Figure 196. Location of filler and drain plugs on the gearbox
To check the oil level, unscrew plug 1 (figure 196) with internal hexagon. Use your index finger to check the oil level; it should reach the lower edge of the filler hole. If necessary, add oil using a hand pump. Always use oil recommended by Mercedes-Benz.
Before changing the transmission oil, you need to drive a few kilometers to warm up the oil. Place a suitable container underneath (approximately 2.5 liters) under the checkpoint (place the car on stands) and unscrew the plug 2 with a hex key (see figure 196). To speed up the draining process, unscrew the filler plug. Allow the oil to drain completely. It's better to wait a while.
Screw in the drain plug and tighten to a torque of 50 Nm. Fill in new oil using a hand pump. If available, you can use an oil syringe for filling, after thoroughly cleaning it first. About 1.8 liters are required to fill the gearbox. If it is difficult to estimate the volume of oil to be filled, fill to the lower edge of the filler hole. Then screw in the plug and tighten to a torque of 50 Nm.