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
