CUT Balance shaft Belt [Merged 6-7]cutting belts remove

[HiPsiTsiMike]

can you cut the balance belt off? without having any motor problems?
and will it give a difference in HP gain?
thanks

 

[dnhieu]

i have a question towards these responses. how is the motor not out of phase and causing a ridiculious amounts of vibrations???? im "guessing" that the balance shafts are not both insync together???? i have screwed up my balance shafts doing a timing belt job once and it caused a HUGE vibration in my car...


thanks in advance
david

 

[dsm-onster]

Well, having two balance shafts out of phase w/ each other or out of phase w/ the engine is at least twice as bad as having only one rotating in the first place.

 

[wret]

i have a question towards these responses. how is the motor not out of phase and causing a ridiculious amounts of vibrations???? im "guessing" that the balance shafts are not both insync together???? i have screwed up my balance shafts doing a timing belt job once and it caused a HUGE vibration in my car...


thanks in advance
david

Here's the oversimplified answer:

One balance shaft cancels half the normal vibration.
Two balance shafts cancel all normal vibration possible.
Balance shaft out of phase cancels no vibration but adds to it.

 

[daren_p]

There was a discussion on this topic on a local board, one member posted this quote that was from a Mitsu tech. Just thought I'd add it to the discussion:

Consensus is that it sucks.

It's cheap, dirty and doable much like the chubby girl at the end of the night, but it's bad for a number of reasons just like the chubby. I'll explain...

The front balance shaft is belt driven, the rear shaft is integrated into the oil pump. Removing the belt only makes things vibrate, this does and will loosen up bolts. Many of those bolts are important. You can feel if a balance shaft belt is broken just by sitting in a car at idle, you can really tell about 3000 rpm. Those who say it's not that bad aren't quite right if you ask me.

Removing the rear shaft and replacing it with the stubby shaft or a turned down shaft is preferred. You can do this with the engine in the car. This frees up three things: some hp, some oil pressure is gained and you'll no longer live in fear of having that rear bearing back there seize up. Odds are when it seizes, it'll take out a rod bearing and other important stuff too.

Leaving the front shaft in is where alot of people live though. After removing the rear shaft, cutting the balance belt is tempting, very easy and you won't fight the vibration issue as much. It's still bad though, even worse. Cutting that belt for the front shaft gains you only two things: frees up some more hp and even less fear of catastrophic engine damage. No oil pressure is gained here; this is where it gets important and is why you shouldn't do it.

That front balance shaft has two bearing surfaces on it. The front bearing surface, by the sprocket, has a groove all the way around it constantly losing oil pressure. This bearing surface always has lost some pressure though, it is designed to flow that way and is accounted for by the DSM Gods.

It's the rear bearing surface that's got chubby chick all over it. It has an oil groove that is only cast into half of the bearing surface. If the balance shaft is always sitting so that the groove is up on the oil galley, you're constantly losing oil pressure on that galley. Your oil system was not designed for that to happen like that. It was designed to spin X times crank rpm and this allowed for a set oil pressure and flow drop at that point. Now the bad news is that your crank thrust bearing is fed from that very same oil galley. So it's 50/50 on whether leaving your front balance shaft in is gonna cost you a crankshaft or not at some point. Do ya feel lucky? 50/50 is probably about the same as whether or not your friends catch you with the chubby. You'll remember a crank and that chubby for a long time, if you know what I mean.

Do it right.

The part of this that doesn't seem to make much sense to me, is he's talking about the isses with the rear shaft not spinning & why its bad & then say's that the front shaft not spinning can effect this. The rear shaft is still spinning, so why is this an issue?

 

[dsm-onster]

I believe he's talking about leaving the bs belt (though removing the rear shaft) so that oil is still fed properly to all the block bearings. He primarily discusses the crank thrust bearing. It seams that the oil to this bearing is fed directly from the front balance shaft ? ? ? .

Waht are the chances that the front shaft rotates and STAYS at a position where it drops pressure to the thrust bearing. Further. If the shaft rotates (because of vibration is my only guess), what is the likelyhood that it will stay there ? Why wouldn't it keep rotating until the oil is again fed properly. PLUS there is a very small degree of rotation where the bs lines up w/ its bearing so as to lower pressure.

 

[RoadRage78]

So, after reading this thread I'm wondering how I should approach the b-belt issue I just found. I'm getting ready to install a motor into a '94 and when I pulled the cover off to inspect the timing belt, I found there is no balance shaft belt, aside from a big chunk of rubber dust on the bottom of the auto-tensioner. Should I attempt to replace the belt, or should I completely remove the balance shafts? I've already driven the car this motor was in, and I really didn't notice much vibration (although it's been almost 2 years since I've driven this car) aside from what sounded like valve train noise. I'm not sure which route to take, so I'm looking for some pro's and con's from both sides here. Thanks in advance!

