An endless track assembly wherein the weight of an associated vehicle/equipment is supported by the track framework. The track assembly provides a framework having a number of idler rollers and a drive sprocket that mounts to a rotational drive power source. The weight of the vehicle is transferred from a vehicle/equipment support flange that cooperates with a complementary support surface of the track framework and an intermediate bearing liner. The bearing support surfaces cooperate to permit the track frame to pivot relative to the chassis independent of the drive sprocket. The track assembly is particularly adapted to pivoting irrigation systems.