crazy vibration

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Darren

Darren

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hey guys i just rebuilt my engine and put a new clutch in my 68 cuda 383 4 speed. my question is when i let the clutch from a dead stop i have a crazy vibration / banging coming from i think is the rear suspention. i thought it was the tranny mount (it was kinda split) but after installing a new mount i still have it. once the the clutch pedel is out there is no noise. the car is a fomula S factory 4 speed any thoughts?
 

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i forgot to mention that i drove the car last year with the unrebuilt engine and cooked stock clutch and there was no vabration. and i also had my stock flywheel resurfaced. and my new clutch is a street Mcleod.
 
Causes of Clutch Chatter or Shudder
• Improper break-in procedure
• Flywheel not properly resurfaced before installing a new clutch
• Flywheel or clutch disc friction surface not parallel with the crank flange surface
• Flywheel has severe hard spots or hot spots
• Flywheel has an improper step or cup dimension
• Defective pressure plate and/or disc
• Disc has inadequate or no marcel (not enough cushion between friction facings)
• Oil or grease contamination on clutch facings
• Worn or damaged clutch linkage
• Bent cover assembly and/or clutch disc
• Damaged/excessively worn U-joints or CV joints
• Misaligned U-joints
• Excessive backlash in differential
• Excessive driveline angle
• Improper gear ratio versus tire diameter
• Improperly tuned engine
• Worn/damaged engine or transmission mounts
• Bad leaf springs, bushings or mounts

Also if your engine was align-bored , the bellhousing alignment needs to be checked due to the crank centerline being changed.
 
i would lean towards somthing with the clutch because it did not vibrate lastyear. one thing i will add is i have a small valve cover gasket leak and the oil runs down to the back of the engine. i have my inspection plate off still. what are the odds that the spin of the clutch is slinging up a bit off oil?
just a shot the dark. thanks
 
Did you use a new flywheel? You say you fried the clutch, you may have hot spotted the face or even warped it.
 
Was the flywheel turned on a flywheel grinder , it takes a special machine to do it right..
 
i had the flywheel turned at a good machine shop. new pilot bushing. what do you guys think about the oil leck theory
 
well i sprayed the clutch area with a can of brake clean the blew it down with air. one thing i noticed if i release the clutch pedel without giving it any gas it is really smooth. when you resurface a flywheel is the key to get it square (flat) someone said somthing about stepped flywheel. thanks
 
Flywheel not properly resurfaced before installing a new clutch
Worn/damaged engine or transmission mounts

Those would be the two things I would look at. If the clutch engagement was fine before engine rebuild , I would think something happened related to engine/clutch replacement.
I would question how your machine shop turned the flywheel, because some shops use brake lathes to turn flywheels and it is not an acceptable method , needs to be turned on a dedicated flywheel grinder.
Or engine /trans is moving around with load taking off and getting u-joint /driveshaft angle to the point of a vibration.
As far a oil getting on your clutch , usually that is from a rear main leaking and getting slung over time into the bell housing area, or grease being applied too heavy/incorrectly on assembly.
 
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