 

[dsm-onster]

'If it ain't broke, . . .'

I think the thread has already discussed the pros and cons.

 

[luvmygst]

I eliminated my b/s for less than 5 bucks. Take the front shaft out. use the shaft backward to knock out the back bearing, find a socket (big) that is the same size as the front bearing and knock it out. Re-install the bearings 180 deg out to block off the oil passages. for the back one just take the shaft out of the oil pump and cut the end of it off just behind the end of the oil pump housing. You will have a hole in the middle of the shaft you have to weld this up if you dont you will have a big oil leak the, the back shaft is oiled through the shaft. For the front cover find a freeze plug that fits in the hole and JB weld just to be sure it doesnt come out. Then you just have to buy a shorter bolt to put back where the b/s belt tensioner went. Total investment less than 5 bucks.

 

[TunaTalon]

With the balance shafts out of phase the engine will shake left and right as well as up and down which we consider “normal”. When the harmonic imbalance frequency matches the natural frequency of your car’s chassis/suspension the vibrations will be amplified.

See page 41 of http://www.kidzuku.com/StrokeOrNot.pdf. For the physics involved.

 

[dsm-onster]

With the balance shafts out of phase the engine will shake left and right as well as up and down which we consider "normal". When the harmonic imbalance frequency matches the natural frequency of your car's chassis/suspension the vibrations will be amplified.

See page 41 of http://www.kidzuku.com/StrokeOrNot.pdf. For the physics involved.

Great. But, running w/out the BS belt does not constitute 'balance shafts out of phase'. See: Post 53.

 

[TunaTalon]

Great. But, running w/out the BS belt does not constitute 'balance shafts out of phase'. See: Post 53.

Post 53 was correct in every word, just simplified to the point of missing some words.

My post 59 was simplified too, trying to get some physics added to the anecdotal posts.
Following are a few more words to cover various things that can go wrong with balance shafts. Of course all vibrations discussed below are at twice the engine RPM.


NORMAL OPERATION
One balance shaft cancels half the normal vertical vibration forces from harmonic imbalance but adds horizontal forces.

The second balance shaft cancels the other half of the vertical forces from harmonic imbalance and cancels all of the horizontal forces from the first balance shaft.

ABNORMAL OPERATION
Two balance shafts out of phase with the engine but in phase with each other will add to the vertical vibration but not add horizontal forces.

Two balance shafts out of phase with each other will add both vertical and horizontal forces.

One balance shaft in phase with the engine will cancel half of the vertical vibration but add horizontal forces.

One balance shaft out of phase with the engine will add to the vertical vibration and add horizontal vibration.

 

[LowDime]

i just read this entire thread, and now i am more confused than i was. Some people have had no problems and some people have had failure. I am new to the dsm world and was curious about this cause i have heard the horror stories of the BS belt breaking and taking out the timing belt leading to valves and possibly a new head. So where did you all get your bs removal kit

 

[wret]

The dicussion in this thread is not so much on balance shaft elimination, but on balance shaft belt elimination, whether deliberate or accidental. I don't think anyone disagrees that the full elimination kit is the best way to go but there are some differences of opinion concerning the safety of removing just the belt.

 

[shadowguard]

when my lower balance shaft falled i was wondering why, then i looked somebody who had the car had removed the belt ,it killed two cylonders,it cost me for a head and a balance shaft removal kit

 

[TurboTsiThatFly]

okay so my a/c belt broke and took out my crank position sensor. so i had to go in and repalce the sensor and the timing belt components. when we pulled the front timing cover off the car. (when i say we i mean me and my mechanic.) we noticed that the balance shaft belt had been brokein and from the looks of it, it had been broke for a really long time. so we turn the motor over to TDC. and my exhaust cam was one tooth out of timing. along with my oil pump being a couple teeth out of timing. Long story short i replaced my timing belt my b/s belt, alternator belt, a/c belt, power steering belt. i got the car all back together and it runs fine. but my belts side of the notor are making a turning sound that increase's with rpm increase. i was wondering if maybe my balance shaft is what is making the noise because it hasnt been turned in forever. also when i crank my car in the morning the noise i hear is louder. alos my car doesnt want to crank up in the morning. it just kinda stumbles and dies. then i turn the car over again and it starts up but kinda stumbles before clearing itself up.

Anyone have any ideas on my theory? the noise my belts side of the motor makes, makes me not even want to drive the car.

