Performing a transmission fluid flush softens and removes normal contamination from the inside of the transmission. It is especially helpful in removing dirt that collects inside the torque converter. Because the torque converter spins at a high rate of speed, dirt suspended in the transmission fluid is spun outward inside the converter, which then builds up on its inner surfaces. Dirt continues to build up until it reaches a sufficient thickness that then begins to flake off in chunks. The chunks of dirt restrict the flow of fluid through very small passages inside the transmission. Reduced fluid flow causes the transmission to overheat leading to rapid wear of vital transmission components and premature transmission failure. Routine transmission flushing can double or triple the life of your automatic transmission. It is one of the most cost-effective services you can perform. Recommended every 30,000 miles.