speedometer reading too fast

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willis63v
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speedometer reading too fast

Post by willis63v »

what causes the speedometer to read faster than you are going? when driving about 30-35 mph the speedometer reads 90-100, its also kinda noisy.
66vairguy
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Re: speedometer reading too fast

Post by 66vairguy »

It could be a number of problems, but if the error is constant the most likely cause is a speedometer input bushing that is worn out allowing the magnet to get too close to the to the needle cup. If the speedometer part the cable fits into can be wobbled around then the bushing is worn out.
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willis63v
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Re: speedometer reading too fast

Post by willis63v »

ok, thanks
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bbodie52
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Re: speedometer reading too fast

Post by bbodie52 »

:welcome2: :wave: Welcome to the Corvair Forum!

You did not mention the Corvair model year or model. Several designs have been installed in Corvairs during the ten year production.

I have attached an article extracted from the CORSA Communiqué magazine regarding 1965-66 Corsa Speedometer Overhaul (CORSA Communiqué May 2012). It describes some speedometer principles of operation so the article may be useful to you.

Corsa Speedometer Repair - Communique - 2012 May - Vol 34 - No 4.pdf
Corsa Speedometer Repair - Communique - 2012 May - Vol 34 - No 4
(785.62 KiB) Downloaded 21 times

:dontknow: I would like to encourage you to restart and expand on your earlier post and tell us more about yourself, as well as about your Corvair. If you can provide your personal assessment of your mechanical skills and abilities, that would help a lot. Members of the Corvair Forum love to be helpful in assisting other Corvair owners with technical support and advice, but it helps a lot if we have some understanding of your technical background and mechanical abilities, your Corvair-related knowledge, etc. Helping us to know more about you will help us to write comments to you that are tailored to your needs and experience. Knowing your specific location is also useful, because knowing where you live can sometimes suggest possibilities.

The link below will provide you with a list of useful websites that are Corvair-related. Some of the links will lead you to an extensive technical library that will allow you to download shop manuals and other technical references in Adobe Reader format at no cost. There is also a link that will help you to locate nearby CORSA (Corvair Society of America) club chapters. While the Corvair Forum can be very helpful as you work on your Corvair, having local friends and contacts in your region who are knowledgeable about the Corvair can also be very helpful. These family-friendly CORSA chapters often offer picnics, group scenic drives, technical training and assistance, car shows, and competition events that can greatly enhance your enjoyment of Corvair ownership. You will also find a list of essential Corvair parts suppliers. Clark's Corvair Parts is the biggest and oldest Corvair supplier in the world. You will find a link that can provide you with a series of videos that amount to a tour of the Clark's Corvair Parts facilities. I think you will be amazed at the quality of the reproduction components they offer — particularly the interior carpeting and re-upholstery items. Parts suppliers such as this truly make our Corvair hobby possible.

Common and Useful Corvair Websites

:link: viewtopic.php?f=225&t=6007

:welcome:
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
66vairguy
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Joined: Tue Dec 21, 2010 3:44 pm

Re: speedometer reading too fast

Post by 66vairguy »

The CORSA article is for the Spyder or Corsa speedometer with the "trip odometer". The Monza speedometers are not as complicated.

At one time parts were common, but now most speedometer shops do not have parts. Even after a repair the unit must be magnetized to make it accurate.

I've done a few and it convinced me not to do them for a fee - very labor intensive to get them right.

There are still some good used units out there, but you have to lubricate them to ensure they will last. I usually re-lube the bushing by setting the end of the speedometer where the cable go in in a cup of DEXRON ATF (automatic transmission fluid) for couple of days and turn the input every six hours. It will free up and lube the bushing.

The only other option is a complete teardown and rebuild. Clark's did sell rebuilts at one time.
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