Abstract: A rocker arm stabilizer bar assembly that is designed for use with a tandem axle travel trailer and it is used when one of the four tires of the trailer goes flat. It is used temporarily in place of a spare tire until the driver can get to the nearest service station to repair the flat tire. The stabilizer bar assembly is clamped into position between the bottom surface of the trailer frame and the top surface of the rocker arm. The stabilizer bar is channel-shaped and it is vertically oriented. A bolt passes through a horizontal aperture in the stabilizer bar and a horizontal aperture in a spanner plate and it has a nut threaded on its end to clamp it into position adjacent the respective ends of a U-shaped bracket that supports the rocker arm. The stabilizer bar has a pair of intermediate horizontal walls having tongue portions that function to center the stabilizer bar within the walls of the U-shaped bracket that supports the rocker arm.