An agricultural harvester, such as a combine harvester, which has an auxiliary axle assembly for support of the feeder house of the harvester. The auxiliary axle assembly can be provided in a retracted position when in a field mode, and can be locked in an extended position when in a road mode, where a wheel of the assembly contacts the ground. When in the locked, extended position, the auxiliary axle assembly supports substantially all of the weight of the feeder house and any attached implements, allowing the feeder house to pivot relative to the main chassis of the harvester.