Vibration over 2500rpms
Thread Starter
Drifting
Joined: Sep 2003
Posts: 1,726
Likes: 18
From: Brighton, MI
Vibration over 1800rpms
Hello Guys,
I'm having an issue here with a c5 z06 with an ls7 installed.
Problem:
Vibration over 1800rpms
It happens no matter what. Clutch in, clutch out. Gear in gear out, moving or stationary.
My guess:
Pilot bearing.
History:
This car came from another shop. The car didn't vibrate the first time I tuned it. Customer installed an RPM transmission, clutch and carbon fiber drive shaft. Afterwards, the vibration started.
Engine had oiling issues so it got pulled.
New engine from LME was installed.
Vibration still. While on the other shop, they turned the car back to stock but with the LME engine. They did change the clutch and everything.
Vibration still.
Any thoughts?
Thanks
I'm having an issue here with a c5 z06 with an ls7 installed.
Problem:
Vibration over 1800rpms
It happens no matter what. Clutch in, clutch out. Gear in gear out, moving or stationary.
My guess:
Pilot bearing.
History:
This car came from another shop. The car didn't vibrate the first time I tuned it. Customer installed an RPM transmission, clutch and carbon fiber drive shaft. Afterwards, the vibration started.
Engine had oiling issues so it got pulled.
New engine from LME was installed.
Vibration still. While on the other shop, they turned the car back to stock but with the LME engine. They did change the clutch and everything.
Vibration still.
Any thoughts?
Thanks
Last edited by The Highlander; Aug 19, 2011 at 05:41 PM.
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
Hello Guys,
I'm having an issue here with a c5 z06 with an ls7 installed.
Problem:
Vibration over 1800rpms
It happens no matter what. Clutch in, clutch out. Gear in gear out, moving or stationary.
My guess:
Pilot bearing.
History:
This car came from another shop. The car didn't vibrate the first time I tuned it. Customer installed an RPM transmission, clutch and carbon fiber drive shaft. Afterwards, the vibration started.
Engine had oiling issues so it got pulled.
New engine from LME was installed.
Vibration still. While on the other shop, they turned the car back to stock but with the LME engine. They did change the clutch and everything.
Vibration still.
Any thoughts?
Thanks
I'm having an issue here with a c5 z06 with an ls7 installed.
Problem:
Vibration over 1800rpms
It happens no matter what. Clutch in, clutch out. Gear in gear out, moving or stationary.
My guess:
Pilot bearing.
History:
This car came from another shop. The car didn't vibrate the first time I tuned it. Customer installed an RPM transmission, clutch and carbon fiber drive shaft. Afterwards, the vibration started.
Engine had oiling issues so it got pulled.
New engine from LME was installed.
Vibration still. While on the other shop, they turned the car back to stock but with the LME engine. They did change the clutch and everything.
Vibration still.
Any thoughts?
Thanks
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
No there are balance plug holes on the back of the flywheel... the flywheel itself is zero balanced,, but the holes are to balance the rotating assembly of the engine...using the original factory weights will bring the rotating assemby into final balance. you need to know what weights were used in the original flywheel or you need to get the engine balanced.. the flywheel is were the weights are added to zero out the whol rotating mass. Some engines require very little weigh ( like 3 grms. ) but others require more.. its these motors that will vibrate when not properly balanced. also the whole clutch assembly ( flywheel, disk, pressure plate ) need to be match marked at zero balance and assembled the way it was balanced. Then weighs are added to the flywheel to complete the motor balance.
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
Torque tube is not an issue here because the OP has stated that the vibration is present even with the clutch in ( disengaged )and out of gear.... making this a flywheel, pressure plate, forward issue.
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
ET is right on the mark here. With the proper equipment and someone that knows how to use it, this type of imbalance can be corrected with engine in the car. It can take about 1 to 3 hours to complete a good balance. From GM the harmonic balancer can also have added weights to correct the front plain imbalance of the engine.
Racer
Joined: Mar 2011
Posts: 476
Likes: 1
Yep, my mistake.. I have an A4(in which the torque tube spins no matter what) I had a vibration from mine being off center after putting it back together.
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Thread Starter
Drifting
Joined: Sep 2003
Posts: 1,726
Likes: 18
From: Brighton, MI
No there are balance plug holes on the back of the flywheel... the flywheel itself is zero balanced,, but the holes are to balance the rotating assembly of the engine...using the original factory weights will bring the rotating assemby into final balance. you need to know what weights were used in the original flywheel or you need to get the engine balanced.. the flywheel is were the weights are added to zero out the whol rotating mass. Some engines require very little weigh ( like 3 grms. ) but others require more.. its these motors that will vibrate when not properly balanced. also the whole clutch assembly ( flywheel, disk, pressure plate ) need to be match marked at zero balance and assembled the way it was balanced. Then weighs are added to the flywheel to complete the motor balance.
But the problem began with the other engine which was a stock engine. So what is causing is a "carry over" to this engine.
I am still guessing is the pilot bearing. I am looking to see where to start looking for this issue.
Last edited by The Highlander; Aug 21, 2011 at 02:15 AM.
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
I am using a perfectly balanced engine from late model engines.... this is not a stock engine.
But the problem began with the other engine which was a stock engine. So what is causing is a "carry over" to this engine.
I am still guessing is the pilot bearing. I am looking to see where to start looking for this issue.
But the problem began with the other engine which was a stock engine. So what is causing is a "carry over" to this engine.
I am still guessing is the pilot bearing. I am looking to see where to start looking for this issue.
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
I am using a perfectly balanced engine from late model engines.... this is not a stock engine.
