clutch replaced on'96 LT4, now shifter vibrates more >4500rpm.

[G Winter]

Well....DUH!

You don't feel imbalance "in the car" because the powertrain is soft mounted.

As someone who seriously-flamed ZR51 Performance (the ZFDoc) for making statements which were... ...I am astonished that you didn't know that.






ZR51 Performance, the "ZFDoc," is one of the best choices in ZF S6-40 service and rebuilding. In my opinion, the slanderous statements expressed by "dmg" that Bill Boudreau makes statements which are... ...and that he is attempting to misrepresent transmission problems to unsuspecting ZR-1 owners with the intent to profit fraudulently, are so much shear speculation on "dmg's" part that they are laughable.

"Dmg" has no basis in fact to make such statements. What he posted about the ZFDoc is pure B.S.

I must come to Dmg's defense here,you didn't read very carefully what Dmg stated.
Dmg stated this.

"His site is full of misspellings, grammatical errors and use of vocabulary which is in excess of his actual knowledge"

He only stated that he is skeptical of the ZF Doc. because of his writing ability .For the most part he didn't flame him.
Hib , you need to not be so quick to flame other people. I respect the information you post but at times your attitude is really unexceptable and should be tempered.
Arrogance is not a positive attribute.

Glenn

 

[dmd]

Dammit Halverson, I hate it when your arrogant jerk switch gets tripped. You've really asked for it this time, and you picked the wrong cowboy to tangle with today.

I've known you for more than a dozen years, going back to the ASU VetteNet in the mid-90s, and I and friends of mine have been attacked by you before. My skin is far too thick to be bothered by it anymore, but I will not take this sitting down. Generally I enjoy reading your articles and insight when you keep it objective and aren't shilling for JVD or Red Line, but I've rarely seen someone so likely to go off half-cocked as you when you're so full of it. Your tactic of quoting things out of context to make a case for something that isn't even relevant will not fly with me. I encourage you to go back and re-read my original post in the context of your flaming answer, and realize that it is completely irrelevant to my problem or my other assertions.

First, anyone can feel imbalance vibrations in automotive powertrains regardless of whether they are rubber mounted. Sit in any running car with a GM Iron Duke from the 1980's before you lecture me about that.

Second, I do not have a vibration problem anywhere below 4500rpm. I couldn't care less about the 3000-4000 range.

Third, I did not install an aftermarket clutch, I installed a factory-replacement OEM clutch.

Fourth, I never said that Boudreau makes statements in excess of his actual knowledge. I was referring only to the vocabulary that he uses on his website. You know when people say "penultimate" when they really mean "extraordinary"? Know what the real difference is? Or when somebody writes a long-winded, condescending post to someone else but can't even spell their name correctly? That's what I'm talking about. I have never met the man nor spoken to him in person, but my point was that his site does nothing to bolster my confidence in the accuracy of the information posted there nor in his knowledge or abilities as an expert on the S6-40, rather it is just the opposite.

Now I know your ego is far too big to allow you to apologize for all this, so I will ask you to get your napoleonic ass OUT of my thread and don't come back! I have a problem I am trying to solve and you are not helping!

 

[KANE]

I've closed this thread based upon the Rules of Conduct...

Inappropriate Language
The use of inappropriate or offensive language is not permitted in these forums. Inappropriate or offensive language includes, but is not limited to, any language or content that is sexually oriented, sexually suggestive or abusive, harassing, defamatory, vulgar, obscene, profane, hateful, or that contains racially, ethnically or otherwise objectionable material of any kind. We ask that you please be considerate to other members in the forums when posting your messages.

Folks- keep it clean. No reason for insults- we are all on the same team with the same interests... Corvettes.

 

[Hib Halverson]

Dammit Halverson, I hate it when your arrogant jerk switch gets tripped. You've really asked for it this time, and you picked the wrong cowboy to tangle with today.
(snip)
...when you keep it objective and aren't shilling for JVD or Red Line, but I've rarely seen someone so likely to go off half-cocked as you when you're so full of it.
(snip)
....get your napoleonic ass OUT of my thread and don't come back!

Ouch! "dmg"! You torched me, cowboy! :flamingGet me to the freakin' burn ward.

Ok, guess I struck a nerve. I admit, some of my comments were over the top. The "Well...duh!" remark in my earlier post was uncalled for. I apologize to "dmg" for that. I was trying discuss flywheel imbalance and got carried away.

