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Old 04-19-2012, 04:07 AM   #1
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Speedo is 10mph off.......

I replaced the Speedo cable on my 86 5 speed and noticed that my mph is off by 10. The gauge reads 25mph and I'm at 35mph on my GPS. I know my GPS is accurate for sure. I bought the car like this. I used the same Speedo gear when I replaced the cable. Anyone know what gear I can buy to correct this? As far as I know the rear end is stock. Thanks
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Old 04-19-2012, 07:35 AM   #2
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was it off that much before you changed it bc i know the speedo on foxes arent the most accurate from the factory.
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Old 04-19-2012, 08:45 AM   #3
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Re: Speedo is 10mph off.......

if someone modified the rear end gears it can throw off the speedo as well
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Old 04-19-2012, 02:09 PM   #4
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Quote:
Originally Posted by SpectorV
if someone modified the rear end gears it can throw off the speedo as well
Yeah i had to change my speedo gear i switched from 410s to 373s
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Old 04-19-2012, 03:43 PM   #5
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you need to check your rear gear ratio. thats the only way to find out which gear you need.
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Old 04-19-2012, 04:06 PM   #6
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When I bought the car the Speedo wasn't working because it melted on the exhaust so I wouldn't know if it worked correctly before. How would I find out what gear I have? I know I could give the dealer a call, but that won't answer my question if it's a diff gear. Thanks
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Old 04-19-2012, 04:23 PM   #7
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mark the drive shaft.then trurn the tire exactly 1 turn while watching your mark. count how many times the driveshaft spins.3 3/4 spins = 3.73. 4 1/10 spins = 4.10 gears etc.
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Old 04-19-2012, 05:02 PM   #8
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Ok, thanks for the info
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