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Quick question about balance shafts

vscalais951

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Hey guys, probably a dumb question but here goes..........

Bit of back story, my VS V6 ute developed a rattling noise that sounds like its below the the inlet manifold, in the top of the motor, after a bit of a read through the forum and watching some YouTube links, i thought it sounded like the timing chain and tensioner probably needed replacing. So i went ahead and replaced all that, only to start the engine and find the rattle is still there :(

So back onto the forum i went, and now im starting to think the balance shaft bearings are on their way out or something. So i figure ill disconnect the balance shaft temporarily to see if that's my problem.

So i just want to confirm that to disconnect the balance shaft i remove the smaller gear off the end of the balance shaft itself, and retain the larger of the gears that goes on the cam to basically act as a spacer behind the camshaft sproket? Is that correct?
 

vombil

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if you've got a noise in the top end it's probably lifters mate. what is this balance shaft you speak of?
 

woteva

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greenacc

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But surely they put it there for a reason?
 

vs-lover

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Yeah to balance the engine and make it more comfortable to drive.

Disconnect it and see what happens.

This was the common problem with the Astron engine fitted in the Sigma's and Magna's. The balance shaft chain would stretch rather quickly from new with no more adjustment left in the tensioner and then the motor would not idle smoothly.
Many back yarders decided to take that chain out along with the balance shaft and yes they got more power but they then also found that the engine became far more of a pig to live with on a day to day basis.

The same would apply to the Buick and Ecotech power plants I'm sure.
 

immortality

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The balance shaft is there to cancel out some of the strange harmonics due to the 90° V6 engine configuration. I tool the balance shaft out of my VN and it wasn't really any worse than with. I did also fit new engine mounts and then a proper harmonic damper and IMHO it was smoother than with balance shaft/stock balancer.
 

vscalais951

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Cheers for the replies guys, I have undone the gear on the shaft and will finish putting the motor back together after some gaskets arrive and see how it goes. It may not be the issue but for the price of the gasket I can cancel it out and go from there :) I'll post up a final answer once the motor is back together. Thanks again :)
 

woteva

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Keen to hear how it goes.
 

vombil

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i'd just rip it out and get on with things. a good motor is only $300
 

zeropalooba

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You don't have to take the balance shaft out, just take the cog off the end. A good reason for leaving the shaft in place is that it seals an oiling hole at the rear of the engine. If you take the shaft out without plugging the hole it might cause your oil pressure to drop. I disabled the shaft when I put on a double row timing chain. Same as Immortality, I noticed no real difference.
 
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