How do I replace the cutless bearing on an Arcona 400?

First check whether your Arcona 400 has a conventional propeller shaft or a saildrive: a saildrive has no conventional cutless bearing to replace. On a shaft-driven boat, remove the propeller, release the bearing retainers and extract the bearing with a suitable puller or press; some installations also require shaft withdrawal.

Identify the installation and bearing

Look underneath the hull. A saildrive has a substantial gearbox leg projecting down through the hull, with the propeller fitted directly to its lower shaft. A conventional installation has an exposed propeller shaft emerging from a stern tube, sometimes supported by a separate P-bracket.

Do not order a bearing by the Arcona 400 model name alone. Engine and propulsion installations vary, and previous owners may have changed components. If yours has a saildrive, identify its make and model before investigating propeller movement. Wear may be in the propeller hub, its bushes or the drive itself.

For a conventional shaft, establish these details:

• Shaft diameter, measured on a clean, unworn section.
• Bearing outside diameter and overall length.
• Whether the bearing sleeve is metal or composite.
• Whether it sits in a P-bracket, a fixed stern-tube housing or a removable carrier.
• The position of retaining grub screws and access for an extraction tool.

Metric and imperial bearings can look nearly identical. A 25 mm shaft and a 1-inch shaft, which measures 25.4 mm, require different bearings. Take the dimensions from the existing part or a confirmed installation drawing.

Assess wear and extraction access

With the engine stopped, move the shaft sideways and vertically immediately beside the bearing, watching its movement against the rubber lining. Movement at the propeller alone can include play in a folding or feathering hub. Use the bearing maker's clearance limits; there is no universal replacement figure.

Investigate uneven clearance, damaged rubber, a scored shaft or recurring vibration. A new bearing will not cure a bent shaft, loose bracket or poor alignment.

Work only with the boat securely supported ashore and the engine isolated against accidental starting.

A purpose-made tool can remove some P-bracket bearings with the shaft still installed, provided its split sleeves fit the shaft and bearing housing. A bearing in a stern tube may require shaft withdrawal. Check clearance to the rudder before disconnecting anything. The rudder does not always need to come off.

Remove the propeller and bearing

1. Photograph the propeller assembly and record the order of nuts, spacers, locking devices and anodes. Follow the propeller manufacturer's dismantling instructions.
2. Remove the propeller with the appropriate puller. Protect the shaft threads and retain the key.
3. Clean paint and fouling from the bearing housing. Find and remove all bearing-retaining grub screws; check for a second screw stacked above the first.
4. Support the shaft independently before removing its bearing support. Do not let its weight hang from the gearbox coupling or shaft seal.
5. Extract the sleeve with a correctly sized puller or press arrangement that bears against the housing and pushes on the sleeve.