Balance shaft question...............

[black_ss_blazer]

How important are the Balance shafts for our motors...????
Can it be taken out if the crank, rods and pistons are all Balanced..???

[03 Rado]

You would need to at least make up some dummy plugs per each bearing surface hole otherwise you would never build any oil pressure up!

[black_ss_blazer]

doesnt sound that hard......has anyone here done this..???

[nomaboy]

not much of a point. you probly won't gain that much, if any power doing that.

[black_ss_blazer]

not much of a point. you probly won't gain that much, if any power doing that.

i think your gunna GAIN power anytime you take away or lighten up ANy reciprocating mass......................

[Matt 4.3 TBI]

If you remove the balance shaft you give yourself a lot more cam choices as well. Those definitely make power, and are worth the effort!

[Maximus]

If you take it out you have to block off the rear oiling hole with a bearing turned 180 degrees.I don't know if you can just remove the sprocket and leave it in with no issues or not.

[Sparky2263]

It's easiest to just remove the gear from the shaft and leave the shaft in there. Picks up about a tenth in the 1/4 and vibrates like a non-balance shaft motor.

Doesn't do anything for cam selection. Still have to run a balance shaft cam. Dimensionally different.

[black_ss_blazer]

It's easiest to just remove the gear from the shaft and leave the shaft in there. Picks up about a tenth in the 1/4 and vibrates like a non-balance shaft motor.

Doesn't do anything for cam selection. Still have to run a balance shaft cam. Dimensionally different.

a tenth huh............makes that decision easy..!
gunna remove the gear...

[biglouie_underpressure]

It's easiest to just remove the gear from the shaft and leave the shaft in there. Picks up about a tenth in the 1/4 and vibrates like a non-balance shaft motor.

Doesn't do anything for cam selection. Still have to run a balance shaft cam. Dimensionally different.
keep telling me ways to out run you..so far you told me how to gain .2 :D

[Maximus]

I was thinking you used a non balance shaft timing chain set to use a non balance cam.I could be wrong but I think I seen that some were.

[LEADFOOT]

I've never seen that area in these motors, but if you remove the gear don't you have to shorten the chain since it is not going around that gear anymore?

[LEADFOOT]

It's easiest to just remove the gear from the shaft and leave the shaft in there. Picks up about a tenth in the 1/4 and vibrates like a non-balance shaft motor.

Doesn't do anything for cam selection. Still have to run a balance shaft cam. Dimensionally different.
How bad of a vibration? Is that there just to make it run nice and smooth for the average buyer?

[Sparky2263]

It vibrates just like a non-balance shaft V-6. Mostly noticeable at idle, feels like's it's cammed up.

There is a gear on the backside of the cam that meshes with the gear on the balance shaft. Removing the balance shaft gear leaves the drive gear on the cam. Cam gear has double the teeth of the balance shaft gear. This increases balance shaft speed to crankshaft speed dampening the natural vibrations of the crankshaft.

I'll post a pic of the shaft when I find it.

[LEADFOOT]

So the gear is on the back of the motor? If thats the case the tranny will need to be pulled away from the motor to get to it huh?

[Sparky2263]

Here they are.

[Sparky2263]

Sorry, bad description. The balance shaft drive gear is directly behind the camshaft driven gear attached to the front of the camshaft. Pulling the timing cover reveals all.

[LEADFOOT]

Cool. I think I might do that. Do all the accesories on the front of the motor have to come off, ie alt. and bracket, ps pump and bracket, a/c?

[Sparky2263]

Dunno on an '02. I'll check Alldata and post back.

[Sparky2263]

File In Section: 06 - Engine/Propulsion System

Bulletin No.: 00-06-01-023B

Date: December, 2002

INFORMATION

Subject:
Engine/Balance Shaft "Rattle" Noise

Models:
1992-2003 Chevrolet and GMC C/K, S/T, M/L, G and P Models
1992-2001 Oldsmobile Bravada
1992-2001 Isuzu Hombre
with 4.3 L V6 Engine (VINs W, X - RPOs L35, LF6, LU3)

This bulletin is being revised to add additional model years. Please discard Corporate Bulletin Number 00-06-01-023A (Section 06 - Engine).

The following information is to be used when diagnosing noise conditions such as an engine "rattle" noise, spark knock, etc.. The noise may occur in the 2000-2500 RPM range, under a moderate to heavy load, with a warmed-up engine. This noise may be due to a natural torsional vibration in the cam drive system, loading and unloading of the balance shaft and gear drive assembly. GMPT Engineering has determined that this noise does not present any durability risks to the engine or any of its components. Attempts to solve the noise condition by changing cam drive or balance shaft components may prove unsuccessful. It is imperative that all normal diagnostic techniques be followed to assure that the rattle noise is not spark knock, piston rattle, bearing knock, or some other noise for which repairs should be made.

Interesting, eh?

[Sparky2263]

Remove the engine oil pan.
Disconnect the crankshaft position (CKP) sensor electrical connector.
Remove the crankshaft balancer.
Remove the water pump.
Remove the CKP sensor.
Remove the crankshaft position sensor seal (0-ring).
Discard the crankshaft position sensor seal (0-ring).



Remove the engine front cover bolts. Important: After the composite engine front cover is removed do not reinstall the engine front cover. Always install a NEW engine front cover.
Remove the engine front cover.
Discard the engine front cover.
Clean all sealing surfaces.


Hmmm.......remember pulling a couple of these. Don't remember removing the pan and DAMN sure didn't buy a new cover. Pretty sure I just loosened the pan bolts.

[Sparky2263]

Notes

Bulletin No.: 03-06-01-024B

Date: March 04, 2004

TECHNICAL

Subject:
Rattle Noise In Engine (Install Timing Tensioner Kit)

Models:
1996-2003 Chevrolet Astro, Blazer, Express, S-10, Silverado
1996-2003 GMC Jimmy, Safari, Savana, Sierra, Sonoma
1996-2001 Oldsmobile Bravada
with 4.3L V6 Engine (VINs W, X - RPOs L35, LU3)

Supercede:

This bulletin is being revised to change warranty information. Please discard Corporate Bulletin Number 03-06-01-024A (Section 06 - Engine/Propulsion System).

Condition

Some customers may comment on a rattle-type noise coming from the engine at approximately 1800 to 2200 RPMs.

Cause

The spark, rattle-type noise may be caused by torsional vibration of the balance shaft.

Correction

If detonation noise is present , perform detonation/spark knock diagnostics first.

Install a new tensioner assembly kit using the procedure below.


he he, kinda contradicts the first bulletin, huh?

[LEADFOOT]

Thanx for the interesting info. I hope the oil pan doesn't have to be pulled. I know its a pain in the ass. My oil pan gasket was leaking and it was still under extended warranty so about 2 weeks ago I took it in and they replaced it. They said they had to pull the engine. Get this they said they had to pull the headers off and was not gonna put them back on. I gave them a piece of my mind (kindly) and they managed to do the job without having to remove them. I told them they better not scratch my $500 headers. Any way I hope the oil pan doesn't have to be pulled, if so I can scratch that project off the list.

[Hammer]

yes you definitely still have to use a balance shaft cam, the cam is longer i believe with balance shaft.