Abstract: A wheel tread adjusting device has a flat plate provided with a plurality of holes. Two of the holes align with the jack screw bores normally present in a tapered sleeve-type hub to mount the plate to the tapered sleeve. A cut-out bore allows the plate to rest flush against the tapered sleeve without interfering with the normally present lug bolts. Two additional bores are positioned radially outside of the tapered sleeve and hold jack screws to unwedge the tapered sleeve from the hub. An adjustment rod is selectively engageable with either of two adjustment bores in the plate. Another portion of the rod can be threaded through a bracket mounted to the end of the axle, or through a lug bolt bore in the hub of an outer wheel, if dual wheels are present. The structure is extremely simple, uses the normally present bores to the maximum extent, and is made predominantly of standard available parts.