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Hey guys first time poster. I apologize the first time posting on this site is a cry for help! I would like to thank all those who do post helpful comments to spread the wealth of knowledge. That being said there I was, trying to install a new distributor in my 350 sbc. While trying to find TDC the crankshaft bolt housing ending up getting stripped and the bolt pretty much fell out.
I’ve seen some videos out there of guys being able to rethread the “housing” with a tap then use a slightly bigger bolt.
Anybody had this problem before? Any advice?
Thanks again guys any bits of knowledge is greatly appreciated.
 

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1965 2door HT Helena, GA 31037
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First you are going to need to know what size the bolt was that striped out. That'll tell you what size the original threads were in the housing. If the threads aren't messed up on the bolt you can visit a local hardware store and compare your bolt with one they have in stock to get the correct size. Then you can go online and buy a kit which includes the heli-coil and installation tool, the correct bit to drill the hole and a tap. These kits are somewhat expensive but very easy to use. See a tutorial on youtube on how to install a heli-coil. FYI, it's been proven that installing a heli-coil is way stronger than the original threads so that should solve your problem with torquing on the bolt in the future.

 

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Never use the harmonic balancer bolt to rotate the crankshaft. Even if it has heli-coils installed from someone else screwing it up.

It's a common (rookie) mistake that even experienced mechanics sometimes make because it is an easier shortcut to doing it the right way.

The crankshaft bolt is deigned to do one thing. Hold the pulley and/or harmonic balancer onto the end of the crankshaft. It is not designed to rotate the crank.

To do the job properly you rotate the harmonic balancer using the pulley mounting bolt holes or a special socket with the crankshaft key cut into it if the harmonic balancer is removed.
 

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Being the cheap guy I am, I would simply buy a longer bolt to get into the threads that are undamaged.
 

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Being the cheap guy I am, I would simply buy a longer bolt to get into the threads that are undamaged.
ARP and some of the other bolt manufacturers make an extra-long bolt just for that purpose. I think Proform sells them too. If there are a few threads left deeper down you can screw the longer bolt in but I always goop the bolt up real good with red locktite too which will help give it some extra strength in what is left of the stripped threads too.

I had a stripped stud in my KX250 dirt bike that I used a longer bolt and JB Weld for reinforcement but a stud doesn't have to be removed like a bolt. The JB Weld is super strong stuff but I don't know how easy it would be to ever remove the bolt if you needed to.

As far as Heli-Coils go, I think that the thicker threaded inserts are stronger.

I stripped one of my cranks once years ago and drilled it out to a larger bolt.
 

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Your harmonic balancer boot is 7/16-20 I personally would just go up one size to 1/2-20 which is BBC size I have raced with some guys with SBC with blowers that upsize to 1/2” to hold the crank hub better.
 

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Never use the harmonic balancer bolt to rotate the crankshaft. Even if it has heli-coils installed from someone else screwing it up.
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I use the bolt all the time, just go slow and let the pressure drop after each 1/8 or less turn. I know I shouldn't but it's right there and so dam easy to do if everything is buttoned up. I do use a snout socket while setting it up though.

I'd drill and tap to next size up over grabbing the last few threads with a longer bolt unless it's a temp fix. That way you can rotate the engine with confidence using the bolt again:sunglasses:
 

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I use the bolt all the time, just go slow and let the pressure drop after each 1/8 or less turn. I know I shouldn't but it's right there and so dam easy to do if everything is buttoned up. :sunglasses:
I've done it before too. I've also stripped the crank just like this guy did. It's a very tempting shortcut to make... especially if you don't have the tool to do it right.

It's definitely not recommended and you are risking stripping the crank every time you do it. It's a rookie mistake that a lot of backyard mechanics make. I guess you can decide if it is worth the risk. The correct tool is cheap though and well worth the price even if you only use it once or twice. Trying to drill and tap the end of the crank while the engine is still in the car is a major PITA!

You only have to strip one to realize that it was not worth the risk.

I've also just taken three bolts and screwed them into the pulley mounting holes and used a harmonic balancer puller to rotate the crank. Anything other than the harmonic balancer bolt.
 
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