A gear box for a reciprocating kneader comprising: a casing; a gear box primary shaft adapted for coupling to a motor; a primary rotational gear attached to said gear box primary shaft which rotates in concert with said gear box primary shaft; a secondary rotational gear engaged with said primary rotational gear which rotates in concert with said primary rotational gear; a gear box secondary shaft attached to said secondary rotational gear which rotates in concert with said secondary rotational gear; a primary oscillation gear attached to said gear box primary shaft which rotates in concert with said gear box primary shaft; and a secondary oscillation gear engaged with said primary oscillation gear which rotates in concert with said primary oscillation gear wherein said secondary oscillation gear rotates on said gear box secondary shaft; characterized in that the gear box for the reciprocating kneader further comprises: an eccentric coupled to said secondary oscillation gear wherein said eccentric rotates in concert with said secondary oscillation gear wherein said eccentric comprises lobes; a yoke engaged with said eccentric wherein said yoke oscillates on an axis perpendicular to said gear box secondary shaft in response to contact with said lobes of said eccentric during rotation and said gearbox secondary shaft moves along its axis in concert with yoke oscillation; a housing pivotally attached to said yoke at a yoke pivot axis and pivotally attached to said casing at a casing pivot axis wherein said yoke pivot axis and said casing pivot axis are not parallel; and a coupling on said gear box secondary shaft adapted for attachment to a screw of a kneader of said reciprocating kneader. a casing; a gear box primary shaft adapted for coupling to a motor; a primary rotational gear attached to said gear box primary shaft which rotates in concert with said gear box primary shaft; a secondary rotational gear engaged with said primary rotational gear which rotates in concert with said primary rotational gear; a gear box secondary shaft attached to said secondary rotational gear which rotates in concert with said secondary rotational gear; a primary oscillation gear attached to said gear box primary shaft which rotates in concert with said gear box primary shaft; and a secondary oscillation gear engaged with said primary oscillation gear which rotates in concert with said primary oscillation gear wherein said secondary oscillation gear rotates on said gear box secondary shaft; characterized in that the gear box for the reciprocating kneader further comprises: an eccentric coupled to said secondary oscillation gear wherein said eccentric rotates in concert with said secondary oscillation gear wherein said eccentric comprises lobes; a yoke engaged with said eccentric wherein said yoke oscillates on an axis perpendicular to said gear box secondary shaft in response to contact with said lobes of said eccentric during rotation and said gearbox secondary shaft moves along its axis in concert with yoke oscillation; a housing pivotally attached to said yoke at a yoke pivot axis and pivotally attached to said casing at a casing pivot axis wherein said yoke pivot axis and said casing pivot axis are not parallel; and a coupling on said gear box secondary shaft adapted for attachment to a screw of a kneader of said reciprocating kneader. an eccentric coupled to said secondary oscillation gear wherein said eccentric rotates in concert with said secondary oscillation gear wherein said eccentric comprises lobes; a yoke engaged with said eccentric wherein said yoke oscillates on an axis perpendicular to said gear box secondary shaft in response to contact with said lobes of said eccentric during rotation and said gearbox secondary shaft moves along its axis in concert with yoke oscillation; a housing pivotally attached to said yoke at a yoke pivot axis and pivotally attached to said casing at a casing pivot axis wherein said yoke pivot axis and said casing pivot axis are not parallel; and a coupling on said gear box secondary shaft adapted for attachment to a screw of a kneader of said reciprocating kneader.