Modern transmissions typically house one reverse gear and multiple forward gears (4, 5, 6 or more) that are selected hydraulically (automatic transmission), mechanically (manual transmission), or electronically (semi-automatic or dual-clutch transmission).
Dual-clutch transmissions offer the best of both the automatic and manual type gearboxes, though the technology could not be mass produced until recently when inexpensive electronics and solid internal components became available.
Manual and automatic transmissions
Manual transmissions are the oldest type of gearbox, and are said to have been invented in the late 1800s. The system comprises a gear selector and clutch, both of which are operated by the driver, in order to change gears according to the speed of the vehicle. The gears in a mechanical gearbox are constantly moving, though they’re not positively connected to the output shaft – each gear is engaged individually.
In an automatic transmission, the gears are selected for you via a torque converter that helps to translate the engine speed to the gear selection. As the engine RPM climbs, the torque converter causes fluid pressure in the engine to increase and actuate other processes that ultimately increase the speed of the vehicle.
With this basic explanation of the two most common types of transmissions on the market, it should be easier to understand the DCT version.
How a DCT works
A DCT gearbox comprises of two jointed manual transmissions: one containing odd gears and the other containing even gears. But unlike a manual, the clutches are operated by sophisticated computer technology – not the driver’s foot. The fact that there are gears on two different shafts implies that two gears can be engaged simultaneously to facilitate constant power flow.
DCTs operate like automatics without the intervention of the driver, but they also contain a manual-mode that gives the driver some level of control by allowing the manual selection of gears via a console-mounted selector or paddle shifters. That said, there is no physical connection between the transmission and the shifters.
Comparison of different gearboxes
Compared to manual transmissions, automatics sell better because they’re easier to drive. However, automatics are more expensive and less fuel efficient than their mechanical counterparts. A DCT, on the other hand, combines the efficiency of a manual and the ease of use of an automatic, delivering better fuel economy.
Moreover, for car enthusiasts who love performance, dual-clutch gearboxes shift instantaneously, drastically reducing lap times. This is one of the reasons why performance car auto makers are beginning to embrace the DCT, as with the six-speed variant in the Nissan GT-R or the Mitsubishi AWD Lancer Evolution X with a dual-clutch box, owing to its super-fast shifts. The DCT offers many benefits, and with manufacturers seeking new ways to get the most from their vehicles, there could be more of this gearbox in new cars.
Whether you drive a manual, automatic, or dual-clutch transmission, we know your transmission. At Pro-Tech Transmissions, we specialize in all kinds of transmission problems. Whether it is transmission maintenance, a simple repair, or a complete rebuild, you can be sure that our highly trained technicians will get it done properly and promptly.
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