More M59 repair fun.

  
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Hersheyfarm

Hersheyfarm

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I agree with you that the engineers really took weight saving into account with this machine. For me it would be hard to go back full size working in a mostly residential environment...but....

My machine is a 2008, and I have had it almost 6 years I think and put 720 hours on it. I'm not sure what the next 720hr will be like and that is starting to worry me. So, patch and go for now.
 
  
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Hersheyfarm

Hersheyfarm

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image.jpeg

New pin and beat back into place. Had to grind and smooth things out before I painted. No cracks in weld or metal and that's what I was afraid of so that's good.Just waiting on my steel hydro line, which must be made of gold..
 
   #13  

Gator6x4

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View attachment 463621

New pin and beat back into place. Had to grind and smooth things out before I painted. No cracks in weld or metal and that's what I was afraid of so that's good.Just waiting on my steel hydro line, which must be made of gold..

Have the hydro pumps been tweaked?
 
   #15  

5030

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That has nothing to do with hydraulic pressure. If the system was set over spec or a relief valve stuck, it would pop a seal on a cylinder (the weakest one first). For kicks and grins, I set off the loader on the M9, no easy task, the big tractors and big loaders aren't easy to separate, and checked my pins with everything depressurized. My pins are pristine at 3000 hours on the loader. Some burnishing but thats it. But then my units are 10 years old so the steel I'm sure is different.

I thought abbout taking the loader off the 105 too, but I run a set of auxillary lines on the 105 that operate a hay accumulator so it's even more of a PITA.

Little CUTS and Sub Cuts are easy to pull loaders compared with the big units, but I wanted to look. No issues with mine.

Gave me a chance to clean out the old accumulated grease and ruin some old shop towels too.
 
   #16  

mike69440

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1984 Kubota B7200D (Sold 2015,) 2005 L39 Kubota, 2006 RTV 900 1997 Komatsu PC75UU2E w/ Thumb & Blade, 2013 Mahindra Max28XL Shuttle
Tweeked? No they were both replaced at 70hr under warranty because they imploded. The relief valves are set to stock standards.

I have been runing my main Pump/ loader on my L39 for years at 2900 PSI, there abouts. Spec is 2770 PSI. Does not load the motor down much more than factory setting and Pumps are nice and quiet with 2000 hrs on the tractor. These pins, even weaked by a grease hole, should not be snapping.

I have not played with my BH pressures.
 
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   #17  

5030

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I wasn't aware they had 2 pumps. I thought mine had one pump for everything but mine are gear drive / hydraulic shuttle units. Never had a reason to investigate because nothing breaks. My M series do hold a lot of fluid. A full change is 15 gallons. Needs a BIG change pan. I use a cut in half truck diesel fuel tank. Needs a big wallet too. Super UDT ain't cheap.
 
   #18  

SPYDERLK

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That has nothing to do with hydraulic pressure. If the system was set over spec or a relief valve stuck, it would pop a seal on a cylinder (the weakest one first). For kicks and grins, I set off the loader on the M9, no easy task, the big tractors and big loaders aren't easy to separate, and checked my pins with everything depressurized. My pins are pristine at 3000 hours on the loader. Some burnishing but thats it. But then my units are 10 years old so the steel I'm sure is different.

I thought abbout taking the loader off the 105 too, but I run a set of auxillary lines on the 105 that operate a hay accumulator so it's even more of a PITA.

Little CUTS and Sub Cuts are easy to pull loaders compared with the big units, but I wanted to look. No issues with mine.

Gave me a chance to clean out the old accumulated grease and ruin some old shop towels too.
Do any of your pins have a cross drilling and groove in the center to distribute grease?
 
   #19  

rScotty

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View attachment 463448 not sure why pics are sideways, but if you click on them they expand straight.

So the left side bucket cylinder top pin broke about 2 months ago. Broke right in half at the grease port. No biggie, because half of it slid out a little and I caught it. Today, not so lucky. Didn't notice that the other one broke in half, and half must of dropped out and boom. The cylinder pulled loose from the half of pin as it contracted, busting the steel line that feeds the hose and bending ears on the boom...
(SNIP)
I'm wondering If this thing is better off for landowners instead of using it for a business. Its a great size and can really move dirt but...

Hershey, I've been looking at those pictures and at my own M59 and still don't haven't come up with any explanations that satisfy me.

For those that don't know me, I'm a welder and machinist as well as an mech. eng., and spent a lifetime designing equipment of all types. Still do a bit of it in retirement. And I have the same tractor. Mine is also a 2008 with similar hours. It hasn't been totally problem free but darn near. I also use mine reasonably hard and sure haven't had anything like the problems that Herseyfarm has had.

