There are four options available when an automatic transmission fails; each of these options has pros and cons. The option that you choose is usually based on the cost element, quality and the time the car will not be available.
*New: Once a car has been manufactured and sold this option actually is not available. New transmissions are used exclusively as a production part. If you purchase an automatic transmission for the dealer you purchased the car from you are actually getting a remanufactured unit.
*Rebuilt: The term is usually associated with a repair facility. The transmission is removed from the car, totally disassembled and inspected by a knowledgeable technician. Any parts found to be worn or damaged are purchased from automatic transmission parts suppliers and then reassembled.
*Remanufactured: In a sense a rebuilt transmission and a remanufactured transmission are the same thing; the difference is that a rebuilt unit is done in a repair shop while a remanufactured unit is done in a factory setting. As these facilities focus on remanufacturing automatic and manual transmissions they can use two different approaches when performing the work. In one instance a team will deal with a transmission; one team member will take the unit apart, another clean it, another will replace components while another will reassemble it. In other cases the transmission will be remanufactured completely by a specialist that does all the work.
*Repaired: As the term implies, a repaired transmission is one where a component that has failed is replaced. For example, if a shaft failed, it would be replaced without disassembling and rebuilding the entire unit. Those that repair transmissions know the automatic transmission parts suppliers in the area and can often do the work quickly.
Often the solution is not known until the problem has been assessed and the transmission inspected. Not all options are available or practical; a lot depends on the problem, the vehicle and the mileage.
