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)

 

[delta448]

the removal of the BS does not affect the rotating internals..

when you push in the clutch more vibration will be transferred to the thrust bearing

These 2 statements almost contradict each other.

The problem I have with all this fuzzy logic is that there are other 4 cylinder engines with single plane crankshafts that don't even use balance shafts, and they don't have the blown-out-of-proportion claims of crankwalk like the 7 bolt 4G63 does. So if block vibration causes crankwalk, why don't those engines have it way worse?

As for the rear BS spinning at those RPM's not that much oil can stay on it

Remember that the oil pump is spinning faster too...

 

[jackblack65]

The moment is multiplied by the distance from center so the transmission length
is what add's the increased chatter to the bearing face.
As for other I4 designs having more or less vibration and all things being equal,Stroke plays the biggest role, more stroke more velocity snapping the slugs back.Only so much angle can be applied to the rods so the cranks balance is changed by how far it is pushed.
This motor just happens to be the highest output I4 ever made so it doesn't surprise me at all it has some ballance issues.
I would only feel comfortable removing the BS if I could increase the surface area of the thrust bearing.

 

[DearestNameless]

For the OP.

Here is the vfaq on how to eliminate the balance shafts.

Balance Shaft Eliminator Kit Install

And as for a place to get the kit.

4G63 4G63T 2.0 4G64 2.4 Balance Shaft Eliminator Kit Mitsubishi and Hyundai

^ There are more vendors here who have this kit and might be more reliable.

As far as answering your concerns about rather to do it or not you can use the search function here on the forums.

DSM Forums - Search Forums

Type in "Balance Shaft" and select "Titles Only" then press "Search".

The system will then locate multiple threads which will mostly likely answer your questions.

If you have any other questions that the forums can't answer you can pm me, pm a wiseman (If they don't mind), or post up another thread.

Sorry for all the rage in your current thread.

 

[dexterholland04]

The moment is multiplied by the distance from center so the transmission length
is what add's the increased chatter to the bearing face.

I disagree with the use of this statement. The distance termed in "moment" is a radial distance, for which you are referencing an axis (or an axial) distance.

As for other I4 designs having more or less vibration and all things being equal,Stroke plays the biggest role, more stroke more velocity snapping the slugs back.Only so much angle can be applied to the rods so the cranks balance is changed by how far it is pushed.

I agree that the greater the stroke of the engine, the greater the force exerted on the pistons. But, remember that as two pistons are going up (either on compression or exhaust strokes), two pistons are also traveling down (on intake or combustion strokes). These forces virtually counteract each other, save for the slight differentiable tolerances in piston/rod mass between each cylinder. The only other major imbalance would be the crankshaft itself; because although it is balanced, it is not perfectly balanced. Stroke does not speed up the velocity of the pistons...as they are physically linked to the crank. Common engine speed is common engine speed. The stroke distance, (in terms of vibration) merely serves to multiply the vibrations caused by the differences in mass between the pistons/rods.

 

[jackblack65]

I am trying to stay on topic here so let me explain my balance concerns first
but quickly say my use of moment is radial i.e. the center of crank rotation.
Transmission length meaning length from coc to outside radius of clutch or TC.
OK back to vibration,as an example if the vibration at COC were 1/16 of an inch,
And you were running a 10" clutch with 400 lbs of pressure the initial contact could
be 5/16 off and vibrate itself to center upon full contact with a 2000 lb initial force.
making some nasty chatter.I hope there is not that much play in your pilot bearing
but almost any wear to the pilot bearing or shaft will result in TB failure.
In fact ANY misalignment will cause failure.

 

[9!'clipseDOHC]

OP, I had a similar instance just a few hundred miles after a rebuild several years back. On my current engine I have eliminated my BS's and will never run them in a 4G63 again. With Prothane motor mount inserts, I didn't notice any additional vibrations going from having balance shafts to eliminated shafts. For me it has nothing to do with weight loss or freeing up horsepower, it's about preventing catastrophic engine failure.

Here was my BS bearing in the oil pan:

 

[jackblack65]

. Stroke does not speed up the velocity of the pistons...as they are physically linked to the crank. Common engine speed is common engine speed. The stroke distance, (in terms of vibration) merely serves to multiply the vibrations caused by the differences in mass between the pistons/rods.

Consider this :
in a stroked motor the piston moves farther in 1 RPM.
So yes velocity is increased on the piston.

Your other coment about radial vs axial has me thinking though
that my concern would not apply unless the vibration were in fact being transmitted axially,and I believe you are correct.
Finally a decent argument for removal.
Just because "they sell parts kits " means nothing.
They also sell umbrellas for golfers.

 

[dsmornothing]

Oh. My. God. People have been doing BSE for YEARS. Its a Mitsu part. It does not increase vibrations within the engine or really anything solidly mounted to the engine. The vibrations do transmit throughout the car but that is all. I fail to see how you are looking at this whole topic.

With how much arguing you are doing, All you are doing is Pissing people off who have been there and done these things. And PROVED it does not hurt your engine. Remember this when you are looking for help when your car is broke down and nobody wants to help you.

 

[joe sobo]

wow, i never heard so much mis-information in my life, in one thread. damn, why can't i give negitive rep points.

 

[jackblack65]

Yes I know this pissed everyone off going through all of this but put yourself in my shoes,how the hell am supposed to sleep at night now knowing I am driving a ticking timebomb?

 

[nightmares GS-T]

Yes I know this pissed everyone off going through all of this but put yourself in my shoes,how the hell am supposed to sleep at night now knowing I am driving a ticking timebomb?

Time bomb? How so? Since you obviously are the authority here on I4 cylinder engines. In your entire argument you have not even once considered the fact that the balance or silent shafts dont prevent vibration, in fact the dont prevent a damn thing other than the driver feeling the vibrations. The shafts dont affect the rotational assembly's balance either. The only thing they do is ABSORB some of the rotational assembly vibration. Regardless of whether or not they are in there the vibrations are still present. Mitsu simply didnt want the drivers feeling that. I mean after all would you buy a new car if it was vibrating more than usual (which likely wouldnt happen with stock motor mounts) when you went for a test drive? No.

 

[Alex7747]

BSE causing crankwalk?! c'mon man you can't be serious..can you??