AutoSalvageList

The automobile gearbox is normally referred to as the vehicle’s transmission. The transmission is the unit that allows the vehicle to shift from one gear to another. There are two popular types of automobile gearboxes in use today. The first one which is a manual transmission uses a simulated stick connected to a lever on the outside of the transmission which will in turn shift the gear from one speed to another usually in a v shape or in more modern vehicles an H shape, depending on how many speeds the transmission has been built for.

In some of the larger trucks and semis, the gearshift will have a dual shift, which splits the speeds by depressing a button. For example, starting off in 1st gear, the driver would have to depress the button for the lowest speed available, considering the load amount, then by pressing down the clutch and pulling the button up, (or pressing the button again, depending on the type of button that is installed on the gear shifter), at the same time, the gear box will then shift into 1st speed Hi. Of course, the driver will have to do this for each gear, but many professional drivers know which gears they can start in and which gears they can skip.

Later as women began to drive, automobile gear boxes were manufactured which would eliminate all the shifting and depressing of the clutch petal, so the automatic transmission was invented. This type of gearbox used hydraulics and RPMs to change gears. A flywheel and a torque converter is placed between the engine and the transmission, and as the vehicle reaches a certain speed (RPM) the hydraulic fluid is forced into the transmission and causes the levers to change to the next speed. Each speed is set to a particular Speed in order for the transmission to shift into the next gear.

In most vehicles today, in an automatic transmission (gearbox) there are normally three gears 1st, 2nd, and 3rd gear, with 3rd gear aimed as a cruising gear. In some cases an over drive is available for times when the driver needs more power. The automatic transmission/gearbox has become so popular that many vehicles including trucks come equipped with them. In the beginning, automatic transmissions were not very reliable, but with all the constant improvements in vehicle parts, automatic transmission/gearboxes have become an advantage. As an example, many drag racers use an automatic gearbox because it allows the car to be stopped and still be able to maintain a high RPM ratio, which will give the driver a quick launch once the brakes are released. It is also good for turbo charged engines as well, as the turbo charger needs to keep spinning at a very high RPM, in order to keep the boost pressure up. Still there is a need for the old manual shift gearboxes and many stock cars use them to get the most speed out of their transmission, as well as the motor itself. 

There is another type of automobile gearbox known as a semi automatic transmission, which allows the vehicle to handle the shifting of the clutch automatically, and the driver can still have control of the gear shifter, selecting the gear as they wish. These types of transmissions are sometimes called a dual-clutch transmission. Some of these types are found in autos that use Easytronic, or Geartronic transmissions.