Read about the ins and outs of checking and changing transmission fluid.
Transmission fluid lubricates the moving parts within the transmission of your car. The function of a transmission is to change the rate of speed and power supplied to the axles and wheels by the engine. Fluid is required to sustain the appropriate amount of pressure within the transmission that is required for efficient performance. The properties of transmission fluid vary slightly depending on whether the fluid is automatic or manual transmission fluid.
Automatic transmission fluid is specifically formulated for an automatic transmission. It contains additives that are designed to cool and cleanse the internal mechanisms of the transmission. As the components continue working, the constant movement of the parts generates heat that must be controlled. Over time, the coolants and cleaning properties of automatic transmission fluid begin to wear out and may need replacement.
Manual transmission fluid is replaced to avoid damage caused by fluid contamination. Transmission fluid for manual vehicles lubricates the transmission's internal mechanisms. Transmission fluids are meant to work in the car as a lubricant; however, over time, manual fluid may become grainy as friction wears down the metal gears and deposits fragments within the transmission.
Transmission fluid has a sweet scent and is supposed to be a vibrant red, translucent liquid. Worn out fluid might appear opaque or take on a dark, muddy red color. Transmission fluid should not have a burnt or burning odor. If the fluid has taken on any uncharacteristic features by the time it is checked, the vehicle may already have incurred damage.
Transmission fluid loses its effectiveness over time as its properties are broken down. Longer term use changes the consistency, but not the amount of transmission fluid. Transmission fluid is not consumed or burned up like other fluids in a vehicle, such as oil and gas. Therefore, a driver should get the vehicle checked if the transmission fluid level is low. Low levels of transmission fluid are a strong indicator of a leak.
Many car maintenance service providers, such as AAMCO Transmissions, Incorporated, offer transmission fluid flushing, a maintenance service that replaces old transmission fluid and cleanses the transmission of impurities that may eventually erode the internal parts.
According to SmartMotorist.com, flushing transmission fluid could prolong the efficient performance of a transmission for two or three times longer than average. Whereas flushing your vehicle's transmission fluid costs about $60, replacing an entire transmission costs about $2,000.
Wynn Oil Company recommends that motorists replace their vehicle's transmission fluid with a flush every two years or every 30,000 miles. Wynn also advises consumers to have transmission fluid replaced by a mechanic with the proper equipment for completely cleaning out the old fluid.
In order to change transmission fluid, the vehicle should be lifted, and the transmission pan removed and drained. Once the fluid has drained, the transmission filter and pan gasket should be replaced before refitting the pan. Once the gasket, filter and pan have been replaced, fill the pan with clean transmission fluid. To remove the remaining fluid, disconnect and drain the hoses that carry it to and from the transmission. Have someone else prepared to add new fluid to the vehicle, and turn on the engine. The old transmission fluid will pump out. At this point, add the new fluid to the pan. After all the old fluid has been replaced, turn off the engine and reconnect the hoses.
It is not necessary to remove and drain the connecting hoses, but it is a recommended step, as the hoses retain a significant portion of the old transmission fluid. The complete removal of the old transmission fluid is what makes this procedure a flush as opposed to a basic change. When changing transmission fluid, it is important that no dirt, dust or lint fall into the transmission.
Because transmission fluid is hazardous, it must be disposed of properly. The U.S. Environmental Protection Agency (EPA) provides specific guidelines for the disposal of transmission fluid. The EPA mandates that service fuels such as transmission fluid, power steering fluid and oil be disposed of as hazardous material. Many vehicle maintenance businesses have drains in the floors of their car bays that allow waste to drain into a dry well or septic system, called a motor vehicle waste disposal well. Use of existing motor vehicle waste disposal wells is permitted provided that the well was created before April, 2000; that it does not encroach upon protected ground water; and that the state in which the well is located has not banned their use.