Your automatic transmission is one of the most expensive items to repair on your car. In many cases, a failing transmission may need to be removed from the car and rebuilt or replaced. This is a job that can easily cost several thousand dollars, which is usually enough to ruin anyone's week (or month, for that matter). Certain symptoms, such as gear slipping, make it obvious beyond any reasonable doubt that trouble is brewing in your transmission. Other warning signs may be more subtle, however, and they can be easy to miss. If your car has any of these problems, it may be time to get your transmission checked out by a professional.
Most people assume that any unusual noise that their car makes must be coming from the engine, but your transmission is a complex piece of equipment with enough moving parts to make a variety of interesting and disconcerting noises when something has gone wrong. Transmission noises can sometimes be difficult to notice, but once you know that they exist, they are usually somewhat distinctive. Pay special attention to a mechanical whirring or whining noise. If you notice this, try to determine if the noise goes away when the car is in neutral or park.
Automatic transmissions can produce grinding noises as well. These will usually occur when the car is already in drive, and they may be accompanied by noticeable jerks as the car shifts or very obvious vibrations. A whining from the transmission can sometimes be caused by low or dirty transmission fluid, but a grinding noise usually indicates a more serious internal failure.
A burning smell is usually associated with the engine oil being burned off, but the sudden appearance of an acrid, burning stench is more likely to point to transmission trouble. Transmission fluid is one of the more foul-smelling fluids on your car, and it's usually fairly obvious when it is burning. This can be the result of a leak that is causing fluid to make its way to the exhaust or some other hot surface, but it can often be caused the transmission itself overheating.
Oddly enough, this can also be a symptom of low transmission fluid. Since your vehicle's transmission fluid is responsible in part for keeping the transmission cool, insufficient fluid can result in the transmission overheating and burning off portions of the fluid that remains. Your car should not be burning any fluids under normal conditions, so never ignore unusual smells such as this.
While a rough idle is rarely the result of a failing transmission, you should pay attention to any vibrations that you notice in the cabin. Vibrations caused by your vehicle's gearbox will usually manifest when the car is attempting to change gears, so try to pay attention to the vehicle's shift points as you accelerate. If your car is equipped with a shiftable automatic, see if you can reproduce the problem by shifting up or down a gear.
Keep in mind, however, that an idle that becomes rough when switching from park to drive is not necessarily indicative of a transmission problem. Switching out of park puts additional load on your engine, which can make any existing idle problems more noticeable.
For more information on what can indicate that you need a transmission service, visit a website like http://www.budgetautomotivetucson.com.