Please help....

[Tabone777]

Ok here is the deal I have a 67 chevy stepside with a 350 in it. The other day im driving down the road and I hear a clunk and look out the window and see something rolling down the road. I pull over and notice that the harmonic balancer and pulley had came off. I noticed that the crank threads are now stripped out a lil bit.

I wanted to get the crank helicoiled so I called a automotive shop and they wont do it. So im considering helicoiling the crank myself. I have never done this and was hoping someone could give me a good break down on what to do. I saw o'reillys has a helicoil kit you can purchase but dont know what size i need.

Also the pulley and harmonic balancer are trash now and I dont have the bolt that came out either. Should I go to a junk yard and pull the pulley and harmonic balancer or just by a new one. Is there a specific size balancer I will need? What size bolt will i need now?

Sorry for alll the questions. anyone's help would be appreciated.

[E.Furgal]

the 350 could have 2 different sized balancers.. you'll need to know what one you have
next I'd not use heli coil..
look into these..
http://www.timesert.com/

[Tabone777]

Ok, should I just bring the one I have and match it by size?

[jocko]

you can buy a balancer bolt from summit or any big auto parts supplier, and it'll just be a SBC crank bolt for the balancer retention, all should be the same. Despite different pulley availability, the crank should still be drilled the same way. Pulleys from a junkyard are an option. I would only install a new damper, but that's just me.

I personally would not exactly be comfortable helicoiling a crank snout. I'm not sure there is a safety reason behind that feeling, but there could be. If the crank is forged, it would be tough to do (but probably still doable) - cast crank should be easy enough to do. I would definitely make sure the heli-coil can withstand the torque you need to reply and to hold that torque. I think it should, but again, I'd probably replace the crankshaft. Yes, that would suck. Bottom line - before you do this, I'd contact the Heli Coil company and just ask if it's not ok to do...

Heli-Coil how to: Buy the kit (and there are far from cheap) - drill out the hole, tap it (tap and drill usually in the kit), then screw the heli-coil (several included in the kit) into the fresh threads and snap the tab off (that is what is used to twist it in - if you don't remove it, it would block the bolt you're trying to screw in).

Not sure I helped. I'd think hard abotu heli-coiling if the machine shop wouldn't do it? DId they give a reason? It may be ok to do, but their refusal would make the hair on the back of my neck stand up. Could be liability-related, which means maybe a heli-coil might not be the best route.

[midniteblues]

Are all the threads in the crank gone or just some?
maybe a longer bolt would work ??
Could it just be drilled and retapped a lil' bigger size?
Idk if a lil' bigger size bolt would be available.
Since the balancer came off did it mess up the crank snout?

[Tabone777]

Well I didnt call a machine shop I called my local mechanic and he just said that he did not feel comfortable doing it . I didnt think about a machine shop. Anyway I guess Im going to give it a try since I need my truck to get back and forth to work. I just hope I dont destroy the crank trying to do this.

And as far as the threads go they are not all gone but a good amount are smoothed out. The snout looks ok from what i can see.

[71swb4x4]

If you need the truck to get back and forth to work you should probably let a machine shop handle it. Sounds like you might only get one shot at this one.

[odog]

I agree, Heli coiling a regular bolt hole s no big deal if you screw it up, but screw up the crank and thats it, your done. Not saying I dont have faith in you, but maybe find a machine shop, they should do it with no problem and not to much $$$. I understand the mechanics not wanting to, its not really in their field, but any machinest worth his salt should be comfortable doing it.

Just my .02

[hugger6933]

Have you tried to run a bolt or a thread chaser in the hole to make sure the threads are gone? One option that has not been brought up is epoxy in the crak snout .Quicksteel and others are tappable once cured sound last ditch now that I have typed it. Chase the treads just to see they may only be flattened at or toward the outside edge.

[jablack]

I would just tap the threads and use a new bolt. Make sure you install the new balancer all the way.

[mud.man.rj]

I have just chased the threads and used a bit thinner washer and have also heli-coiled them, no big deal because a few years previous on 283 and some 327 engines there was no bolt to retain the balancer at all from factory, just a press fit, so long as you have something and thread retainer (loctite) no big deal.

[Tabone777]

I have not tried chasing a thread on it. The front half looks to be gone. There is still good threads at the far back of it. Probably the last half.. I appreciate all of yalls input on this. Im trying to chase a pulley down that will match what I had..
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