How to Add Transmission Fluid to a Mercedes C320

by Matt Scheer

The Mercedes C320 is a compact vehicle that requires a transmission fluid change every 30,000 miles or two years, whichever comes first. Changing the fluid keeps the gears lubricated and shifting smoothly. Fresh fluid also regulates engine temperature to keep it from overheating. Performing this regularly scheduled maintenance requires only a few tools and about an hour's work. The job is important because it can prevent costly engine damage.

Park the Mercedes C320 on a level surface, Let the engine cool for 20 to 30 minutes after driving. Raise the front of the car up on a pair of jacks to access the underside of the vehicle.

Slide underneath the C320 and locate the gear box. It resembles a round metal tank and is located in the center of the engine. Place a drain pan (5 quart minimum) under the gear box to catch the fluid that falls.

Remove the fill plug on the pipe coming from the rear of the gear box with the 1/2 inch socket wrench. Also remove the drain plug in the front of the gear box. Wait for the fluid to drain completely into the pan below. This usually takes 15 to 20 minutes, so use this time to wash the drain plug and remove the residue. Replace the drain plug.

Place the plastic tube of the fluid pump into the fill plug and fill it with 3 quarts of transmission fluid. The tank is full when the fluid is level with the bottom of the hole. Usually, the liquid begins to drip from the fill plug when the gear box is full. Replace the fill plug and lower the car from the jacks.

Items you will need


About the Author

Matt Scheer began writing professionally in 2005. His work has appeared in "The Daily Texan" and "The New York Tribune." Scheer holds a B.A. in English and a B.A. in history, both from the University of Texas. He is also a certified Yoga teacher and Web designer.