Welp, My first post here and it's a doozie. Tractor is a 2014 MX4800 HST with 300 hours on it 
Here's the story: My father was running our tractor with a grapple up front moving piles of cedar. My best guess as to what happened is a cedar branch got lifted up when he was rolling backwards, and actually hit the engine oil filter, unspinning it slightly from the sealing surface. That's unfortunate, but here is the kicker: he thought the low oil pressure light was the DPF light, and continued to use the tractor until he felt the engine bog down, then shut it off and left the tractor where it was.
I wasn't out at the land with him at the time, but came back out the following week to assess the damage. I filled up the engine oil, reseated the oil filter, and fired the tractor back up. Oil pressure light was no longer illuminated after a few seconds. Engine sounded healthy as I let it idle for a few minutes, so I thought we got lucky. The problem came as soon as I revved it up to drive it back to the overhang we park it under. The engine had a knock.
I didn't want to just leave the tractor in the field and work on it in the texas summer sun so I drove it a hundred yards (knowingly driving it with a knock) to get it parked under the shade.
Hoping that the issue was a spun big-end rod bearing, the following weekend I went back out and drained the oil, removed the front driveshaft, pulled off the sump and found lots of babbit. Fortunately, there was no other type of metal.
After pulling the DPF and fuel injectors, I was able to rotate the engine with a wrench and start inspecting the rod bearings. 3 of them looked brand new, one of them had very slight wear on it. Damn! That wouldn't be the cause of the knock. Since I was there I checked the valve lash and all were fine.
Now I'm almost certain that one of the main bearings is spun and the source of the babbit in the sump. I have a service manual on order and am wondering if I should run the engine one more time (with new oil & filter) in order to remove the front loader, or do you think the engine can be pulled with the front loader still attached? I have access to an engine hoist, or a neighbors tractor if need be. My other concern with one more run is damaging the crankshaft even more. I might end up having to get the crank machined anyways for thicker bearings, but I'm hoping not to have to do that and be able to use standard bearings.
I only get to go out to my land one day a week at most, so this will be a long process. I'll try my best to update this post as events unfold, but I'm anticipating several months of work before it is back together and running healthy again.
TLDR: Almost certainly a bad main bearing, should I run the engine one more time to remove the front loader, or try and remove the engine with the front loader still attached?
Thanks for reading
Here's the story: My father was running our tractor with a grapple up front moving piles of cedar. My best guess as to what happened is a cedar branch got lifted up when he was rolling backwards, and actually hit the engine oil filter, unspinning it slightly from the sealing surface. That's unfortunate, but here is the kicker: he thought the low oil pressure light was the DPF light, and continued to use the tractor until he felt the engine bog down, then shut it off and left the tractor where it was.
I wasn't out at the land with him at the time, but came back out the following week to assess the damage. I filled up the engine oil, reseated the oil filter, and fired the tractor back up. Oil pressure light was no longer illuminated after a few seconds. Engine sounded healthy as I let it idle for a few minutes, so I thought we got lucky. The problem came as soon as I revved it up to drive it back to the overhang we park it under. The engine had a knock.
I didn't want to just leave the tractor in the field and work on it in the texas summer sun so I drove it a hundred yards (knowingly driving it with a knock) to get it parked under the shade.
Hoping that the issue was a spun big-end rod bearing, the following weekend I went back out and drained the oil, removed the front driveshaft, pulled off the sump and found lots of babbit. Fortunately, there was no other type of metal.
After pulling the DPF and fuel injectors, I was able to rotate the engine with a wrench and start inspecting the rod bearings. 3 of them looked brand new, one of them had very slight wear on it. Damn! That wouldn't be the cause of the knock. Since I was there I checked the valve lash and all were fine.
Now I'm almost certain that one of the main bearings is spun and the source of the babbit in the sump. I have a service manual on order and am wondering if I should run the engine one more time (with new oil & filter) in order to remove the front loader, or do you think the engine can be pulled with the front loader still attached? I have access to an engine hoist, or a neighbors tractor if need be. My other concern with one more run is damaging the crankshaft even more. I might end up having to get the crank machined anyways for thicker bearings, but I'm hoping not to have to do that and be able to use standard bearings.
I only get to go out to my land one day a week at most, so this will be a long process. I'll try my best to update this post as events unfold, but I'm anticipating several months of work before it is back together and running healthy again.
TLDR: Almost certainly a bad main bearing, should I run the engine one more time to remove the front loader, or try and remove the engine with the front loader still attached?
Thanks for reading