal use. Till there is no plate material left... Yes, the plates probably needed replacing anyway, but after this happening twice now, I have STOPPED this procedure and just operate the cutter as normal. SO>>>>> make your own decision and live with the results. At the ranch where we are clearing heavy brush, I have to replace a shaft about one a year due to twisting... At the farm and the home property, I never have a problem but again, I stay out of rocks and stumps at the second two properties. But again, every time I loosen the clutch and then tighten it, I have had very bad results and the clutch failed on implements that had been working fine. Horsepower of the tractor also has a lot to do with the results. ymmv.

I fully understand an overrun clutch as I have an 8N with one on it.
I fully understand mowing rocks and debris, could be why I needed another bush hog? I keep a supply of shear bolts as old bush hog would shear them regularly.
With this slip clutch I'm thinking it might not be a bad idea to use a shear bolt to attach it to the gear box for insurance until I figure out the adjustment.
I've pulled my old one, 5ft. King Kutter, with the 8N but now use a 2600 diesel.

Your right, I was thinking of a over run clutch.

Pat

I just found info on setting the clutch up, don't know if it's correct. I found a few sources that said to back all of the nuts off and then tighten until they contact the spring. Then tighten 1 1/2 turns past initial contact/

Nothing wrong with that info. Just if it slips in heavy material, just keep cranking till it stops slipping. If I had any implements with the clutch, which I
avoid when purchasing, the first thing I would do every season is what I said below and I would store it in a shed during the season. Otherwise I
wouldn't trust it to save my drivetrain at the second of need.