Removing the valve body on a Mercedes automatic transmission
Required tools and materials:
* Set of spanners (metric system)
* Hex keys
* Oil filter wrench
* Extension cord with ratchet
* New valve body gasket
Removal procedure:
1. Disconnect the negative terminal of the battery. This will de-energize the vehicle and prevent the ignition from being turned on accidentally during operation.
2. Drain the transmission fluid. To do this, unscrew the oil pan drain plug and drain the liquid into a suitable container.
3. Remove the oil pan. Unscrew the bolts securing the oil pan to the automatic transmission housing. Carefully remove the pan and drain the remaining transmission fluid.
4. Disconnect electrical connectors. Carefully disconnect all electrical connectors going to the valve body.
5. Disconnect the cooling lines. Locate the cooling lines leading to the valve body and disconnect them. Be careful not to damage the lines.
6. Remove the automatic transmission control unit (TCU). The TCU is usually attached to the valve body body. Remove the bolts holding the TCU in place and carefully remove it.
7. Unscrew the valve body bolts. Locate the bolts securing the valve body to the automatic transmission housing. Unscrew these bolts using a hex wrench.
8. Carefully pull out the valve body. When all the bolts are unscrewed, carefully remove the valve body from the automatic transmission housing. Be careful not to damage seals or gaskets.
9. Replace the valve body gasket. Clean the surfaces of the valve body and automatic transmission housing where the new gasket will be installed. Install the new gasket and position it correctly.
10. Install the valve body. Carefully install the valve body back into the automatic transmission housing. Tighten the bolts securing the valve body.
11. Install TCU. Install the automatic transmission control unit (TCU) to the valve body and tighten the bolts.
12. Connect the cooling lines. Connect the cooling lines to the hydraulic unit and tighten the connections.
13. Connect the electrical connectors. Connect all electrical connectors to the valve body and make sure they are securely fastened.
14. Install the oil pan. Reinstall the oil pan and tighten the bolts.
15. Fill with transmission fluid. Pour the required amount of new transmission fluid into the automatic transmission through the filler plug.
16. Connect the negative terminal of the battery.
Adviсe:
* Before removing the valve body, take photographs of the location of the cooling lines and electrical connectors to facilitate subsequent assembly.
* Be careful not to damage seals or gaskets when removing and installing the valve body.
* When tightening the valve body bolts, use a torque wrench to avoid overtightening the bolts.
* Check the transmission fluid level after assembly and adjust if necessary.