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Old Apr 7, 2011 | 09:24 PM
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Default Speedo problem

i have a P/G in my '65 and my speedo reads to fast, says i'm doing 60 mph when it's actually doing about 45. Would someone tell how do i determine which speedogear I need to order to remedy this?? The rear end is stamped AS3 15 65 .... the AS designation appears to be for a 3:70 non-posi and it is a non posi, car was built on APril 06/65 would it be the original rear end?

Last edited by vt65; Apr 7, 2011 at 09:41 PM.
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Old Apr 7, 2011 | 09:35 PM
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The best info I can gather from my GM parts book calls for a green 22 teeth gear. Someone else recheck this please. Dennis
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Old Apr 7, 2011 | 09:38 PM
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thanks Dennis, i think it's a purple gear in there now
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Old Apr 7, 2011 | 09:52 PM
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there was never a purple one. Like Dennis said it should be a GREEN 22 teeth gear
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Old Apr 7, 2011 | 09:54 PM
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great that's what i'll order,,, thanks again
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Old Apr 8, 2011 | 09:19 PM
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pulled the gear today it was a red 21 tooth, i think with the big difference in mph between the speedo and my GPS i have to go with a black 23 or yellow 24? I'll order all 3 and see...thanks again for the replys
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Old Apr 8, 2011 | 09:30 PM
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My parts book says for that axle ratio and stock tire size 22 teeth is all you need
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Old Apr 8, 2011 | 09:34 PM
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Originally Posted by vt65
pulled the gear today it was a red 21 tooth, i think with the big difference in mph between the speedo and my GPS i have to go with a black 23 or yellow 24? I'll order all 3 and see...thanks again for the replys
This might be a drive gear thing since there is such a wide variance.

While I always try to use the correct specified gear for a car, you can use as a rule of thumb 5 mph per tooth.
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Old Apr 8, 2011 | 09:40 PM
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Originally Posted by Willcox Corvette
This might be a drive gear thing since there is such a wide variance.

While I always try to use the correct specified gear for a car, you can use as a rule of thumb 5 mph per tooth.
thanks for that !
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Old Apr 9, 2011 | 02:09 AM
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No problem.. Hope you narrow it down.. with three to pick from you should nail it.
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