How do I replace the cutless bearing on a Hallberg-Rassy 31?

First check whether your Hallberg-Rassy 31 has a saildrive or a conventional propeller shaft: many HR 31s have a saildrive, which does not use the external cutless bearing described here. On a shaft-driven installation with a removable sleeve bearing, you may be able to replace it with the shaft in place, but identify the housing and its retaining screws before applying force.

Identify the drive and housing

A saildrive has a substantial underwater leg with the propeller mounted directly behind it. A conventional shaft emerges through the hull and runs through a water-lubricated rubber bearing, either in a stern housing or a separate supporting bracket.

On a saildrive, movement at the propeller calls for checks of the propeller hub, shaft splines and gearbox bearings; do not attempt the stern-bearing procedure below. Propeller-shaft seals and internal bearings require the procedure for that saildrive model.

For a conventional shaft, clean the housing until you can identify:

• The bearing's outer sleeve: usually metal, though some installations use composite sleeves.
• Grub screws hidden beneath antifouling or filler.
• A housing flange and its securing bolts, if fitted.
• Any exposed bearing sleeve that a suitable extractor can grip.

Hallberg-Rassy used different arrangements across its range. Do not assume the later composite-bearing instructions for HR 40, 43 and 48 models apply to an HR 31.

Measure before dismantling

With the boat ashore, lift the shaft gently beside the bearing. Feel for radial movement and watch the shaft relative to the housing. Movement in a folding propeller's blades or hub is a separate issue. Uneven rubber wear, substantial movement or shaft contact with the sleeve warrants investigation. Use the bearing maker's clearance limits rather than a universal wear figure.

Record the shaft diameter, bearing outside diameter and sleeve length. Do not order by boat model alone: a previous owner may have changed the shaft or stern gear. Measure the shaft on a clean, unworn section and confirm the housing bore once the bearing is out.

Have the correct propeller puller, Allen keys, measuring tools, shaft support and a bearing extractor to hand. Photograph spacers, anodes, locking washers and propeller components before removal.

Work only with the boat securely supported ashore. Isolate engine starting and support the propeller shaft so it cannot hang on the gearbox coupling or damage the shaft seal.

Extract with the shaft in place

1. Remove the propeller with the correct puller and keep its key, spacers and locking components in order.
2. Remove or fully retract every bearing-retaining grub screw. Check for a second screw beneath the first.
3. On a suitable rubber-lined sleeve bearing, try passing a smooth wire hook carefully between shaft and rubber to catch the bearing's inner end. This method is used on some Hallberg-Rassy bronze stern housings.
4. Draw the sleeve aft with steady force along the shaft's axis. If it resists, use a suitable extractor bearing against the housing and sleeve without loading the gearbox.
5. Stop if the sleeve will not move, the hook scores the shaft, or the housing starts moving against the hull.