Chevy 700r4 Speedometer Gear Chart Pdf, This chart is designed to be used as a ready reference to determine the speedometer gear combinations for each particular passenger car model dependent upon the transmission, rear axle ratio and rear tire size. It is suitable for use behind engines producing up to 450 lb-ft of torque. Determining the precise speedometer drive gear/driven gear combination required for a rear axle ratio change is surprisingly easy-if you know the existing combination and axle ratio. GM 4-Speed Automatics 700R4/4L60E/4L80E There are two basic GM 4-Speed automatics: The light duty 700R4/4L60E found mainly in half ton and car applications, and the heavy duty 4L80E in the heavier applications. Feb 21, 2023 · General rule of thumb for the TH-400/ 700R4 style of gears is each tooth on the drive gear is about 5-6 mph and each tooth on the driven is about 3 mph change on the speedo. 08, and want to get the speedo calibrated before it goes in. it is also dripping fluid. Chevrolet / GMC trucks and vans used the THM350-C until 1986. You would need a 39 tooth driven to get close to the 10 mph you need to change on the speedo. 700R4 Speedometer Gearing Assembled with information from revx1000 @ www. 700R4/4L60E’s have a low 3. At this point, pull the speedometer gear out of your transmission tail housing by removing the small bolt and clamp that retains the speedometer gear sleeve and pulling on the speedometer cable. Changed out the rear gear to 3. The B&M TH-700R4 is a specially modified transmission intended for performance and heavy duty applications. One fits gears from 34 - 39 teeth and the second one fits gears from 40 - 45 teeth. Found a good site to calculate the driven gears, but need the size of the drive gear to determine Sep 24, 2024 · My speedometer is about 20 miles per hour off. (too fast). 4dr Belair I just purchased. com by rohde1017 With 15 Tooth Drive Gear With 17 Tooth Drive Gear This document provides instructions for replacing the drive and driven gears to ensure speedometer accuracy after changing tire size or axle ratio. What trans speedo gear color should I use for accurate speedometer reading with 700R4 transmission? 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. It includes gear charts and step-by-step installation guidelines. What gear should I use? I have a 700r4 with what I am pretty sure is a 355 rear gear. Then count the teeth, subtract or add to the number of teeth and select a new gear from the appropriate chart below based on your transmission. 06 first gear which is good for initial take off but this makes the transmission have the widest ratio … Continue reading GM 4-Speed Auto → For the 1981 model year, a lock-up torque converter was introduced which coincided with the new EMC control of most GM cars; this version is the THM350-C, which was phased out in 1984 in GM passenger cars for the 700R4. Use this TCI Auto Speedometer Gear Calculator Formula for any GM, Ford or Chrysler vehicle. Generally most cars took a 15 tooth drive gear with a low end gear ratio, though there were some exceptions. If your cable-driven speedometer is reading incorrect mph, in order to correct the problem, you first need to know four things about your car: tire diameter, rearend ratio, the transmission’s drive-gear tooth-count, and the speedometer’s driven-gear tooth count. This covers most small block Chevrolets and mild big blocks. 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! Determining the precise speedometer drive gear/driven gear combination required for a rear axle ratio change is surprisingly easy-if you know the existing combination and axle ratio. dieselplace. was directed to a great site but i need to know the drive gear to find Use the Spicer Transmission Ratio RPM Calculator to determine your engine’s RPM based on the transmission gear ratio, tire height, MPH, and ring and pinion gear ratio. Feb 26, 2018 · Here’s how to dial-in cable-driven speedometers. 36 from 3. * The "Drive" gear is located on the transmission output shaft and directly turns the Driven gear ** The "Driven" gear is usually located in the transmission housing and directly drives the speedometer cable Two housings, each made from either aluminum or plastic, are available for driven gears with 34 or more teeth. did a gear change and need to correct the difference in the speedometer. Whip out your calculator and follow along. Apr 4, 2013 · The 700R4 uses a 15 to 19 tooth drive gear depending on transmission year, model and axle combination of vehicle it came out of and a 34 to 45 tooth driven gear. In GM’s case most of the parts are still available from the dealer or aftermarket sources. Aug 30, 2010 · Transmissions and Drivetrain - anybody know the stock drive gear of 700r4 - i can check but dont feel like jacking up car just to check when someone probably knows here. Oct 30, 2019 · Sometimes, it might require a little more work. . yxzc, opgu6n, j59y71, sys, cjeag, paw, hs, oi8cvcmnn, sk4, 83vp,