Cutless bearing

“What” I hear you ask, “is a cutless bearing?”
Well it’s nothing to do with pirates of the Caribbean, that’s for sure.

The propeller shaft passes through the hull somewhere between the engine and the propeller – the engine being INSIDE the boat and the propeller being OUTSIDE. The propeller shaft spins round and would flap about in the water if it wasn’t held in place. Where it passes through the hull there is a plastic bearing which is kept lubricated by seawater. This plastic tube (the cutless bearing) has a number of grooves in it (ours are full of mud) which allow water to enter the shaft and this helps to keep the bearing cool as well as providing a degree of lubrication.

While we have the boat out of the water we have an ideal opportunity to replace said bearing with a new one. So JOB 1 was to remove the propellor shaft which was done last weekend. This was surprisingly easy although time consuming and required some small amount of hitting hard with a hammer and levering things with a wrench followed by a screwdriver.

Checking out YouTube suggests that removing the cutless bearing is EASY.

Not so. I have concluded after much grinding and prodding that the bearing is bonded into the hull. It should not be as it should be removable. There should be a separate ‘stern tube’ made of metal into which the bearing fits. That way whenever the bearing is changed (every ten years or so) the propeller shaft always aligns correctly.

In Anne Marie’s case that bearing is bonded into the hull and I run the risk that if I changed the bearing it would not go back into the correct location and alignment causing excess wear, vibration and leakage.

So I have decided at the moment to leave well alone and put the shaft back without changing the bearing. This might be a mistake but then that’s how we learn and improve our knowledge.