Unclear on "zero balancing" flywheel....
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Originally Posted by Cobra4B
I do however have a mild vibe in the shifter... upon driving a few other C5's I'm finding that they all have it too...
Advanced
Joined: Jun 2000
Posts: 66
Likes: 3
From: Camp Hill PA
In my 02 Z06 (which has had the clutch/flywheel replaced by the dealer) I can feel a small vibration at
1600 rpm
2500 rpm
around 4000 rpm
I can feel this in the shifter and steering wheel. It's not real obvious but I used to be an automotive engineer and have been trained to look for issues like this.
My car is at the dealer now for a number of warranty items and I've complained about this vibration.
1600 rpm
2500 rpm
around 4000 rpm
I can feel this in the shifter and steering wheel. It's not real obvious but I used to be an automotive engineer and have been trained to look for issues like this.
My car is at the dealer now for a number of warranty items and I've complained about this vibration.
Racer
Joined: Mar 2003
Posts: 292
Likes: 0
From: Southbury CT
Sidsestep: It appears from the picture of your flywheel showing the installed weights that you also have "dimples," or partial holes drilled on the perimeter as well, some near one of the weights. Balancing can be performed by either adding or removing (drilling) weight. To do both in the same area of the flywheel indicates either a mistake in removing too much weight when balancing, or two separate balancing operations. Perhaps the flywheel (and clutch) are zero balanced during production (so it can be used in a replacement situation as well) and when bolted to a new engine, the flywheel is again used (along with the harmonic balancer on the front) to make up for any imbalance caused by the crank, rods and pistons. Just a thought to address earlier questions in this thread.
Melting Slicks
Joined: Apr 2001
Posts: 2,877
Likes: 7
The only way to go is to have your new assembly balanced exactly the same as what you took off.
Then install the new assembly in the same orientation on the crank as the old.
If you don't your rolling the dice
Then install the new assembly in the same orientation on the crank as the old.
If you don't your rolling the dice
Melting Slicks
Joined: Oct 2002
Posts: 2,200
Likes: 0
Originally Posted by Tree
Sidsestep: It appears from the picture of your flywheel showing the installed weights that you also have "dimples," or partial holes drilled on the perimeter as well, some near one of the weights.....
Burning Brakes
Joined: Aug 2000
Posts: 889
Likes: 0
From: DFW tx
Some vibration through the shifter is normal. When things are out of balance, you will know. It will be more than just the shifter shaking, the whole car will shake.
My vibration starts at 2100 RPM and continues up to redline. Around 4k it gets bad. Since I have 4.10's, cruising on the highway at just over 2k RPM's is very annoying due to the balance issue. On full throttle upshifts and on downshifts the vibrations get more severe.
I had heads/cam with a pulley installed for about 9 months until I replaced the clutch/flywheel. I had no balance issues at all until the clutch/flywheel was replaced. I am hoping the clutch assembly is a zero balanced unit as I no longer have the original unit.
My vibration starts at 2100 RPM and continues up to redline. Around 4k it gets bad. Since I have 4.10's, cruising on the highway at just over 2k RPM's is very annoying due to the balance issue. On full throttle upshifts and on downshifts the vibrations get more severe.
I had heads/cam with a pulley installed for about 9 months until I replaced the clutch/flywheel. I had no balance issues at all until the clutch/flywheel was replaced. I am hoping the clutch assembly is a zero balanced unit as I no longer have the original unit.
Team Owner
Joined: Nov 1999
Posts: 26,679
Likes: 17
From: This vette goes to 11 Milford MA
St. Jude Donor '03-'05
Originally Posted by Cobra4B
Same thing here.... when we're talking imbalance are we talking a mild vibration in the sifter or something that shakes the whole car. If we're talking shaking the whole car... as one member put it "my drive shaft feels like it's going to snap on high RPM downshifts", then I don't have any of that. I do however have a mild vibe in the shifter... upon driving a few other C5's I'm finding that they all have it too, and the vibe may be planted in my head by the mechanic telling me there was a mild vibe and me getting in the car on the lookout. 
Melting Slicks
Joined: Oct 2002
Posts: 2,200
Likes: 0
Originally Posted by Jeff Jeff
Some vibration through the shifter is normal. When things are out of balance, you will know. It will be more than just the shifter shaking, the whole car will shake.
My vibration starts at 2100 RPM and continues up to redline. Around 4k it gets bad. Since I have 4.10's, cruising on the highway at just over 2k RPM's is very annoying due to the balance issue. On full throttle upshifts and on downshifts the vibrations get more severe.
I had heads/cam with a pulley installed for about 9 months until I replaced the clutch/flywheel. I had no balance issues at all until the clutch/flywheel was replaced. I am hoping the clutch assembly is a zero balanced unit as I no longer have the original unit.
