How do I replace the stern gland (shaft seal) on a Hallberg-Rassy 46?

Replace the shaft seal on your Hallberg-Rassy 46 with the boat ashore, usually by disconnecting and removing the gearbox-end shaft coupling so the old seal can slide off forwards. Identify the fitted gland and measure its connections before ordering: an older HR 46 may have replacement equipment, and the fitting procedure depends on the seal design.

Identify the fitted gland

Clean the assembly and inspect the seal, shaft coupling and stern-tube connection. Photograph any markings and record the boat's hull number and year. Hallberg-Rassy or a seal supplier can use these details and your measurements to identify a replacement.

• Moulded rubber lip seal: a compact rubber body, such as a Volvo Penta shaft seal, grips the stern tube and seals directly against the rotating shaft.
• Face seal: a bellows supports a stationary sealing face against a rotating collar, as on a PSS installation. Bellows compression and collar position must be set correctly.
• Packed gland: a metal stuffing box with an adjusting nut or follower needs a different repair, which may require only replacement packing.

Measure the shaft diameter with a vernier calliper on clean, unworn metal. Establish the stern-tube spigot's outside diameter, the available installation length and any water-feed or vent connections. Do not order a nominal 35 mm or 40 mm seal because it looks close. Both the shaft bore and stern-tube connection must match.

Maintenance instructions for nearby HR models do not establish the HR 46's original equipment. Nor should you assume that the later HR 40/43/48 cutless-bearing removal procedure applies to your boat.

Remove the shaft coupling

Have the boat securely supported ashore and isolate the engine starting supply before opening the shaft line.

1. Expose the coupling and mark its relationship to the gearbox flange. Photograph spacers, flexible elements and fastener positions.
2. Support the shaft independently before disconnecting it. Do not let its weight hang on the gearbox output flange or the seal.
3. Disconnect the coupling and release its shaft attachment. Previous modifications may mean dealing with clamp bolts, retaining screws, a key or a taper-lock arrangement.
4. Remove the coupling with the appropriate puller or extraction arrangement. Do not hammer against the gearbox or use its casing as a levering point.
5. Restrain the shaft against sliding aft, then remove the old gland and its clamps.

The coupling is often the hardest part of the job. Bring in a marine engineer if it is seized, the keyway is damaged or there is too little room for extraction. Moving the shaft aft may require propeller removal; check clearance to the rudder before starting.