Shear pin misery... only thing left is adding a slip clutch?

[ruffdog]

The location of the pto clutch makes it a bit hard to repair and that is the reason we treat it with care.

 

[JRobyn]

Dad, I believe that your instincts that the manufacturer supplied the WRONG shaft are absolutely correct. Gentle starting at idle may work sufficiently to keep things going in the short term, but if I were in your shoes, I would be aggressively pursuing a heavier replacement (correct) shaft from the manufacturer. As a warranty replacement on their nickle. Even if does come by slow boat!

 

[PILOON]

Being an import the shear bolt is for sure metric.
Be sure you have the correct fit and again I would suggest a grade 5 or even a bit higher.
Graded will shear clean while soft will stretch and fail all too easily.
Added to what all has been said engagement at low RPM's will lessen the shock loading.

 

[mapper]

I might add that I not only start implements turning at an idle I also let the clutch out slow, there is a lot of mass that has to get moving back there.
Side note, my operators manual very clearly states that you always engage the pto at an idle!

 

[kthompson]

Not knowing the tractor you have, how does the pto engage? Do you engage it manually with foot clutch or hand control lever or is it electrical engagement where it engages in a shock fashion. IF you engage it manually, can you not rev the tractor up to rpm speed and slowly engage manually so there is no shock to the system. The other quesion is your tractor does not have a 1,000 rpm and the cutter is 540 do you? The pto shafts should prevent you this happening due to difference in groves.

I am with others here who say never engage at full pto rpm.

 

[rustyshakelford]

I might add that I not only start implements turning at an idle I also let the clutch out slow, there is a lot of mass that has to get moving back there.
Side note, my operators manual very clearly states that you always engage the pto at an idle!

Not knowing the tractor you have, how does the pto engage? Do you engage it manually with foot clutch or hand control lever or is it electrical engagement where it engages in a shock fashion. IF you engage it manually, can you not rev the tractor up to rpm speed and slowly engage manually so there is no shock to the system. The other quesion is your tractor does not have a 1,000 rpm and the cutter is 540 do you? The pto shafts should prevent you this happening due to difference in groves.

I am with others here who say never engage at full pto rpm.

He's running a 5100e Deere. It's a knob you pull up so no feathering to engage the pto. Have to rely in the pto clutch. They are 540/540ePTO so no 1000 confusion

I think he's got great info and hopefully will be problem free

Brett

 

[CincyFlyer]

Have you checked the gearbox for overfilling? You can build up some serious pressure when it's spinning up that you won't notice turning it by hand.

 

[Texasmark]

Being an import the shear bolt is for sure metric.
Be sure you have the correct fit and again I would suggest a grade 5 or even a bit higher.
Graded will shear clean while soft will stretch and fail all too easily.
Added to what all has been said engagement at low RPM's will lessen the shock loading.

My experience is that the higher grade is brittle and snaps whereby the non graded (grade 2) can survive a whack with slight distortion, aka cutting partially through the bolt allowing for several moderate whacks before breaking. Other thing I noticed was that it was easier to find a lower grade remnants in the shaft since it does smear and leave some material visible beyond the hole to help in locating.

Also my experience has been to use a locking nut and not to run it all the way down. Leaving some slop seems to help in bolt shank integrity.

10-4 on the idle start up and slow rpm advancement.

To each his own. We work through our tasks with what works for us under our sets of conditions. What works for me may not work for you and vise versa.

 

[Farmer495]

I think it's a combination of tractor engagement versus RPM

Have a 4x4 NH round baler, it uses a TINY approx 5/16" shear pin. Running it on 42 PTO HP tractor, engage at idle with IPTO (hyd lever feathering) no way could I start the baler turning with a bale in the chamber without the shear pin breaking. Run it now on a 64 PTO HP tractor,engage at idle with IPTO and hyd lever feathering, I can easily start the baler turning with a full bale...never break a shear pin. Same operator, same baler, same tiny shear pin, different tractor with SAME PTO engagement style.

I NEVER engage PTO at anything above idle/slightly over idle, and this in in real world in a farming environment trying to beat weather. Broken equipment makes no hay.