Balance Shaft myth debunked!!

[Hitchhikingmike]

The engineers that developed the engine spent tens of thousands of hours doing NVH testing under a whole lot more widely varied operating conditions than your 2000-3000 RPM test, and determined that the balance shaft was necessary for some specific reason.

Oh, you mean just like how the engineers spents thousands of hours and simulated tens of thousands of miles to test the chain tensioners too right?

riiight...

 

[McSlug]

Oh, you mean just like how the engineers spents thousands of hours and simulated tens of thousands of miles to test the chain tensioners too right?

riiight...

My sentiments exactly.
I would not use the genius of those engineers as a basis for my argument.

I'm thinking their conversation's went something like this:
"How are we going to turn the other cam?" "I know we'll turn the head around and put the chain at the back."
"What should we make the chain guides out of?" "Some kind of plastic I guess."
"What about the primary tensioner?" "Two no,no three flimsy leaf springs better be safe eh?"
"Should we put some timing marks on these?" "No"
"We got a small vibration,nothing major,could effect sale's though" " I'll call the tractor shop and order a million balance shaft's"


I think the negligible vibration elimination,to improve the drive for sale's theory is quite believable.

 

[Rudy602]

Another better idea? Ford's credibility is nil. I remember reading how the Explorer was the most profitable business in the world at one point - clearing $10,000.00 PROFIT on each one. No wonder using such poor quality parts. I wonder how much it costs to do it right the first time? A dreamer, I know.

 

[cjmedina]

I have a dilemma.....

I can repair my engine for more then the price of one from the junk yard....

Or, I can buy a Junkyard motor not knowing the condition of the guides'


I have two engines in sight right now.

A 2005 Explorer SOHC 4X4 with 89K miles on it for $700....

Or, A 2005 Mustang 4.0L SOHC with only 21K miles it in like new condition for $588.

I know a fellow that has a 2002 4X4 ranger with the 4.0L SOHC that slipped timing from broken chain guides. He pulled the engine to find there was no Balance shaft! He never had a problem with vibrations!!!!

So with all these suggestions I'm confused about which way to go. As far as the2 engine options, it's not the difference in price but the amount of miles on the motor.....

Your Thoughts.............

 

[CDW6212R]

If both had an auto trans, get the lower mileage one. Skip any manual trans engine, they are run hard almost always. You still need to do the updates to the tensioners for any engine you buy, unless it really truly is super low mileage. The parts are still dirt cheap compared to buying a new engine.

 

[Kris Guilbeaux]

You can put a newer SOHC in a 2nd gen Explorer but it will require changing over a lot of stuff. The motor I put in the 99 sport that had the balance shaft (which I removed) was from a 03 Explorer XLT. I did have to remove a freeze plug at the top of the motor to install the small vacuum box.

Right now I have 2 Core SOHC motors in my garage I plan to rework, One have a blow head gasket the other has bad timing guides. Both motors are over 200K

 

[cjmedina]

You can put a newer SOHC in a 2nd gen Explorer but it will require changing over a lot of stuff. The motor I put in the 99 sport that had the balance shaft (which I removed) was from a 03 Explorer XLT. I did have to remove a freeze plug at the top of the motor to install the small vacuum box.

Right now I have 2 Core SOHC motors in my garage I plan to rework, One have a blow head gasket the other has bad timing guides. Both motors are over 200K

The engine is from a 2005 Mustang automatic.

I have been told the harmonic balancer was upgraded so there is no need for a balance shaft but if it's an manual **** the balance shaft engine is installed.

It sound like it has to do with the way engine is loaded. A manual shift and the 4x4 put a higher load on the crank thats why it needs to be offset

 

[rydrew55]

Mustang motor

The engine is from a 2005 Mustang automatic.

I have been told the harmonic balancer was upgraded so there is no need for a balance shaft but if it's an manual **** the balance shaft engine is installed.

It sound like it has to do with the way engine is loaded. A manual shift and the 4x4 put a higher load on the crank thats why it needs to be offset

So did you decide on using the non-balance shaft motor or not. I see you replied on my engine swap thread and I am curious to your final decision / results. I must say I am a little spooked now about installing the mustang motor that I bought, and am thinking about selling it and looking for a balance shaft ex motor now.

 

[rydrew55]

Another balance shaft opinion

Just to make this more confusing (or maybe clear it up if you believe the opinion).
From justask.com "Ford Mechanics"

My question:
What effect if any will I have if I put a 4.0L sohc w/o balance shaft (05 Mustang automatic) into a 98 explorer 4wd which had a 4.0L sohc with balance shaft. The 4wd's all had balance shafts as I understand it. I am also told that the manual shift mustang has a bs where the auto did not. swapping intake/exhaust/sensors etc.

Answer from justanswer.com
Professional Licenses: FLM certificationsExperience: Ford trained Tech. Trans, X-fer Case, Steering & Suspension & Brakes, Engine, ElectricalDegree: Vocational, Technical or Trade Scho

Chris (aka- Moose) :
Hello, I'm Chris. I will do my best to answer your question fast and accurate using the info you have provided. Thanks for visiting Just Answer.

Working on all the ford engines I have been into, I personally see no reason you cant do this swap, I have had customers come in for internal repairs on the balance shaft engine and there was not even a shaft in the vehicle from a prior repair.

rydrew55 :
Were these 4wd? It seems there must be a reason ford put them in only 4wd and the manual mustang. If it was only to make it a little smoother I will do it, but I am worried that the harmonic vibrations could cause damage or become unbearable over time. My original explorer engine has a cracked crankshaft so there must be some rough forces.

