What is a Transmission Gearbox?

A Gearbox is a machine-driven process of shifting energy from one device to another. A transmission gearbox is most frequently positioned at the junction point of a power shaft, and is used to generate a right angle change in direction. It provides a range of gearing to multiply the engine’s torque.  A direct connection from the engine to the road wouldn’t provide enough torque at the wheels to move the car.  Thus, the gearbox’s multiplication of the toque is what helps overcome the car’s inertia and gets it moving.  I hope the gearbox is better at multiplication then I am, or my car is not going anywhere.

There are three main types of gearboxes; Front Engine-Front Wheel Drive, Front Engine-Rear Wheel Drive, and Rear Engine-Rear Wheel Drive.  A FWD drive is condensed and will commonly contain the gears, the final drive, and the differential. There are two shafts, an input shaft and an output shaft. The gears are constantly meshing but just one gear is secured to the shafts at all time.

The RWD gearbox has three shafts.  Just like the FWD it has an input and an output but the RWD also contains a lays half shaft.  The input and output shafts run parallel to each other and the lays half sits below the two and overlaps them.  The input shaft drives the lay shaft through a pair of meshing gears.  This act is continuous and goes by the term, “constant mesh.” This term does not apply to your friend who constantly just wears mesh basketball shorts. The lay shaft and output shaft have a pair of gears rotating on them and from the constant mesh gearing onwards it behaves just like the FWD gearbox. The main difference between a FWD and RWD gearbox is what is known as a direct ratio, which is when a system locks the two shafts together and bypasses the gear cluster.

Transmission gearboxes are either automatic, manual, or continuous.  A manual transmission can be a sliding mesh or a constant mesh style. The sliding mesh uses straight cut gears and requires the driver to time the change from one speed to another.  If it is not timed right there will be a loud grinding sound and increase the rate of wear and tear on the gears teeth, and it will also cause you to yell at your girlfriend.  The constant mesh system has diagonally cut gears that are permanently meshed. This creates a smoother transition between speeds.  The constant mesh is used mostly by agricultural equipment and race cars.