PTO DRIVESHAFT and slip Clutch questions / advice needed

[hunter townsen]

I have been operating equipment for 30 years, but never professionally. I have been hiring out part time for a few years. I plan on making this full time. I don't have a lot of $$$$ to invest, so I have been gathering used attachments for years and repairing and/or modifying for my needs , plows discs tiller mowers etc. my issue has been with pto shafts, everything is shear pin. After researching , I am definitely going to clutch style. The issues have been from yokes bending from tree roots to u joints snapping, for many various reasons I aware of. The soil conditions in my area from clean to basketball sized rocks , (my solution for that has been to plow, disc , heavy rake , light rake , have homeowner assist in removing rocks, then roto till. In other words I have a handle on my situation , at least I believe , but I am very open minded , so any suggestions are appreciated . Any way I have made the decision to replace all of my pto shafts with new. I see on ebay all ranges of prices, I don't mind spending money for good equipment when necessary. I would like suggestions on this forums opinions of the best bang for the buck pto shafts, and or clutches. As many of you know high price doesn't always mean high quality. Thank you for all opinions and suggestions , btw I am running a 4600 JD, 43 HP 35 HP PTO RATING

Rob

 

[Poopdeck Pappy]

If the PTO shafts are not damaged, why not just buy a slip clutch to replace the shear pin assembly. Something like this for example:

Weasler Universal Friction Clutch, 1-3/8 in., 6 Spline Both Ends - Tractor Supply Co.

 

[hunter townsen]

My issue is that I live so far out it costs me 30 bucks in fuel to go to the nearest napa, god forbid I have to go to portland . I do plan on keeping my old shafts and buy a slip clutch. But I will use the only for back ups. Tbh I am tired of messing with the old shafts, I also suspect they are fatigued. I have twisted a yoke with a proper shear pin installed, yoke gave b4 the pin. As I plan to eventually do this full time, break downs get expensive, especially in the area I live.
Ty for your reply

 

[cruz54982]

This is just a note regarding slip clutches - make sure you loosen them and slip them after they sit for longer periods or the repairs will be much higher than the cost of sheer bolts as the clutches tend to stick after sitting . good luck !

 

[Dave M7040]

I want to provide you with another aspect of pto shaft life that many owners dont consider.
The chart I am providing applies to one specific set of circumstances but relatively speaking you can draw conclusions about many other operating situations.
The shafts have a finite life. In other words they will not run forever before they fail. The greater the angle they run at the shorter the life.
Components like the yokes and joints are subjected to high fatigue loads and these cyclic loads create cracks in the parts that you will not see with the naked eye.

Adding a slip clutch to your pto may increase the angle the shaft runs at and shorten the shaft's life.

Dave M7040

 

[oosik]

Dave M7040 - - My Kubota dealer told me to keep the pto shaft angle as close to zero as possible to extend the life. He didn't have the nice charts and figures you show there.

That is why, rather than sitting my Wally BX62S chipper flat on the ground, I've made a heavy duty stand that it sits on and the pto shaft angle is zero.

Who knows how much longer it will extend the shaft life - - I saw a pto yoke fail on a commercial auger rig and send the broken yoke over 100 feet away and right thru the side of a brand new Cadillac. Fortunately, no body was hurt but there were sure a lot of under ware changes made that morning.

 

[kebo]

If the PTO shafts are not damaged, why not just buy a slip clutch to replace the shear pin assembly. Something like this for example:

Weasler Universal Friction Clutch, 1-3/8 in., 6 Spline Both Ends - Tractor Supply Co.

Let's think this over some....

You can't just simply add a slip clutch to a PTO shaft used on a gearbox that is set up for a shear bolt. Gearboxes that are set up for a shear bolt protection have smooth input shafts (meaning no splines), while gear boxes set up for a slip clutch have splines on its input shaft. A slip clutch has six splines on BOTH ENDS, which is how the slipclutch you linked is made. At least, that's how I've always seen them.

Now maybe the OP was thinking he could put the slip clutch on the opposite end, where it attaches to the PTO output shaft on the tractor? In that case, you would have a slip clutch on one end of the PTO shaft, but you would still have the same old shear bolt on the other end where it attaches to the gear box of the implement. What do you gain by doing it that way??

Or did I misread this and I'm confused here???

 

[geneP]

I have a slip clutch that is attached to the gearbox with a shear pin and have never broken the pin. I suspect I have the clutch adjusted to slip before the pin is shocked. If the blades hit something briefly I never know it slips, but if it gets hung on a root, stump, etc, the clutch slips until I lift the cutter up.

 

[Fallon]

Just upgrade from a grade 5 sheer bolt to a grade 8. That way the new clutch should be the weak link.

Bad idea if you aren't adding a clutch though.

 

[hunter townsen]

I am aware and conscientious of driveline agles and the wear issues, being my equipment was used , idk of the previous owners. I do inspect them regularly. all off my equipment but my ph auger do not have shear pins at the gear boxes. my pto shafts have a split yoke, with a bearing in the middle and a flate plate where a 5/16 grade 3 bolt goes. I plan on buying a slip clutch for each piece of equipment. ty for all your advice, and I will put the chart to use