Like many of your car's vital components, your automatic transmission relies on the use of fluid to function property. The fluid used in almost all automatic transmissions is an oil with various additives to help the fluid last longer and to clean and protect the parts of your transmission that it comes into contact with. The primary purpose of your automatic transmission fluid is to provide lubrication, but it also serves a vital role in keeping your transmission and torque converter cool. Old, dirty fluid or fluid that is too low can lead to a number of serious issues, but burnt fluid may indicate a problem as well.
How Can You Check Your Fluid?
Unfortunately, not all vehicles have an easy way to check the level or state of the transmission fluid. Consulting your manual is the best way to determine if you can perform this check on your vehicle. In most cases, a dipstick will be located somewhere near the rear of the engine toward the passenger cabin. When checking your fluid, note both the level of the fluid and its condition. Since your transmission fluid operates as a closed system, a low fluid level indicates a leak or other problem.
Dirty or Burnt?
Over time, transmission fluid can become dirty and require replacement. Many cars now come equipped with "lifetime" fluid, but if your car has a recommended manufacturer replacement interval then it should be followed as closely as possible. If the fluid smells burnt, however, then something more serious may be amiss within your transmission. In general, fluid that has overheated will first turn brown and then later turn a dark black color. If this appears to be the case with your transmission fluid, then it is time to have your transmission inspected.
What Does Burnt Fluid Mean?
Your automatic transmission generates a large amount of heat during normal operation. One of the roles of the transmission fluid is to keep this heat under control, but excess heat can sometimes be generated anyway and cause your transmission fluid to overheat and "burn." If you have been pushing your transmission particularly hard, such as by towing payloads or driving on steep grades, then it is possible that your transmission is simply overworked. In many cases, however, burnt fluid indicates an internal problem within the transmission that is resulting in excess heat.
Dealing with Burnt Fluid
Unfortunately, internal transmission problems usually necessitate transmission rebuilds. If your fluid appears burnt or you are smelling burnt transmission fluid from within the vehicle, then it is important to have your transmission serviced as soon as possible. Depending on the condition of the fluid, most shops will recommend a flush and replacement. Once this is done, the transmission fluid can be reevaluated in the near future to determine if the fresh fluid is overheating as well. If it is, then there is likely a problem within the transmission that will require significant repair work.
Contact a transmission repair service in your area.