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How to check gear ratio?

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Old 09-11-2009, 12:48 PM
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Default How to check gear ratio?

is there any way possible to check what gears i have in my car with out taking off the rear cover and counting teeth i have the TA HD cover and its a pain to take off and torque back up but i just want to know by maybe looking at the drive shaft and tire movement and going from there

thanks matt
Old 09-11-2009, 01:43 PM
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jack the rear end up off the ground, put a tape mark on the 12 oclock position of both wheels and then us a magic marker on the drive shaft. have a friend watch the tires turn 1 full revolution when you turn the drive shaft. as you get around 3 times around with the shaft you should be closing on 1 full tire revolution. when the friend says you've gone 1 time around, look at where your mark on the drive shaft is. The 3.23 will be easy to see the mark in the direction you were turning halfway up. 3.42 will be hard to see since it'll nearly be at the top and so forth...
Old 09-11-2009, 01:48 PM
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Jack the back of the car up. You want one exact turn of the wheel. So roll it around till there is something to reference. For instance, I used the valve stem at a perfect 12 o'clock position. While under the car, mark the driveshaft facing directly 6 o'clock with a sharpie. Have someone spin your wheel exactly one turn. Count the times the driveshaft turns. So 3 full turns plus another 1/4 of the DS means you have 3.23s. Slightly more then four full turns would be 4.10s. And so forth.

Last edited by 01ssreda4; 09-11-2009 at 03:34 PM.
Old 09-11-2009, 01:59 PM
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awesome thanks alot guys




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