A system for a vehicle differential includes a coil and a drive member movable between a first position and a second position. The drive member has an axis and includes a first body that is magnetically responsive, a second body formed at least partially from a second material that is not magnetically responsive and a third body that defines a radially inner surface of the drive member. The first body, second body and third body are coupled together with the third body being formed from a material having a lower coefficient of thermal expansion than the second body. The system may also include a lock member driven by the drive member to engage a gear of the differential in at least one position of the lock member.