For most car owners, having their tires rotated and getting oil changes at an auto repair shop are simple ways to keep their vehicles in working order. But like timing belt inspections and fuel-filter replacements, transmission services are often overlooked in lieu of more obvious issues. Whether it's a fluid replacement or a full system flush, having regular service performed can help protect the system from damaging contaminants - and lessen the likelihood of expensive repairs in the future.

For manual and automatic cars alike, the transmission is a key component for the engine's performance and needs to be maintained on a regular basis. This system is responsible for sending power from the engine to the wheels, providing multiple gears that are activated as driving conditions change. The fluid that runs through the transmission, meanwhile, is important for keeping it lubricated and cool.

In automatic vehicles, transmission fluid breaks down over time from the high internal heat; in manual cars, it can get contaminated by gears and other parts wearing out. What happens if the fluid isn't replaced on schedule? The life of the transmission can be reduced if dirty fluid is allowed to run through the component, as it could contain metal shavings and other loose bits of metal and dirt.

The best way to keep the system in good condition and prevent later problems is by servicing it according to your manufacturer's maintenance schedule. For manual vehicles, service every 30,000 to 60,000 miles is usually recommended, while automatic vehicles have a suggested interval of 60,000 to 100,000 miles. A general transmission service often consists of a fluid replacement, in which the liquid in the pan is drained and replaced. But because this process only actually replaces about 40 percent of the fluid, mixing the new with the old, a transmission flush is sometimes a better option. A pressurized flush completely replaces everything in the system, cleaning out all the components and also helping to find any cracks or leaks as the fluid is washed out of the compartment. However, the pressure from this service can be harmful in older vehicles, and can even blow out system seals or cause blockages with dislodged debris.

To prevent any damage to the system, an auto repair professional should determine what the best method is for your vehicle. It can cost upwards of $1,800 to replace a transmission; following a consistent maintenance schedule can extend the life of the part and ensure that it runs as smoothly as possible.