Thread: Balance Shaft

Someone tell me how to remove that frickin' thing. I cant find a write up anywhere. I see some retainer rings on the gear side, but I have not been able to work them free yet.

If I get on my laptop tonight I'll get instructions from my GM SI manual for you and you'll get an e-mail.

BFH

Originally Posted by Abrasive

BFH

The thought had already crossed my mind.

Thank you Sabrewings

You've got mail.

eegads. I guess Jay was right after all, I just need a BFH. Thanks for that info Sabrewings. Though, are they using the slide hammer on the front cover side or on the rear cover side? My assumption is on the front cover side since it would probably screw into the gear bolt hole.

Personally, Im torn between whether or not to pull it out permanently. To take it out, you need to have the crank balanced and then you have to plug the oil holes for the balance shaft.

I had not really planned on pulling it permanently and I guess I need some more understanding and insight as to what the true advantages are and whether or not they are worth the effort.

I know thats not a lot of help, but Im still kind of on the fence about this myself. I really dont want to even pull it out of the block I have but I have to in order to get the block checked cleaned and treated, otherwise I would not even touch it.

Really? Why then do they call it a 'balance' shaft if it does not figure into the balance of things. I would be curious also to their explanation of why when you have the crank 50% balanced it is recommended you remove the balance shaft.

I dunno, maybe my understanding is way off but Im not sure about that statement from them, but Im open to the idea that I havent a clue what Im talking about either and am way off base.

But, the inherent design of a V configuration motor is that you need something to counter the forces of the up and down motion of the pistons. Engines like the boxer and rotary wouldnt need any balancing because they are naturally balanced by their configuration. Unless there is some other counter balance in the engine Im really baffled by the zzp statement.

Hopefully someone will come in and clarify everything.

You don't need t pull it and I wouldn't recommend pulling it unless the engine is out of the car. You can easily remove all the gears and leave it in there and it won't hurt a thing.

My was removed with a BFH as well and only the rear hole gets plugged IIRC with a 1/8"NPT allen head set screw.

Thanks Vinnie. The engine is out of the car. Its a spare block I bought along with a crank and set of heads to build up.

When you say rear hole, you mean the one opposite of where the timing chain is?

The hole we plugged was the one in the rear cover, yes oposite the timing chain.

Guess I'll be pounding that sucker out this evening.

It can be called a counter balance if anything.

Two bolts remove the front retainer next to the gear. Then a love tap with a hammer pops it out of the block.

The hole you need to tap, and plug is BEHIND the rear engine cover. Once thats removed, you will see a small hole just under the rear bearing/bore the balancer rode on, its about in the 4:00 position, only one like it near that hole. Tap, plug, done.


I'm making something to aid in this, where you don't have to pull the motor to plug that hole off if you remove the balance shaft.


~F~

why even take it out? weight savings?

i just left mine in. its still there just chillin. it doesnt hurt anything being there.

Originally Posted by SyntheticShield

Really? Why then do they call it a 'balance' shaft if it does not figure into the balance of things. I would be curious also to their explanation of why when you have the crank 50% balanced it is recommended you remove the balance shaft.

I dunno, maybe my understanding is way off but Im not sure about that statement from them, but Im open to the idea that I havent a clue what Im talking about either and am way off base.

But, the inherent design of a V configuration motor is that you need something to counter the forces of the up and down motion of the pistons. Engines like the boxer and rotary wouldnt need any balancing because they are naturally balanced by their configuration. Unless there is some other counter balance in the engine Im really baffled by the zzp statement.

Hopefully someone will come in and clarify everything.

It's not part of the balancing of the crank and pistons, but the 90* V design leaves some inherent vibrations at low speeds that can't be accounted for. You add the balance shaft as a counter balance to smooth out the engine as a whole at those speeds. With or without it your bottom end parts are balanced. It's just that the pattern of forces with a 90* V will cause a few shakes at low speed.

It's my personal belief that the balance shaft isn't perfect at it's job and some of these excess vibrations build to the "shake" the 3800 makes at idle. That's what causes people to believe the engine is missing for some reason when it's purring along none the wiser.

Thank you Farns for that info. And yes Sabre, counter balance is probably a better word for what that shaft does. I should have thought of that myself.

I did find a shop in Tulsa that has done work on 3800's. How much I dont know as I have not went there personally yet. So if all checks out I'll probably take everything there and just have the whole thing balanced and be done with it. We'll see how that goes though.

Im half tempted to have everything blueprinted and balanced. If I knew for a fact I could afford to do so I would but Im sure that is going to involve some work. I really need to sit down and just lay everything out on paper that I want to do and start pricing stuff out that way I know what Im in for and what can be sacrificed and what cant.

The way I look at it, and maybe it's not the right way, but it's a lot cheaper to replace shortbolcks then to put money into them, but I'm also only 3 hours from Ed so my views may be unique