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bjam2 04-27-2004 02:48 PM

SBC 350 Crank Balancer Problems
Ok i'm rebuilding my first engine, a 1980 Chevy 350, and i've had nothing but problems. It has taken so long and its just one problem after another.

The current problem is that I can't get the bolt that goes into the crank over the balancer and pulley on. Before I couldn't get the harmonic balancer on cus i was afraid i was gonna strip the bolt hole. Well I finally got it on and now the bolt which I've used 20 times in that hole that is most likely stock won't fit. So i've been having problems and now I think the crank is getting stripped anyway. Bolts still screw in but don't seem to tighten now. The balancer appears to be in as far as it will go.

What can I do? I'm currently freaking out cus this is about the 900th problem and delay I've had.

If I just use a half inch longer bolt and a couple washers along with some silicone or loctite or all thread or whatever will that hold it even though it doesn't wanna tighten?

I really don't wanna have to tap it or anything like that because I don't know anything about doing that and it will probably just create more problems.

87442lover 04-27-2004 03:22 PM

Re-tap the balancer bolt hole.

Robinson Robin 04-27-2004 03:50 PM

Probably a heli coil is the best answer

Goldduster360 04-28-2004 08:49 AM

Never install a balancer without the proper installation tool:spank: You stripped the front portion of the threads on the crank. Run a thread tap to clean it up and re-install balancer with the proper tool, Disount auto should have them, they are cheap. When the balancer is seated properly on the crank you can use the bolt to snug it up.

I feel your pain, been there done that but only once, won't repeat that mistake again.

PS, a balancer installation tool is not a big hammer:nono:

bjam2 05-04-2004 09:06 AM

Ok I tapped it and the tap broke off in the whole. The guy at the store said to use oil and do it by hand and keep backing it out and going back in. It worked ok but then it snapped and it wasn't even very tight. The dang tap barely looks like metal on the inside.

Remember what i said in the first post about it creating more problems? That seems to be how it is with this stupid car, i swear it's never gonna run.

So what do I do now! Drill it out? I started to try and it didn't work well, I doubt my drill is powerful enough.

If i'm not mistaken aren't 283's balancers etc held on with no bolt, just by friction or centripetal force or something. Would mine stay on?

tresi 05-04-2004 09:23 AM

I find that the taps you find at most parts stores aren't very good. If you're just a little crooked or bind it up they'll snap like a twig. They do make an extractor to remove broken taps if isn't in too deep. Your not going to like this but the best thing to do is to remove the crank and take it to a machine shop that has an EDM machine and have them burn it out. Auto Auto machine shops don't have these machines. Your best bet would be to try a general purpose machine shop.
If you feeling really lucky and have some high quality small punches and chisels you can try to break the tap into pieces and dig them out of the hole. Try to spin the tap to the left with you chisel blows, sometimes you can get them to back out when you tap on them. Now your threads will really be screwed a Heli-coil and new bolt will be needed for sure.

machine shop tom 05-04-2004 09:43 AM

You can try to get a tap extractor from an industrial supply house or well-equipped auto parts store. But yes, the older SBCs just used the press fit to hold the balancer on. The bolt is for peace of mind and wouldn't hold a loose balancer on for long anyway. If you balancer is tight enough, you should be okay. And and this point, you have no choice but to pound it on. Pound on the center hub with a flat piece of metal to protect the hub mounting area.

k-star 05-04-2004 09:51 AM

MSC sells a tap extractor by a company called walton. They have 4 fingers that go along the flutes in the tap and 90 percent of the time will back them out. They cost like $15.00 plus shipping. It might be worth a try.

There phone number is 1-800-645-7270 and they take plastic!!!!

usually have the stuff in 2-4 days.....


bjam2 05-04-2004 07:36 PM

Thanks for your help so far.

I bought an Easy Out thing and am gonna try it. It's like a pyramidal wedge and you drill a hole in the tap and stick it in and try to screw it out.

If it doesn't work then i'm just gonna leave it and hopefully the harmonic balancer doesn't shoot off like a frisbee.

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