If your automatic transmission fails while your car is still covered by the manufacturers limited warranty you have nothing to be concerned about, it is the dealers responsibility to either repair it or replace it with a factory fresh unit. Unfortunately, this simple solution is not available if your car is no longer covered by warranty; should you find an automatic transmission for sale or have the one in your car repaired?
Buy a factory rebuilt transmission:
As a consumer, the manufacturer of your car will not sell you a transmission directly. Knowing this, when you are looking for an automatic transmission for sale you should be looking at those that have been factory rebuilt to the manufacturers specs.
A factory rebuilt transmission will usually cost more than having the failed transmission rebuilt locally; however, there are advantages to buying a factory rebuilt unit.
The time factor:
If your transmission does fail and you elect to have it removed, rebuilt and replaced you are looking at perhaps as long as a week to accomplish the task. In many cases, this is especially true for high volume vehicles; you will find a factory rebuilt unit ready to purchase and have installed.
Although a local rebuilt transmission may be perfectly good, a factory rebuilt unit will be better as it was rebuilt under very strict quality control.
Every major community will have one or more shops that specialize in rebuilding transmissions; perhaps they will even have an automatic transmission for sale which matches the one in your car.
The cost of doing the work all depends on what the mechanics find when they remove it and open it up. The cost to repair an automatic transmission can run from one to three thousand dollars.
The locally rebuilt unit may come with a short term warranty but it will never equal that of one which has been rebuilt under strict controls.