  The physical mechanism(s) responsible for transitioning from a spherical
Asymptotic Giant Branch (AGB) star to an asymmetric post-AGB (pAGB) object is
poorly understood. In particular, excess momenta in the outflows of pAGB
objects suggest that a binary may be required to supply an additional source of
energy and angular momentum. The extraction of rotational energy from the
engine is likely fundamental and may be facilitated if a dynamo is operating in
the interior. In this regard, single star magnetic outflow models have been
proposed as mechanisms for producing and shaping PNe, however these models
neglect the back-reaction of the large-scale magnetic field on the flow.
  Here we present a transient $\alpha-\Omega$ dynamo operating in the envelope
of an AGB star in (1) an isolated setting and (2) a common envelope in which
the secondary is a low-mass companion in-spiraling in the AGB interior. The
back reaction of the fields on the shear is included and differential rotation
and rotation deplete via turbulent dissipation and Poynting flux. For an
isolated star, the shear must be resupplied in order to sufficiently sustain
the dynamo. We comment on the energy requirements that convection must satisfy
to accomplish this. For the common envelope case, a robust dynamo can result as
the companion provides an additional source of energy and angular momentum.
