Greasing your car or lawn tractor after an oil change lubricates the movable components of your suspension system. The grease fitting allows for grease to be inserted through a small hole. Occasionally, the tip of the grease fitting will break off if it is hit by road debris or rocks. When this happens it is necessary to change the grease fitting as soon as you notice it is broken. Grease fittings are available at auto parts stores.
Clean the area around the broken grease fitting with a rag. Remove all dirt and debris around the faulty fitting. This helps prevent dirt getting inside the cavity when you remove the grease fitting.
Place an appropriate size open-end wrench around the hex nut of the fitting. The hex nut is actually part of the fitting. Turn the fitting counterclockwise with the wrench until it is completely out of the grease hole.
Thread a new grease fitting into the grease hole until you can no longer turn it by hand. Turn the grease fitting another 1/2-turn with the wrench.
Apply grease to the fitting as usual with your grease gun. If grease seeps out between the hole and bottom of the hex area, tighten the fitting another 1/4-turn.