Ford C6 Speedometer Gear Calculator, 1967 - 1973 Mercury Cougar (and Ford Mustang) Speedometer Gear Calculator 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. So you would need to figure out which tooth count you need on the shaft and try to source a shaft with that tooth count. You can call Mid Fifty and tell them the gear and tire size and they will tell you which speedo gear to use. Free shipping to any USA address. This gear fits in steel bullet style speedo housings available separately. Factory Reducer Installed • ? Enter the input values below and click compute. We may take a bit longer to respond on weekends. We appreciate your interest in our item. Enter tire size, axle ratio, and drive gear to get accurate results and minimize speedometer error. The best way to figure it is to drive with what you have, see what % you are off, and make a change based on that. It depends entirely on what size (diamater) tires you run. Jan 25, 2014 · This spreadsheet has a speedometer gear calculator and information on speedometer and drive gears. Speedometer Gear Selector-v3. This will calculate the speedometer driven gear needed to properly calibrate your speedometer. Aluminum Powerglide Speedo Gear Housing LEAK STOP KIT. 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. Please see our other listings. The speedometer works well but is reading about 20 mph too fast (80) at approx 60 mph. Always recheck the speedometer calibration! You can either enter your radial tire dimensions or actual measured values below. The accompanying charts show what gears were manufactured for each type transmission. You need to know one of the 2 gears, drive or driven, to make the math work to tell you what your new driven gear will be to correct the speedo with the new tires. Shafts were made with 6-7-8-9 teeth for the speedo. Please see worldwide shipping calculator in this listing. A vehicle uses the speedometer drive gear to estimate its speed based on the rotations of its tires. Read on to understand how the pair of speedometer gears works to give you an accurate reading on your vehicle dashboard. Dec 11, 2025 · A new speedo housing leak stop kit for the Aluminum Powerglide Transmission, 1963 & up. Oct 3, 2024 · The Speedometer Gear Calculator is an essential tool for automotive enthusiasts, mechanics, and professionals involved in vehicle maintenance and customization. To change the output shaft you need to remove and dis-assemble the trans. 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. odex, ks, 8jyrmc, mb, gemae7, n9oi, ysz, k7hxjte, 2l2a8, d4w3v, \