Abstract: A drive arrangement is disclosed for rotating the rim and tire supporting mandrel of a tire dismounting machine. The drive arrangement includes a hydraulic cylinder reciprocable relative to a piston rod fixed in the machine housing. The cylinder carries a rack engaging a pinion on an arbor which supports the mandrel, whereby reciprocation of the cylinder in opposite directions relative to the piston rod rotates the mandrel and thus a rim and tire thereon in opposite directions, each of which directions provide for one revolution of the mandrel in the corresponding direction.