Cracked Case - Oil Splattering All Over the Place

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Ok... any mechanics out there?  Here's the deal... this is an aluminum short block for a lawnmower... but I'm guessing that should not matter to people who like to work on motors.   I found the crack and I want to fix it.  The problem is ... I have never done this sort of thing before and I am not intimidated to learn and try.  After all, I rebuilt the transmission on this thing and it works like a champ.  People told me fixing a transmission is too difficult for a noob but I proved them wrong.  Another reason for wanting to learn how to fix this thing is if I'm on the road with my bike to Alaska and get stuck in BFE I would like to be able to fix a hole or a crack so I can limp into town or keep going if the fix is good enough.

Here are the photos of the beast.
I'm looking for the right solution - so all you grease monkeys out there... here's your chance to shine and show what you know: JB Weld, Steelstick. tig welding, Alutight, brazing, ???  
Your advice and instructions will be very much appreciated.

[2talltim]

Common problem with these engines, the saying goes you have to have "courage " to buy one.  Honestly I'd replace it with a new or used engine.  These things are built to be disposable. You should be able to replace it with a new engine for around  $500 and maybe find a mower with a good engine  bad tranny you can get for a song. I sold my old LTD mower for $100 because the guy wanted the motor. Think you will just be chasing gremlins with this one even if you had it repaired. 

[2talltim]

If you really  wanna 

 

[Wandering Soul]

I'm going to disagree with Tim; my experience with those motors has been good, I'm on my third one in 40 years.  One of them still running for a lady I know.

Is the crack all the way through?  Getting oil out of it?  In order to tig or brazed, it has to be cleaned and the crack stop-drilled at it's end 1/16" drill is good.  Clean it with soap, water, and compressed air acetone doesn't seem to like tig/brazing.  I would not use JBWeld as suggest in the video.  If that stuff falls into the crankcase who knows what all it'll fuck up.  Someone sells aluminum bars that a MAP gas torch will melt.  Seen a Sportster primary cover fixed with one of them.  Two years now and holding up good.

There's videos on youtube about the aluminum stick and MAP gas.  Also on Kohler engine repairs.  Find Kohler's website and download the manual for that motor (free).  Also order any gaskets and pieces you need.  I love my local dealer, but Kohler's site is cheaper even with shipping.

[Wandering Soul]

Here's a video on the Aluminum brazing.

 

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21 minutes ago, Wandering Soul said:

I'm going to disagree with Tim; my experience with those motors has been good, I'm on my third one in 40 years.  One of them still running for a lady I know.

Is the crack all the way through?  Getting oil out of it?  In order to tig or brazed, it has to be cleaned and the crack stop-drilled at it's end 1/16" drill is good.  Clean it with soap, water, and compressed air acetone doesn't seem to like tig/brazing.  I would not use JBWeld as suggest in the video.  If that stuff falls into the crankcase who knows what all it'll fuck up.  Someone sells aluminum bars that a MAP gas torch will melt.  Seen a Sportster primary cover fixed with one of them.  Two years now and holding up good.

There's videos on youtube about the aluminum stick and MAP gas.  Also on Kohler engine repairs.  Find Kohler's website and download the manual for that motor (free).  Also order any gaskets and pieces you need.  I love my local dealer, but Kohler's site is cheaper even with shipping.

Thanks for your generous post. The crack must be all the way through because oil was all over the garage floor and bone dry.  I'm hoping this is the only crack.

I'm glad you said something about acetone.  I was going to use it to clean.  I'll hold off on that.

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39 minutes ago, 2talltim said:

If you really  wanna 

 

JB Weld looks like a quick and dirty solution.   I wonder if I can get 5 years out of that method.

[2talltim]

32 minutes ago, Wandering Soul said:

I'm going to disagree with Tim; my experience with those motors has been good, I'm on my third one in 40 years.  One of them still running for a lady I know.

 

I'm not saying kohler is a bad engine I'm saying the courage series is a dud. Don't think they have been making this series for 40 years.  Yea kohler in general are great. My old man has one in his cub with 5000 hours on it and never been rebuilt (but it needs it now) and my mower has a pro command series on it and I'm very happy with it.

[ReconRat]

I've fixed cracked aluminum castings various ways. None lasted forever. All methods leaked again. Probably the number of heat and cool cycles just crack the patch. Even a weld. Super glue impressed me, it was just so easy to do, even if having to put more on often. Trying to fix or plug up a large crack or hole is a waste of time. But it might work for a while.

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1 hour ago, ReconRat said:

I've fixed cracked aluminum castings various ways. None lasted forever. All methods leaked again. Probably the number of heat and cool cycles just crack the patch. Even a weld. Super glue impressed me, it was just so easy to do, even if having to put more on often. Trying to fix or plug up a large crack or hole is a waste of time. But it might work for a while.

Yeah... I don't expect this to last forever...  I'll use duct-tape before spending more than $500 on this engine. 
If I'm going to put more than $500 into this engine... I'm going jet.

