Pic. 196. Location of filler and drain plugs on gearbox
Remove plug 1 to check the oil level (pic. 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, fill with oil using a hand pump. Always use oil recommended by Mercedes-Benz.
Before changing the gear oil, drive a few kilometers to warm up the oil. Substitute a suitable container (about 2.5 liters) under CP (put car on stands) and unscrew plug 2 with a hex wrench (see fig. 196). To speed up the drain, unscrew the filler plug. Let the oil drain completely. It's better to wait a while.
Screw in the drain plug and tighten to 50 Nm. Fill in new oil using a hand pump. If available, you can use an oil syringe for refueling, after thoroughly cleaning it. About 1.8 liters are needed to fill in the gearbox. If it is difficult to estimate the volume of oil to be filled in, fill up to the lower edge of the filler hole. Then screw on the plug and tighten to 50 Nm.