🔍 Key Concepts
• Tail shaft and stern tube – how the propeller shaft is supported as it exits the hull
• Stern bearing wear and misalignment – how they affect shaft movement
• Difference between problems at the engine versus problems at the shaft/bearing
💭 Think About
• If the tail shaft is visibly wobbling, which part of the system is actually moving – the engine, the shaft support, or the water around the vessel?
• Would shallow water or a misfiring engine cause side‑to‑side shaft movement, or would they show up in some other way (e.g., vibration, loss of power, noise)?
• What mechanical condition would allow the shaft to move off‑center as it rotates – something too tight, something too loose, or something out of line?
✅ Before You Answer
• Distinguish between engine problems (misfire, power, RPM changes) and shaft alignment/bearing problems (wobble, uneven rotation)
• Consider what a tight tail shaft gland would do – restrict movement and create friction, or allow wobble?
• Visualize where the stern bearing sits and what happens if it is worn or not lined up correctly with the shaft.