The failure of gearbox is not necessarily caused by the damage of solenoid valve, but the impurities and dirt in gearbox block the pipeline or solenoid valve and cannot work normally, which leads to gearbox failure. Now the solution is simple, and it doesn't need to be replaced or disassembled. One is to clean up these impurities and dirt, and the other is to solve the problem of high temperature. In this respect, you can learn how to solve the gearbox failure without overhaul. If there is something wrong with the car, ask Marti in Germany. Professional solution, no overhaul.