High Speed Engine Shaking - Team Camaro Tech
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post #1 of 8 (permalink) Old Oct 8th, 02, 09:53 AM Thread Starter
Join Date: Apr 2002
Location: san jose, ca, usa
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I just finished a 15 month restoration on my 1968 camaro. I did not replace 1) the harmonic balancer 2) the drive shaft. The motor really starts to shake at 65+ mph. The car runs really smooth from 0-60mph. I assume this shake is from the harmonic balancer, but wanted to make sure that it wasn't also the drive shaft.
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post #2 of 8 (permalink) Old Oct 8th, 02, 09:55 AM
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are you sure it is the engine and not coming from a wheel being out of balance or a poor alignment? Did it do this before the restoration?
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post #3 of 8 (permalink) Old Oct 8th, 02, 11:16 AM Thread Starter
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Location: san jose, ca, usa
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Yes, it did this before the restoration. I only had the car for 3 months and drove it little during that time. I just had an alignment done three weeks ago.

[This message has been edited by Brevdog (edited 10-08-2002).]
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post #4 of 8 (permalink) Old Oct 8th, 02, 11:25 AM
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Determine if it's engine- or speed-related; take it up to the speed where it shakes and put it in neutral and let it drop back to idle; if the shaking stops, it's engine - if it doesn't, it's prop shaft or tire related. Then you can chase it from there.

'69 Z28 Fathom Green
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post #5 of 8 (permalink) Old Oct 8th, 02, 11:40 AM
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If the shake is from your balancer it will be at a certain RPM more so than a certain speed. Try running your engine in neutral or park at the same RPM that it is at when you're running 65 MPH. This should give you a better idea if the vibration is in your engine.
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post #6 of 8 (permalink) Old Oct 8th, 02, 11:58 AM
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Pinion angle? U-Joints? Loose motor/tranny mounts? Start with the obvious and work your way through the rest of the car. Could even be an exhaust pipe rubbing the frame.

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post #7 of 8 (permalink) Old Oct 9th, 02, 07:02 AM
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who owned the car before you? are you sure it is the factory harmonic balancer on it? a common mistake is putting the wrong balancer on your motor because the car may be one year and the engine another. some engines are internally balanced and do not require the same balancer as other years. If the balancer is suspected, take it off and look at the rubber ring inside of it for wear or just check if the balancer is damaged in any way. Did you put some new universal joints in the driveshaft??? If you did and did'nt mark the driveshaft's position before pulling the slip yoke from the tranny, then the shaking could very well be from that. If you think it is that, take the driveshaft up to a machine shop for proper balancing.
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post #8 of 8 (permalink) Old Oct 9th, 02, 01:11 PM
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I had the same problem on my 76 camaro. I was told by a driveshaft shop to drive the car at the speed I had trouble at; which was about 65 mph and above, put the car in neutral and if the car stopped shaking then it was an engine drivetrain problem. If the problem did not stop then it was my driveshaft. I took the driveshaft to be rebalanced, straightened and had new u joints installed. So far It has solved the problem. I can do 65 mph and faster on the freeway with no shaking. The motor is fairly new and was installed by me and my uncle.
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