Manual transmissions aren’t necessarily simple, but they’re much easier to understand in concept than their automatic counterparts. You’re probably aware there are gears in manual transmissions - but there’s a little more to it than that. Here are some of the major components you’ll find in a manual transmission.
Shafts - There are three main shafts inside a manual transmission. There’s an input shaft where engine power is transferred via the clutch, and that drives the layshaft, also known as the countershaft. The countershaft has different sized gears to achieve various gear ratios. Corresponding gears on the countershaft connect to the output shaft. The output shaft is connected to the driveshaft, which powers the differential.
Gears - Pairings of different gear sizing on the output shaft and countershaft determine gear ratios. A small gear on the countershaft paired with a larger gear on the output shaft means more torque at lower speeds. A large gear on the countershaft paired with a small gear on the output is for high speed, low torque - your overdrive gear. Power is only sent through one set of gears at a time, and the gear is selected by the shifter.
Bearings - The shafts ride on bearings inside the truck’s transmission, holding everything in place and allowing for smooth quiet transfer of power. Synchronizers. The synchros allow gears in your SUV to shift seamlessly and easily, so you don’t have to force or grind the transmission into gear. Friction from the synchros matches the speed at which both gears are spinning, so they mesh up perfectly and the transmission slides into gear.
Shift Forks - The shift forks are operated by the truck’s shifter - they move a sleeve forward or backward along the shaft, engaging the corresponding gear.
Case - The case is the housing, which holds all the internal parts. There’s gear oil in there as well, to keep everything lubricated.
Now that you know what’s inside a transmission, the inner workings are hopefully becoming a little clearer. At Cecil's Automotive in Collierville we have the tools and the skill to service your manual transmission. Call or come by the shop today!
