Q: Changing Transmission. Do I have to replace ball body module? - 2007 Mercedes Benz S550

Assuming you are talking about the valve body control module, the answer is typically yes. However, it depends on the situation and what specifically is wrong with your transmission. The Mercedes transmission in this generation is a very solid transmission that is very rare to have replaced. I would recommend checking to be sure it is in fact your transmission that has failed before spending that much money to replace it.

Often times transmission problems are related to other components, such as the valve body itself, or even sometimes something as simple as low battery voltage which can cause the car to go into limp mode. If you would like to have the car looked at before doing a transmission change, consider consulting a certified pro from YourMechanic. They can come to the car’s location for a complete inspection of the vehicle.