an improved tire changing apparatus including a base provided with an elevated tire supporting surface . an arm has one end pivoted to the base and a bed breaker tool receiving structure adjacent its opposite end . a pawl is disposed intermediate the ends of the arms and a ratchet having plural teeth is pivoted to the base above the arm and below the tire supporting table and depends in adjacency to the arm so that the pawl may selectively engage any one of the teeth to adjust the position of the tool receiving formation relative to the support surface .