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pto slip clutch

Posted: Thu Sep 09, 2010 2:42 pm
by Gman
Hello to all. I'm looking to buy a pto slip clutch to use with my bush hog in order to protect the pto system. I was under the impression that the slip clutch would be mounted on the pto shaft on the tractor but reading on other sites it is stated the slip clutch should be mounted on the bush hog. Would like to know what is correct. Thanks for all advice.

Posted: Thu Sep 09, 2010 4:38 pm
by super6954
Hi all of the slip clutches I have seen are on the implement end of the shaft . I guess it is done so you dont screw the pto shaft off with torque when the mower jams, Also they are big and heavy so being nearer the gearbox will carry the weight better than the tractor pto . Most of the pto's i have seen with shear pins are at the tractor end but have seen 1 with it on machine end. Are you sure that your mower does not have a shear pin in somewhere. the one I use has a pin instead of a slip cluth :wink: .
Regards Robert

Posted: Thu Sep 09, 2010 5:11 pm
by Gman
Thanks Robert: I have an old bush hog and it does have a key with a set screw where the drive attaches to the gear box. When I bought the tractor 25 years ago the previous owner told me he was always breaking shear pins in his bush hog (not the same bush hog I have). I have once stalled the tractor out with the bush hog and then one time the bush hog split the tube part of the drive shaft betweeen tractor and bush hog when it grounded out, it did not shear the key, I guess lucky I didn't tear up pto gear box. It was not easy getting the drive shaft off of the gear box end, had to use heat and a big hammer. Again thanks for your advice, glad I have not bought one because the ones I have looked at are for spline connection and the gear box end of drive shaft is smooth.

Posted: Fri Sep 10, 2010 5:30 am
by super6954
I think this topic may be getting a little away from the fordson page and is nearer the implement topic. maybe we should not be suprised if the great ones move it for us :wink: .
I guess you where lucky that the shaft was a week link in the drive the bearings went out on ours. I caught it in time $150 of bearings and seals later i fixed it. The gearboxes are near a $1000 up here in Canada :cry: .
Im guessing that to buy a complete new shaft and clutch is going to be expensive. Could you find a company that maybe sells the clutch and use some your shaft to upgrade. or buy one with just the shear pin :wink: . The other guy may of had worn components in his shaft and that will cause bolts to break. ours did it until I re bushed it and drilled new holes for the shear pin and its about ready to be done again after 10 years of abuse on the farm .
I think i would rather replace a $ bolt and nut once in a while yeah it may happen once or twice but its better than the other option of stuffing your Mower or tractor. That screw and key will not act as a shear point it is just to stop the coupling turning on the shaft and keep it all locked together.
Regards Robert

Posted: Fri Sep 10, 2010 12:43 pm
by Dandy Dave
I have had my share of bush hogs, toppers, brush mowers, though the years. The last was a 4 foot Bush Hog squealer model. The shear pin was on the PTO gear box end but the FPM had too much power for the unit and would shear the pin in an instant. A slip clutch assembly was available for the unit for around $120 US from my local dealer to replace the share pin problem. I now have a Woods 184 MD which has a slip clutch and is better matched to the FPM. Dandy Dave!

Posted: Fri Sep 10, 2010 1:58 pm
by Gman
Thanks Robert and Dave: I have repaired the bush hog drive shaft using stainless steel tube so do not think this part will break again but besides the key I don't think there is a shear pin anywhere. I put a raised pto on not long ago and do not want it or any part of pto system broken so I am back to looking for slip clutch I guess. Glad I learned it attaches to bush hog and not to pto shaft on tractor.Thanks again.