Bing Bang Pow!

[North Idaho Wolfman]

Witness The Power Of Kubota Internal Destruction!

 

[Wild and Free]

From the looks of it a rod cap bolt must have broke or come loose and caused the damage alone or possibly caused by the rod bearing failure causing it to hammer itself apart eventually but it would have had to have ran that way for quite a period of time with a healthy knock and low oil pressure since the rod itself is fully in tact yet. Had there been any lower end engine work done to it previously that you know of?

 

[clark_bailey]

No lower end work, I was told. Interesting is #2 rod, #1 rod is darkened from heat and both #1 and 2 rod bearings were thinned. 3 and 4 rod, bearings look like new. The story was the tractor was stuck pulling a log up a steep hill. Knocking began and her husband said keep bucking it, then Bing bang pow. Looking at the crank to rod surfaces I think more is to the story like low on oil for more than just a minute or two. However I am surprised if that was the reason because the filters and all other fluids were appropriate, date and hour marked too. Since I was not witness to the event (s)...

 

[North Idaho Wolfman]

That is what happens when you hydro lock them.
That could happen because it blew a gasket or cracked the head, or floated a injector and flooded the piston with diesel.
All of those could have happened on pulling a long hill working it real hard.

 

[JeffL]

When I first looked at the rod I thought hydrolock also. Then I noticed the offset steps as you move down the rod. I think the crank was hitting the rod after the cap came off. each hit was further up the rod as the piston moved down due to gravity. I suspect the radius on the left side of the rod matches the diameter of the crank pin. This is the radius that lines up with the paper towel.
With all the rod bearings damaged the initial failure was most likely loss of oil pressure.

 

[clark_bailey]

There is a crank bolt broken off in the rod.

 

[lugbolt]

I didn't read the replies, but I seen the picture....that plug you found that was out? I have one at the house right now (neighbor's tractor) and that plug-or one just like it-is out. Oil pressure is 3 psi hot at full throttle. It would run a while on 3 psi. But not forever. The plug that came out on his was on the side, and intersects the oil pump suction passage-explaining why it has little oil pressure.

Could that be your problem as well?

 

[clark_bailey]

that was a suspect to me, yes the plug was out of the block, laying in some oily residue next to the steering cylinder, just below the front cover on the engine.