Sistemas y guías
Propeller shaft seals on cruising yachts
Stuffing box vs dripless shaft seals — drip rates, alignment, and haul-out inspection for owner crews.
Overview
The propeller shaft passes through the hull via a shaft seal — either a traditional stuffing box (controlled drip) or a dripless face seal. Both need haul-out inspection and correct engine alignment.
Types
| Type | Normal sign |
|---|---|
| Stuffing box | Steady drip when shaft turns — not when static |
| Dripless (PSS-style) | No drip — check hose and set screws |
| Cutless bearing | No play when wiggling prop at haul-out |
Survey focus
- Drip rate — adjust packing nut incrementally; overtightening overheats
- Hose clamp on dripless — double clamp per manufacturer
- Shaft zinc — protects strut and prop; replace on schedule