balance shaft, bearing got chewed up and tossed around...

[Hortanica]

A few months ago, and 6k miles ago, my rear balance shaft chewed up a bearing and when i dropped the pan, i noticed bearing material in the pan.

So i replaced the front case, oil pump, and did the BSE with leaving the front shaft and bearings in place. everything was fine, except i had really high oil pressure (~80psi to 100psi from 4000rpms and up). Everything was cleaned in the pan as well, and i cleaned the pickup.

The last couple days ive been taking the engine and tranny apart outside of the car, to redo some stuff and clean up some rust in the bay, and when i took the oil pan off to redo the gasket and drill out the drain for a larger one, i looked down in the engine and saw this just hanging out, wedged under (over?) the front balance shaft:

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I took it out, and felt the front balance shaft. There was no play in it at all, and the bearings seemed tight (read: not missing).

So i took that in the house, and looked at it and noticed there were no oil holes in it. like it wasnt the front balance shaft bearing....

My question is, should it have a hole in it for oil if it is the front, and i just got effing lucky with no engine damage (theres been 6k miles put on the car after i did the BSE kit install)

 

[talonDSMerr]

The front balance shaft bearings have oil holes in them. The rear one doesn't, however...

 

[1991 awd talon]

ok im a noob i know. but im just starting out learning about my cars. and i cant quite figure out what the hell a balance shaft is!

 

[talonDSMerr]

They're eccentric shafts inside the engine block that are meant to counteract some inherent imbalances in 4 cylinder engines.

 

[1991 awd talon]

so. ok. whats the point in eliminating them/(it?) then? is it for weight reduction? how much do they/(it?) weigh?

edit: o.p. sorry for jacking the thread!

 

[MaKaPhiLLy]

It's not for weight reduction but it will take a few pounds off. It's because the front bs runs off a belt if that belt snaps it most likely snaps your timing belt as well then your really screwed. And deleting them I read can free up anywhere from 5-12 hp isn't much but it's better than nothing. The elimination doesn't need to be done it just prolongs your engine from something that doesn't need to happen.

 

[drknorris]

The elimination is good, just one less thing you need to worry about and maintain. Just need to watch out for the increase of oil pressure.

 

[Hortanica]

IM gonna bump this for one more question:

I started replacing the water pump, and noticed oil around the balance shaft gear (left shaft in place...) and then i started turning it, it turned fine, and then i pulled on it, and there is about a 1/4-1/2" of play in and out on teh shaft. Is this normal or should the shaft be "stuck" in place and have no in/out movement.

 

[MaKaPhiLLy]

I'm not 100% sure but it probably shouldn't move at all. While your already there why don't you remove it n block it off.

 

[Hortanica]

Well i figured it out today, and it was my own retarded fault .


When i replaced the front case before, i did it with the engine in the car, and i never noticed the balance shaft and sproket were keyed, so it wasnt on the shaft all the way, allowing me to move it the thickness of the sprocket in the center...all fixed now though!

 

[jackblack65]

The balance shaft runs at twice the speed of the crank to save the engine from harmonic vibration.
It is there for a reason and you can afford the 10 hp it cost to run it,unless of course you LIKE crankwalk and stuff like bell housing cracking and other metal fatigue.

 

[2slow4now]

Really they are silence shafts. The harmonic vibration your talking about is still there in the crank because the rotating weight is still on the crank. This is a normal mod and you can even buy OEM balance shaft elimination kits. They just make the car more consumer friendly. Just like alot of guys put in a cone filter and chuck the air box. Its louder which doesn't fit regular consumer standards.

 

[1gdsmftw]

ORRRRRRRRRRR instead of doing all this. Just invest in a nice gates racing balance shaft belt. All the bs delete is, is a piece of mind mod. It doesn't free up hp, it just removes rotational mass and eliminates 1 less area oil has to travel. Doing this allows oil psi to raise requiring the ofh's pressure valve to be ported a little to allow the oil pressure to lower some. This prevents any damage to the bottom end from excessive oil pressure. Honestly though, I just stuck with a gates belt and called it a day.

 

[Robbyd]

so whats the disadvantages of taking it out?

 

[jackblack65]

ORRRRRRRRRRR instead of doing all this. Just invest in a nice gates racing balance shaft belt. All the bs delete is, is a piece of mind mod. It doesn't free up hp, it just removes rotational mass and eliminates 1 less area oil has to travel. Doing this allows oil psi to raise requiring the ofh's pressure valve to be ported a little to allow the oil pressure to lower some. This prevents any damage to the bottom end from excessive oil pressure. Honestly though, I just stuck with a gates belt and called it a day.

Good advice.
However the extra rotational mass is what the balance shaft is for and is needed to smooth out the vibration.
The problem is getting oil to the bearings spinning at twice the speed and going up
quadratically proportional to RPM.
I would drill the rear bearing for an oil pass if I were already in there replacing the originals that failed.

