As illustrated here, there are many parts that make up a manual transmission. Gears, cogs, syncro rings, shafts,
and bearings all come together to complete the picture. Gears and most of the internal parts are made of
extremely hard heat-treated steel for long-lasting service. Manual transmission cases are either made of cast
iron or aluminum.
Case and Related Parts
The following is a typical manual transmission setup that is usually found on
front-wheel-drive vehicles.
As you can see, there are a lot of parts that make up a manual transmission.
Configurations vary with vehicle year, make, and model; however, the basic
design of multiple gears, shafts, and bearings make up the underlying theme.
You achieve motion through meshing one or more gears via the manipulation of
the shifter and clutch in concert with vehicle speed and load.
To the right is a typical automatic transmission setup.
The difference between the manual and automatic transmissions lies in how
they achieve forward motion.
The manual transmission achieves forward motion through a mechanical
medium. During the process, gears mesh one to another and, at the same time, a
clutch disc is pressed tightly to a smooth-faced device called a flywheel. The
flywheel is bolted directly to the back of the engine’s crankshaft. This
connection transfers the power of the engine through the transmission
throughout the drivetrain and ultimately to the drive wheels.