How to Check the Transmission Fluid in a SLK230

1. Start the car and let the engine warm up. The transmission fluid should be at 176 degrees F for an accurate reading.
2. Park the car on a level service. Open the hood and locate the black transmission fluid cap on the back of the engine. Remove the red plastic locking tab on the transmission fluid cap, then remove the cap. The locking tab will break and need to be replaced.
3. Insert the transmission dipstick workshop tool into the transmission filler neck tube. Up to 8 inches of the workshop tool might stick out of the transmission tube. Stop inserting when the workshop tool will go no further.
4. Remove the workshop tool and read the end like you would a dipstick. Lines on the ends of the tool indicate high and low transmission fluid levels.
5. Replace the transmission fluid cap. Install a new locking tab to secure the cap.