The point I was trying to make was the imbalance "dmg" has--which is, as others have stated, is likely caused by the new flywheel's "trim-balance pins" not being in the same spots as those of the old wheel--is just bad enough for one to feel through the shifter but not quite strong enough to be felt "in the seat of your pants" because the imbalance is not creating a vibration severe enough to get though the powertrain's rubber mounts. My guess is the imbalance is 7-15 grams which is not real bad, but yet still can be very annoying to feel at higher rpms.

It was also unwise for me to have characterized "dmg's" comments about the Bill Boudreau the "ZFDoc" as "BS". I apologize for using that term.

The statements made in this thread about Mr. Boudreau--that he uses words in excess of his actual knowledge and that he is taking advantage of ZR-1 owners concerned about transmission noise to sell unnecessary, $5000 transmission overhauls--remain slanderous and untrue, however, I should not have used the expletive "BS" to describe "dmg's" views. I apologize for that.

Also, I apologize for not reading "dmg's" comments about his clutch correctly. Initially, I misread the first post and thought the clutch was aftermarket.

Lastly, I resent the "napoleonic ass" comment. I'm of average height and my Wife thinks I have a cute ass.

Hope this makes everyone feel better.

Happy Christmas and Merry New Year, everyone.

 

[dmd]

I'm impressed. I guess you've matured a bit in the last decade or so, Hib. I don't know why you still can't get the three letters of my screen name correct, but that's a mystery for you to solve not me.

My question remains: This isn't that bad, so if I can live with it (and actually I think it makes it a little more exciting), will the engine be okay if I leave it this way? Hib has pointed out that the '96 manual not only doesn't address it but deliberately removed the info, and from c4c5specialist's comment it looks like the answer is yes, so what's the verdict? Is this just minor NVH tuning, or is it critical engine balance?

Honestly, as much abuse as this engine has already taken in 155k miles and not only survived but shined even brighter (I've actually missed the 2-3 shift near redline for 1st gear and it didn't hurt it, though it gave me the ride of my life - far lesser offenses are fatal for BMW M3 engines), I find it hard to believe that this or any Corvette engine could be so fragile as to be bothered by a dozen grams of flywheel imbalance. One of the reasons I am so personally committed to GM products is how impressively solid their engineering is. Every time I take one apart I am impressed by the choice of materials and the robustness of the design. They are built to take abuse without failure. Maybe I'd be worried if it were a Ford or Chrysler engine, but not GM - a company whose engines may sometimes run badly, but they do so longer than most others run at all.

-DMD

 

[Hib Halverson]

The one durability problem with engine vibration is the effect it can have on the engine's main bearings. Obviously, the effect on durability varies with the severity of the vibration.

I did a C5 clutch change several months ago. The first aftermarket clutch I had in there was defective...it had an imbalance of 40 grams which made for a vibration far worse than the one being discussed here. The concensus amongst myself and the two techs at the shop I had do the work was that, in the short term even that level of vibration was probably not a reliability problem but that long term, it would probably affect the main bearings. We replaced the first clutch with a McCleod...problem solved.

Typically, an imbalance will have the most pronounced affect on the bearings nearest the imbalance so, if the flywheel is out-of-balance, any potential damage will occur to the #5 and perhaps the #4 main.

That said, I'd think that the level of vibration being discussed here is probably more of an annoyance than a threat to the engine's durability but...that's a wild-assed guess on my part, based strictly what I read in this thread.

As for the brief discussion about service manuals, I WOULD NOT assume that because a discussion of the trim balancing pins was omitted from the 96 FSM means it's not important. For MY96 GM made a big change in the style and design of it's service manual content. Most likely, the discussion of balance pins was omitted by mistake and not by a decision by GM that engine balance was no longer important.

Lastly, I have no idea why I was saying "dmg" instead of "dmd". Maybe it's my imaturity.

 

[Hib Halverson]

All of a sudden this thead went dead.

"dmd" what happened with your vibration?

 

[dmd]

the bigger problem is that once things get good and hot, I now have the opposite problem as I did when I started: the clutch isn't disengaging. I need to flush the fluid or make a shim on the end of the slave piston, so the car is parked for now.

 

[Hib Halverson]

Initially, I misunderstood your clutch hardware to be aftermarket, but it is actually OE or OE replacement..correct?

If so, did you have the problem with the clutch failing to disengage before?

 

[dmd]

No, I didn't have this problem before. It disengages fine with room to spare when it's cold. I can drive it a good 60 miles before it starts to lose travel. Clutch/PP is Valeo and the master/slave are original. Brake fluid is currently a cloudy black and I know it needs to be flushed, but I am not confident that this will solve the problem. I've tried the fast-50 pedal pump but that didn't make any difference.

 

[Hib Halverson]

Try this:
1) make sure the clutch lines are not near any exhaust parts
2) change the clutch fluid.