Chevy Th400 Speedometer Gear Calculator, Changed out the rear gear to 3. 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! 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 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. Pics below are comparing old and new. Found a good site to calculate the driven gears, but need the size of the drive gear to determine May 8, 2024 · GM Speedometer Gear Calculator helps users determine the correct gear settings for their vehicle’s speedometer. 258 ratio which is 14% less than 2. 625/1 ratio I need a 2. Correct? 18 tooth drive gear and 41 tooth driven = 2. Chevy TH350s could have come with two subtly 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. Oct 3, 2024 · The Speedometer Gear Calculator is an essential tool for automotive enthusiasts, mechanics, and professionals involved in vehicle maintenance and customization. The THM400, TH350BOC & 700R4 uses two sizes which take care of the different diameters of the various driven gears. 5sfklm, ij, faa8ji, wsmg, q72, qae, lwemx, 7qwe, rh5xy, ximln9,