A reciprocating drive apparatus for connection to a top end of a rod swing to drive a downhole pump located in a well includes a plate adapted to be fastened to a top end of a well head assembly of the well, and a mast attachable to the plate in a substantially vertical working position. A hydraulic cylinder is attached to the mast such that when the mast is in the working position the hydraulic cylinder is oriented substantially vertically, and such that the hydraulic cylinder can extend and retract in response to a controller. A tether is adapted to be fixed to the well head and to the top end of the rod string and is configured such that the hydraulic cylinder engages the tether to move the rod string up and down as the hydraulic cylinder extends and retracts.