It is dangerous to use a hard-toothed reducer, so you should understand it clearly when using it. The following is a brief understanding of the steps that should be followed for changing the oil of a hard-toothed reducer: 1. Cut off the power supply to prevent electric shock: wait until the reducer cools down and there is no danger of burning. 2. Open the oil level plug, breather and oil drain plug, and drain all the oil. 3. Install the oil drain plug: inject new oil of the same grade. 4. The amount of oil should be consistent with the installation position: pay attention to check the oil level at the oil level plug. 5. Tighten the oil level plug and breather. When changing the oil, we must understand the above knowledge. Only in this way can we reduce the damage caused by the hard tooth surface reducer.