Whats the difference between transmission service and a flush?
A transmission service consists of a test drive, removing the transmission pan, draining the fluid, changing the filter and pan gasket, test driving again, and adjusting the linkage and bands if necessary. A flush consists of attaching a machine to the transmission and removing virtually all of the fluid and replacing it with new fluid. Unless the pan is removed, the filter cannot be changed. At some facilities, the vehicle is not test driven or the linkage and bands adjusted.