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I've been reading through the post on vibration problems that other people have been having and it sounds like I may be having a Flywheel or balancer problem. Here's where I'm at right now. I have a 454 (.060 over) that starts to vibrate at around 3000 rpm's. It does this in every gear. When I rebuilt the engine I installed a new Crank, new rods, new pistons, a new Cal auto Transpeed balancer (HB454C) and a resurfaced 454 flywheel. I've been driving it once in a while on weekends to break in the motor but I notice that when I get to around 3000 rpm's I get a vibration that is too significant to ignore.

I first started looking into possible drive train issues such as driveline balance, pinion angle, and the such, then I came to my senses and realized that it happens whenever the engine is at a certain rpm, and not when the car is only as a certain speed.

I'm not sure where I should go from here, but here's my train of thought. When I was installing the flywheel I noticed that my crank didn't have a dowel pin on it, so I lined up the bolt holes and everything seemed to be okay. Maybe that is causing the vibration, some kind of flywheel mis-alignment. My only other thought is also with the flywheel. When I was bolting the clutch pressure plate to the flywheel, I had to re-tap one of the bolt holes. As I look back on this I wonder if the bolts that I used to hold the pressure plate to the flywheel were not shouldered and maybe the plate / clutch assembly is shifted enough to vibrate at 3000 rpm's. My last thought was maybe the reconditioned flywheel that I used was not balanced properly. I noticed that there were several holes drilled on the opposite side of the external balance weight of the flywheel.

I could use a few suggestions to try before I go and pull the trans back out to get to the flywheel and maybe replace it.

Any advice is appreciated guys, thanks.
 

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sounds like a flywheel problem if you are sure its not a car speed problem (tire balance over 65 mph) I had asimilar problem w/a bent flywheel cost me two (some times i'm a little slow )tranny's . :cool:
 

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I have preeched on many websites the importance of balancing an engine as you installed NEW CRANK and did not have it balanced and there are a lot of brand new cranks that are not balanced and I am sure a piston that is .060 is heavier then a standard piston and if it is a forged piston it will even be heavier.

Now you have a new balancer and a resurfaced flywheel that has not been balanced with the crank and also a pressure plate that should have been spun up as well.

Hopefully you don't have to tear it down and have it balanced but if the car is setting there still and at 3000 rpm it vibrates you then have an issue with some of the new parts you installed.

One place to look is check and see if you put the pilot bearing in the back of the crank and from there take off the pressure plate and run it to see if it stops vibrating.

Good luck and I hpoe its nothing serios.
 
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