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speedometer error

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Old Oct 31, 2008 | 02:19 PM
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Default speedometer error

I removed my cruise control on my 81 auto and replaced the cable direct to the tranny. Now it reads 5 mph higher at all speeds. Do I need a different tranny gear..
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Old Oct 31, 2008 | 02:23 PM
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Are you sure that the extra 5 is not correct? I usually do the milemarker thing on the highway. 5miles =5 min.
If it is off then yes you can change the trans gear.
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Old Oct 31, 2008 | 02:43 PM
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I checked the MPH with my gps still 5 mph high
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Old Oct 31, 2008 | 02:51 PM
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Originally Posted by palazzopl
I checked the MPH with my gps still 5 mph high
Oops forgot about the new high tech stuff....barely know how to spell gds
I think your going to need about 2 more teeth on your gear.If I remember right its about 2.5 mph per tooth.Someone should pop in and confirm.
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Old Oct 31, 2008 | 03:01 PM
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It shouldnt have made any difference. Its direct drive.
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Old Oct 31, 2008 | 03:32 PM
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the original came with a two piece cable with the cruise module in the middle. now it goes direct to the speedometr
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Old Oct 31, 2008 | 03:33 PM
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the original came with a two piece cable with the cruise module in the middle. now it goes direct to the speedometer
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Old Oct 31, 2008 | 05:43 PM
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Theoretically, it shouldn't change. But, the transducer may have been slipping and had a gear change already. If it reads too high, you'll need a gear with 1 or 2 more teeth.
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Old Oct 31, 2008 | 07:58 PM
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Mine was reading high due to the smaller tires the previous owner put on. I corrected mine by going back to the correct tire height when I changed tires and wheels.

If you happen to be in need of tires, you could affect the change you want by selecting the right size tire.

DC
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Old Nov 1, 2008 | 09:57 PM
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A good rule of thumb here is 1 tooth = 5 mph. You need 1 more tooth.

Willcox
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