Servicing your Automatic Transmission is just as important as changing your engine oil, except it doesn’t have to be changed as often. Transmission fluid should be changed every 25k-30k miles, depending on driving conditions and/or overall fluid condition. For commercial vehicles or vehicles that tow a trailer regularly, 15k-20k miles is recommended. As transmission fluid breaks down with age it is no longer able to properly protect internal transmission components. Much like oil in your engine, this fluid is the backbone to keeping a transmission working properly. Once transmission fluid breaks down it allows moving internal parts of the transmission to fatigue. Most of the time once transmission fluid changes have been allowed to lag for to long you reach the point of no return. With so many important components inside a transmission it is very important to stay on top of this service.