My vibration starts at 2100 RPM and continues up to redline. Around 4k it gets bad. Since I have 4.10's, cruising on the highway at just over 2k RPM's is very annoying due to the balance issue. On full throttle upshifts and on downshifts the vibrations get more severe.
I had heads/cam with a pulley installed for about 9 months until I replaced the clutch/flywheel. I had no balance issues at all until the clutch/flywheel was replaced. I am hoping the clutch assembly is a zero balanced unit as I no longer have the original unit.
Originally Posted by Fastguy
Mine vibrated like it had dropped a plug wire.
Mine is a pulse right 2200-2300 rpms and then nothing else... Like I said I guess there are varying levels of imbalance... I am tempted to knock out the weights and see what it does....
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Le Mans Master
Joined: Dec 2003
Posts: 5,561
Likes: 448
From: Atlanta metro Ga.
Imo..
I read thru all of the posts on this subject, and it seems obvious to me what GM has done in the past..
They start w/ balancing the clutch and flywheel assembly as a unit;
They also balance the motor assembly (or more accurately the crank on its own, etc.) as a unit.
IF they detect a problem (I'm guessing they spin the motor w/ the flywheel / clutch assembly attached at some point in the production line) they add or remove weight to force the entire rotating assembly into balance.
So the obvious answer here is to mark and remove your stock PP and flywheel upon disassembly, have it measured for balance, then have the new PP and flywheel balanced to the same "spec" as the old, and re-assemble in the same orientation.
The up-side of this is you'll never experience more vibration than you had before the clutch job; the down-side is you loose the opportunity to (possibly) improve on the stock GM balance..
They start w/ balancing the clutch and flywheel assembly as a unit;
They also balance the motor assembly (or more accurately the crank on its own, etc.) as a unit.
IF they detect a problem (I'm guessing they spin the motor w/ the flywheel / clutch assembly attached at some point in the production line) they add or remove weight to force the entire rotating assembly into balance.
So the obvious answer here is to mark and remove your stock PP and flywheel upon disassembly, have it measured for balance, then have the new PP and flywheel balanced to the same "spec" as the old, and re-assemble in the same orientation.
The up-side of this is you'll never experience more vibration than you had before the clutch job; the down-side is you loose the opportunity to (possibly) improve on the stock GM balance..
Melting Slicks
Joined: Oct 2002
Posts: 2,200
Likes: 0
Originally Posted by rwj383
...
My understanding: any OE balast weights on stock flywheel was to 0 bal PP/FW assy at factory, not necessarily to 0 bal the motor rotating assy. IF this is the case, then it would stand to reason that simply making sure the new clutch assy is neutral should prevent any vibe issues.
My experience: I've replaced ~ a dozen C5 clutches. I've never transferred weights from old flywheel to new. I usually have the new PP/FW checked for 0 bal, and in each case they were good. Also, I've had several old clutch assy's referenced for balance to find they were at/near 0. I do not recall if these had balast on the flywheel or not. Anyway, I've not had a single clutch balance issue until very recently, possibly. A customer brought me a LUK clutch assy. It had the markings and cuts of a spun-balanced assy. I installed it, then drove it, seemed fine. However, since customer has had the car, he believes there is a vibration at specific RPM. While his vibration could also be his exhaust system moved and touching heat shields (TPIS header floating collector connection always been a problem with Xpipe sliding/moving/leaking), it might be possible the LUK is not balanced.
I will be watching this thread closely to see if anyone uncovers a clear definition of what needs done regarding the matter. Yah, anyone have Dave Hill's phone number?!?!
Robert/ Gen 3 Motorsports
My understanding: any OE balast weights on stock flywheel was to 0 bal PP/FW assy at factory, not necessarily to 0 bal the motor rotating assy. IF this is the case, then it would stand to reason that simply making sure the new clutch assy is neutral should prevent any vibe issues.
My experience: I've replaced ~ a dozen C5 clutches. I've never transferred weights from old flywheel to new. I usually have the new PP/FW checked for 0 bal, and in each case they were good. Also, I've had several old clutch assy's referenced for balance to find they were at/near 0. I do not recall if these had balast on the flywheel or not. Anyway, I've not had a single clutch balance issue until very recently, possibly. A customer brought me a LUK clutch assy. It had the markings and cuts of a spun-balanced assy. I installed it, then drove it, seemed fine. However, since customer has had the car, he believes there is a vibration at specific RPM. While his vibration could also be his exhaust system moved and touching heat shields (TPIS header floating collector connection always been a problem with Xpipe sliding/moving/leaking), it might be possible the LUK is not balanced.
I will be watching this thread closely to see if anyone uncovers a clear definition of what needs done regarding the matter. Yah, anyone have Dave Hill's phone number?!?!
