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Old 12-26-2012, 02:55 PM   #1
harpo1313
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250 six ,sheared crank bolt,options?

I just bought this 66. it sat for a good many years so i pretty much went through it.i cleaned the tank ,the lines new fuel pump ,filter and cleaned the carb,points,cap rotor and plugs.
It fired up ,kinda rough at first but after some adjustment it smoothed out.I found alot of slop at the crank pulley.After checking things out i found the crank bolt was missing.upon looking closer noticed it was broken off inside,with a drill hole on an angle into the crank itself ,not much but enough.I lifted the motor slightly in the front to get a correct angle for the drill to be level with the crank to try and drill it out for my easy out,I heated it ,waxed it many times and no go .
From the looks of it this has been an issue with this motor for some time as the keyway on the crank and pulley are toast,and the fan belt has been holdin the whole mess in place.What are my options.Just thoughts ,But can the balancer be drilled and tapped for a grade 8 ,coned setscrew,with the crank having a landing drilled out to lock it in ,one on each side? This truck will be getting a fresh motor hopefully next summer so i dont want to pull it now ,just drive it localy and do my bodywork on it and save for some susp upgrades. Any thoughts Thanks Ron
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Old 12-26-2012, 03:05 PM   #2
hyatt
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Re: 250 six ,sheared crank bolt,options?

If you are replacing the motor later just spot weld crank to balancer and leave it at that
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Old 12-26-2012, 03:47 PM   #3
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Re: 250 six ,sheared crank bolt,options?

Quote:
Originally Posted by hyatt View Post
If you are replacing the motor later just spot weld crank to balancer and leave it at that
If you are going to do a job, do it properly or not at all. hate to be a person that would ever get one of your vehicles
someone else may get the eng later and then what do they do.
at least now it may still be an easy fix. one could try welding a nut on the end of the bolt depending where it broke, if they can weld it on. try turning it out. with the heat from the weld, sometimes is all it takes to loosen it
ron
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Old 12-26-2012, 04:01 PM   #4
tincan1966
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Re: 250 six ,sheared crank bolt,options?

"If you are going to do a job, do it properly or not at all. hate to be a person that would ever get one of your vehicles"

That comment was totally unnecesary IMO
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Old 12-26-2012, 04:32 PM   #5
64fleetside
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Re: 250 six ,sheared crank bolt,options?

I've seen many without a bolt from the factory-the early ones weren't even tapped.
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Old 12-26-2012, 05:08 PM   #6
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Re: 250 six ,sheared crank bolt,options?

Quote:
Originally Posted by hyatt View Post
If you are replacing the motor later just spot weld crank to balancer and leave it at that
Agree.

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Originally Posted by padresag View Post
If you are going to do a job, do it properly or not at all. hate to be a person that would ever get one of your vehicles
someone else may get the eng later and then what do they do.
at least now it may still be an easy fix. one could try welding a nut on the end of the bolt depending where it broke, if they can weld it on. try turning it out. with the heat from the weld, sometimes is all it takes to loosen it
ron
That's pretty harsh. The original poster said the keyway in the crank and balancer are both "toast". A good spot weld is a viable route to getting some more miles out of an engine that needs a crankshaft replacement or repair anyway. If the crank is already junk, a spot weld or two won't make it any more junky.
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Old 12-26-2012, 05:47 PM   #7
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Re: 250 six ,sheared crank bolt,options?

That was my first thought,tack weld on each side.I didnt want to mention that,might stir some feathers.lol And as far as someone who gets the motor sometime ,they will get it free and know the issues.but i will put a new gearset and gasket in it before hand.
one more question,what if anything holds the larger timing gear in? It is scraping the timing cover rather harshly to the point its leaving weld snot inside the cover thanks for the replies.
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Old 12-27-2012, 09:11 AM   #8
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Re: 250 six ,sheared crank bolt,options?

There is a retainer plate behind the cam gear that secures the cam in place.
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Old 12-27-2012, 09:33 AM   #9
hyatt
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Re: 250 six ,sheared crank bolt,options?

My suggestion to spot the balancer was as a temporary fix He said he was pulling the engine at a later date A spot weld can be removed with a die grinder and everything is back to normal and it a lot easyier to do a proper fix after its out And if crank and keyway is bad you havent harmed anything By spoting balancer on you might prolong having to replace the engine for another year or so
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Old 12-27-2012, 12:39 PM   #10
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Re: 250 six ,sheared crank bolt,options?

Hyatt , I had this happen to a plow truck once and I did weld the balancer to the crank and drove it for another year .. if your crank keyway is wallowed out ,or the balancer is loose on the shaft , then the damage has been done .. then you dont have anything to loose.. the right way is to pull the engine and replace the crank .. I simply used an electric over hydraulic pump for the plow .. you will need to weld a bit then cool it so the seal dosent burn .. ,that being said anyone that tries to use a bolt to hold a balancer that has gotten loose on a shaft is going to be sorely disappointed .. the harmonics alone will loosen it up .. good luck
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Old 12-27-2012, 12:50 PM   #11
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Re: 250 six ,sheared crank bolt,options?

Quote:
Originally Posted by harpo1313 View Post
That was my first thought,tack weld on each side.I didnt want to mention that,might stir some feathers.lol And as far as someone who gets the motor sometime ,they will get it free and know the issues.but i will put a new gearset and gasket in it before hand.
one more question,what if anything holds the larger timing gear in? It is scraping the timing cover rather harshly to the point its leaving weld snot inside the cover thanks for the replies.
Since it already needs a crank dont was time on a gearset , on a 6 the only right way to replace the gears is to remove the cam from the engine ..I have done it otherways but it is real difficult to do in the vehicle and it is a real pain ... dont skimp on the weld make sure you put a good bead all the way around ,tach weld wont last .....But by the sounds of it it has multiple problems if the big gear is hitting the cover....
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Old 12-27-2012, 01:10 PM   #12
harpo1313
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Re: 250 six ,sheared crank bolt,options?

Thanks for all the replies,looks like i will weld it up and see how far i get.I would like to blow this truck apart and redo it all at once but its not gonna happen as i dont have my shop anymore and i want this one to stay on the road while it gets updated a little at a time.
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