Between Xmas & New Years I replaced my stock clutch with a Z06 assembly. Flywheel, clutch, pressure plate, throw out / slave assembly and pilot bearing.

On the way home Friday night I thought I had broken a motor mount, see - http://forums.corvetteforum.com/zero...ply&id=5206591

That turns out to not be the case. After having fixed the problem discovered in the earlier post, I now find I have a drive train vibaration from ~ 3500 rpm up. It does seem to smooth out again ~ 5000. I'm going to assume that I didn't feel it before because of the loseness of the torque tube to bell housing bolts.

So here's the problem. During the replacement I carefully tracked the position of the old and new flywheels and moved the one weight I found in the old flywheel to the new one. Now it seems to be out of balance.

How should I go about bringing the flywheel clutch assembly into balance that will only require opening up the clutch assembly one time? There is no way I'm going the trial and error route.

 

They talk about that in the manual...Why in gods name would they have you move a weight from one flywheel to the next if that weight was part of the balancing procedure..

Imagine getting new rims for your car and having the installer carefully mount the weights from the old rims to the new ones... :rolleyes:

I heard this new online info differs from the manual.

Important

The flywheel, clutch, and pressure plate are a balanced assembly and are not available as individual components. The pressure plate mounts or locates onto the flywheel via two dowel pins in the flywheel. If the pressure plate is not aligned properly onto the dowel pins and tightened down, the pins may bend and the plate may be incorrectly positioned which will effect component balance.


Existing flywheel, clutch, and pressure plate assembly onto the existing engine: Flywheel position must be marked prior to removal and installed to the original position. Refer to Engine Flywheel Removal .

Existing flywheel, clutch, and pressure plate onto a new engine: Remove balance weights, if applicable from the flywheel.

New flywheel, clutch, and pressure plate assembly onto an existing engine: Do not transfer or install balance weights.

New flywheel, clutch, and pressure plate assembly onto a new engine: Do not install balance weights.

 

I would pull the clutch disc and plate out and rebalance as a unit.
Phillip

 

I had my clutch replaced in my 00 and there wasn't a balance procedure in the replacement instructions. I didn't get to the highway before I went back and told them I can't even hang onto the shifter. It was 11 grams off which I understand is conciderable. After balance wa-la smooth as glass.

 

I purchased a ZO6 clutch set and installed it over the hollidays. I had it checked first to find out the new flywheel was off by 8 grams. I was glad I had it checked. I ended up installing an aluminum flywheel instead of the original steel flywheel that came with the clutch (also balanced). BTW, the pressure plate was out of balance as well. Have them zero balanced seperately. Then, the next time you replace the clutch, you only need to have the pressure plate checked. My new clutch seems to be smoother than it was stock.

 

I had the clutch assembly balanced in our 90 C4 along with the LT4 engine. It is as smooth as it gets. The engine was balanced to 1/4 gram +/- and the clutch and flywheel the same. It is smoother than out Z06. I have some shifter rattle in the Z06 and none at all in the C4. If I ever pull the Z06 apart I will have it balanced the same. The C4 is vibration free all the way to redline.

 

I sent my clutch assembly over to have the pieces balanced before they were installed. It really did make a difference. Car is smoother than stock.

 

Although I know you are dreading pulling the thing apart, I have to agree with Phil.

You guys saved my azz. If I did not read a thread about (I think it was yours) a clutch job, where Enloe mentioned balancing the flywheel and the pressure plate, I would have let the dealer use my stock flywheel, either witout resurfacing it, or with resurfacing it (where they might have milled too much off), and without balancing the flywheel and the pressure plate.

Thanks to you guys, I bought a flywheel to install with my Cartek clutch, and had the two zero balanced before I took the car and the parts to the dealer.

Listen to your Corevetteforum bruthas - they have already made these mistakes.

:D :cool: :cheers: :yesnod: :) :chevy :thumbs:

 

What sort of machine shops balances clutch kits? This is the first I've heard about balancing clutches...

 

A machine shop that is also a balance shop.

-or-

Go to a balance shop.

Not to be a smart azz, but you don't think people build race motors without balancing the harmonic balancer and the flywheel or flexplate? Balance shops do this. On internally balanced motors, I beleive they zero balance the harmonic balancer and the flywheel/flexplate and use slugs of mallory to balance the motor internals. On externally balanced motors, they add weight or remove weight to the harmonic balancer and flywheel/flexplate.

I paid $65 to have my pressure plate and flywheel balanced.

:chevy

 

:iagree:
I'm with HARDTOPV8!! Can any machine shop ballance the assembly and "about" how much did they charge you to do it?

ALSO

Does an alunium fly wheel make that much difference in the ability of the engine to perform better??

Bill

 

Any regulay engine machine shop should be capable of balancing your set up. Expect to pay between $60 to $100.

