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Old 07-04-2007, 09:41 PM   #1
goldengoat2
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whats the gear ratio?

I have a 77 3/4 ton 4x4 with a open rear end, whats the best way to figure out the gear ratio. thanks
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Last edited by goldengoat2; 07-04-2007 at 09:53 PM.
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Old 07-04-2007, 10:32 PM   #2
70short/step
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Re: whats the gear ratio?

The only way to know for sure is remove cover and count the ring gear teeth and then the pinion gear teeth and divide.
You can lift the rear and turn the tire one revelution and count the number of turns of the driveline but not always accurate that way.
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Old 07-04-2007, 10:37 PM   #3
1969k10stepside
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Re: whats the gear ratio?

Or get the numbers off the ring gear and use this chart:
That's alot easier than counting teeth...
Ratio 2.56:1 - Tooth Combination 41,16
Ratio 2.73:1 - Tooth Combination 41,15
Ratio 3.07:1 - Tooth Combination 43,14
Ratio 3.08:1 - Tooth Combination 40,13
Ratio 3.08:1 - Tooth Combination 37,12
Ratio 3.31:1 - Tooth Combination 43,13
Ratio 3.36:1 - Tooth Combination 37,11
Ratio 3.42:1 - Tooth Combination 41,12
Ratio 3.55:1 - Tooth Combination 39,11
Ratio 3.73:1 - Tooth Combination 41,11
Ratio 4.10:1 - Tooth Combination 41,10
Ratio 4.11:1 - Tooth Combination 37,9
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Old 07-04-2007, 10:43 PM   #4
jimfulco
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Re: whats the gear ratio?

Lift ONE tire only, then count driveshaft revolutions during TWO full rotations of the tire.
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Old 07-04-2007, 10:45 PM   #5
krue
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Re: whats the gear ratio?

That's how I figured out what I had.
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Old 07-05-2007, 07:34 AM   #6
goldengoat2
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Re: whats the gear ratio?

Thanks everyone
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