Broken Crank, What to do?

[kenmac]

Wonder what crank your friend ordered / recieved. My yanmar 3110 (JD 950) is the same as yanmar 3810 ( JD 1050) except for turbo & I believe injector pump timing for a little more fuel

 

[Kernopelli]

No idea on the crankshaft. You bring up something pretty cool, you obviously don't need a turbo to get some extra HP out of that engine because I assume your 3110 is not turbo'ed but is more than the 950's 27 HP.

He just related this story to me about a week ago when I told him I was putting my Mitsubishi K3F back together. He said he initially assumed he had installed something backwards or clutch,flywheel.....something-anything wrong but repeated teardowns proved everything correct. He had several friends come over and look at it and eventually had one of the mechanics from work who worked on all of their Deere equipment come by and go through it completely with the same results. Finally called the Deere dealership and they told him the about the "separation of serial numbers" etc. That is what led him to start doing some type of measuring/marking when he tried to pull the two halves together and he decided it left him with 2 choices.....either order another crank or cut the input shaft. He said Deere had charged him about $1000 for the crank and blamed him for the "mix up" so another crank was out of the question. In the end, the tractor ran fine and he used it in his tree trimming business for several years before selling it to upgrade to a skidsteer.

QUOTE=kenmac;3032082]Wonder what crank your friend ordered / recieved. My yanmar 3110 (JD 950) is the same as yanmar 3810 ( JD 1050) except for turbo & I believe injector pump timing for a little more fuel[/QUOTE]

 

[kenmac]

Well, They say that the 3110 is 37 engine HP. I have never seen any proof ( on a dyno) that my engine is 37 HP. My engine plate list ( I'm going off memory now cause I'm not around my tractor) 30 or 33 HP.I know it doesn't list 37 hp anywhere

 

[Kernopelli]

37 sounds about right, the grey market machines are almost always numbered by PTO HP not engine HP....3110= rated 31 PTO HP which would take at LEAST 4-5 additional engine HP to achieve.

Well, They say that the 3110 is 37 engine HP. I have never seen any proof ( on a dyno) that my engine is 37 HP. My engine plate list ( I'm going off memory now cause I'm not around my tractor) 30 or 33 HP.I know it doesn't list 37 hp anywhere

 

[kenmac]

37 sounds about right, the grey market machines are almost always numbered by PTO HP not engine HP....3110= rated 31 PTO HP which would take at LEAST 4-5 additional engine HP to achieve.

Yes ,That's what I've heard, but like I stated. I've never seen proof of this. I would like to see the proof of this. .It just doesn't seem to have that much hp.Although, it may have 37 hp.I just have nothing to compare it to or know how 37 hp should behave power wise

 

[uofa314]

Got it torn down this morning. Thankfully, I didn't see any damage to the block at all. We are taking the head and block to the machine shop to get checked out. Also going to get the machine shop to replace the cylinder liners and main bearings while they have it there. I have rebuilt a couple of engines before, but I don't have much experience at this. I did find a service manual on ebay and ordered it so maybe that will help.

As far as the cause of the broken crank, I didn't see anything. When I pulled the head, I didn't see any signs of anything wrong. All three pistons and cylinder walls looked equally good. There was no signs of the head gasket leaking or any signs of fuel problems.

Also, the tractor was running fine until this happened. So, maybe the crank had some minor imperfection that caused the crank to fail due to high cycle fatigue. I'm a mechanical engineer at an old plant. Sometimes I see things like this, something breaks and can't find the cause. We send the broken parts to the lab. They can identify the failure mechanism. Sometimes it was caused by 40 years of vibrating back and forth.

But anyway, I'm about to order the parts. I'll take better pictures as I'm putting it back together. Will probably be next weekend.

 

[kenmac]

metal fatigue ??? did you try fredricks for the parts or just getting them from JD ?

 

[uofa314]

Kenmac, I ordered most of the parts from Hoye Tractor Parts and I ordered a used exhaust manifold and turbo from Worthington Ag Parts. I also got some of the studs and bolts for the manifold from John Deere.

 

[kenmac]

That's good. Reason I mentioned Fredricks is, I thought you could make the drive to Hartsel AL for less than shipping from Texas or, shipping from Fredricks for less . I Hope everything works out for you & you get your tractor running again soon

 

[uofa314]

Well, we got the engine back together and the dealer put the tractor back together. The engine is running fine and everything is good, except, now the hydraulics don't work. The frontend loader and lift don't do anything. The dealer says they checked everything and the pump is spinning, but isn't pumping. They said the only thing left to do is replace the hydraulic pump. It was working fine before the crank broke and we didn't do anything do the pump. We just took the timing cover off of the engine and the pump is attached to that cover. Is it possible for the pump to just stop working like that?