The ornamental design for a trailerhitchballcover, as shown and described.
FIG. 1 is a perspective view of the trailer hitch ball cover, showing my new design.
FIG. 2 is a front elevation view of the trailer hitch ball cover of FIG. 1.
FIG. 3 is a rear elevation view of the trailer hitch ball cover of FIG. 1.
FIG. 4 is a right side elevation view of the trailer hitch ball cover of FIG. 1.
FIG. 5 is a left side elevation view of the trailer hitch ball cover of FIG. 1.
FIG. 6 is a top plan view of the trailer hitch ball cover of FIG. 1; and,
FIG. 7 is a bottom plan view of the trailer hitch ball cover of FIG. 1.
Portions or features of the trailer hitch ball cover not shown in the drawings form no part of the claimed design. The broken lines in the drawings form no part of the claimed design.