An actuator assembly includes a housing, a piston rod, and a lost motion device. The housing defines a housing bore that extends along a first axis from a first housing end towards a second housing end. The piston rod is at least partially disposed within the housing bore. The piston rod defines a piston bore that extends from a first piston end towards a second piston end along the first axis. The lost motion device is at least partially disposed within the housing bore and extends into the piston bore. The lost motion device and the piston rod are arranged to move relative to the housing along the first axis.