 

[Turbotalon25]

If I was you, if you have time I would get rid of the balance shafts. Get a removel kit. It sounds like it has bad bearings. If they freeze up if could take out your timing belt or even worse you could lose oil pressure like I did and destroy your whole engine. My ballance shaft froze and took out every thing. Just an Idea for peace of mind.

 

[TurboTsiThatFly]

this is exactly what i was a afraid of. can you remove both balance shafts with the motor in the car?
I need a wiseman to lead me in the right direction.

 

[Turbotalon25]

Well your going to have to take off the upper motor mount and losen the other mounts and lower your motor down. your going to have to take the oil pan off and also the timing belt and pullys. If you were going to replace your timing belt this would be a great time. also you will have to take your oil pump off of the motor. at this point you will be able to take the balance shafts out. You will need the kit like I said. I will give you links for this mod and a link for the kit in just a min.

 

[Turbotalon25]

DSMparts Balance Shaft Eliminator Kit - DSM Internal Engine Parts - Engine - DSMparts.com THE KIT: you can find it cheaper on Ebay.

Eclipse Balance Shaft Removal Instructions.

Let me know if this helps.

 

[pj91gsx]

Yea, you can remove the BS with the motor in, Just make sure you flip the bearings 180 degrees. One BS has an oil feedline in it so the bearing doesnt have an oil hole.

 

[JusMX141]

Same exact thing happened to my buddy's '95 TSi AWD. We pulled the cover for a routine timing belt service (and to repair leaking cam seals), and here's what we found:

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It had been that way a very long time, and we never knew a thing was wrong with the car. The only sign was occasionally under hard launch the oil light would come on....apparently the balance shaft would rotate enough to allow oil to flow right through it, then fall back when the car got moving.

We didn't have an elim kit on hand and I didn't feel like dropping the pan and doing all the extra labor to eliminate the balance shafts, so we simply installed a new belt. The engine will be coming out this winter anyway, at which time the elim kit will be installed. Here's the finished product:

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[TurboTsiThatFly]

Yea, you can remove the BS with the motor in, Just make sure you flip the bearings 180 degrees. One BS has an oil feedline in it so the bearing doesnt have an oil hole.

Same exact thing happened to my buddy's '95 TSi AWD. We pulled the cover for a routine timing belt service (and to repair leaking cam seals), and here's what we found:

You must be logged in to view this image or video.

It had been that way a very long time, and we never knew a thing was wrong with the car. The only sign was occasionally under hard launch the oil light would come on....apparently the balance shaft would rotate enough to allow oil to flow right through it, then fall back when the car got moving.

We didn't have an elim kit on hand and I didn't feel like dropping the pan and doing all the extra labor to eliminate the balance shafts, so we simply installed a new belt. The engine will be coming out this winter anyway, at which time the elim kit will be installed. Here's the finished product:

You must be logged in to view this image or video.

DSMparts Balance Shaft Eliminator Kit#-#DSM Internal Engine Parts#-#Engine#-#DSMparts.com THE KIT: you can find it cheaper on Ebay.

Eclipse Balance Shaft Removal Instructions.

Let me know if this helps.

Well your going to have to take off the upper motor mount and losen the other mounts and lower your motor down. your going to have to take the oil pan off and also the timing belt and pullys. If you were going to replace your timing belt this would be a great time. also you will have to take your oil pump off of the motor. at this point you will be able to take the balance shafts out. You will need the kit like I said. I will give you links for this mod and a link for the kit in just a min.

So do you think that the sound i hear on my timing belt side of the motor is my balance shaft makeing the noise. because it hasent been turned in a long time? because i never heard the sound before and we assume the B/S belt has been broke for at least 10,000 miles. and now that we have a new Gates Racing Performance belt. belt on it. i have what sounds like bearings chirpings. im not saying that is what the noise is thats just what it sounds like. So do you guys think that my b/s shaft is pretty much f'ed?


And to Turbotalon25
i have allready replaced the timing belt and balance shaft belts. with Gates belts that how i figured out the B/S shaft belt was broke. now i have this weird sound. and i wanna know if it could be my balance shaft bearings. because they havent been turned in forever. like 10,000 miles ago.????

 

[JusMX141]

Is it possible that a front balance shaft bearing took a dump which is what caused the belt to break in the first place?

Did you try to turn the front b/s gear when the belt was off? Did it spin freely?

 

[pj91gsx]

My BS belt was broken in my jdm swap when I got it. might as well do away with it.

 

[TurboTsiThatFly]

Is it possible that a front balance shaft bearing took a dump which is what caused the belt to break in the first place?

Did you try to turn the front b/s gear when the belt was off? Did it spin freely?

my mechanic had to turn it to get it back in time with the motor. so i assume there was no problem turning it. but idk ill have to ask hiom.