1966 vibration
Thread Starter
Cruising
Joined: Mar 2024
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From: CAPE COD, MA
1966 vibration
Would worn out clutches in the posi-traction cause a vibration to increase asspeed increases? Under 40mph its fairly smooth but after that a deep vibration increases that you can feel in your butt. Suspension and u-joints are tight.
Race Director
Joined: Jan 2002
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From: Close to DC
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Has any service work been done on the driveline recently or not at all? There are a few things in the driveline that, if worn can cause vibrations. Is the balance weight still on the driveshaft? Is the pinion snubber secure. Are the half shafts u-joints new or old? If old, are there signs of rust around the caps? Have you checked the trailing arm bearings by grabbing the tires at the top and rocking the assembly. Should not be excessive. 
Dennis
Dennis
Thread Starter
Cruising
Joined: Mar 2024
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From: CAPE COD, MA
66 427 vibration.
Its a 66 427. Tracks perfect, no vibration in the shifter. Had it check by a respected corvette guy in Taunton. The clutches in the rear end are shot. He suspects the rear end clutches. I a vibration you feel in the seat of your pants. Could the rear end be the issue? Thanks.
Melting Slicks
Joined: Sep 2005
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From: Warminster PA
Lots of good suggestion already.
Check the tires for proper inflation and try swapping front to rear to see if the vibration moves with the tires. I doubt worn posi clutches could cause a vibration like that. How was it determined that the clutches are bad?
Check the tires for proper inflation and try swapping front to rear to see if the vibration moves with the tires. I doubt worn posi clutches could cause a vibration like that. How was it determined that the clutches are bad?
Le Mans Master
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At speed, is the view through your rear view mirror distorted because of the vibration?
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That is the break away torque test. Usually requires 40 ft/lb to slip the clutches, unless it is a tuned posi. Do you know how the posi was rebuilt?
Le Mans Master
Joined: Feb 2014
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From: Richardson Texas
Melting Slicks
Joined: Jun 2014
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From: NJ
I can't imagine worn out clutches causing a vibration as speed increases. I suspect a driveshaft/ u-joint/ trans tail shaft bushing or a pinion bearing problem. The tail shaft and pinion bearing are highly unlikely but worth checking , if either of these are bad there will be fluid leaking from their respective seals. But, I would go after the driveshaft first, the speed and RPM that you mention , is when these vibrations will start to surface. Also worth noting is: like others have said, out of balance wheel/bent rim, slipped cords/ belts in the tire, flat spots on the tire (from sitting too long in one position). Let us know what you find, I'm curious to know!
Le Mans Master
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Ya know the second post in you were asked about your tires - which are the very first things you check - before you begin chasing down the dozens of suggestions that followed - on a fairly complicated suspension - comparatively speaking.
Old radial tires fail internally, steel belts rust and they separate internally. At speed they can wipe out a quarter. I had one such total failure and caught another just before failure when the car picked up a vibration...
Dan
Old radial tires fail internally, steel belts rust and they separate internally. At speed they can wipe out a quarter. I had one such total failure and caught another just before failure when the car picked up a vibration...
Dan
Thread Starter
Cruising
Joined: Mar 2024
Posts: 14
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From: CAPE COD, MA
The tires are brand new and there is no vibration in the steering wheel. I don't believe its the tires although, as has been said, check the easy things first. The down side is that I have real knock-offs and they are a pain.
Team Owner
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brand new never means they are good. what brand? does the rear end make any noise doing tight turns?
