The hydraulic tie rod with code 0743814-5.3 is a precision tensioning component used in the MAN L21/31 engine to secure the cylinder head and crankcase assembly with uniform clamping force. By applying controlled hydraulic pressure during tightening, the tie rod ensures even load distribution, compensates for thermal expansion, and minimizes distortion under high combustion pressures. This system enhances sealing reliability, reduces mechanical stress, and significantly improves engine durability, particularly during long operating cycles and frequent load variations.