Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

Making engine run quieter/smoother, ideas?

Brett_jjj

Well-Known Member
Joined
Oct 16, 2009
Messages
6,805
Reaction score
108
Points
48
Location
Tamworth NSW
Members Ride
vs commodore
The workshop manuals says that if the front balance shaft bearing shows to be out of spec, then the front bearing and balance shaft must both be renewed as an assembly. The front balance shaft bearing controls the end float of the balance shaft, and if the bearing/shaft is out of spec and not replaced, it will make the engine rattle its head off and just run noisily.
If you find that the balance shaft bearings are stuffed, and are making the engine run heaps noisy, you can just remove the balance shaft drive sprocket so the shaft doesnt run any more.I know a couple of guys who have done this with no problems, and they dont get any excessive vibrations etc from the engine.
If the rear balance shaft bearing is replaced at all, the new bearing must be located in the correct position. which is from around 0.99 to 1.49 mm inwards from the rear of the engine block.
EDIT- its 0.99 to 1.49 mm for ecotec, and 22.18 to 22.68 mm for buick.
 
Last edited:

Jxfwsf

Well-Known Member
Joined
Feb 20, 2011
Messages
4,852
Reaction score
108
Points
48
Location
Aus
Members Ride
commodore
Providing the rear bush that replaced the needle roller used in the buicks is still within spec and not worn i don't see why you couldn't just replace the 6205NR bearing on the front, fair enough if the bush is flogged out then yes the whole lot would need to be replaced or remove the drive gear.
For the sake of a $10 bearing and a $5 gasket, if i ran into this i would at least attempt it, if it didn't help then pull the gear off.

It's a press fit that requires no special alignment (except for the groove placement) on the buick balance shaft and is retained by the drive gear.

bbs.jpg
 

Brett_jjj

Well-Known Member
Joined
Oct 16, 2009
Messages
6,805
Reaction score
108
Points
48
Location
Tamworth NSW
Members Ride
vs commodore
Obviously theres a good reason for them to say that the front bearing and shaft must be renewed as an assembly, otherwise theyd say to just replace the front bearing on the shaft.
 

Z2TT

Member
Joined
Dec 21, 2008
Messages
315
Reaction score
1
Points
18
Members Ride
VL Commodore
It's amazing to find that the bearing IS in fact removable after being told by 2 people it's not.
I'm still not sure why the whole shaft has to be replaced too by best practice?
Does the shaft wear itself where the bearing slides onto it?

And surely putting a new bearing on with an old shaft would be BETTER than OLD BEARING and OLD SHAFT?
There may be probably something i'm misunderstanding please explain guys.

Customcreations --- are you 100% sure the NSK 6205NR that you use on the Buicks would be an exact fit on the ecotec because I'm going to go and buy one,
in all dimensions, fitment etc? Is it rated for the type of environment/application etc? as I've never seen any information on this bearing being used possibly because people just buy the whole balance shaft with bearings? or most people just disconnect the shaft or remove it but I want to keep it but can't find much info on bearing changes.

And I take it the Torrington J-2412 is for the bearing at the rear of the motor or is another one of the front bearings?

Just wondering why do you mention the rear needle bearing part number when it's not replaceable as you said?

To confirm the balance shaft cannot be removed unless the transmission is out? Even if you have access to the valley while doing the inlet manifold gasket change? Somebody did mention using a sliding hammer to remove the entire shaft from the front?

I'm just wondering what the repercussions would be of changing the front bearing and not changing the entire shaft, I don't see how the shaft can wear in any way that would cause problems if you put a new bearing in? Brett I didn't understand your post well if you could clarify, wouldn't changing the bearing fix any end float problems thus reducing
noise and/or vibration even with keeping the old shaft?
 
Last edited:

Jxfwsf

Well-Known Member
Joined
Feb 20, 2011
Messages
4,852
Reaction score
108
Points
48
Location
Aus
Members Ride
commodore
the ecotecs don't use a needle roller in the rear, that was the buicks.

BALANCE SHAFTS
There have been three balance shafts used in the 3800. The early ones have a needle bearing in the block and the later ones use a sleeve bushing for the back journal.

From a write up on the v6
 

Customcreations

PORTED GETS IT SORTED
Joined
Apr 27, 2012
Messages
236
Reaction score
2
Points
0
Location
Cessnock Australia
Members Ride
VS Commodore V6 EcoTech Custom Ported by me
Thats very interesting as I have and 95 model ecotec engine in the shed with the heads off and the balance shaft
which I took out this morning to get the part numbers HAS got the needle bearing at the rear.
Are you possibly thinging of the spigot bush which is copper and does not use a needle bearing?
 

