A suggestion has been made that the Voyagers may run out of propellant and so may not be able to maintain pointing near the Earth for communications.
According to @BowlOfRed's answer:
Although the craft can be turned if necessary, the voyager probes are not intentionally rotating. They use small thrusters that try to zero out any rotations.
These thrusters aren't infinitely precise, nor are the instruments that drive them. So there is some error in the firing that means the probe has a (small) residual rotation. Instead of having a perfectly fixed direction, it will slowly drift away from the intended attitude over time. When the residual rotation moves the platform too far from the antenna pointing at earth, the thrusters fire to to return the alignment.
With what little remains of the Voyagers' cold gas thruster propellant, could the spacecraft be given a slight rotation in order to approximately stabilize one axis of their attitude?