an axle assembly according to the present invention which is identical in structure and operation to above described axle assembly 210 except as follows axle assembly 210 comprises electromagnet 220 u2032 which is fixed to the axle housing 108 rather than being rotatably supported about casing part 216 b u2032 bearing 110 u2032 is disposed in cup 124 which extends inwardly of the axle housing to engage and support electromagnet 220 u2032 notably bearing 110 u2032 is somewhat smaller than bearing 112 or bearing 110 of fig3 by moving the electromagnet to the axial end of casing 216 u2032 opposite that at which ring gear 104 is located however larger bearing 112 located near the ring gear 104 is more heavily loaded during operation with reference now to fig5 8 there are shown various bearing means for axially and radially supporting electromagnet 220 in axle assembly 210 fig5 which is an enlarged fragmentary view of fig3 shows electromagnet 220 which comprises coil 252 is separated from casing 216 by flat annular roller thrust bearing 254 and by annular bearing 256 molded of a self lubricating sp polyimide resin such as for example vespel u00ae manufactured by dupont bearing 256 has an l shaped partial cross section providing integral cylindrical portion 258 and flat annular portion 260 snap ring.