How to check transmission and discover possible transmission problem when buying a used car.

An automatic transmission becomes more reliable these days, but still it's a most-easy-to-break and very-expensive-to-fix part of the vehicle.
If heavily abused, the automatic transmission can be easily destroyed within just half an hour. For example, a friend of mine had burnt the automatic transmission up in 20 minutes when he was trying to free his shiny Audi from the snow in the next day after he bought it! It cost him about $2000 to rebuild it and after one year it broke down again.
Also, an automatic transmission is very sensitive to the transmission fluid quality and condition. Improper fluid type can damage the transmission. A person I know added a gear oil (oil for manual transmission) into the automatic transmission, guess what, 30 minutes of driving was enough to kill the transmission.
Obviously, when buying a used car, the automatic transmission is one of the most important parts to check. In this article I described few signs that may indicate potential transmission problem in a used car. In addition, I strongly recommend to have the used car inspected by a mechanic before buying it, it will well worth it.