How to Change Transmission Fluid on a ML430


1. Park the vehicle on a level surface and allow the engine to cool down. Raise the front of the vehicle with a floor jack and support the front end with jack stands. Crawl underneath the vehicle and locate the transmission drain pan. The drain pan is in the middle of the engine undercarriage.
2. Place a layer of newspaper on the ground underneath the transmission drain pan. Position the catch pan underneath the drain plug. Use a ratchet with a 5 mm hex socket to remove the drain plug and allow the fluid to drain into the catch pan. Reinsert the drain plug when finished.
3. Use a number 30 Torx socket to remove the six bolts holding the drain pan in place. Carefully lower the pan and tip it towards the catch pan to drain away any remaining fluid.
4. Inspect the drain pan and the condition of the old transmission fluid. Metal particulates in the bottom of the pan or in the fluid indicate signs of impending transmission failure. Wipe down the drain pan and bolts with a shop towel.
5. Pull the transmission filter out of its mounting area inside the transmission. Tip the filter towards the catch pan to drain any remaining fluid. Insert the new transmission filter into the transmission.
6. Locate the oval torque converter housing ahead of the transmission pan. Have a partner turn the engine with a 27 mm socket and a long breaker bar applied to the crankshaft pulley nut until the drain plug becomes visible through the open slot. Position the catch pan under the torque converter and use a 5 mm hex socket and a socket extension to remove the drain plug. Allow the fluid to completely drain and reinsert the drain plug.
7. Inspect the drain pan gasket for any signs of aging and wear. If needed, replace the drain pan gasket with a new one. Otherwise, reuse the gasket when reinstalling the drain pan. Place the gasket around the lip of the drain pan and lift the pan into place. Insert and torque the six retaining bolts to 106 inch-pounds.
8. Remove the catch pan and newspaper from underneath the vehicle. Seal the pan and set it aside for proper disposal. Remove the jack stands and lower the vehicle to the ground. Open the hood and locate the transmission tube near the firewall on the left side of the engine compartment. Place a long neck funnel into the tube and pour 6 liters of Mercedes Benz automatic transmission fluid into the tube.
9. Start the engine and take the vehicle on a short drive. This will allow the transmission to come up to operating temperature. Place the vehicle in Park and use an infrared thermometer to measure the temperature of the transmission drain pan. The temperature should read around 80 degrees Celsius.
10. Use the Mercedes Benz dipstick tool to measure the fluid level while the vehicle is idling. Insert the dipstick through the transmission tube until it hits the bottom of the transmission drain pan and then remove the dipstick. The amount of fluid inside the transmission should be within the 80 degrees Celsius mark on the dipstick. If the fluid level is below the bottom fill mark, add more transmission fluid as needed. If the fluid level is above the top fill mark, immediately drain the excess fluid.
11. Dispose of the old transmission fluid at the nearest automotive parts outlet or repair shop. Most shops will dispose of the fluid free of charge.