What is a Transmission Gearbox?

A Gearbox is a machine-driven process ofshifting energy from one device to another. A transmission gearbox is most frequentlypositioned at the junction point of a power shaft, and is used to generate aright angle change in direction. It provides a range of gearing to multiply theengine’s torque.  A direct connectionfrom the engine to the road wouldn’t provide enough torque at the wheels tomove the car.  Thus, the gearbox’smultiplication of the toque is what helps overcome the car’s inertia and getsit moving.  I hope the gearbox is betterat multiplication then I am, or my car is not going anywhere.

There are three main types of gearboxes; Front Engine-FrontWheel Drive, Front Engine-Rear Wheel Drive, and Rear Engine-Rear WheelDrive.  A FWD drive is condensed and willcommonly contain the gears, the final drive, and the differential. There aretwo shafts, an input shaft and an output shaft. The gears are constantlymeshing 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 anoutput but the RWD also contains a lays half shaft.  The input and output shafts run parallel toeach other and the lays half sits below the two and overlaps them.  The input shaft drives the lay shaft througha pair of meshing gears.  This act iscontinuous and goes by the term, “constant mesh.” This term does not apply toyour friend who constantly just wears mesh basketball shorts. The lay shaft andoutput shaft have a pair of gears rotating on them and from the constant meshgearing onwards it behaves just like the FWD gearbox. The main differencebetween a FWD and RWD gearbox is what is known as a direct ratio, which is whena system locks the two shafts together and bypasses the gear cluster.

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