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Bent Crank

mowfixer's Avatar

Join Date: Nov 2003
Posts: 117

12-26-04, 07:02 PM   #1  
Bent Crank

Is it safe to have the crank straightened or should it just be replaced? My daughters husband hit a stump on a brand new $700 mower with a 6.5Hp Briggs and bent the crankshaft.

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sceptre's Avatar
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12-26-04, 08:58 PM   #2  
i have disassembled a few briggs and have managed to straighten the shafts, but it takes a lot of patience to get it right though. then you have to check the pto bearing also for damage. it's your judgement call....


cheese's Avatar
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Join Date: Jul 2001
Posts: 16,567

12-26-04, 09:06 PM   #3  
Hello mowfixer!

I have heard both sides....that it's safe, and that it's not. Personally, I have never seen any problems with a straightened crankshaft, and wouldn't be afraid to use one that was straightened. If it were me, I'd get it straightened. You'll probably have a sheared flywheel key too, and a bent blade possibly. As mentioned, there could be damage to the pto bearing, but usually not.

"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

snoman's Avatar

Join Date: Dec 2003
Posts: 326

12-27-04, 05:33 AM   #4  
I don't straighten cranks anymore, I just replace them and know it's done properly.
When I've had to straighten cranks, there were a few things to contend first. The whole motor had to be together for the crank straightener to mount up. The crank had to be long enough to (sticking out of the engine block) to allow the straightener to work. The bottom engine case had to be checked for cracks due to the mishap. It can be done but if you think it's straight and you find out later it's not, you have to tear the engine down again later and most likely change the crank.
So my opinion on this is just to bite the bullet and replace the crank, seal, gasket and if you want to do a complete job, the rings also.

snoman (been there...done that....)

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