Abstract: A tool for mounting and demounting of large tires from associated multi-piece wheel rims. The tool includes upper and lower tubular arms each having a length adapted to span the diameter of a demountable tire retaining flange of the wheel rim while oriented perpendicular to the axis of the wheel and tire assembly. Each arm has pusher plates dependent therefrom adapted to engage the outer periphery of the tire bead retaining flange. The arms are connected by a pivot bolt so that the same can pivot relative to one another about the axis of the wheel assembly and are lockable in a given transverse crossing orientation. A pair of hold down bolts are carried on each arm spaced from one another to correspond with the diameter of the wheel disc mounting bolt hole pattern for insertion of the bolts through diametrically-opposed pairs of wheel mounting bolt holes.