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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.

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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.

Luffydog said:

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.

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Don't extrapolate your customers problems to cover the entire run of engines.
Most Husqvarnas sold down here are fitted with Courages and very few of them have problems with the bolts loosening.
As for balancing, most are balanced very well, far better than the equivalent Inteks so it will be a 3rd , 4th or higher resonance that is causing the problems.

The new kohler engine has 2 in it now. Their reason is for quieter but the main is for the balance.

Picked up another Toro Timecutter with a Courage. This one runs great but has the typical hairline crack. See pics. What can I expect to pay to have this welded or should I just use JB Weld or similar?

Go about 1/8" to 1/4" past the end of the crack and drill a 1/8" hole
This helps to arrest the crack getting bigger.
If you wash the crack really well, JB Weld will fill the crack reasonably well.
Just make sure the bolts on the cover plate are kept tight.
The crank will start weeping after a while, but I have managed to keep a couple of these owned by non - profit / charity clubs running like this.
Also check the oil EVERY time you use the mower.

OTOH I can now weld the cases , with oxy using a DHC 2000 low pressure gun and fine filler rod.
Electric welding does not work as well as you have to get the crack surgically clean & dry in order for the weld to work.

Unless you have a friend who welds, or the gear yourself, a short block will be a better and most likely cheaper if you want a permenent fix.
Products like Lumiweld and similar alloy "welding" rods ( they are actually solders ) can also do a reasonable fill if the crack is really really clean.
But again this is not structural and has little more strength than the JB weld but at least it will not leak.

bertsmobile1 said:

Go about 1/8" to 1/4" past the end of the crack and drill a 1/8" hole
This helps to arrest the crack getting bigger.
If you wash the crack really well, JB Weld will fill the crack reasonably well.
Just make sure the bolts on the cover plate are kept tight.
The crank will start weeping after a while, but I have managed to keep a couple of these owned by non - profit / charity clubs running like this.
Also check the oil EVERY time you use the mower.

OTOH I can now weld the cases , with oxy using a DHC 2000 low pressure gun and fine filler rod.
Electric welding does not work as well as you have to get the crack surgically clean & dry in order for the weld to work.

Unless you have a friend who welds, or the gear yourself, a short block will be a better and most likely cheaper if you want a permenent fix.
Products like Lumiweld and similar alloy "welding" rods ( they are actually solders ) can also do a reasonable fill if the crack is really really clean.
But again this is not structural and has little more strength than the JB weld but at least it will not leak.

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What keeps the crack from going around the hole?

The crack is longer than what you can see.
The root will be around 1/8" in front of what you see.
Cracks are like water & electricity, they take the easiest path and the hole is an easy path for them to go into but hard for them to leave.
Check the top plate carefully, if the bolt holes are flogged oval, replace the top plate, I forgot to put that in the reply.
If there is no movement then there is no energy to drive the crack growth

bertsmobile1 said:

The crack is longer than what you can see.
The root will be around 1/8" in front of what you see.
Cracks are like water & electricity, they take the easiest path and the hole is an easy path for them to go into but hard for them to leave.
Check the top plate carefully, if the bolt holes are flogged oval, replace the top plate, I forgot to put that in the reply.
If there is no movement then there is no energy to drive the crack growth

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That makes sense. I was always told to drill right at the bottom of the crack but I will do what you recommend. Thanks.