Balance Shaft Rattle, getting rid of.

Hey All, if you read my old post http://forums.justcommodores.com.au/showthread.php?t=33038
you will see I have had a rattle in my engine since I got it. I have finally checked out the Balance shaft.......this is after, Gearbox, Crankshaft and every other possible thing that can move.

Basically I removed my timing cover (bout 1 hr job) and can sit there and move the end of my Balance shaft around and in and out. Its only minimal play but would make a f&%k load of noise when running. The Timing chain and tensioner looks brand new, so that was good news.

Either today or tomorrow ill be removing the Balance shaft end pully putting it all back together and running the car with out the Balance shaft all together.(although it will still be in the engine). Ill take some pics and let you know how it all goes. Any comment or suggestions are welcome.
Peter.

the balance shaft was fitted to the engine by holden to do exactly as the name suggests. running without it would unbalance the engine further then it already is as it's not the most well balanced engine around as we all already know etc. would be interested how it runs though

yeah I know where your coming from, apart from the rattle the engine is real smooth so I thought even if it roughens it up a little it will be better then the freakin rattle I have to put up with!!

This may be a little off-centre, but back in the 70's when the first Valiant Hemi's came out, they had a bad timing chain rattle which caused the sprockets to wear prematurely. The camshaft bearings also developed fore and aft play. The easy fix was drill a 3/8 hole thru the timing cover directly over the camshaft - then weld a nut to the cover over the hole and screw a threaded bolt in till it put pressure on the end of the camshaft to stop fore and aft movement of the camshaft. Maybe something like this could stop the balance shaft from rattling.

cam shaft end play your talking about. still an issue on small block chevys but lots of simple fixes now for that. normally you fit a special cover thats been machined for a torrington thrust bearing. works a treat. anyway, where exactly is the rattle in the balance shaft?

immortality said:

cam shaft end play your talking about. still an issue on small block chevys but lots of simple fixes now for that. normally you fit a special cover thats been machined for a torrington thrust bearing. works a treat. anyway, where exactly is the rattle in the balance shaft?

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I've seen 2 types on Valiants - one with a dish-end bolt with a steel ball running straight on the camshaft and another which was a hardened bolt onto the camshaft. They both stopped endfloat which was so bad that the timing chain became misaligned wearing the sprockets. Also saw a Hemi with a side mounted chain tensioner which could be externally adjusted to keep the chain tight. All backyard jobs of course.

The benefits of removing the balance shaft are that you can fit a double row timing chain, but if you do it without having the bottom end completely balanced you run the risk of ruining the bottom end as it will be out of balance.

You will have vibrations that are going to drive you more mental then the current rattle you have. Fix it properly or you'll regret it. Trust me.

now if holden had just put a little more time into sorting the balance of the botom end instead of just fitting a balance shaft we wouldn't be in this situation.................................:bang:

You will have vibrations that are going to drive you more mental then the current rattle you have. Fix it properly or you'll regret it. Trust me.

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The thing is im willing to take the risk. For a two hour job in total which could get rid of this stupid F&%king rattle ill take the chance. Just out of curiousity, has anyone actually done this before. Without balancing the bottom end? nor a double row timing chain? or will this be a virgin job and every one just SAYS it will cause viabrations?

Im not stupid and know that it has to effect the balance in some way but Im so keen to see how much it does.

vracclaim2 said:

The thing is im willing to take the risk. For a two hour job in total which could get rid of this stupid F&%king rattle ill take the chance. Just out of curiousity, has anyone actually done this before. Without balancing the bottom end? nor a double row timing chain? or will this be a virgin job and every one just SAYS it will cause viabrations?

Im not stupid and know that it has to effect the balance in some way but Im so keen to see how much it does.

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I reckon I'd give it a go as well. Keep your fingers crossed that the rattle is not still there!
There's a great write up on this engine at:
http://en.wikipedia.org/wiki/GM_3800_engine