Balance Shaft myth debunked!!

[CDW6212R]

Good deal i will just pull the chain and time the motor without the balance shaft but really i wont be timing it hust replacing the chains and cartridges in the motor im putting in as a pm to prevent the inevitable. the one in it now doesnt overheat but it blows air bubbles in the overflow. i replaced the driver side head gasket and its still bubbling in the overflow so im going to get the motor out before something happens.

You do need the timing tool kit to replace any of the timing chains or cassettes etc. Loosening one cam bolt or jackshaft bolt lets the timing go. It's an infinite timing setup, the parts don't have any splines or gears, just smooth round hole against smooth shaft, held by the tightness of the bolt.

 

[thunder71173]

I know I have the timing tools I mentioned earlier i already did the driver side headgasket

 

[CDW6212R]

Gotcha, I thought that but figured I'd mention it.

 

[thunder71173]

hey guys we have talked about removing the balanced shaft but it looks like you have to remove the oil pan to get the tensioner iut or am I missing something?

 

[CDW6212R]

hey guys we have talked about removing the balanced shaft but it looks like you have to remove the oil pan to get the tensioner iut or am I missing something?

The BS tensioner is in the front/bottom. You can easily remove the chain from it with care.

 

[thunder71173]

I knew where the chain was it wont come off unless you remove the woodruff key in the crank. I cut it with bolt cutters

 

[Everett Bartz]

Well, except for the fact that they ARE bolted to one another....



Not true. Harmonic vibrations can occur under a whole host of operating conditions, not just a specific RPM.



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. It's likely that the extra weight/inertia/shape/polar moment of the transfer case added to the driveline, or possibly the front half of the driveline adversely affects the vibration of the engine, or the engine itself transmits vibrations in some undesirable way to some component (be it the engine itself, the mounts, the passenger compartment, or any of a thousand places) and tha undesirable vibration is unique to the 4x4 drivetrain in some way. At any rate, it was installed there for a reason, so unless you know something the engineers don't, I don't think you can call it a 'myth' in the first place, let alone 'debunk' it based on one instance.

The question was never whether or not it was possible to bolt a 2wd engine into a 4x4 truck. They are the same engine, aside from the balance shaft. The question is whether or not doing so would have any negative side effects. One can only infer from the original design that there was some specific reason the engineers opted to install the balance shaft on ONLY the 4x4 vehicles, and one can logically infer that the engineers would not have insisted on installing it if there wasn't a need for it. Should you choose to do otherwise, then it must mean you are much wiser than all the engineers that designed, tested, and developed that engine.... And that's a pretty bold claim, IMHO. I guess nearly 20 years of powertrain development must be wrong....

Let's not overlook the fact that it would appear that now ALL of the SOHC motors include the balance shaft, regardless of whether it's a 2wd or a 4x4. I didn't check to see exactly when that change occurred, but the service manuals for the '09 no longer specify the balance shaft for 4x4s only.... Again, if there was no benefit derived from it, they would have gone the other way and removed it from all the engines.

I see that its being suggested that all 4.0s made after 09 have the balance shafts in them whether used in a 2wd or 4wd. IS that correct? I am looking at a 2010 4.0 for my 4wd explorer. ANd is a "N" designation for a Mustang meant to signify that it does not have the balance shaft or is that something else? Thanks and good day.

 

[thunder71173]

I just put an early 4x4 motor in my 01 explorer sport trac. I just cut the counter balance chain because its not needed on the 2wd. mine runs fine.

 

[08EddieCA]

2wd w balance shaft

• 08EddieCA
• November 22, 2018

I just purchased a 2003 Explorer XLS 4.0 2WD Flex Fuel model (I had no idea there was such a thing as a Flex Fuel model). When I took the timing cover off, to my surprise, there is a balance shaft. Any way to determine if this is the original motor by the cast numbers or any other markings on the motor? I'm curious to see if the motor had been replaced with a 4x4 SOHC motor.

 

[boominXplorer]

All 02+ 4dr explorers have balance shafts reguardless of 2wd or 4wd I have seen (easily 50 by now). I'm actually working on an 05 2wd now and it has a balance shaft chain.

