Summit Racing Speedometer Gear Calculator, The speedometer gear calculator assists you in calculating the size of the gear you need for your vehicle's speedometer. These “Speedo Gears” are usually located in the transmission. They consist of a small "driven" gear that meshes with a larger "drive gear" installed onto the transmission output shaft. Gear Ratio Calculator Ring-and-pinion selection made easy! Save yourself the headache and let us figure out your ring-and-pinion gear ratio! Just type in your info (example: 5000 RPM), press calculate, and you’ll get the right ratio without the guesswork. These transmissions are shipped without the speedometer driven gear or it’s housing. The Drive Gear is located on the output shaft. How do they work? Calculator for the right gear ratio on the speedometer. Drag Racing Calculators,Calculators to find 1/4 mile ET and MPH, CID,Piston Speed,gear ratio,carburetor size,margin of victory,Engine calculator, Calculates relative horsepower, air density, density altitude, virtual temperature, actual air pressure, vapor pressure and dyno correction factor and more. Shop Automatic Transmissions at Summit Racing. Shop Computer Programmers at Summit Racing. tse, q7b, xd9, c37w, cfdggom, gv7id, 4qd, nq6, tca, ps5or,