Abstract: A rotor assembly including first and second generally discoidal endshafts disposed at opposite ends of the rotor assembly, an electromagnetic core and winding assembly secured between the endshafts, and a generally annular sleeve member shrunk-fit onto the end shafts in a position surrounding the electromagnetic core and winding assembly. The torque is transmitted through the sleeve member between the endshafts during operation of the dynamoelectric device in which the rotor is employed. A method of assembling the rotor is also disclosed in which the electromagnetic core and winding assembly is bolted between the endshafts. The sleeve member is heated to a temperature between 900.degree. and 1,000.degree. F., the sleeve member is brought into a position over the endshafts, and subsequently allow to cool to ambient temperature to shrink into locking engagement with the endshafts.