Always use a gear puller of the required size or larger. Use a 3-jaw puller, if possible.Ensure that the gear puller is aligned with the shaft. The jaws should be parallel with the screw. This assures a straight pull.Be careful when removing a stubborn gear or bearing. Always strike the head of the centre screw squarely. If after two sharp blows the gear or bearing remains stuck, select a larger puller and proceed to remove the gear or bearing.