Chris (aka- Moose) :
It is for harmonic vibration reduction and from what I learned at ford school it was introduced for low rpm vibrations like during a almost stall event on a manual transmission or low rpm event when in low range off road.

rydrew55 :
Good answer. So you think it will run OK at normal speeds and rpm's?

Chris (aka- Moose) :
I see no problem at all running in the application you have choosen

 

[CDW6212R]

That is a more plausible explanation than any others we have come up with. Maybe in such high stress/torque low rpm there is a vibration to be concerned with. I think with most car issues if the owner/driver knows about potential issues, they can manage them.

I still would not hesitate to buy a non 4WD SOHC without the balance shaft, for any application. I'd avoid the SOHC altogether, but that's another issue entirely, the timing chains. Regards,

 

[2000StreetRod]

Engine imbalance

I recently posted my comments on another thread and decided to post them here.

Two types of imbalance associated with the SOHC V6 engine are rotational imbalance and reciprocating imbalance. The crankshaft counter weights reduce rotational imbalance. The balance shaft is used to reduce reciprocating imbalance. That is one reason that the balance shaft rotates much faster than the crankshaft. A symmetrical opposing (flat) engine needs no balance shaft because the reciprocating forces of one piston are offset by those of an opposing piston.

I remember many years ago as inline four cylinder engine displacement increased from year to year that there was a common belief that two liters was the maximum size possible due to vibration concerns. The industry incorporated balance shafts to exceed the two liter limit. Some engines even had two balance shafts rotating in opposite directions.

4WD associated components are all rotationally balanced. I suspect that Ford chose to implement the balance shaft for reduced vibration for customer satisfaction rather than increased serviceability. Ford produced millions of V6 engines (OHV and SOHC) with no balance shafts and no associated recall notices due to premature failure. I'm not aware of any technical service bulletins regarding premature crank failure related to the absence of a balance shaft. Some standard shift performance enthusiasts purchase lightened flywheels for reduced rotational mass and increased throttle response. The negative impact is a slightly less smooth idling engine. I think the balance shaft issue is an analagous trade off.

I would not be concerned about premature crankshaft failure when using an engine with no balance shaft.

 

[Hunz]

Another update here, i just rolled past 20,000 since the 2wd donor swap and she's still purring

 

[kevinspann]

I shouldn't have put the balance shaft in my engine. I think it may have been off a tad, and now I have a vibration in the rpm range where I shouldn't. fail on my part.

 

[99SportX]

Does anyone know the part number for the oil passage plugs? I plan to remove my balance shaft and plug the oil passages.

 

[99SportX]

I stopped by the dealer and have a package of 5 plugs on order. The parts dude asked what I was doing and kind of cringed when I told him it was to remove the balance shaft. He said he has had someone come in and order those same plugs for the same reason and the end result was not too great. I hope I prove him wrong. lol

I have the motor apart now and will be reinstalling it within the next week. I will be sure to post my results. I have the part number for the plug and will post it later. Only two plugs are needed per motor.

 

[Kris Guilbeaux]

I guess they guy did not go in to further details of what the end result was?

The 99 sport I did it to is still running fine.

I stopped by the dealer and have a package of 5 plugs on order. The parts dude asked what I was doing and kind of cringed when I told him it was to remove the balance shaft. He said he has had someone come in and order those same plugs for the same reason and the end result was not too great. I hope I prove him wrong. lol

I have the motor apart now and will be reinstalling it within the next week. I will be sure to post my results. I have the part number for the plug and will post it later. Only two plugs are needed per motor.

 

[99SportX]

Yeah, he didn't give me much info other than saying that those motors are best left alone. I am willing to bet that the person who pulled the balance shaft did something wrong. It looks extremely straightforward to me. There is not much that can be screwed up. I removed the crank side balance shaft sprocket and installed a 2wd primary timing crank sprocket. As long as the passages are plugged and the correct sprocket configuration is used on the crank, there is nothing that can go wrong. Leaving the balance shaft sprocket in place and using a 4x4 crank sprocket is also an acceptable alternative IMO.

 

[99SportX]

Just to let you guys know, I got my engine back in and running last weekend after performing service on the timing components and removing the balance shaft. All is well and runs just great.

The part number for the plugs I ordered is F5RZ6026F. They come 5 to a pack and were $1.21 a piece. 2 needed per engine. Tousley Ford has this plug for $0.80 a piece. They say it is 1/8-27 thread (1/8 NPT).

This is the same plug that is supplied with the 00M12 front tensioner kit. Since I had one from this kit, I only needed one from the pack of 5. As a result I have 4 plugs left, enough for two more engines. If anyone is interested, let me know as I don't see me needing these plugs anytime soon.

Removal of the ladder frame (upper oil pan) is required to remove the balance shaft. It is an involved process. It may be easier to just remove the balance shaft chain and leave the shaft assy in place.

edit: corrected thread size

 

[vipersinu2]

I have an 03 explorer 2wd 4.0 sohc K vin

I put in a 2010 ranger 4x4 4.0 sohc engine e vin

I can't get it to run right do these shafts have anything to do with it?

 

[vipersinu2]

my problem was................... Autozones's mass air flow sensor did not set the computers correct timing, and I tried four sensors from autozone all no good,

the factory ford mass air flow fixed the problem, the tech even said if i buy the part from ford dealer that there will be no charge for the diagnosis (he even put 10 updates in the computer) or labor putting the mass air flow sensor on, Great deal in my book I went nuts for two months trying to figure this out.