 

[Wandering Soul]

I'd prefer something a little more traditional...

 

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1 hour ago, Wandering Soul said:

I'd prefer something a little more traditional...

 

Hell yeah!  I can dig it.
I just might go that route if this doesn't work.
I went and got me some toys and a little more know-how.
First I'll try the cheap and nasty J-B Weld to BJ the thing.  
If that don't work... I'll try to braze.
J-B Weld is rated for 550F, which seems good enough as these motors run something like 250F
J-B Hi-Temp Red Silicone Gasket Maker is rated for 650F
On a side note Aluminum melts at something like 1200F, which my friend and I do for casting.

Now, if all that kludge gets FUBAR I'll try Aluminum brazing.  
The one's in the attached picture is bronze... wrong stuff and another reason why I'm trying the J-B Weld first: I don't want to go back to the store and buy more stuff.

And a shout out thanks to @Qman for mentioning a regulator "Wow...a pressure regulator!  My compressor already has one on it!" on the "Tire Gauge Sale On Amazon" topic.  I picked one one up from Lowes which ... which I attached after blowing a valve on my new crappy grinder from Harbor Freight.
Source: 

 

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Alright... this is the first engine I ever opened... I don't think I'll every buy another Kohler if I can help it.  One crummy bolt was loose and because of it the block cracked.  
For the future, if there's a future for this engine, I might be able to get to the bolt to tighten it without removing the fly wheel.  

As for Kohler to know that this design flaw exists on every vertical shaft engine of their's for years and not address the problem in my opinion says a lot about Kohler.  I never had problems like this with Briggs&Stratton engines.  

For this project I had to buy a puller, another first, and discover if the bolts are standard or metric.  Lucky me... this entire lawn tractor is mixed.
 

[Wandering Soul]

The old loose cover bolt trick.  How old is that motor?  Kohler has all but admitted they had assembly problems.  Just wasn't torqued right.  That puller you brought is good for steering wheels and other stuff.

As long as you got the cover off, get a new seal where the crank comes up through.  As long as you've got the flywheel off...

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28 minutes ago, Wandering Soul said:

The old loose cover bolt trick.  How old is that motor?  Kohler has all but admitted they had assembly problems.  Just wasn't torqued right.  That puller you brought is good for steering wheels and other stuff.

As long as you got the cover off, get a new seal where the crank comes up through.  As long as you've got the flywheel off...

The engine is a 2008.
I'll probably never use the puller again, but it's good to know that I can use it for many other things.  
And I'm glad you mentioned the seal.  
A friend of mine said go get a gasket and not use the JB Sealer.  You echoing that convinces me to go get the right part.
I'm concerned about the timing when I put it all back together.
I'm glad I took a lot of pictures.   Hopefully that will help.

[Wandering Soul]

As long as you didn't disturb the cam gears timing will be where it needs to be.  At one time Kohler offered on line manuals you could down load in PDF for all their engines.  Try calling 800.544.2444 and ask them if they still offer those.  Has torque specs, illustrations, and assembly steps right down to the bare crankcase.

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4 hours ago, Wandering Soul said:

As long as you didn't disturb the cam gears timing will be where it needs to be.  At one time Kohler offered on line manuals you could down load in PDF for all their engines.  Try calling 800.544.2444 and ask them if they still offer those.  Has torque specs, illustrations, and assembly steps right down to the bare crankcase.

Thanks... I appreciate your support.  I'll definitely look up the PDFs.

 

[Fin]

Finally after getting a long awaited tool, a Bristle Disk for aluminum,  can proceed.
 

[wolfeman28]

Be careful with map gas on the cast aluminum. Not all castings are made the same and some will start to melt before you can even get your filler to wet out and stick. Watch the heat in thin areas.

Edited April 23, 2017 by wolfeman28

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20 hours ago, wolfeman28 said:

Be careful with map gas on the cast aluminum. Not all castings are made the same and some will start to melt before you can even get your filler to wet out and stick. Watch the heat in thin areas.

Thanks for telling me this.  I'm just getting to know the material and the use of AL-3 and Alumiweld.   On a practice piece I see exactly what you are saying.  I melted part of the aluminum.  Ouch!

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My first brazing attempt with AL-3. I also bought some Alumiweld from Harbor Freight, but the AL-3 seemed to do the trick.
I saw a guy preheat his block in a gas BBQ.  I don't know if that is necessary, but from my knowledge of microchips and heatsinks it sounds like a damn good idea.
Now I just need to unbolt the block from the frame and put it in my wife's oven and pre-heat it to 400F without her being home and knowing about it.
Any comments and suggestions is appreciated, including excuses for the Mrs if she finds out.
 

[Fin]

Back together she goes.

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A man's work is never done.  Everything looks great.. then the muffler blew from an earlier repair.  Who makes this crap!?  Does anyone have a muffler?