Ford C4 Transmission Speedometer Gear Calculator, We may take a bit longer to respond on weekends. 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. These gears do not fit the 4 speed Toploaders as they have reversed tooth direction. 1967 - 1973 Mercury Cougar (and Ford Mustang) Speedometer Gear Calculator Use this TCI Auto Speedometer Gear Calculator Formula for any GM, Ford or Chrysler vehicle. Select which one you want used for calculations with these radio buttons: Use Measured Diameter (best) Use Radial Designation Calculator Instructions This calculator provides the necessary information needed in order to determine what transmission speedometer gear is needed in order to properly calibrate a speedometer. 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. FITS C4, C6, FMX or 3 Speed. We appreciate your interest in our item. 5" and 8. Hurst also has a variety of automatic shifters for street and racing use. This method is purely calculations-based and you should always check your manufacturers specifications. Verified purchase: YesCondition: NewSold by: quirkparts Hurst is the original name in shifters. Is there a way to determine the speedo drive gear without pulling the tailshaft housing? I really need to get my speedo showing the right speed. May 8, 2020 · Get the right speedometer gear for your 1979-98 Mustang based off of rear gear ratio & tire size! No guessing with this Mustang Speedometer Gear Calculator! Tip: If your result is outside the range for your transmission, consider changing the drive gear, using a ratio adapter, or recalibrating the speedometer. Always recheck the speedometer calibration! You can either enter your radial tire dimensions or actual measured values below. . Aug 9, 2009 · I have a 1978 C4 from a RWD car. the right part for my Ford C4 trans speedo. Made in USA. 15"/16"/17" tires (800-815 revolutions/ mile). This ensures that the speedometer displays the correct speed, especially after CALCULATORS & SPECIFICATIONS Ford C4 Bellhousing Reference Gear Ratios Racing Calculators Speedo Gear Calculator Transmission Cooler Fitting Specs Transmission Dimensions GENERAL TECH Automatic Transmission & Torque Converter FAQ Torque Converters Explained Transmission Life Expectancy New Automatic Transmission Dos and Don'ts Speedometer Gear Calculator Enter your tire size Tire diameter may vary slightly depending on the manufacturer. Aluminum Powerglide Speedo Gear Housing LEAK STOP KIT. Available in 16, 17, 18, 19, 20, 21 or 23 Tooth Gear. 888-324-1617 See less Dec 11, 2025 · A new speedo housing leak stop kit for the Aluminum Powerglide Transmission, 1963 & up. A new front pump bushing for a FORD C-4 and C-5 Transmission, 1964-1986. Apr 7, 2021 · The calculator that I developed (Speedometer Gear Calculator | Mustang 428 Cobra Jet Registry) doesn't have an option for a 7-tooth drive gear because those were never used on the transmissions found behind a 428 CJ. Our legendary manual shifters reduce throw and increase precision to make you faster and more accurate when you're banging the gears of your Chevrolet, Ford, or Dodge muscle car. Speedometer gear uSage chart — 7. If in doubt use manufactures posted diameter. The speedo was reading to high went from 17 to 21 gear. 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! This will calculate the speedometer driven gear needed to properly calibrate your speedometer. Oct 3, 2024 · The Speedometer Gear Calculator is an essential tool for automotive enthusiasts, mechanics, and professionals involved in vehicle maintenance and customization. Apr 19, 2024 · What speedometer gear for 1968 GTCS with Eaton Truetrac? Allen Taylor BLUE OVAL MUSCLE CARS & COLLECTIBLES 30w · Public I have a 1968 GTCS with a C4 transmission I just installed a new 3rd member with an Eaton truetrac my gear is a 3. 40 my tire size is a 235/60/15 what speedometer gear should I run ? Paul Hazard and 65 others 66 reactions Dec 11, 2025 · FORD C4 C5 Front Pump Bushing 1964-86. 1967 - 1973 Mercury Cougar (and Ford Mustang) Speedometer Gear Calculator 21 teeth speedo gear the right part for my Ford C4 trans speedo. It aids in accurately calculating the size or number of teeth needed on a speedometer's driven gear, based on the tire size and axle ratio of a vehicle. Aug 22, 2025 · Welcome! Transmission parts - Buick Dynaflow torque Ball repair kit Rebuild Parts 700R4 Electric to mechanical speedo gear conversion Powerglide TH350 TH400 700-R4 C4 C6 TF6 904 TF8 727 Jetaway Turbo 350 400 leak stop repair seal speedometer gear calibration. j4f7me, db, dgl, 3oplu, prol, vypkb, pus, 3ux6se, lmz, ejqfzs, \