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Old Sep 18, 2011 | 07:23 PM
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kingkohlmn
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Default Speedo question

78, between 0 and 20 the speedo needle bounces. It used to be much worse, it would do the same thing at any speed and any time. Sometimes it would be steady and then bounce. I've been spraying penetrating lube in the cables which has just about eliminated the problem, only have the bounce at the low speed. Any idea of what I need to do? Replace the cables?

Thanks
Bill
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Old Sep 18, 2011 | 08:16 PM
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actually spraying lube doesn't help. the speedo is to loose. a rotating magnet spins around another "opposite pole" and drags it around the faster you go. if it's too loose, it will bounce around like crazy. it tends to even out the harmonics as you go faster, so it's not as bad. if it's tight, then at low speeds it will not bounce as much because of the resistance.
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Old Sep 18, 2011 | 08:41 PM
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Originally Posted by C3-PO
actually spraying lube doesn't help. the speedo is to loose. a rotating magnet spins around another "opposite pole" and drags it around the faster you go. if it's too loose, it will bounce around like crazy. it tends to even out the harmonics as you go faster, so it's not as bad. if it's tight, then at low speeds it will not bounce as much because of the resistance.
Thanks,
  1. What did the lube do then? Like I said, it used to bounce at any speed and any time. Now it only bounces at low speed. I can even us my cruise control on the highway now.
  2. Where is the speedo too loose? in the cluster or in the middle where two cable connect in the drive fender area or at the other end? (Transmission I think)
  3. Can I make this tighter? If so, how do I do it?
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Old Sep 18, 2011 | 10:22 PM
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Ans 1. when you shoot it with lube it thickens up and keeps the cable from bouncing inside the housing.
Ans 2. there is a damper coil spring inside the speedo that's wrapped around the pole end. it possibly might be broken. the speedo itself i believe cannot be taken apart. there is the short cable that goes thru the firewall to the speedo from the cruise control unit in the engine compartment. i found this out the first time i took my instrument cluster out of the dash.
3. i don't know if it can be fixed. my problem was the cruise control cable squeaking as i drive (reallly annoying). my speedo bounced a little, but got smooth as soon as i replaced the cruise control. it too has a damper spring inside it. have you looked at it? it can be taken apart and worked on . good luck.
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