A screed assembly for a paving machine is disclosed including a main screed portion and a screed extension portion being laterally exterior to the main screed portion. Furthermore, a screed extension tube is coupled to a screed frame and a screed extension portion frame, the screed extension tube adjusts a width of the screed extension portion. The screed assembly may further include an extension tube support mechanism having a bushing circumferentially surrounding the screed extension tube and disposed within a bushing recess defined in the screed extension portion frame. The extension tube support mechanism further having a retainer ring that circumferentially surrounds and is in direct contact with at least a portion of the bushing, and the retainer ring is capable of being adjusted between the bushing and the screed extension portion frame to eliminate an uncontrolled movement of the screed extension tube and the screed extension portion.