A drive unit for a molding machine for longitudinally displacing a movable first machine component relative to a second machine component, includes a rotationally drivable spindle mounted in a linear movement-locking manner on the second machine component, a spindle nut arranged in a rotational movement-locking manner on the first machine component for positive-locking engagement with the spindle, and a fluid chamber which at least adjoins the spindle and/or the spindle nut, and contains a lubricant. A temperature control element for controlling the temperature of the lubricant is arranged in and/or on the fluid chamber at least in areas.