How do I replace the cutless bearing on an X-Yachts X-372?

Replace the cutless bearing with the boat ashore, using a properly supported puller or press after removing the propeller and releasing every bearing retainer. On an X-Yachts X-372, confirm the propulsion arrangement and measure the fitted bearing first, as the model name alone does not establish its size or removal method.

Check the installation

Start beneath the stern. A conventional shaft installation has a propeller shaft emerging through the hull, with a water-lubricated rubber bearing in a separate bracket or stern-tube housing. A saildrive has a leg projecting beneath the hull. Its propeller-shaft bearings need a different procedure, so these cutless-bearing instructions do not apply.

Original equipment and later engine or shaft conversions can differ. Do not assume that the threaded housings or two Allen-screw arrangements found on some Hallberg-Rassys apply to your X-372.

With the gearbox in neutral and the engine isolated, lift the shaft immediately beside the bearing and watch for movement between the shaft and bearing sleeve. Movement here suggests bearing clearance; movement of the whole bracket points to a mounting problem. Rotate the shaft and inspect for uneven clearance, damaged rubber, scoring and fishing line.

Have the yard secure the boat on suitable supports. Isolate engine starting and support the shaft throughout removal so its weight cannot load the seal or gearbox coupling.

Measure the bearing

You need three dimensions: shaft diameter, bearing outside diameter and bearing length. Measure a clean, unworn section of shaft with a micrometer or good vernier calliper. Measure the sleeve and housing accurately once accessible. A 25 mm shaft and a 1-inch shaft differ by 0.4 mm and require different bearings.

• Shaft diameter: establishes the bearing's nominal internal size.
• Outside diameter: must suit the housing and specified installation fit.
• Length: must match the housing, support requirements and water passages.
• Sleeve material: identify whether the existing bearing has a metal or composite shell.

Record any markings before discarding the bearing. Order through a marine sterngear supplier using those dimensions, rather than asking simply for an "X-372 bearing". Confirm whether the replacement should be pressed in or installed with a specified retaining compound.

A suitable split extraction tool can sometimes remove a bracket-mounted bearing with the shaft still installed. Otherwise, the shaft may need withdrawing. Check clearance to the rudder before dismantling the coupling; do not assume the shaft will slide straight out.

Remove the worn bearing

1. Photograph the assembly, measure the bearing's installed position and record the order of nuts, washers, spacers and anodes.
2. Remove the propeller with the correct puller. Follow the manufacturer's dismantling procedure for folding and feathering propellers, and retain keys and small locking parts.
3. Clean paint and deposits from the housing and locate all grub screws, locking screws or other retainers. Remove them fully before applying extraction force.
4. Support the shaft. Fit a bearing extractor with a receiving sleeve that clears the bearing shell and a pusher that bears squarely on the shell.
5. Apply steady pressure, supporting the housing close to the load. Stop if the bracket bends, the tool cocks sideways or the bearing refuses to move.