  We consider hyperfine-mediated effects for clock transitions in
$^{176}$Lu$^+$. Mixing of fine structure levels due to the hyperfine
interaction bring about modifications to Land\'e $g$-factors and the quadrupole
moment for a given state. Explicit expressions are derived for both $g$-factor
and quadrupole corrections, for which leading order terms arise from the
nuclear magnetic dipole coupling. High accuracy measurements of the $g$-factors
for the $^1S_0$ and $^3D_1$ hyperfine levels are carried out, which provide an
experimental determination of the leading order correction terms.
