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Take it to the local Chevy dealer, claim a vibration occurs only during high speed turns. See what the service adviser says may be the problem.
Drivetrain vibration in 1966 Corvair
- Thread starter 007
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The chances that a service advisor at any Chevy dealer has actually ever seen a '66 Corvair are slender.
I'd like to watch what transpires. You Tube territory.
I'd like to watch what transpires. You Tube territory.
Originally Posted by Cdn17Sport6MT
Originally Posted by GSCJR
Originally Posted by Trav
Check the U joints and anything else connected to the drive axles, these types of components are a common cause of vibration.
+1
If memory serves, the rear half-shafts do not telescope... on the '65 and later (specifically). Meaning that they act as the upper wishbone... or link... and they run in compression. Like how the first few Corvette Stingrays were.... I guess, all the way up to the early 90's ??? The U Joints have to be in good nick. Same as the Jaguar IRS.
+ a few more ...
Originally Posted by GSCJR
Originally Posted by Trav
Check the U joints and anything else connected to the drive axles, these types of components are a common cause of vibration.
+1
If memory serves, the rear half-shafts do not telescope... on the '65 and later (specifically). Meaning that they act as the upper wishbone... or link... and they run in compression. Like how the first few Corvette Stingrays were.... I guess, all the way up to the early 90's ??? The U Joints have to be in good nick. Same as the Jaguar IRS.
+ a few more ...
Originally Posted by JHZR2
Get a vibration analysis app for your smart phone - I use a free one called VibrationAnalysis. Take a reading at actual 60MPH and another at a recorded actual speed where the vibration is worst.
Verify your tire size's true rpm/mile rating. From there all it takes is math to determine what in the drivetrain is causing the worst vibration.
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4891490/1
Knowing what frequency you're truly feeling will be helpful.
You'll get something like this if it's legit wheel and tire:
![[Linked Image from i.imgur.com]](https://i.imgur.com/U7E5xfwl.jpg "[Linked Image from i.imgur.com]")
And this when fixed:
![[Linked Image from i.imgur.com]](https://i.imgur.com/PuEGdF3l.jpg "[Linked Image from i.imgur.com]")
Note the y axis.
When you know the number of tire RPMs/mile, and are at 60MPH, so its one mile per minute, the math starts to get easy.
Since the diff ratio is known, if its that, it will be mathematically the harmonic that is the ratio multiplier of the tire RPM, or more specifically Hz (oscillations/sec).
What is the link for the APP?
Get a vibration analysis app for your smart phone - I use a free one called VibrationAnalysis. Take a reading at actual 60MPH and another at a recorded actual speed where the vibration is worst.
Verify your tire size's true rpm/mile rating. From there all it takes is math to determine what in the drivetrain is causing the worst vibration.
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4891490/1
Knowing what frequency you're truly feeling will be helpful.
You'll get something like this if it's legit wheel and tire:
And this when fixed:
Note the y axis.
When you know the number of tire RPMs/mile, and are at 60MPH, so its one mile per minute, the math starts to get easy.
Since the diff ratio is known, if its that, it will be mathematically the harmonic that is the ratio multiplier of the tire RPM, or more specifically Hz (oscillations/sec).
What is the link for the APP?
Check the front wheel bearings especially the right front. I had a 65 monza 140 hp (4 one barrels). The speedo cable was attached (actually went thru) the right front hub and was poorly sealed. This allowed a lot of water and crud to contaminate that bearing "very" quickly. I remember having to replace mine about every 10K miles or so (Michigan weather....life could be shorter if in wetter areas). I started to repack the bearings at about 4 to 5K miles. The front end would shake as the bearing began to seize, races scored and the bearing cage even began to fail. Very easy repair as I recall. It was more apparent at highway speeds then around town until it started to whine and grind.
Originally Posted by 007
What is the link for the APP?
Yes, I'd like to know too.
What is the link for the APP?
Yes, I'd like to know too.
For mor info, the FB page Corvair Owners Group has lots of good people to answer, but I can think of 5 things off the top of my head. Bent wheel, bad bearings, or bad u-joint, out-of-balance brake drums, bad pitman or idle bushing.
The bent wheel might be seen by a pedestrian while you drive, or raise the wheel and turn it with a fixed object next to it. They can be straightened, as I did on my Dauphine.
I have a vibration on my 88 BMW 325ic that can only be corrected with the high speed balancing on the car, and its been a few years since I found anyone who still had that equipment (that I could never use on the rear because of the limited slip differential and rear wheels that don't fin on the front.
The bent wheel might be seen by a pedestrian while you drive, or raise the wheel and turn it with a fixed object next to it. They can be straightened, as I did on my Dauphine.
I have a vibration on my 88 BMW 325ic that can only be corrected with the high speed balancing on the car, and its been a few years since I found anyone who still had that equipment (that I could never use on the rear because of the limited slip differential and rear wheels that don't fin on the front.
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