crack in crankcase

V

Vulnavia

Member
Nice,sunny day yesterday and thought I should get a jump on yard work. Riding along noticed the right side foot rest had some little dots of moisture on it. Wasn't drizzling, then I noticed oil spewing from the crankcase.
3" crack.( I can't figure out how to post a picture), It starts at the top of the case. New engine, plus bit of work to install it, $1260.00. New 46" mower, $2350.00. Can I weld it? maybe, but not sure it will last long.( I am a competent welder, have a tig and mig welders). Mower is a Cub Cadet LT 1040, 15yrs old and this engine has been a lot of trouble.
Any thoughts?

Thanks,
Will
 
Sorry but to me JB Weld is hell of a con job. Nothing I have tried to has held. Either find a welding shop that an experienced aluminum welder or just replace the short block.

Besides it takes nearly 3000 F just to break the aluminum oxidation layer and the aluminum itself will melt quickly at 800-1500F. And that oxidation layer is pretty thick too.
 
After taking it apart and looking inside, I can see the crack split in several directions. It looks like a bit more cracking and a piece will fall out. Don't think it is worth trying to fix.
Engines for Less has a replacement for $1200. Any recommendations on engine suppliers?
Thanks,
Will
 
The SV540 in those was known for cracked engine blocks. From what I've seen and what I've read over the years the Courage series was problematic.
I think I'd be looking at cutting my losses with that engine and maybe retrofit an older Command engine or anything you wish that will fit. A good CV15 or even the 20hp V twin would work fine.
I don't think I'd waste any money on the original engine with such a bad track record. I suppose it would be fairly easy to buy a parts machine with a donor motor, the Sears and Husqvarna models used them extensively in the late 90's and most I find have super low hours. (Lots of small yards and big tractors around here).

I've never been impressed with the SV540, which was supposed to be 18hp, but I replaced one with an old 11hp Briggs and Stratton on a buddies Cub and neither of us could see any loss of power, if anything it gained some torque. It did use slightly more fuel though but not enough to matter.
He had a 5 acre lot to mow, he had gotten 620 hrs out of the Kohler before the block opened up, his didn't just crack, a piece just dropped out one day and it dumped half its oil all at once. He brought it to me to scrap and wanted to find a good used mower. A few days later he came over with an old Dynamark with a rusty deck that hadn't run in years. I got that running, then suggested we put that motor in the Cub Cadet. He didn't want to at first but I went ahead anyway. I had him come over and run it on my lawn, and, not telling him what motor I put in it. Either the 18hp SV540 was really lame, or they're embellishing the hp numbers a bit because the 11hp was a really good match for that. He sold the Dynamark as it sat with no motor for more than he paid so it was a win-win for him.
 
If you can TIG, weld the sucker up. As you already know, it's all about the prep work. V grind away at the area and go to town. OP sounds like a capable fella'.

If nothing else, you can learn on that block and tell all us noobs how to do it proper.
 
Hello V.,

JB Weld is an epoxy and is not designed to handle this kind of repair. It is a weak band aid at best. No epoxy is a reliable repair.

Welding is not a good solution because it a poor-quality casting issue. It will just crack in other places near the weld areas. The Courage engines were just a plain bad/cheap casting design.

My vote is check out eBay for a different but used engine. Stay away from the courage line of similar engines. A Kohler command should be a straight replacement without a lot of changes. In a pinch even a low hours B&S would do
 
I have a few years of welding and fab training and experience. Mostly tig welding, but also stick and mig, oxy/acl and others. In my opinion and having tried before, welding cheap, porous aluminum, its difficult and doesn't work well. Usually cracks next to the weld anyway. Hard to get the material really clean. Some cleaning solvents will kill you when heated, regardless of how "dry" the material is. I felt it best to replace the engine. All the replacements I found either didn't come with a warranty (even new)or were junk. Plus they cost almost as much as the mower when new. Bought a new, wider cut mower. Still trying to get used to the "forward/reverse pedal.
Thanks to all for your suggestions.
Will
 
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