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Keep the balance shaft?!?!??

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drcolt

20+ Year Contributor
76
12
Jun 27, 2003
Toronto, ON_Canada
I am in the middle of changing cams to performance cams and I figured to replace the timing belt and all seals and pulleys and waterpump, etc....... remove balance shaft. or not. I dont know the history of the motor I have. All I know is the donor car had over 530K kms on it.
I then recalled this was talked about a few years back, found this site, http://www.jackstransmissions.com/pages/keep-your-balance-shafts


That article makes a lot of sense. I believe BS failure is improper maintenance. I do have the kit for deleting, but now I am thinking I might just keep them. I am not after big hp. I do want a nice driving motor, although there is nothing smooth about the colt!

This should be a good read for new dsm owners.
There have been nissans that have had issues with knock at high rpms when balance shafts have been removed.
Porsche makes their motors with BS, as well as many other manufacturers of large displacement 4 bangers.
 
leave them in . just put a gates timing belt and balance shaft belt and always keep an eye on your engine oil level and you shouldn't have any problems .
 
I could be wrong... but I believe the Mitsubishi Siruis engine platform (4g6x family) started out as a 1.6L. That version of the engine did not have balance shafts. However, when they bumped the displacement up to 2.0L, there was a noticeable increase in NVH which led to implementation of the balance shafts to counter that issue for people buying car with those engines (hard to sell cars if you feel vibrations all over the place). That would explain the comment above about leaving balance shafts for a stroker motor (even more displacement). That is why you can perform that "mod" using factory Mitsubishi parts... you are effectively using the parts found in the 1.6L enigne.

Like I said, I could be completely wrong because I am not an expert. It honestly seems that the whole balance shaft debate is really a matter of preference for the individual.
Yea and like other have said, its ok if youre running stock but if youre going to mod it then its best to delete it , you dont wanna ruin your built motor , the risk greatly out weight the benefit LOL.
 
I kept my bs did the belt change about 6 years ago and still running solid. Making double the hp and seen a lot of track events and I mean abused! Will be doing this to my spyder and keeping the bs soon. Everyone has a different experience, I personally didn't like a few of my dsms without the bs. I don't know if it's just me but the Rpms feel smoother with the bs then without. But don't take me on that. Lol
 
My issue with the "keep the balance shafts" arguement is that I've never seen a shred of empirical evidence showing balance shafts provide any real benefits. Only assumptions and lessons learned by various people. Low oil pressure, clutch issues, etc...These can all be corrected without balance shafts.

Alternatively, there are tons of real world, proven cases where balance shafts have failed for various reasons leading to complete destruction.

Your balance shafts may never fail. But, if they do, you better be willing to assume the risk of destroying the entire motor, worse case. If you're fine with that risk, then keep them.
 
I like them. They will stay in. I enjoy having a smooth car and its worth the "risk" for me. I feel like having a balance shaft issue is like a freak accident. I don't live my life worrying about freak accidents.
 
like anything else you take care of your vehicle and it will take care of you . leave them in if you don't do it right you will open up a can of worms .

Go to Jacks Transmissions web sit and under general tab they explain why you should keep your balance shafts .
 
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Go to Jacks Transmissions web sit and under general tab they explain why you should keep your balance shafts .
We have all read it. still doesn't save your motor when the belt breaks and takes out the timing belt!

Fact.

Also, for your viewing pleasure:

And here's what happens when a balance shaft bearing eats itself, dislodges from its bore, and takes out an oil squirter.

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Not only that. Spun BS bearings, most of the time, go on unnoticed. Its not until you have a failure that you realize the BS bearing was the reason. All those metal shaving are never completely captured by your oil filter either as they constantly go into bypass. The complete oil system will have been contaminated. That means the turbo will require a rebuild and you will need all new bearings minimum, best case scenario. Worst case/is new motor from spun main/rod bearings and trashed crank/rods/cams. Couple that with the possibility of belt failure and taking out the head, I think I'll stick to reducing the over all failure rate/possibility by removing them. Im my situation, a free mod such as a BS removal is better that taking out a $2000 turbo and $5000+ motor. I see no negatives.
 
there is always a reason why things break . it can be your crank and connecting rod bearings ,it can be a seized camshaft or a lean condition causing a piston to melt . all i know is every time something broke on my car is because i did something stupid . Me and my son both have 2g eclipses with over 100,000 miles with balance shafts . he did finally sell his but i still have mine running 30 psi of boost with meth and no problems. maintain your car properly and you shouldn't have any problems .
 
