cwalsh

My flywheel came with the pretty half moon machining marks on, why should I have it done again?
Chris

87ROC

Don't the flywheels have balance weights on them like a wheel or a driveshaft. Did you notice if there where any weld spots that where missing the wieghts.

cwalsh

I honestly did not look for weights at all. I figured that since the LT1 & L98 were internal balance then bolting on the LT1 flywheel should be a no brainer. I thought.

87ROC

The weights on the flywheel is just another long shot. But it seams like they where on there last time mine was out. I'm pretty sure torque converters and flex plates have them also. Flywheels are pretty heavy so you would think they had to be balanced. But I would look for a much more reliable source than me before disassembling.

kjlvilla

I agree with you, it has to be a flywheel balance problem. You said with the cluth depressed and engine revved you get the vibration. The only thing spinning is the engine/flywheel and trans input shaft. The LT-1 flywheel has balance weights on it. If you replace the flywheel in an LT-1 you need to put the weights from the original flywheel into the same locations on the new flywheel. If you did a swap like you did, you need the flywheel balanced to the engine. The only way I know how to do this is with a strobe balancer. The GM dealer can do this with a tool called the EVA (electronic vibration analyzer). It's not easy to do but possible. You can also check with trans. shops or maybe a driveshaft specialty shop, they may be equipped to do this. A reputable machine shop may also help. GM never recommends machining a flywheel. It can cause clutch disengagement problems because the pressure plate becomes further away from the fork or concentric slave. Depending on the set-up the trans has. Hope this helps.

cwalsh

Thanks for the input. I have heard that from some people around here as well. I actually have gotten fed up with it and have ordered a McLeod 0 balance flywheel and clutch assembly. Also while in neutral with it revving I had in gear as to eliminate the input shaft bearings.