Park your truck on a level surface, such as a flat driveway. Turn the engine off.
Remove the oil cap from the snow plow assembly. The oil cap is labeled with the universal oil-drop symbol or the word “Oil.”
Insert a craft stick into the oil tank. Make sure the stick touches the bottom of the tank. You may also use a straw or anything that enables you to see where the oil level is. Do not use anything that is dirty or may break off into the oil, such as a stick from a tree.
Draw a horizontal line on the stick with a black marker where the stick meets the top of the oil tank. Pull the stick out of the tank. Compare the length between the marked line and the oil line on the stick with the appropriate oil level outlined in your snow plow manual. As a general rule, if the oil line is more than 1-1/2 inches away from the top of the oil reservoir, add oil.