Robert/ Gen 3 Motorsports
Mfrnka and I decided to experiment and knock out the two weights that I had transferred from my old flywheel to the new one. Believe it or not the pulsing/vibration at 2200-2300 rpms is absolutely gone! It feels much smoother than with the weights in the flywheel...
Just my experience...
Last edited by SideStep; Dec 15, 2004 at 12:11 AM.
Thread Starter
Race Director
Joined: Dec 2002
Posts: 10,233
Likes: 21
From: Baltimore suburbs Maryland
Originally Posted by SideStep
Hey Robert guess what.....
Mfrnka and I decided to experiment and knock out the two weights that I had transferred from my old flywheel to the new one. Believe it or not the pulsing/vibration at 2200-2300 rpms is absolutely gone! It feels much smoother than with the weights in the flywheel...
Just my experience...
Mfrnka and I decided to experiment and knock out the two weights that I had transferred from my old flywheel to the new one. Believe it or not the pulsing/vibration at 2200-2300 rpms is absolutely gone! It feels much smoother than with the weights in the flywheel...
Just my experience...
Unfortunatley my butt is still too sore from slipping and falling in tranny fluild last week so its preventing me from doing alot of work to my car, and being away this past weekend put a damper on the progress of my car. Havnet pulled the flywheel yet. I also havent had the time to drop off the flywheel/p plate (both old and new) cause of my darn work schedule, to get them spun balanced to see how close to zero each one is.
I just talked to a friend who just did his F body, he put in a Mcleod clutch and aluminum flywheel. He did not transfer any weights (nor does he remeber if his old FW had weights) and he relied on the factory "prebalancing" of the mclod kit, he reports no vibration.
Last edited by eRiCdWoNg; Dec 15, 2004 at 12:18 AM.
Le Mans Master
Joined: Dec 2003
Posts: 5,561
Likes: 448
From: Atlanta metro Ga.
Originally Posted by SideStep
Hey Robert guess what.....
Mfrnka and I decided to experiment and knock out the two weights that I had transferred from my old flywheel to the new one. Believe it or not the pulsing/vibration at 2200-2300 rpms is absolutely gone! It feels much smoother than with the weights in the flywheel...
Just my experience...
Mfrnka and I decided to experiment and knock out the two weights that I had transferred from my old flywheel to the new one. Believe it or not the pulsing/vibration at 2200-2300 rpms is absolutely gone! It feels much smoother than with the weights in the flywheel...
Just my experience...
Good job on fixing your problem.
Racer
Joined: Sep 2004
Posts: 360
Likes: 0
From: Riverview Florida
This is a great thread. I am having a vibration issue with my new spec stg 3 clutch and new spec billet steel flywheel. It is driving me crazy. Spec told the shop i went to that the vibration will end after 500mile break in period. They said it was due to some "high spots on the disc that need to be worn in". I find this very hard to believe. It is obvious this is a pretty common problem. I am getting very frustrated.
Pro
Joined: Apr 2003
Posts: 550
Likes: 0
From: Northeast IN
Originally Posted by jeclarke
In my 02 Z06 (which has had the clutch/flywheel replaced by the dealer) I can feel a small vibration at
1600 rpm
2500 rpm
around 4000 rpm
I can feel this in the shifter and steering wheel. It's not real obvious but I used to be an automotive engineer and have been trained to look for issues like this.
My car is at the dealer now for a number of warranty items and I've complained about this vibration.
1600 rpm
2500 rpm
around 4000 rpm
I can feel this in the shifter and steering wheel. It's not real obvious but I used to be an automotive engineer and have been trained to look for issues like this.
My car is at the dealer now for a number of warranty items and I've complained about this vibration.
I took it back in and the GM regional guy told the dealer to just pull out the 2nd clutch, order a 3rd factory clutch, have it balanced and put back in. There is still a faint vibration at these same RPMs but really minor now. What I have now is what sounds like exhaust leaks, really loud ticking sounds from 1800 to 2500, so I am guessing the exhaust was not bolted down correctly.
Now I have contacted our district rep and he is sending the car to Bill Estes in Indy, they have 2 very good vette technicians, our local dealer didn't even have the right tools to do the shift fork TSB (alum to steel).
Thread Starter
Race Director
Joined: Dec 2002
Posts: 10,233
Likes: 21
From: Baltimore suburbs Maryland
Update: I finally got around to sending my unit off to a machine shop to be "match balanced". The tech said that the OEM flywheel was pretty much balanced. BUT, that the aftermarket one WAS NOT in spec. I dont remember exactly how much but the aftermarket one was off and the tech said I would have gotten a noticeable vibration if it was not match balanced. I'm real glad that I got it match balanced cause I woulda been really PO'd if I put it in and my car shook.
IIRC the Pro Gold kit the flywheel is a Fidanza?
IIRC the Pro Gold kit the flywheel is a Fidanza?
