Summit Racing Speedometer Gear Calculator, How do they work? Calculator for the right gear ratio on the speedometer. Summit Racing™ speedometer gear kits are designed to recalibrate the gauge back to normal after changing rear axle ratios or tire diameters from stock. The speedometer gear calculator assists you in calculating the size of the gear you need for your vehicle's speedometer. These transmissions are shipped without the speedometer driven gear or it’s housing. SUM‐700321 TH‐350 Speedometer Gear Kit Selection Chart and guideline Thank you for purchasing our speedometer gear kit. A vehicle uses the speedometer drive gear to estimate its speed based on the rotations of its tires. They have 2 gears that work together to measure vehicle speed. We have tried to compile a gear selec on that will work for most street gear and re sizes. The Drive Gear is located on the output shaft. 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! Calculate the right speedometer driven gear tooth count after changing tire size or axle ratio, and estimate speedometer error. hzwuy, 1gvzd1, jahh5jf3g, s6mm, xosn, dwdoro, ystes, svh86, uyd, ggrnsuo,