But the problem began with the other engine which was a stock engine. So what is causing is a "carry over" to this engine.
I am still guessing is the pilot bearing. I am looking to see where to start looking for this issue.
But the problem began with the other engine which was a stock engine. So what is causing is a "carry over" to this engine.
I am still guessing is the pilot bearing. I am looking to see where to start looking for this issue.
You are asking for help, we are both trying to give you some, but refuse to consider we may actually know something. Something as simple as the pressure plate being out 120 degrees from the flywheel would be a much higher reason for your balance problem. IN most cases pressure plates can attach to flywheel in any of three locations thus the 120 out. Match marks are placed on both the pressure plate and flywheel to have a zero balanced assembly. Then this assembly is connected to the engine. This assembly is also used to adjust the internal rotating assembly. Like adding weights to a wheel and tire balance rotation.
Thread Starter
Drifting
Joined: Sep 2003
Posts: 1,726
Likes: 18
From: Brighton, MI
Point being! We had a perfect stock ls7 and it was ok! This customer installed a clutch/ driveshaft and an rpm trans onto the stock ls7! Vibration started!
Engine got busted and a new engine from lme was installed!
Same vibration
Stock clutch was installed and stock driveshaft! Same vibration
Went to balance the new clutch! Some balancing was done, albeit very little! Same vibration
Just a fyi! This is not a small vibration! This is a huge vibration!
This was done by his previous mechanic and im tasked to find it now!
Thread Starter
Drifting
Joined: Sep 2003
Posts: 1,726
Likes: 18
From: Brighton, MI
FYI. for your information, Eric and I are both Corvette platform Factory Engineers, while I am retired, Eric is still working. I started on the C5 platform in 1995. Like Eric has said, why are you focused on the pilot bearing? It is a very small concenteric item . You could spin a pilot bearing at at 10,000 rpm and it will still be perfectly balanced.. Again " what is a perfectly balanced engine from Late model engines?
You are asking for help, we are both trying to give you some, but refuse to consider we may actually know something. Something as simple as the pressure plate being out 120 degrees from the flywheel would be a much higher reason for your balance problem. IN most cases pressure plates can attach to flywheel in any of three locations thus the 120 out. Match marks are placed on both the pressure plate and flywheel to have a zero balanced assembly. Then this assembly is connected to the engine. This assembly is also used to adjust the internal rotating assembly. Like adding weights to a wheel and tire balance rotation.
You are asking for help, we are both trying to give you some, but refuse to consider we may actually know something. Something as simple as the pressure plate being out 120 degrees from the flywheel would be a much higher reason for your balance problem. IN most cases pressure plates can attach to flywheel in any of three locations thus the 120 out. Match marks are placed on both the pressure plate and flywheel to have a zero balanced assembly. Then this assembly is connected to the engine. This assembly is also used to adjust the internal rotating assembly. Like adding weights to a wheel and tire balance rotation.
My guess is that if the pilot bearing was misaligned it could cause this vibration!
Either way i have to open up!
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
Where is the vibration felt, shifter, seat, steering wheel? Is there an rpm that is worse compare to others or does it continue to increase in amplitude the higher it rev’s? What flywheel is currently installed?
I’m not sure who “lme” is, but have you talked to them about the vibration? Are you using stock or aftermarket engine mounts?
Chances are the vibration has nothing to do with what was in the car before the engine swap, even though it may feel the same. Once the above questions are answered I could better suggest how to fix it.
I’m not sure who “lme” is, but have you talked to them about the vibration? Are you using stock or aftermarket engine mounts?
Chances are the vibration has nothing to do with what was in the car before the engine swap, even though it may feel the same. Once the above questions are answered I could better suggest how to fix it.
Thread Starter
Drifting
Joined: Sep 2003
Posts: 1,726
Likes: 18
From: Brighton, MI
Where is the vibration felt, shifter, seat, steering wheel? Is there an rpm that is worse compare to others or does it continue to increase in amplitude the higher it rev’s? What flywheel is currently installed?
I’m not sure who “lme” is, but have you talked to them about the vibration? Are you using stock or aftermarket engine mounts?
Chances are the vibration has nothing to do with what was in the car before the engine swap, even though it may feel the same. Once the above questions are answered I could better suggest how to fix it.
I’m not sure who “lme” is, but have you talked to them about the vibration? Are you using stock or aftermarket engine mounts?
Chances are the vibration has nothing to do with what was in the car before the engine swap, even though it may feel the same. Once the above questions are answered I could better suggest how to fix it.
A heavy rrrrrrrrrrrrrr vibration! It gets worse with rpms! Comes on at about 1800rpms
Stock mounts!
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
Time to get out the balancing equipment. No need to pull the drivetrain apart.
Good luck!!
Last edited by Eric D; Aug 21, 2011 at 04:14 PM.
Thread Starter
Drifting
Joined: Sep 2003
Posts: 1,726
Likes: 18
From: Brighton, MI
I really appreciate your inputs!
Currently it has a spec clutch installed
Drifting
Joined: Sep 2002
Posts: 1,614
Likes: 7
From: South Florida
For my education...could it be an unbalanced drive shaft...or a universal joint? If no, what would indicate a problem in these areas?
If yes, has the OP looked at this. He said there was a new cf drive shaft.
If yes, has the OP looked at this. He said there was a new cf drive shaft.
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
I’m sure or I would like to believe you meant imbalance, which the propshaft could have, however, the OP stated it vibrates with the clutch disengaged. When the clutch is disengaged the propshaft doesn’t rotate with the car stopped. As far as universal joints causing an imbalance, I suppose this has a possibility; however this stock Corvette does not have universal joints, so this also would be a no to a vibration source.
