Hydraulic concrete mixer

A hydraulic concrete mixer comprising:

• a drum having a mixing blade attached to an interior thereof;
• a frame supporting the drum;
• an engine mounted on the frame;
• and
• a drive train extending through at least a portion of the drum, the drive train comprising:
• a hydraulic motor;
• a first rigid plate between the hydraulic motor and the drum;
• a second rigid plate inside the drum and coupled to the first rigid plate such that a portion of the drum is held between and in fixed relationship to the first rigid plate and the second rigid plate;
• a first shaft at least partially inside the drum and adjacent to the second rigid plate;
• a second shaft adjacent to the first shaft;
• and
• a mounting plate coupled to the second shaft,
• wherein:
• the first shaft comprises:
• a first end;
• and
• a second end substantially opposite the first end;
• and
• the first shaft defines a passageway extending between the first end and the second end.