Ford Super Duty Owner's Manual page 385

384
The following step applies to F-250 and F-350 Single Rear Wheel vehicles
only:
2013 F-250/350/450/550 (f23)
Owners Guide gf, 2nd Printing, December 2012
USA (fus)
Wheels and Tires
22. When installing the wheel center
ornaments, ensure that the ornament
retention towers on the back side of
the ornament are aligned with the
studs or lug nuts. The retention
towers are designed to be installed
over the studs or nuts and retain to
the flange on the lug nut.
If the ornament retention towers
are aligned between the studs or lug
nuts, the ornament is improperly
installed. This improper installation
may appear and sound correct, but
will not keep the ornament on the
vehicle. Ornaments improperly
installed in this manner will fall off
or become loose with minimal force
or impact.