A couple of things bother me about these pins. Yes, I know from other conversations that Hersey beats his machines hard. We've talked about that before. But even so, there just isn't any easy way to get a shearing stress onto the center of that pin - especially when there's a locking bolt still in place that prevents the pin from sliding laterally.... And what with the decent geometry and bulky end support it is equally hard to see how the pin break could be deflection induced either. And the other bother is that you say this wasn't the first pin you've had break. Hmm....Have you checked all the other pins on the machine? Of course once that pin did break then things could progress just as you said - your sequence sounds reasonable to me - what with the outer half of the pin working it's way out and once that happens the off-center push bending the ear until the hose failed. But trying to see how to initially get enough stress on center of the pin to start the sequence is the problem I'm having.

It's sure sounding like it started as a pin material problem. And that's surprising because Japanese steel is generally right there with the world's best. I assume that the pins are hardened or plated at some point...could that be a clue? Of course there are ways to check where and roughly why a fracture starts. Doing that formally is likely to be more expensive than this relatively inexpensive repair, but any metallurgist and most mechanics who have a 50x microscope and a few chemicals can tell you a lot about a break like this.

For my part, I'm sure going to pull the pins on my M59 and see how they look before the season starts. And I'm going to talk with the guy that owns the local cylinder fab shop to see if I've missed considering something obvious.... then I'm going to sit down and do some more thinking.

I'll not condemn the M59 or it's loader design because of this, but will certainly check mine carefully.
Oh, I forgot to ask; do you use any other buckets or QA bucket attachements on your M59? Is there any missing info there?
Thanks,
rScotty
 
   #20  

SPYDERLK

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Hershey, I've been looking at those pictures and at my own M59 and still don't haven't come up with any explanations that satisfy me.

For those that don't know me, I'm a welder and machinist as well as an mech. eng., and spent a lifetime designing equipment of all types. Still do a bit of it in retirement. And I have the same tractor. Mine is also a 2008 with similar hours. It hasn't been totally problem free but darn near. I also use mine reasonably hard and sure haven't had anything like the problems that Herseyfarm has had.

A couple of things bother me about these pins. Yes, I know from other conversations that Hersey beats his machines hard. We've talked about that before. But even so, there just isn't any easy way to get a shearing stress onto the center of that pin - especially when there's a locking bolt still in place that prevents the pin from sliding laterally.... And what with the decent geometry and bulky end support it is equally hard to see how the pin break could be deflection induced either. And the other bother is that you say this wasn't the first pin you've had break. Hmm....Have you checked all the other pins on the machine? Of course once that pin did break then things could progress just as you said - your sequence sounds reasonable to me - what with the outer half of the pin working it's way out and once that happens the off-center push bending the ear until the hose failed. But trying to see how to initially get enough stress on center of the pin to start the sequence is the problem I'm having.

It's sure sounding like it started as a pin material problem. And that's surprising because Japanese steel is generally right there with the world's best. I assume that the pins are hardened or plated at some point...could that be a clue? Of course there are ways to check where and roughly why a fracture starts. Doing that formally is likely to be more expensive than this relatively inexpensive repair, but any metallurgist and most mechanics who have a 50x microscope and a few chemicals can tell you a lot about a break like this.

For my part, I'm sure going to pull the pins on my M59 and see how they look before the season starts. And I'm going to talk with the guy that owns the local cylinder fab shop to see if I've missed considering something obvious.... then I'm going to sit down and do some more thinking.

I'll not condemn the M59 or it's loader design because of this, but will certainly check mine carefully.
Oh, I forgot to ask; do you use any other buckets or QA bucket attachements on your M59? Is there any missing info there?
Thanks,
rScotty
Good development. I dont see where you factored in the design of the pin tho. For lubrication, I believe these are drilled down the diametral center - then cross drilled and grooved at their length center to favor even greasing. Do you see a stress riser? ... Now consider that the pin sees force reversal and is prevented from turning. This combination of design choices presents the absolute best case for the pin to fail by fatigue. ----- The fact that a collar surrounds the pin groove alleviates but does not eliminate. The design described is unsound.

,,,After breaking 3 such sabotaged pins on my 7520 I replaced all pins in the curl circuit with solid pins and put a grease fitting on the collar. The only grooved pins left are the 2 that pin the lift cyls to the arms. They dont see such large forces or reversals. I am watching them closely.
 
 
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