Broken crank bolt

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arch252

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• Oct 29, 2018 / Broken crank bolt

• #1

So I just finished a rebuild on a 16hp Kohler, CV460S. Everything went fine until I snapped the crankshaft bolt on the flywheel side....bad...about 3/4" deep. There is no getting the bolt out. Replacing the crank is not an option, the engine just isn't worth it. Are there any options? Could I drill and tap the top 3/4" inch of the shaft and put another bolt in? Any ideas? I have nothing to lose at this point.

 

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bertsmobile1

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• Oct 29, 2018 / Broken crank bolt

• #2

Start by heating the crank then applying your favourite penetrating oil.
Do it a couple of times.
Next get a Left hand drill and drill the bolt
Usually this will cause it to screw out.
If not get a tap 3/8 UNF L/H and thread the hole
Next use a grade 9 L/H 3/8 UNF Socket headed cap bolt as an extractor with an inhex socket head on an impact driver of some sort.

 

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arch252

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• Oct 29, 2018 / Broken crank bolt

• #3

Thanks Bert, I was hoping to avoid heat, I'll have to replace the new top seal that I just installed. Oh well, I'll give it a shot.

 

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bertsmobile1

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• Oct 30, 2018 / Broken crank bolt

• #4

Nope, don't need to get it red hot just too hot to touch which is about how hot it gets when running.
Pt some oil over the seal then a washer or something to divert flames hot air contacting it directly.

 

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arch252

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• Oct 30, 2018 / Broken crank bolt

• #5

Great idea Bert, thanks again

 

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SidecarFlip

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• Oct 30, 2018 / Broken crank bolt

• #6

If that don't work a spline drive easy out will...

 

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arch252

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• Oct 30, 2018 / Broken crank bolt

• #7

Got it! Did just what you said Bert and it came right out. I would have sworn that bolt was in there for good. Got it all buttoned up now and running like a sewing machine.

 

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Boobala

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• Oct 31, 2018 / Broken crank bolt

• #8

arch252 said:

Got it! Did just what you said Bert and it came right out. I would have sworn that bolt was in there for good. Got it all buttoned up now and running like a sewing machine.

Click to expand...

Thanks for your reply post AND the pic, it may just help another member in the same predicament ......:thumbsup:

 

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John Fitzgerald

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• Oct 31, 2018 / Broken crank bolt

• #9

Boobala said:

Thanks for your reply post AND the pic, it may just help another member in the same predicament ......:thumbsup:

Click to expand...

Yes, follow ups are good. Many threads are left hanging, with no stated outcome.