slow speedo
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Joined: Nov 2010
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From: port saint lucie florida
slow speedo
on my 76 ever since i bought it the speedo it doesnt bounce its just runs slow i was going to purchase a new cable but i notice theres either a one piece or a two piece cable how would i know which one is on my car?? also i see the 45 degree adaptors are they worth installing on my car thanks tim bob
Pro
Joined: Feb 2012
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on my 76 ever since i bought it the speedo it doesnt bounce its just runs slow i was going to purchase a new cable but i notice theres either a one piece or a two piece cable how would i know which one is on my car?? also i see the 45 degree adaptors are they worth installing on my car thanks tim bob
The two piece cables are for cars with cruise control. If you have cruise you have two cables. It's possible the slow reading is from the cable dragging inside the sheath which may be dry and it's binding slightly. More than likely though as mentioned above it's because someone put on a wheel and tire package that is not stock and the diameter difference is affecting the speed your speedometer shows. Can you post the tire size?
Race Director
Joined: Apr 2011
Posts: 11,183
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From: North of Toronto - Ontario
If you want to see if it's a two piece cable (auto only I believe) have a look underneath, you will see a joint in the cable about 6" or so up from the bottom of the firewall
Again, if it's just running slow compared to your speed, (proportional, like 10 mph slow) you need a new gear
Mooser
Instructor
Joined: Apr 2011
Posts: 113
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From: duluth minnesota
had problems with the speedo in my 77. it was bouncing then it quit working except for the ocassional bounce from 0. turns out it was in the cruise control. my mechanic is a vette owner and knew what the problem was right away. i can ask him what he replaced if you would like.
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Melting Slicks
Joined: Dec 2009
Posts: 3,212
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From: Thunder Bay
Get a GPS. And I agree, you need to change the sppedo gear in the transmission. Once you know how far you're out, and how many teeth are on the gear you have, some simple math will tell you what gear you need. Simple fix.
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Joined: Nov 2010
Posts: 83
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From: port saint lucie florida
i will put car back together and get a gps and see what the differance is in speed i wonder why it would have changed ill order a new cable instead of putting old one back on it will take me alittle while to reassemble car but will post results in what i find. if anyone else has any ideas please pass them on thanks everybody tim bob
