A powered hammer includes a housing, a tool holder coupled to the housing and configured to hold a tool, a motor within the housing, a cylinder disposed within the housing, and a piston slideably mounted within the cylinder. A drive mechanism converts rotary output of the motor into a reciprocating motion of the piston. The drive mechanism includes a crank shaft rotationally driven by the motor, a drive pin eccentrically mounted on the crank shaft, and a con rod with a first end connected to the drive pin and a second end connected to the piston. A ram is slideably mounted forward of the piston that is reciprocatingly driven by the piston. A beat piece is slideably mounted forward of the ram. The beat piece is repetitively struck by the reciprocating ram, which in turn repetitively strikes an end of the tool when held in the tool holder to transfer the momentum of the ram to the tool. Lubrication fluid covers at least part of the drive mechanism. A rear piston chamber is formed within an end of the cylinder, rearward of the piston, the volume of which repetitively changes as the piston moves within the cylinder, causing air within the housing to be at least one of drawn into and blown out of the rear piston chamber. The movement of air causes the lubrication fluid to move within the housing. A longitudinal passageway defined in at least one of the crank shaft and the drive pin enables passage of air and the lubricating fluid to assist in movement of the lubrication fluid within the housing.