C6 Speedometer Gear Calculator, The current gear is 16 tooth blue/green plastic and is about 2 inches long. ) Tire Height - Please use Inches when measuring Speedo Revolutions Per Mile - The number of RPM's the speedometer needs to turn at 60mph Speedometer Driven Gear Calculator Driven gear tooth count = Drive Gear tooth count x Axle Gear Ratio x Drive Tire Revolutions per Mile (or 20168 / Drive Tire Diameter) / 1001 The accompanying charts show what gears were manufactured for each type transmission. Enter tire size, axle ratio, and drive gear to get accurate results and minimize speedometer error. A vehicle uses the speedometer drive gear to estimate its speed based on the rotations of its tires. Use Monster Transmission’s Speedometer Gear Calculator to find the ideal driven gear for your setup. 91, 4. They consist of a small "driven" gear that meshes with a larger "drive gear" installed onto the transmission output shaft. To determine the correct gear ratio of the speedometer for your car, use the following formula to calculate the number of teeth on the driven gear (round to the nearest available gear): Use the following formula to calculate "tire revolutions per mile" for the formula above:. 89, 3. The original gear I Jun 16, 2023 · Speedometer gears are crucial components located inside the rear of your transmission. Enter the number of drive teeth, axle ratio, and tire diameter to calculate the right speedometer driven gear. When changing the size of the wheels and tires on a vehicle, it is often necessary to recalibrate the speedometer to account for speedometer error. Use the Tire Height This page provides a simple formula to aid in selecting the proper speedometer gears for your transmission application and charts showing the various gears available for each transmission. This is very useful when there is no established baseline from which to work from such as replacing a transmission in a vehicle that was purchased without a drive line! 1967 - 1973 Mercury Cougar (and Ford Mustang) Speedometer Gear Calculator Rear End Axle Ratio (ie 3. The speedometer gear calculator assists you in calculating the size of the gear you need for your vehicle's speedometer. If in doubt use manufactures posted diameter. 10 rear. 1967 - 1973 Mercury Cougar (and Ford Mustang) Speedometer Gear Calculator Rear End Axle Ratio (ie 3. Calculator for the right gear ratio on the speedometer. 30 Rear End Reducer for 4 Speed Manual w/ 3. Speedo Gear Calculator by Wallace Racing Todays date is 7/6/2026 Wallace Racing BACK to Calculators Speedo Gear Calculator At the bottom of the speedometer face, look for the numbers 940, 960, 1000, or 1020. Instructions Drive Gear Teeth - The Number of teeth for the transmission Rear End - Rear Gear Ratio (3. These gears play a pivotal role in measuring your vehicle's speed and ensuring your speedometer provides accurate readings. 11 or 4. Apr 20, 2024 · The Speedometer Drive Gear Calculator is an invaluable tool for automotive enthusiasts, mechanics, and DIYers. Speedometer Gear Calculator Enter your tire size Tire diameter may vary slightly depending on the manufacturer. 30 Rear End Speedometer Driven Gear Calculator Here is a link for a multitude of automative related calculators. The speedometer works well but is reading about 20 mph too fast (80) at approx 60 mph. Use this TCI Auto Speedometer Gear Calculator Formula for any GM, Ford or Chrysler vehicle. 30 Rear End Use Monster Transmission’s Speedometer Gear Calculator to find the ideal driven gear for your setup. 25, 4. Dec 25, 2018 · 1973 - 1979 F-100 & Larger F-Series Trucks - C6 speedometer driven gear - Hey guys, I had previously swapped the Speedo driven gear to match my 4. Ford Speedometer Driven Gear Calculator Enter the input values below and click compute. Note: Drive gear refers to the gear that is on the transmission output shaft. These numbers correspond to the number of revolutions the speedometer cable must make to register one mile on the speedometer. 08, 4. I installed a speedometer cable in place of the broken one. 11) Rear Tire Height (Tire Diameter in Inches) Drive Gear Teeth * Factory Reducer Installed • ? None Reducer for C6 w/ 3. This calculator helps users determine the correct number of teeth for a speedometer drive gear based on several input variables that define the geometry and mechanics of the vehicle’s transmission system. '77 2wd with 29 tall tires which was a stock setup. Most older GM speedometers are 1000. This will calculate the speedometer driven gear needed to properly calibrate your speedometer. 11, etc. 50 gears and am wondering if anyone knows offhand what gear I need. C6 Speedometer gear question??? I recently purchased a 1958 F100 with a 1970 351C and C6 trans. Now I'm swapping in 3. Always recheck the speedometer calibration! You can either enter your radial tire dimensions or actual measured values below. gu, mgs, 9d5jd, ye79, o1dtl, o5v, qhzb, mlkt, m62tp, 5jq4,