Jxfwsf

Well-Known Member
Joined
Feb 20, 2011
Messages
4,852
Reaction score
108
Points
48
Location
Aus
Members Ride
commodore
that's got my attention, everything i researched and read said the ecotecs didn't have it.... does the balance shaft have the notches in the weights and the oil pressure relief hole up the center? maybe holden carried over the buick design in the early ecotecs?
 

Customcreations

PORTED GETS IT SORTED
Joined
Apr 27, 2012
Messages
236
Reaction score
2
Points
0
Location
Cessnock Australia
Members Ride
VS Commodore V6 EcoTech Custom Ported by me
It's amazing to find that the bearing IS in fact removable after being told by 2 people it's not.
I'm still not sure why the whole shaft has to be replaced too by best practice?
Does the shaft wear itself where the bearing slides onto it?

And surely putting a new bearing on with an old shaft would be BETTER than OLD BEARING and OLD SHAFT?
There may be probably something i'm misunderstanding please explain guys.

Customcreations --- are you 100% sure the NSK 6205NR that you use on the Buicks would be an exact fit on the ecotec because I'm going to go and buy one,
in all dimensions, fitment etc? Is it rated for the type of environment/application etc? as I've never seen any information on this bearing being used possibly because people just buy the whole balance shaft with bearings? or most people just disconnect the shaft or remove it but I want to keep it but can't find much info on bearing changes.

And I take it the Torrington J-2412 is for the bearing at the rear of the motor or is another one of the front bearings?

Just wondering why do you mention the rear needle bearing part number when it's not replaceable as you said?

To confirm the balance shaft cannot be removed unless the transmission is out? Even if you have access to the valley while doing the inlet manifold gasket change? Somebody did mention using a sliding hammer to remove the entire shaft from the front?

I'm just wondering what the repercussions would be of changing the front bearing and not changing the entire shaft, I don't see how the shaft can wear in any way that would cause problems if you put a new bearing in? Brett I didn't understand your post well if you could clarify, wouldn't changing the bearing fix any end float problems thus reducing
noise and/or vibration even with keeping the old shaft?

Dead sure or I'll pay for it. I took the balance shaft out of it myself this morning at around 8:00am to be specific.
I was not suggesting to use a second hand balance shaft with second hand bearing. That was only if it was an emergency and you had no choice.
But I will go to the shed now and double check that someone hasn't played a trick on me
by changing the balance shaft before I took it out.:hmmm:
 

Brett_jjj

Well-Known Member
Joined
Oct 16, 2009
Messages
6,805
Reaction score
108
Points
48
Location
Tamworth NSW
Members Ride
vs commodore
The VS workshop manual (ecotec) says that if the rear balance shaft bearing is excessively worn,the engine will have to be removed and taken to a engine reconditioning workshop and the bearing renewed using special equipment. The buick rear balance shaft bearing can be replaced by just knocking the old bearing out of the block.
 

Customcreations

PORTED GETS IT SORTED
Joined
Apr 27, 2012
Messages
236
Reaction score
2
Points
0
Location
Cessnock Australia
Members Ride
VS Commodore V6 EcoTech Custom Ported by me
:bang: Looks like I might have to pay for it.:bang:

Then again it depends on how you look at it.
I pulled the balance shaft out this morning and grabbed the new needle roller bearing I had here which was a spare from when I put a new bearing set on the B/Shaft for my buick series 1 block so that I could get the part number.
It does have a bush at the back on ecotec.
The needle bearing is how ever the perfect and same fit onto this VS balance shaft I am holding.
I can bet they changed to the bush as it would be cheaper in the manufacturing than the needle bearing.

There was no stopper clip on the front bearing either but it did have the groove for it???
Looking at the rear of the balance shaft I can see but only guess that through changing to the copper bush (or is it a brass bush)
they do so and eliminate the need for the stopping clip as the rear bush does the stopping too.

My guess is they did change to a must replace the whole kit but that they may have fased out old stock which is why I have the balance shaft with removable front bearing. (BIG IF) .Having seen this though I will be rebuilding it using the needle bearing assemble as I am certain they are interchangeable.
This I can see for myself as I have it in front of me right now.

The front bearing is definately removable and part number on it is NSK 6205NR.
The rear is a bush but it is same diameter for the needle bearing to fit. (hope this makes sense)

:idea3:But then again if the back is a bush and is good for lasting as mine is looking good.
It makes sense to leave it a bush and then you dont need to stuff around removing it.
Just a simple swap with the front bearing and your done.
 
Top