Are You Up to Speed on Transmissions?

Until recently, everyone knew how to drive stick. Things are different now—manual transmission vehicles are slowly disappearing. Whether it’s because drivers are getting lazy or because new technologies are constantly emerging, manufacturers admit that barely five per cent of vehicles sold have manual gearboxes. But before you lay blame, let’s take a look at the different types of transmissions.

Manual transmissions

Manual transmissions have been around for as long as automobiles. You press on the clutch pedal which allows you to move the gearshift which in turn engages a gear, depending on the speed of the vehicle and engine. Five- and six-speed manual transmissions are often a springboard for manufacturers—they allow them to offer a low-priced basic model that few buyers would want and then raise the price of their automatic transmission models. Some say that a manual transmission makes it easier to “play” with the engine and power, but tests often show that manual transmissions are not the most energy efficient in terms of fuel consumption. Another sign of the times—even this kind of transmission loses ground in the truck and heavy vehicle category.

Pros:

• Robust transmission that can withstand higher torque
• Greater reliability and easier to maintain

Cons:

• Harder to learn
• Rougher gear shifting

Automatic transmissions

The sale of vehicles with automatic transmissions has by far the largest share of the market—more than 75 per cent—because they are so easy to drive. The automatic transmission is a hydraulic system that is usually controlled electronically by the on-board computer according to the user’s driving style. In older generations of transmissions, the shift caused by the internal pressure of transmission fluid caused a loss of power and more fuel consumption. The advent of the torque converter and electronic control has made these transmissions more reliable. Four-speed transmissions are gradually disappearing; transmissions today reach up to eight speeds, and Ford and Chrysler are working together on ten-speed transmissions. The biggest names in transmissions are BorgWarner (which is where the Indy 500 trophy got its name), Getrag, Aisin Seiki, and ZF.

Pros:

• Easy and comfortable
• Better fuel economy

Cons:

• More expensive
• More fragile system

Semi-automatic transmissions

This is a manual transmission with automatic shifting for sports cars. It still has a gearshift lever but, just like the sequential gearboxes in open-wheel and Berlinetta race cars, it’s mainly the paddle shifters on the steering wheel that are used to shift gears. The shift-by-wire system uses electronic sensor controls, as there is no mechanical linkage to the transmission. Unlike race cars, if you fail to adapt the ratio to your driving, the system will automatically change speeds to avoid damaging the powertrain.

Pros:

• Decidedly sporty driving
• No clutch

Cons:

• Extra cost
• Pricey repairs

Continuously variable transmissions

Continuously variable transmissions may not have been well received in the beginning, but they’ve improved and are quickly gaining market share. There are a couple of versions available and, in addition to being found in hybrid and electric vehicles, they are now even found in sports cars and all-wheel drive vehicles. Today’s transmissions are much more smooth and fuel-efficient, but their poor towing capacity remains their weakness.

Pros:

• Long-term reliability
• Fuel-efficient

Cons:

• Revving when you accelerate
• Limited traction capacity and towing not advised

In conclusion, transmissions are a whole lot more reliable than before, but their level of technological sophistication has made certain components more prone to failure. The lubricating fluids have also improved greatly. That’s why it’s important to have your transmission checked every now and then and, above all, to have it drained according to the manufacturer’s recommendations.