thbwlZ

1. The balance machine used during the hot balance procedure is not a "clutch/FW" balancing machine. It is an ENGINE balancing machine. Weights are installed in the front damper, the FW, or both as required to bring the entire engine assembly down to within 0.5 oz∙in at both front and rear planes. This is a dynamic dual plane balancing procedure.

2. 0.5 oz∙in is a much tighter (lower number) balance tolerance than can be achieved by the regular engine building process.

3. The Flywheels and pressure plates are not put together and balanced as an assembly before going on the engine. The flywheel is installed as delivered, and the pressure plate is installed as delivered. Then the entire engine assembly is externally balanced via the balance weights in the damper, FW, or both, as needed.

4. It is really irrelevant what the starting balance/imbalance of the FW and PP are to begin with, it is the final resulting total engine assembly balance that matters. A flywheel and pressure plate can be perfectly zero balanced, independently, or as a combo, and you could still have vibrations. The as built engine imbalances alone can be greater than 0.5 oz∙in.

5. Yes, All LS engines are an internal balance engine by design. Those going in to manual transmission vettes require a better final balance than can be achieved through normal build tolerances. So they are put through a final external balancing process to get the whole shebang even better.

6. This is done purely for NVH reasons, NOT for reliable engine operation. LS engines going in to automatic vettes, or manual transmission F-bodies did not go through this hot balance.

7. The best a clutch/FW manufacturer can do is deliver a product that is as close to zero balance as possible. They cannot make the balance match what your factory engine "needed". That is impossible. The only way to do that is to have the installer check the balance of the factory FW/PP combo, and make the new FW/PP combo match that balance. It could be zero, slightly higher than zero, or quite a bit out from zero. It is impossible to know without checking.

8. I hope this writing style didn't offend anyone.

KG-02Z

Thanks to all who have countless times tried to advise me on this. The shop who screwed me was New Era Performance are the only LS specialist in the area besides the corvette department at the dealership. I am currently in legal battle having paid twice for a mantic clutch install and getting s**t back. They kept blowing me off and calling me crazy and said it was just normal and would never test drive the car. They were so busy with their own stuff they could careless about my car. And I guess I'm not the first nightmere out of that shop. They only responded to me threatening them and then after I towed the car from their lot they wanted to put an effort forth to rectify it. Mike is a great tuner and I have no idea what to do about my tuning needs now with that bridge burned. It really sucks I have been put through this and all I want is someone to actually care that I get my car back correctly. I've now torn the car apart once at the dealership now, which makes 3 now if your counting, and they found the rear cradle loose from New Era Performance and my car ready to fall apart. But after replacing everything including the input shaft they tore up because I had pilot bearing go bad on the drive home from their shop after clutch install. They told me new clutch chatter was the bad pilot bearing so I kept driving it and ruined my input shaft. Lol. The crap they put me through is never ending. Anyway, still no resolution and the dealership as well as Mantic are advising the balancer to eliminate it as a cause. I guess I could try get New Era to find the original unit but the clutch/flywheel was taken out in July so I'm guessing it's gone. You guys see how long and bad this has been for me cause I was new to corvette ownership and supposed experts knew less than me. If I had access to a lift and no new born baby I'd do it myself!! I hope you all can try to just give me some blunt straight forward advise on how I specifically should deal with this before I sell the damn car. I have yet to drive one time in it at 100 percent. What's weird is the last owner had an LS7 clutch kit and had no trouble like this and didn't seem to know about this balancing thing either. But I guess it could be he didn't know how it was installed. Idk. Please help and thank you all again.

Kevin

Pounder

I would take it to ECS !!!!!! have them document what they find !!!

thbwlZ

That really sucks.
Is the car currently drivable?
From other posts, it sounded like there was just a small vibration, that even the dealership was saying was ok if you could live with it. Is it worse than that?

I think you should contact Doug at ECS. He has already offered his help, and ECS has a great reputation.

0Chuck CoW

Hey Kevin... Bummer to have to go thru something like this.

Please let me know if I can be of any help to you. I'm probably the

next closest guy to you.

Call any time if you've got any questions.

914-332-0049
Chuck CoW

KG-02Z

So come to find out I had a thought that the locating dowel pins might be missing from the flywheel which locate the pressure plate to it. Mantic actually suggested it to me. Come to find out the dowel pins are in fact missing but the dealership is trying to convince me it has no bearing on the vibration issues. But the clutch manufacturer is swearing they have seen these many times where people forget the dowel pins for locating the pressure plate to the flywheel and because it is slightly off center that it causes a vibration. The dealership is telling me that the best course of action is to put an OEM clutch back in the car and that because it is heavier it will have a more dampening effect. But it won't hold my power so I can't do that only to blow the thing right after installing it. I'm not quite sure what to do at this point. Can I just try the washer method and call it a day? Or put dowel pins on the flywheel like there should be and test the car with it still apart and use the washer method for any fine tuning? Any thoughts? Thanks.

