Gm Speedometer Gear Calculator Pdf, TH350 Speedometer Gears Notes: Chevrolet transmissions use a 1" diameter steel driven gear housing located in the tailhousing on all two-wheel drive applications. What do i need to order? Calculator says 38 tooth, current one is 41 tooth and speed off 20mph. The Calculation is based on knowing the number of revolutions required for the speedometer to go (Typically) 60mph. Find speedometer driven gears and other Muncie transmission parts at The Gear Box, your online store for DIY overhaul kits and accessories. TCI® now stocks the most po May 8, 2024 · The calculator helps users determine the correct gear settings for their vehicle’s speedometer, ensuring that the speedometer accurately reflects the vehicle’s speed. Jun 29, 2025 · I need help. Calculator for the right gear ratio on the speedometer. 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: 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. I ordered a gear for th350 and th400, both being smaller than one i pulled from trans. We have tried to compile a gear selection that will work for most street gear and tire sizes. These gears play a pivotal role in measuring your vehicle's speed and ensuring your speedometer provides accurate readings. Speedometer Gear Calculator A simple to use Transmission Speedometer Gear Calculator. The accompanying charts show what gears were manufactured for each type transmission. 73 ratio in my 2WD truck. 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 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. 078" diameter driven gear housing. SUM‐700321 TH‐350 Speedometer Gear Kit Selection Chart and guideline Thank you for purchasing our speedometer gear kit. Ive order 2 different speedometer gears and both are smaller in diameter than one i pulled from trans. Im told trans is th400. They consist of a small "driven" gear that meshes with a larger "drive gear" installed onto the transmission output shaft. This calculator provides the necessary information needed in order to determine what transmission speedometer gear is needed in order to properly calibrate a speedometer. Im doing 50mph and gauge says 70mph Jan 11, 2026 · C3 Tech/Performance - Speedo Drive Gear in Turbo 400 - Hi, About to install a rebuilt Turbo 400 (orig trans) in my 71. rfa, yg, bii, kz5hu, hf4dlf, bvgg, qo7, luhy, cvz8p7, o4,