Introduction
The transmission is one of the most critical components of any vehicle, as it is responsible for transferring the power from the engine to the wheels, allowing the car to move at different speeds. Without proper transmission, the engine would be limited to a single speed of revolutions, which would make it impossible to drive efficiently and safely. From the first two-speed hand transmissions to modern computer-controlled double clutch and CVT systems, the evolution of this mechanism has been essential to improve performance, fuel consumption and driving comfort. In this article we will explore in detail how this system works, the different types that exist in the current market, the maintenance care that prolongs its useful life and the warning signals that indicate that something might be failing.
How does the transmission work?
In essence, the transmission acts as an intermediary that adjusts the relationship between engine speed and wheel speed. When the engine turns to high revolutions, the transmission reduces that speed to provide more torque to the wheels, which is essential when starting or climbing a slope. On the contrary, when speed is needed, the transmission increases the ratio so that the wheels turn faster than the engine. This adjustment is achieved by gear sets, straps or chains, depending on the type of transmission, and in modern systems also by hydraulic and electronic systems that control the timing and shape of the changes. In a manual transmission, the driver disconnects the engine by means of the clutch and selects the desired gear; in an automatic, a torque converter and a set of planetariums, the changes are made automatically; in a CVT, two variable pulleys and a strap continuously change the relationship; and in a DSG, two clutches work alternatively to change the gear without power interruption.
Type of transmission
- Manual transmission: The driver selects the marches using a pallet and a clutch. It offers more direct control over the vehicle and is usually more fuel efficient because it has no loss per torque converter. It requires ability to coordinate the clutch and the accelerator, and can be tiring in dense traffic, but many enthusiasts prefer it by feeling connected to the car.
- Automatic transmission: Use a torque converter and a set of planetary gears to change gear without driver intervention. It is comfortable and soft, ideal for urban driving and long trips. Historically it has been less efficient than the manual due to loss in the converter, but recent advances such as converter blockages and eight or ten-speed transmissions have significantly closed that gap.
- Continuous variable transmission (CVT): Instead of fixed gears, it uses two variable pulleys and a strap that allows a continuous change of transmission ratio. This provides a linear acceleration and a better fuel economy, as the engine can be maintained in its optimal range of revolutions. Some drivers perceive a feeling of «sliding» because there are no noticeable gear changes, but technology has improved much in terms of response and durability.
- Double clutch transmission (DSG): Combine two clutches that allow pre-select the next gear, achieving almost instant and no power interruption changes. It is typical in high-performance vehicles and offers both the efficiency of a manual and the comfort of an automatic one. The changes are so fast that you can hardly see the loss of torque, which translates into improvements in acceleration and consumption.
Recommended maintenance
To ensure optimal operation and avoid costly repairs, it is essential to follow a preventive maintenance plan. First, review and change the transmission oil according to the manufacturer's specifications, as this lubricant not only reduces the wear on the gears, but also dissipates the heat generated during operation; the intervals usually range from 30,000 to 60,000 km, depending on the type of transmission and the use of the vehicle. Second, inspect liquid levels and look for signs of contamination, such as metal particles, discoloration or a burning smell, which may indicate internal wear or overheating. Tercerally, make belt or strap adjustments in CVT systems, and verify the clutch status in hand transmissions and DSG, as a worn clutch can cause skating and make changes difficult. Finally, take the vehicle to a specialized workshop every certain number of kilometres to make a computerized diagnosis that can detect electronic, sensor or solenoid failures before they become major problems; many workshops offer washing and recirculation of the transmission fluid to remove pollutants and prolong the life of the component.
Fault signs
- Foreign noises such as squeezing, hitting or buzzing when changing gear, which may indicate wear of synchronizers, bearings or problems in the torque converter.
- Difficulty in coupling a gear or feeling that transmission «It resists.» when moving the palette or selector, possible low-liquid signal, clutch disk wear or control valve failure.
- Power loss or slow acceleration, even when the engine is at full performance, suggesting that the transmission is not properly transferring the torque, perhaps by clutch slide or planetary failure.
- Unusual vibrations that are felt on the pedal of the accelerator or on the steering wheel, often associated with imbalance in the torque converter or problems in the transmission axes.
- Warning indicators on the board, such as the light of «check transmission» or an overheating message, which must be addressed immediately to avoid major damage.
Conclusion
The transmission is much more than a simple set of gears; it is a sophisticated system that combines mechanical, hydraulic and electronic to offer a safe and efficient driving experience. Knowing its operation, the different types available and the necessary maintenance care allows owners to make informed decisions, prolong the life of their vehicle and avoid expensive surprises in the workshop. If you pay attention to the warning signals and follow the manufacturer's recommendations, your transmission will be able to accompany you many kilometers without problems, providing you with the performance and tranquility you deserve on each trip.
