The transmission of a vehicle is the most important mechanism part in transmitting power from the engine to the surface of the road. It is important to be familiar with certain key terms if you are planning on fixing yours anytime soon. Here are some definitions that may prove helpful to you.
Clutch – In a manual vehicle, this is the device that is responsible for the conduction of power. This is controlled as a pedal in the body of the vehicle and is constantly engaged. When it is pressed down it is disengaged.
Transmission Fluid – This material acts as a lubricant for all the parts of this mechanism. In an automatic, the fluid acts as a coolant and it also transmits power from the engine. Experts recommend that you change it every 30,000 to 60,000 miles.
Gears – This is the ratio of speed variations. In an automatic, the vehicle will choose the appropriate ratio without any intervention by the operator. In a manual, the operator uses a foot pedal to transmit the torque from the engine. There is also a lever installed in the interior of the vehicle or the body of the motorcycle that allows the operator to determine the ratio.
Powertrain – This is the group of mechanisms that generate the car’s power and deliver it to the wheels. This system includes the clutch, differential and drive shafts.
Overdrive – This is the mechanism that allows a car to cruise at a lower RPM and a lower speed. This mechanism allows for better fuel economy, less wear and tear on the engine and lower noise levels. This is usually the first aspect of your machine that will go out. This will not prevent you from operating it, but it is a sign that you need to fix it.
The transmission is one of the more complicated parts of a modern motor vehicle. The majority of new cars have automatic transmissions. Manual gearboxes, also referred to as 'standard' or sometimes colloquially as 'stick', are more common in trucks. Between the two is the 'clutchless manual' transmission, where the driver can change gears with a flick of a lever. On high end sports cars, this lever is often located on the steering column.
Transmissions have changed little since their invention in 1894. Their purpose is to control the torque of the engine, allowing the wheels to move smoothly. Automatic transmissions are not a recent phenomenon, first hitting the market in the late 1930s to early 1940s.
Causes of transmission failures can range from gear slippage, causing the vehicle to waste power, to total failure. A failed transmission may become stuck in neutral, with the car needing to be towed. Or, the box may engage only certain gears, for example, working only in reverse or drive. Damage to parts can be done by shifting poorly with a manual gearbox, or by leaving an automatic in park on a hill without also engaging the handbrake. If the transmission has overdrive, technically a small separate box, that too can fail.
Hydraulic transmissions require special fluid to function properly. This fluid can at times leak and may need to be topped up or even flushed. This and other transmission maintenance is best performed by a trained auto mechanic. In most cases, they are not specialist shops but also handle body work and brake repair.
Transmissions may also be transferred, upgraded or altered. Upgrading the valve body is common. Repairs may include replacing the transmission shaft. In some cases, a custom transmission might be built.