The Mercedes Benz SLK 230 is a compact roadster manufactured since 1997. Checking its transmission fluid can be a challenge because the engine does not have a dipstick. The SLK's transmission is designed to be maintenance-free, so the fluid level does not need to be checked as long as there are no leaks and the transmission fluid and filter are changed at the recommended intervals. If you suspect the transmission fluid is low, you will need a transmission dipstick workshop tool to check the fluid level.
Start the car and let the engine warm up. The transmission fluid should be at 80 degrees C for an accurate reading.
Park the car on a level service. Open the bonnet 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.
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.
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.
Replace the transmission fluid cap. Install a new locking tab to secure the cap.