Shafting system in a ship is probably its most critical component. Problems in the propulsion shafting, connecting engine with propeller may let the vessel dead in the water. This study focuses on three components of the shafting system which are well known to cause problems. These are the aft stern tube bearing, the coupling bolts and the sealing arrangement which prevents the ingress of sea water or the leakage of lubrication oil to the sea. A variety of issues related to these “weak” links of the shafting system is analyzed, based on actual cases of damage.