Kevin

jimmyLSX

Put the dowel pins in the flywheel and put the pressure plate in the correct orientation it was designed to be from mantic, having the PP in the wrong orientation will definetly throw it off, you have 45+lbs of metal spinning hundreds and hundreds a time a sec. But also you should go a step forward and listen to these guys who have repeatedly told you over and over in all your threads and have the clutch assembly balanced. Stop trying to cut corners in trying to remedy your cars problem or else you're gonna have to pull out the drivetrain again. I don't know how many times you've pulled out your drivetrain from reading all your threads, but personally I would of **ot myself In the foot if I ever had pull out my drivetrain a third time around.

Jimmy.

DOUG @ ECS

Once the clutch is installed correctly your troubles will be gone. No dowel pins will absolutely cause your issue.

Sorry to hear of all the troubles you went threw for a simple clutch swap.

thbwlZ

Doug,
Do you know if Mantic balances their clutch kits, FW and PP together as a unit? Do they then match mark how the FW and PP should be put together? The OP's first shop didn't install the dowel pins. The OP's second shop (dealership) took it apart, noticed bad wear on one part of the FW, so they clocked the PP 180° from its orientation to "even out the wear"(since there were no dowel pins to prohibit this). So whatever orientation they are currently clocked, is most likely NOT how Mantic had intended them to be put together from the start.

I know you deal with a lot of Mantic clutches so wanted to ask.

0ggerko

Hey Guys,

Let me shed a little light here. YES...the dowel pins are an absolute necessity. The dowel pins align the Clutch to the flywheel. Each component is balanced separately with the intention that they will be assembled properly with the dowel pins ensuring that everything is rotating about the same center. No matter how perfectly balanced the clutch would be...if its bolted OFF center...then it will vibrate like the finest adult toy available.

If you want to double check everything...pull it apart and have a machine shop check the balance as it is. Then install the dowel pins and check it again...should be significantly better. Oh....only spin up the flywheel and Clutch...the disc has nothing to pilot on and will most certainly be off center...cause aforementioned vibration in aforementioned fashion.

hope that helps

DOUG @ ECS

Every component is zero balanced individually, so it does not matter if it was clocked.

thbwlZ

great answer.

The dowel pins keep the FW and PP CONCENTRIC to each other. When the dowel pins are not used, the clearance holes for the mounting bolts will allow some offset, concentricity is lost, and you have an unbalanced combo.

The OP's dealership is trying to convince him that the missing dowel pins could not cause any balance problems and that he just needs to reinstall a factory clutch.
Time to stop dealing with them.

0ggerko

Yeah....its totally a concentricity concern....had i not been drinking heavily to get me througha spread sheet I should have mentioned that.

Honestly, our MS1001/1002 are a better quality clutch than the OE ones...just based on materials alone...craftsmanship aside. I would not revert back to the OE clutch. Could very well be the dealer trying to solve this issue with a know compnent...but not necessarily understanding the root cause of the problem.

KG-02Z

Thank you all for your support. GGerko has been a huge help from Mantic. He is the best customer support I have ever seen, period. He has done everything in his power to help me through this ordeal and just shows you how great Mantic really is. He has been a huge help in trying to get the dealership to understand the clutch and how it needs to be installed and is currently advocating to get my money back from the original shop who completely screwed me on the install. I will let you all know how it turns out for him. The dealership is currently just trying to clean up the original shops mess.

New Era Performance is the original shop and really screwed me. They left 3 bolts loose in the rear cradle and installed the clutch incorrectly and also put a bent input shaft back into the car. DO NOT USE THEM EVER IF YOU ARE IN ROCHESTER, NY.


Thank you ECS for going out of your way to advise me on this issue when I have never even been a customer. I can't say enough about the community on here and I will not hesitate to help others on here after all the help I have received.


Doug,
Can you tell me if the Mantic kits that you installed needed to have the pressure plate clocked a certain way on the flywheel? And if I am sure to have the dowel pins put in then more then likely I will have my issue resolved? I can't believe 4 times that clutch has been out and no one noticed dowel pins missing. I mean I know the last clutch kit in the car was not counterbalanced as it was an LS7 clutch installed by the previous owner and said it was just a quick, bolt and go install. No balance issues. So I was puzzled why I had this issue of balance when he seemed to have no idea what the hot balance procedure was cause he never encountered the problem. Let's hope this is it for me. I will take the unit, once out of the car and with the dowel pins, to a machine shop just to make sure everything is still okay and balanced correctly.


Kevin

KG-02Z

Nevermind on the clocking Doug. Just read through the posts a bit more thorough and got my answer on that one. Thanks.


Kevin