 

After reading other posts you made within the forum that's all I expect you to be is A SMARTAZZ :D JK :cheers: Thanks for all the ideas...

 

Thanks for all the help. I agree with Phil that pulling it apart and balancing the assembly is probably the surest way to get it right but, that's going to be my last resort.

Thursday night I'm going into a local shop and try removing the weight I transferred and see if that helps. I've figured out a way I can trial and error that one weight into every location around the flywheel to find the best possible location, if removing it doesn't resolve the problem. If I can get it back to near stock smoothness, I can live with it. Right now it's very noticable between about 3k and 4k. It feels fairly smooth above and below those points but, I'm sure it's not doing any good on the rear bearing / seal at any RPM.

Chuckster's information about the new info he read that says not to move the weight really PO's me. If GM changes the manual / instructions on something like this, how's a backyard mechanic supposed to know. Prior to starting the job, I read everything I could find on this forum, other sites and, shop manuals. :mad

Thanks, I'll let you know how it turns out after Thursday night.

:cheers:

 

After pulling the tranny out more than 5 times it is a piece of cake now. I can have the clutch out in roughly 2 hours. There are a few items that will make life alot easier, impact wrench, air ratchet, knowing all the correct sizes up front.
Phillip :leaving:

 

My original clutch vibrated at the same speed. Obviously, that is with the weights in the correct place. I had come to accept that the LS1 just wasn't perfectly smooth and thought the ripper was making it very obvious. I did all the suggestions here for the ripper to no avail. With the balanced clutch the engine is smooth like my Mercedes. There is no vibration at all.

It was not easy to find someone to balance the clutch. It took some calling around. Some people responded like I didn't know what I was talking about. If Andy at A&A hadn't been insistent that I should do it I wouldn't have bothered. Thanks Andy. To anyone considering this, it can be done. It doesn't need to be done with the engine(misinformation I was given). It can be done same day.(some places said it had to be sent out). Cost me $40.

 

I had the 02 Z clutch installed by the dealer and they installed the clutch package including new flywheel with great results.

Phil,
I am about to do the rear end swop and wondered if , in your two hour routine, you lower the drive train without removing torque tube and if for rear you think I can get the carrier off the trans without messing with the shifter and interior. That is just lower the torque tube carefully (not stressing The firewall) and swop carrier???
Thanks,
Bruce


[Modified by see5, 10:52 AM 1/29/2003]

 

Blocktrdr--

Can you elaborate a little bit on what exactly you did?

You had the wheel and pressure plate zero balanced while bolted together?

Did balancing use the GM weights, or did the shop add weight to the PP via small welded-on weights? Or, did they drill the flywheel.

Can this balanced assembly then go in the crank in any position? This is a very interesting question, since you obviously can't *mark* the crank and new wheel location like the manual says to do when removing an existing wheel to reuse.

So please, more specifics!!!

 

see5,

The dealer replaced my rear without removing the TT and trans. There's just enough room to lower/tilt the assemby and slide the rear out. They had a very spiffy jack that had an attachemt for holding the rear. Of course, they also had a number of other jacks and supports to hold the TT/tranny in place in the tilted position. However, I do believe they pulled the shifter, which surprised me. There looks to be plenty of room around the shift hole!

 

Yesterday I was shown the same document that Chuckster refers to.

I am now completely confused.

I had serious vibration after replacing the clutch in my 2000 Coupe. Immediately replaced that clutch with another new one. Still had vibration, although not as bad. Eventually got the vibration reduced sme more by adding a washer to one of the pressure plate bolts. Finally traded it in on a Z06.

Just had the clutch replaced in the Z06 and it came back with a vibration. Fairly minor compared to the old car but still noticeable and really annoying between 2500 & 2600 rpm. I took it back and they fixed it by removing the weights.

I have researched this issue for two years. Trying to find out the why's and wherefore's. The repair manuels all say the same thing. ( I have read 1998, 2000 & 2002 manuels). The weights must be transferred to the new flywheel. This is because the engine is externally balanced. There are balance weights on the harmonic balancer on the front of the engine, too. The clutch assembly is supposed to be neutral balanced. This would allow you to maintain the factory balancing by moving the weights to the new flywheel.

BTW, this is much different than balancing weights on a wheel. No says that wheels or tires are neutral balanced.

Now GM says to remove the weights. Why? Is the factory installed clutch assembly somehow different than the replacement clutch assembly?

One thing I am in total agreement with is that no two clutch assemblies are the same in terms of balancing. They should all be balanced before installation.

The document is titled "Engine Balancing" and it addresses the harmonic balancer weights, also. The document is dated in 2002 and is in the GM online system for Dealer service departments. My mechanic found it while reading about clutch replacement. There is a "link" to Engine Balancing". This document covers 1997 thry 2003 Corvettes.