There's a stamp on the back of the block above the bellhousing for actual build date. Its a rectangle box. I've found the date stamped is usually a week before the date printed on the valve covers. If your engine is very rusty it'll be impossible to see. You can kinda see it in this pic, it's below the passenger head.

 

[thunder71173]

I cut the balance shaft chain and took the tensioner out ouf mine you have to pull the oil pan and its king of a pain to get in. Its not needed.

 

[Obe wan]

is it possible to transfer the balance shaft from a 4x4 to a 4x2 engine?
i bought an engine based on the vin number (E) and it is still to be delivered but i am thinking on replacing all the timing components prior to installation even tho the engine has only 60000 miles on it.
at this point not sure if the donor vehicle was a 2x4 or 4x4.

 

[donalds]

is it possible to transfer the balance shaft from a 4x4 to a 4x2 engine?
i bought an engine based on the vin number (E) and it is still to be delivered but i am thinking on replacing all the timing components prior to installation even tho the engine has only 60000 miles on it.
at this point not sure if the donor vehicle was a 2x4 or 4x4.

It don't matter your 4x2 engine will work fine with no balance shaft
In your 4x4

 

[CDW6212R]

Ditto, I trust others here saying the balance shaft isn't needed. My 99 work truck I don't care if there is any slight vibration from the engine, if that is possible to feel. I'm removing the balance shaft chain when I get there.

 

[BUXTER]

I'll just add that Mitsu owners have been pulling Balance Shaft Belts & deleting Balance Shafts for 20+ years with only GOOD effects - In a typical 2 Liter 4cyl Mitsu all u get is the normal vibe at idle u wd get fm ANY 4cyl designed w/ no Balance Shafts - Above idle there's very little if any difference in vibes - The biggest prob w/ Mitsu balance Shafts is that Balance Shaft turns at TWICE the RPM the Crank does so its prone to Bearing Failures... & that takes out the entire Motor when it throws Balance Shaft Belt & that throws Timing belt & Valves start hitting Pistons in keeping with a long standing Mitsubishi Kamikaze Tradition - Deleting Shaft & Blanking the Bearing Oil feed holes gives better Oil Flow for the Crank & Head - But Deleting just the Balance Shaft Belt in a Mitsu can save u some money too.

 

[410Fortune]

DON'T CUT THE BALANCE SHAFT CHAIN

cutting it allows metal flakes into your engine. It comes apart easy enough just PRY it apart..... this way you can catch all the bits from the one link you pry apart and no metal shavings.

 

[2000StreetRod]

Below is a photo of my engine with no balance shaft.

And here's a photo of CDW6212R (Don's) engine.

It looks like both blocks have the bosses to mount the balance shaft but I wouldn't bother. The balance shaft is balanced with the engine at the factory and I doubt a local machine shop would have the equipment or the experience to balance your engine with an added balance shaft.

 

[CDW6212R]

Below is a photo of my engine with no balance shaft.
View attachment 171369

Clean new parts are great, fewer parts help too.

BTW Dale, were the jackshaft bolts TTY? I bought a new balancer bolt($3) last week, but couldn't remember if the jackshaft bolts were also.

 

[2000StreetRod]

Even though the jackshaft sprocket retaining bolts are torqued in two stages they are not listed as TTY bolts. The following thread may be helpful: Solved - SOHC V6 Torque Specifications

 

[Obe wan]

It don't matter your 4x2 engine will work fine with no balance shaft
In your 4x4

Thank you for the info,
I got another engine with 60000 miles on it.
I am thinking on replacing the upper and lower oil pan gaskets as well as the timing cassettes just because it will be already out and hopefully won't have to mess with it for a while.
Does any body knows how many miles before the timing cassettes can became an issue?
My vehicle is an 2006 and I am replacing it with a 2008 engine, I know that ford corrected or redesigned the cassettes but do not know in which year that iwas corrected.
I am hoping someone has an idea of what year the correction was made and hopefully I won't have to make any changes and just install it as it is.