Speedo needle bouncing badly up to 20 MPH (approx)
03-17-2004, 04:26 PM
#3
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Re: Speedo needle bouncing badly up to 20 MPH (JScott81)
Yeah, It's gonna break.
That's happened in a few of my old rides, and just happened to my 81.
I haven't gotten into it yet to determine what exactly which part of the cable has broken.
That's happened in a few of my old rides, and just happened to my 81.
I haven't gotten into it yet to determine what exactly which part of the cable has broken.
03-17-2004, 04:31 PM
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Melting Slicks
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Re: Speedo needle bouncing badly up to 20 MPH (HankB1)
My speedo was jumpy too. I lubed the cable and it was working fine. But occasionally it will register a speed 20 or more miles higher and the needle moves around bunch when it does that. Is that the cable or speedo?
03-17-2004, 04:52 PM
#6
Cruising
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Re: Speedo needle bouncing badly up to 20 MPH (Never Finished)
I'll check out the transducer. The speedo cable from the actuater to the speedo is brand new. It has a pretty steep curve in it because it seemed to be a tad long even though it is the correct GM part. The cable from the trans to the transducer is probably the original. It was unhooked for about 5 years. The vehicle was not licensed or driven (much) durring that time.
Which lubricant would be recommended since that would be the cheepest and most logical starting point is finding a cure.
Which lubricant would be recommended since that would be the cheepest and most logical starting point is finding a cure.
03-17-2004, 04:57 PM
#7
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Re: Speedo needle bouncing badly up to 20 MPH (JScott81)
As for noise. The vette makes quite a few noises. I am a brand new owner and will need some time to correctly identify them all. It doesn't seem like the speedo is the source of any of them however.
03-17-2004, 05:32 PM
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Re: Speedo needle bouncing badly up to 20 MPH (JScott81)
If it sounds like a whirr/grinding then its probably just the cable... Pickup some lube and see if you can get it from the transmission end :cheers:
If not, then you'll probably want to replace the cable its self... Not sure as to how hard the job is on a Vette, havent done one before on one... Normally its not horrible, most time consumed is spent working on the dash to get the cable off the speedo...
:cheers:
If not, then you'll probably want to replace the cable its self... Not sure as to how hard the job is on a Vette, havent done one before on one... Normally its not horrible, most time consumed is spent working on the dash to get the cable off the speedo...
:cheers:
03-17-2004, 10:42 PM
#9
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Re: Speedo needle bouncing badly up to 20 MPH (JScott81)
I've not done this but a couple of hints I've read recently about the process seem important. When cleaning/lubing the cable(s) pull them completely out of the casings. You can inspect/clean/replace cables as needed and determine whether you need to clean or replace the casings as well. Prelub the cables when you reinsert them. The amount of lubricant is critical-it was emphasized not to allow any lub to migrate into the speedo head which would ruin it. I'd guess the same for the cruise servo. Good Luck.
Marv-
Marv-
03-18-2004, 10:53 AM
#10
Safety Car
Re: Speedo needle bouncing badly up to 20 MPH (JScott81)
One of the speedo cables needs lube or is going bad. On a '78 there is one from the tranny to the cruise, and one to the speedo itself. On my '78, the one from the tranny needs a little lube from time to time; this cures it. The easiset way I have found to lube it, is to buy the grease fitting from Mid America. This fitting fits onto the end of the cable and allows you to pump grease into the cable. The grease will carry up the cable by screw effect and help lube most of the cable. I grease mine at least once a season now and it is smooth.
