A grease fitting is a little port that channels grease gun-injected grease to a mechanical part that needs lubrication. They are commonly found on automobile and truck suspension components such as ball joints, tie rods and swing arms. Grease fittings are threaded, much like screws, and are installed by using either a dedicated grease fitting installation tool or a common wrench. If the top is broken off, a wrench will unscrew the bottom half of the fitting. But if the bottom half is broken or compromised, a specialised tool will be needed to remove it.
Determine which part of the grease fitting is broken. There are three parts to a grease fitting -- the upper grease nozzle, the lower bolt head and the threads which screw into the actual grease port on the vehicle.
Attach a wrench to the lower portion of the grease fitting. This part will look much like a small bolt head and must be completely intact before using a wrench. If the lower bolt head is not intact, the grease fitting must be removed with a grease fitting removal tool, as outlined in step 3. Once the wrench is attached, slowly turn the fitting in a counterclockwise rotation to free the fitting. It may take a bit of initial force to break the fitting free. Remove the fitting and discard it. Screw a new one into its place.
Place a specialised grease fitting removal tool over the grease fitting. A grease fitting tool must be used if the bottom bolt head is damaged, but it can be used to remove any grease fitting.There are differently sized tools for each specifically sized grease fitting. Wiggle and tap it into place with your fingers and hand. The serrated edges inside of the tool will securely grasp what is left of the bottom bolt head portion of the grease fitting. Once firmly in place, turn the tool in a counterclockwise rotation to remove the grease fitting. It may take an initial bit of turning force to break the fitting free.
Although rare, a grease fitting that has broken below the lower portion bolt head must be tapped out. Use a specialised screw tap that is inserted into the broken grease fitting and then carefully turned out.