Here's Your Problem. (19hp Kohler Courage)

Just picked up a Cub Cadet LTX1040 with a blown Courage. Looking around to see where it was leaking oil from and found this under the gas tank...

The self destructing engine aka the bucket engine. I call them kohler croakers

Crankcase time

It will happen again with that engine.

Luffydog said:

It will happen again with that engine.

Click to expand...

It shouldn't. Why did it happen in the first place?

Something about the crankshaft in those engines give away and come Thur the block. Had a brand new do it 2 years ago with less than 10/hrs on it. After replacement engine only less than a year later did it again.

The crank on that engine is an odd one out from what I have seen being that is a malleable iron casting against all of the others that are forgings.
Nothing wrong with that, it drops the price of the crank by near 2/3 and the crank equate to about 1/2 the price of the entire engine.
About 1/2 of all the cars made in the USA have cast cranks and most of the small trucks ( under 4 ton ).

However becuse it is cast , it has to be bigger and being bigger it is heavier and thus you need a heavier counterweight.

My theory is that the crankcase wall is at about it's structural limit with the cast crank.
I would also guess that it was originally designed to have a forged crank, but that made it too expensive.

Now when cranks are cast, and these are a pressure die castings generally a large number of mould are fitted into a fairly big carousel ad at least one of them was right on the border line thickness wise.
Some of those courages have been abused no end and show no signs of giving up, A local baseball club uses their mower to distribute clay around the diamond by mowing over it is a good example, a cricket club's mower never has any oil in it when I come to do the annual service.
The there are others that are just trimming the top 1/2" off a flat 1/2 of lawn that blow up.
No rhyme or reason to it.

Some will loosen the bolts near the block and others are always tight.

I train my customers ( woof woof ) to check those 4 front bolts every season when they remove the blower housing to clean the fins ( a little bonus with that one ) .
About 1 in 12 will tell me the bolts were loose.

Like Bert said those bolts go loose all the time and the starboard side of the block usually cracks...........

The main reason it happens is the engine is not perfectly balanced and with viberations from the engine and from rough terrain causing bolts to loosen up which causes a more unbalance resulting in the crankshaft counter weight to fly out and hit the block causing major damage and failure. Although I have seen one run with hole in the block. He said mower is making a noise and would like for me to check it out. When he cranked it up to unload it off the trailer it was the last time it ran.

I just picked up an identical mower today. Exact same thing with 110 hours. Runs great. I'll be sure to pull the blower cover off and check for loose bolts. That one above is my third blown Courage.