What people dont understand is maintenance isnt the only preventative measures you can take. I've had brand new, oem tensioners fail in a few hundred miles. Nothing you do will prevent failures if you have a factory defective part. Eliminating the probability of it happening in the first place is the only real way to do is, period.
 
its a known fact with detonation the first bearing to fail in your motor will be balance shaft bearing. they wont pass trash like a main or rod bearing. so if you are not confident in your tuning or your luck as you put it. TAKE THEM OUT
nobody is gonna care, really
 
I am in the middle of changing cams to performance cams and I figured to replace the timing belt and all seals and pulleys and waterpump, etc....... remove balance shaft. or not. I dont know the history of the motor I have. All I know is the donor car had over 530K kms on it.
I then recalled this was talked about a few years back, found this site, http://www.jackstransmissions.com/pages/keep-your-balance-shafts

Deleting the balancer does create a lot more vibration but it also made my oil pressure rise by a good bit. If you want a comfortable street car I wouldn't recommend it, but it does leave you one less thing to worry about.
 
The BS delete is not a free MOD. Its about a two hundred dollar mod. Delete kit plus gaskets. Anyhow, so far what this is costing me is time!! I hate gasket scraping, very tedious and time consuming.
I am trying to separate the BS and sprocket from the oil casing!! WTF am I missing. I need to go do more search online!!
Good thing I got right into the timing side. I found a missing oil case bolt, hence the minor oil leak near the balance shaft/ alternator location.
I also found the wrong size bolt holding the idler pulley, extra long with 6 washers!!
Judging by how tight everything has been on , I am worried about popping the bearings out and running into more issues halfway into.
Damn, I am on the fence the with this BS delete. Then I realized I didnt have the sprocket spacer, and I never did order a water pump. So back online I go to order those parts. Another week wait.
Lucky I am in no rush, but it has been two weeks, and I have to move forward.

Any secrets to remove the oil journal stuck on the balance shaft? Without damaging the oil case.

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Last edited by a moderator:
I could be wrong... but I believe the Mitsubishi Siruis engine platform (4g6x family) started out as a 1.6L. That version of the engine did not have balance shafts. However, when they bumped the displacement up to 2.0L, there was a noticeable increase in NVH which led to implementation of the balance shafts to counter that issue for people buying car with those engines (hard to sell cars if you feel vibrations all over the place). That would explain the comment above about leaving balance shafts for a stroker motor (even more displacement). That is why you can perform that "mod" using factory Mitsubishi parts... you are effectively using the parts found in the 1.6L enigne.

Like I said, I could be completely wrong because I am not an expert. It honestly seems that the whole balance shaft debate is really a matter of preference for the individual.

^^^^This.
 
Sorry to bring up an old thread, but I'm looking to get the GSC shaft that supports the oil pump driven gear. After the near catastrophic oil pump failure I had at Lime Rock, I wanna make sure I do this motor right for next season. Everything in my mind tells me it's beneficial. Any cons to having it? My shafts have been deleted for years. I'm not putting in the front shaft. Just the GSC shaft. Thanks.
 
The gsc shaft is nice. Id replace the bearing in the block for a peace of mind. For roadracing its deff a good choice.

For everyone else
Ive always deleted the shafts for peace of mind and higher oil pressure. Ive also done it where i just removed the belt for the front shaft and left the shaft in there. This keeps the oil pressure from going up and you dont have to worry about the belt snappinf and going into your timing belt.
 
Sorry to bring up an old thread, but I'm looking to get the GSC shaft that supports the oil pump driven gear. After the near catastrophic oil pump failure I had at Lime Rock, I wanna make sure I do this motor right for next season. Everything in my mind tells me it's beneficial. Any cons to having it? My shafts have been deleted for years. I'm not putting in the front shaft. Just the GSC shaft. Thanks.


No drawback other than the cost of the shaft, and it's not expensive.

It helps eliminate side loading of the gears, especially in the case of the timing belt being over-tightened.
 
stubby is waay more reliable than running a cut down shaft.

But running a stubby with helical gears has proven to cause side loading, and you can't put the straight cut gears in the helical case. A buddy of mine might have a straight cut case in his garage. Hoping he does, otherwise I'm gonna buy that shaft to keep the driven gear supported.
 
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