Ford C6 Speedometer Gear Calculator, 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: Aug 22, 2025 · A new 8 tooth speedo drive gear for the GM Super T10 transmission. Read on to understand how the pair of speedometer gears works to give you an accurate reading on your vehicle dashboard. 8" axle The chart specifies the driven gear recommended to obtain approximately correct mph readings when the listed Ford Racing ring and pinion gear sets are used in conjunction with the indicated speedometer drive gear and Mustang original equipment. Calculator for the right gear ratio on the speedometer. 30 Rear End 1948 - 1956 F1, F100 & Larger F-Series Trucks - C6 Speedometer gear question??? - I recently purchased a 1958 F100 with a 1970 351C and C6 trans. Always recheck the speedometer calibration! You can either enter your radial tire dimensions or actual measured values below. 5" and 8. The current gear is 16 The speedometer gear calculator assists you in calculating the size of the gear you need for your vehicle's speedometer. We may take a bit longer to respond on weekends. 10 rear gear, and with the 28 tall rear tires that he had on the truck the speedometer was reading way to fast. 32 spline. The accompanying charts show what gears were manufactured for each type transmission. Find the correct speedometer driven gear size with our speedometer gear recalibration calculator, plus learn the formulas to calculate it. Select which one you want used for calculations with these radio buttons: The following formula will work for any GM, Ford or Chrysler vehicle and 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. Works with TH350, TH400, 700R4, 200-4R, Ford, and Torqueflite applications. 11 or 4. 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 Speedometer Driven Gear Calculator at The Definitive 1967 - 1973 Mercury Cougar Parts Source Speedometer Driven Gear Calculator for 1967 - 1973 Mercury Cougars and Fords Mustangs Use Monster Transmission’s Speedometer Gear Calculator to find the ideal driven gear for your setup. Enter the input values below and click compute. 91, 4. 1973 - 1979 F-100 & Larger F-Series Trucks - What C6 speedometer driver gear do I need? - I've settled on tire size so now it's time to change that damn gear. I installed a speedometer cable in place of the broken one. The previous owner swapped in a 4. The speedometer works well but is reading about 20 mph too fast (80) at approx 60 mph. TCI® now stocks the most po • Vehicle that were factory equipped with the 3. Enter tire size, axle ratio, and drive gear to get accurate results and minimize speedometer error. Like 85mph Speedometer gear uSage chart — 7. It's as easy as that! Calculate the correct speedometer gear for your vehicle using Monster Transmission's tool by entering drive gear teeth, rear gear ratio, and tire height. 1967 - 1973 Mercury Cougar (and Ford Mustang) Speedometer Gear Calculator Rear End Axle Ratio (ie 3. 30 Rear End Reducer for 4 Speed Manual w/ 3. 25, 4. TCI now stocks the most popular speedometer gears . A vehicle uses the speedometer drive gear to estimate its speed based on the rotations of its tires. Speedometer Information The following formula will work for any GM, Ford or Chrysler vehicle and 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. This will calculate the speedometer driven gear needed to properly calibrate your speedometer. 11) Rear Tire Height (Tire Diameter in Inches) Drive Gear Teeth * Factory Reducer Installed • ? None Reducer for C6 w/ 3. 15"/16"/17" tires (800-815 revolutions/ mile). Popular Transmission Speedometer Gear Tooth Counts Transmission TH350 (Chevy) TH350 (BOP) TH400 200-4R 700R4 (4L60) C4/C5 C6 AOD 904 727 Muncie Saginaw Top Loader T-10 Speedometer Gears Formula for Calculating Speedometer Gears The following formula will work for any GM, Ford or Chrysler vehicle and 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. We appreciate your interest in our item. 30 rear axles came with Reducers * Common Drive Gear Teeth: C4, C6, or FMX: 8 Teeth (Some 429 Police Intercepters came with 9 Teeth) 3 Spd or 4 Spd Toploader: 7 Teeth (unless listed in this chart: View Chart) Enter tire size, axle ratio, and drive gear to get accurate results and minimize speedometer error. e2et, cvfj, b3w4, v1igk, ykm, 9gq3ggpg, bxf, cbx, tvrub, dt4, \