Gear ratio ?
Thread Starter
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Joined: Jun 2002
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From: Ga
Gear ratio ? Just had gears put in my 10 bolt. From a 3.42 to a 4.10 I think. How do I tell if its a 4.10 or a 3.73. I saw on here once that you put it in 4th gears take it to 60mph and your rpms will be at 3700 with 3.73 and 4100 with 4.10s. I also have the speedo calibrator already programed for the 410 swap. Would this have any effect on the rpms at 60mph if the gears were a 3.73. Could somebody with 4.10 give me a little info on what rpms are at around 55,60,65,and 80mph in 6th gear. Thanks in advance.
TECH Senior Member
Joined: Nov 2001
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From: Troy, AL
Re: Gear ratio ? Mark the driveshaft. Turn the driveshaft to make the rear tires turn over one complete revolution. Did it take 4.1 turns or only 3.73?
Yes, having the speedo calibrated for the wrong gear will throw the speedometer off and thus will make the RPMs appear to be different at a given speed.
BTW, (assuming your speedo is programmed correctly and that you have stock height tires) your RPM would be 2931 in direct (4th gear in your case) at 60 MPH with 3.73 gears or 3221 with 4.10s.
Yes, having the speedo calibrated for the wrong gear will throw the speedometer off and thus will make the RPMs appear to be different at a given speed.
BTW, (assuming your speedo is programmed correctly and that you have stock height tires) your RPM would be 2931 in direct (4th gear in your case) at 60 MPH with 3.73 gears or 3221 with 4.10s.
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Joined: Jun 2002
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From: Ga
Re: Gear ratio ? Thanks Colonel. You really know those ratios good I don't think I would be able to tell the differance between 3.7 and 4.1turns. For some reason my rpms are about 3700 in 4th at 60 mph why is this could it be there is a 3.73 gear in with a calibrator for a 4.10 what would happen then? Any idea? I got my pinion seal changed should I have gotten a new crush collar If so what will happen if I didnt.
