An automatic transmission fluid and filter replacement is needed in order to maintain a vehicle in proper working order. In order to replace the transmission fluid, the transmission pan needs to be removed, allowing the fluid to drain from the transmission. Then the transmission filter is removed and replaced. Next, the oil pan, if applicable, is cleaned and inspected for debris and then reinstalled with a new pan gasket. Finally, the transmission is filled with fresh fluid, and the engine is started. Then transmission fluid level is checked according to manufacturers specification. Then drive the vehicle and recheck fluid level; add more if needed
Manufacturers have their own recomendations on when to replace the transmission filter and fluid and what type of fluid to use. If an automatic transmission filter and fluid replacement is not done and the wrong fluid is used, it could result in a transmission failure.
When changing the automatic transmission fluid and filter, you would be best advised to follow the factory recommended vehicle maintenance schedule for how frequently an automatic transmission fluid and filter replacement is required. This factory recommendation must be adhered by to maintain the validity of your new car warranty and extended auto warranty, if applied. If mechanical breakdown occurs due to the lack of your car's maintenance of the transmission fluid and filter, the warranty would not cover the car repair.