MEYLE Automatic transmission oil change - Mercedes 9 G-Tronic (725.0)

3 min read 8 months ago
Published on Jul 08, 2025 This response is partially generated with the help of AI. It may contain inaccuracies.

Table of Contents

Introduction

This tutorial provides a comprehensive guide on how to perform an automatic transmission oil change for a Mercedes-Benz C-Class equipped with the 9G-Tronic automatic transmission (725.0). Following these steps will ensure a smooth and efficient service, maintaining the performance of your vehicle.

Step 1: Preparation

Before you begin the oil change, ensure that your vehicle is ready for servicing.

  • Perform a Test Drive: Take the car for a short drive to warm up the transmission fluid.
  • Scan for Fault Codes: Use a diagnostic device to check for any fault codes. Make sure there are no errors that could complicate the process.

Step 2: Gather Special Tools

You will need specific tools for the oil change. Make sure you have the following:

  • Hex key for removing the drain plug
  • Special valve tool for adjusting the fill valve
  • Adapter for filling the transmission
  • Filling device (999 990 1000/S)

Step 3: Access and Drain the Oil

Follow these steps to drain the old transmission oil:

  1. Lift the Vehicle: Safely elevate the car using a jack or ramps.
  2. Remove the Plastic Cover: Locate and remove any plastic covers that obstruct access to the oil sump.
  3. Locate the Oil Sump Drain Plug: Identify the drain plug and prepare to remove it.
  4. Use the Special Valve Tool: Adjust the fill valve to the proper position for draining.
  5. Remove the Drain Plug: Unscrew the drain plug from the torque converter to allow the remaining oil to drain completely.

Step 4: Replace the Oil Sump

After draining the old oil, proceed with the following:

  1. Remove the Oil Sump: Detach the oil sump from the transmission.
  2. Install New Sump: Replace it with a new oil sump.
  3. Reinstall the Torque Converter Plug: Secure the plug back in place.

Step 5: Refill with New Oil

Now it's time to fill the transmission with fresh oil.

  1. Fill to Position 1: Use the filling device (999 990 1000/S) along with the 9G-Tronic adapter to fill the new sump with the specified amount of transmission oil.
  2. Check for Leaks: Ensure that there are no leaks from the new sump or torque converter plug.

Step 6: Perform Valve Flushing

This step helps to clean the transmission system.

  1. Use Diagnostic Device: Connect your diagnostic device and initiate the valve flushing process.
  2. Follow On-screen Instructions: Keep the engine running and the brake pedal pressed as you follow the prompts.
  3. Listen for Valve Noises: Confirm completion by listening for the designated valve sounds.

Step 7: Final Checks

After completing the oil change, perform these checks:

  1. Reach Operating Temperature: Allow the engine to run until the transmission fluid reaches a temperature between 35 and 45°C.
  2. Check Oil Level: At Position 3, check the oil level.
  3. Drain Excess Oil: If the oil level is too high, drain any excess while the engine is running.
  4. Additional Filling: If necessary, use the filling device (999 990 1000/S) to add more oil until the correct level is achieved.

Conclusion

By following these steps, you can successfully perform an automatic transmission oil change on a Mercedes 9G-Tronic system. Using the MEYLE-KIT ensures that you have all necessary components, including filters and seals, for a smooth operation. Remember to regularly check the transmission oil level and condition to maintain optimal vehicle performance. For further assistance and more guides, consider subscribing to the MEYLE channel or visiting their website.