 

[Calan]

The balance shaft runs at twice the speed of the crank to save the engine from harmonic vibration.
It is there for a reason and you can afford the 10 hp it cost to run it, unless of course you LIKE crankwalk and stuff like bell housing cracking and other metal fatigue.

The balance shafts have absolutely nothing to do with crankwalk, bell housing cracks, or harmonic vibration within the rotating assembly. They are simply there to counteract imbalances that are inherent to the engine design, mostly for driver comfort as 2slow4now and talonDSMerr mentioned.

Deleting the BS and belt doesn't affect engine longevity, and may save you from having to replace a timing belt and valves due to the belt snapping.

 

[1gdsmftw]

The balance shafts have absolutely nothing to do with crankwalk, bell housing cracks, or harmonic vibration within the rotating assembly. They are simply there to counteract imbalances that are inherent to the engine design, mostly for driver comfort as 2slow4now and talonDSMerr mentioned.

Deleting the BS and belt doesn't affect engine longevity, and may save you from having to replace a timing belt and valves due to the belt snapping.

Of course you are correct. BUT, Without proper support the balance shafts being gone does more harm than good and you know that. The raise in oil pressure would obviously wash out the bottom end. But of course those who are endowed enough to pull the front case off to do the delete would also spend the time to port their ofh as a precaution I would hope.

 

[Nasty Dream]

those who are endowed enough to pull the front case off to do the delete would also spend the time to port their ofh as a precaution I would hope.

What's ofh?

 

[Calan]

OFH = Oil Filter Housing

 

[jackblack65]

The balance shafts have absolutely nothing to do with crankwalk, bell housing cracks, or harmonic vibration within the rotating assembly. They are simply there to counteract imbalances that are inherent to the engine design, mostly for driver comfort as 2slow4now and talonDSMerr mentioned.

Deleting the BS and belt doesn't affect engine longevity, and may save you from having to replace a timing belt and valves due to the belt snapping.

Maybe I should be a bit more specific,my advice is for a daily driver not a race build.
You are correct that the BS has no effect on internal crank vibration.
You however are wrong about anything bolted to the motor being affected by its removal.Vibration will certainly increase leading to the flexplate bolts loosening or snapping,bell housing cracks ( i know of at least 2 instances in a different engine design this mod was done on)motor mount failure,never mind the increased rattling loose of the whole car.
The crank walk issue I point to is for the 7 bolt design because the bearing surface area was reduced so much from the 1G that any mod that affects the crank had better be carefully considered.Removing the extra restraint of the BS will place more strain on it.
Removing the BS has its advantages too but IMO unless you are going to race it are not worth the effort.
Considering spinning to 7k results in the BS spinning at 21k it's no wonder the bearings fail especially since the rear ones are not really lubed!
So what is the solution to have it all?
Some serious dough,
the block could be modified to include tapered roller bearings for the shafts and the belt drive changed to a roller chain setup.I doubt these parts even exist.

 

[Calan]

You however are wrong about anything bolted to the motor being affected by its removal.

Stop putting words in my post. Where did I say anything like that? We're talking about silent shafts.

The crank walk issue I point to is for the 7 bolt design because the bearing surface area was reduced so much from the 1G that any mod that affects the crank had better be carefully considered.Removing the extra restraint of the BS will place more strain on it.

Ok.

Please show me one instance of crankwalk due to a BS shaft being removed.

We're all waiting...

EDIT:

Yeah... that's what I figured.

 

[BrokenTsi]

If raised oil pressure is a concern, then you need to lower the engine oil pressure. This can be done by simply removing some material from the relief port in the filter housing.

 

[jackblack65]

Stop putting words in my post. Where did I say anything like that? We're talking about silent shafts.



Ok.

Please show me one instance of crankwalk due to a BS shaft being removed.

We're all waiting...

EDIT:

Yeah... that's what I figured.

I am not even going to respond to your abusive BS.
Knock it off.

 

[Zack Huffman]

I definitely wouldn't call that comment abusive, but anyway, I'd really like to hear your reasoning or experiences behind stating that keeping balance shafts helps prevent crankwalk.

Also, what did you mean by:

it's no wonder the bearings fail especially since the rear ones are not really lubed

You've got my attention, and here's your chance to earn back some of those lost rep points. Go ahead, impress me, I dare you.

 

[jackblack65]

My reasoning goes something like this:
Increased vibration makes for increased wear on the bearings.
As stated and I agreed the removal of the BS does not affect the rotating internals.
What is increased however is everything else attached to the motor,So when you push in the clutch more vibration will be transferred to the thrust bearing.
Bell housing cracks developed in a chevy 6 cyl after removal of BS.I will post the article when I find it later.
As for the rear BS spinning at those RPM's not that much oil can stay on it.