How do I replace the cutless bearing on a Beneteau Oceanis 38?

First check whether your Oceanis 38 has a saildrive or a conventional propeller shaft, as a saildrive has no conventional cutless bearing to replace. On a shaft-drive boat, replacing the bearing means hauling out, measuring it, removing its retainers and pressing it out with the shaft properly supported.

Identify the drive

Many Oceanis 38s have a saildrive, so do not order a bearing by boat model alone. Check the engine and drive identification plates, then look underneath:

• Saildrive: a substantial gearbox leg projects down through the hull, with the propeller mounted directly on its horizontal output shaft.
• Shaft drive: a separate stainless-steel shaft exits the hull and runs through a water-lubricated rubber bearing, either in a support bracket or at the stern tube.

On a saildrive, movement may come from the propeller hub, folding-propeller pivots or output-shaft bearings. Hold the shaft or hub separately from the blades to establish which part moves. Replacing output-shaft bearings is a gearbox repair that requires the correct drive manual, seals and clearance checks.

The familiar instruction to loosen two Allen screws and twist out a composite bearing applies to particular stern-tube arrangements. It is not a universal Oceanis procedure.

Check wear and dimensions

With a shaft-drive boat ashore, grip the shaft close to the bearing and lift it vertically, then move it sideways. Watch the shaft against the bearing housing. Movement in the propeller itself does not establish bearing wear. Uneven rubber, missing sections and shaft contact with the sleeve call for further investigation.

Measure movement with a dial indicator if possible, then compare it with the bearing manufacturer's clearance limit. A small running clearance is necessary. No single rejection figure suits every shaft diameter and bearing material.

Record these before ordering:

• Shaft diameter, measured on an unworn section with a micrometer.
• Bearing outside diameter and overall length.
• Sleeve material, retaining arrangement and any water-feed passages.

Metric and imperial bearings can look almost identical. A 25 mm shaft and a 25.4 mm shaft require different bearings. Suppliers such as Countrose and Johnson Cutless offer numerous sizes, but confirm the actual installation rather than choosing by yacht length. Budget roughly £50 to £180 for a small yacht bearing, plus haul-out and labour.

Remove the bearing

Have the yard secure the boat ashore and isolate engine starting before working around the propeller or shaft.