Installation of Cutless bearing

[catmandoo]

I have an inboard cutless bearing to install on the port hull of my catamaran.
In planning the installation I have come across a sort of chicken and egg situation .

ie do I install the bearing first and then insert the shaft from inside or do I insert the shaft and tap the bearing in from outside using a slightly larger tube .

I am worried that a tight fit with the new rubber might cause difficulty of insertion of my shaft so what should I do . ( No jokes about KY jelly please )

The previous bearing had a grub screw tapped into the wall of the bronze cylinder which I think contributed to its demise ie as Nigel Calder suggests making it slightly oval causing wear . He suggests putting the screw/s in only as far as the dimples on the outer casing . Problem is my new bearing has no dimples . Any suggestions /ideas for fixing this new inboard bearing ?

 

[alb40]

The grub screw only needs to grip the bearing in order to stop it from trying to rotate. Just tighten it so it grips the bearing but doesnt deform it.

All joking aside, KY is ideal to lubricate the rudder as its water based, it wont cause any damage and it will wash off once in the water.

 

[Juggler7823]

I've always made a dimple for the grub screw by drilling into just the surface of the bearing.

 

[Ardenfour]

just fitted one in mine, the aft bearing carrier part of the stern tube is off boat at present. I had to press the bearing in using a vice (tight fit) so, do I actually need to fit grub screws, there were none in the old bearing, mind you that was a piece of rubber hose...?

 

[alb40]

I had to install mine with a press, so I doubt it will moved. Ive run some locktight around the edges for good measure and to help keep corosion down

 

[catmandoo]

It has been suggested putting the bearing in the freezer part of the fridge to shrink it but what I was concerned about is the difficulty of getting the shaft in once the bearing is in


Incidentally the grooves in my new Vetus bearing rubber are very much deeper than that of the original

 

[Bodach na mara]

I have just removed the housing for mine. Came off with a bit of stern tube still screwed in. Oh dear. I could not find any grub screws either. Tried bashing the cutlass bearing out with a punch and it will not move. Funny that as other posts have suggested they came out easily, even without removing the shaft. Ideas like hooking it out with bent wire have been floated. From the posts in this thread, it seems that they are a tight fit in the housing.

Now has anyone any ideas on whether and how the stern tube can be removed from a Westerly Renown?

 

[catmandoo]

I couldn't find any grub screws at first too. Howevver I took Nigel Calder's advice in his book which was that the only way to remove inboard cutless bearings was to saw them out .

So after removing the shaft I sat in front of the hole with a hacksaw blade wrapped in tape and sawed in and out etc .

Several hours later and with 8 broken hacksaw blades I called it a day . Had shower and went to the local hardware shop to get decent blades . . The next morning with swedish high speed blades I had sawed two parallel cuts at the bottom and removed a strip of bronze along the whole length without damaging the sterntube .

The right hand half of what was left came out easily but only after cutting another groove at the top. The left hand half seemed to be stuck to the wall . It was then that I discovered the hidden grub screws . I also found hidden in the gelcoat covering the tube the remains of previous locating screws

 

[TigaWave]

Bearings can be drilled and tapped to locate them securely. We advise this approach with the fitting of cutters, as long as you have measured ciorrectly and dont use bolts that are too long they can locate the cutter and hold the bearing in place.

The forces on the bearing will be rotational rather than along the shaft, so the locating screws or bolts are there to stop it rotating and wearing its outer surface or the bearing carrier.

 

[catmandoo]

Do you Mean Rope cutters? I have rope cutters but they are only clamped on the stern tube and shaft . cant see where they would impose a torque on the bearing . ???

 

[kengill]

If you've lost the KY in the sheets you can always use Swarfega - just as soluble in water and won't damage rubber
Ken

 

[wiggy]

When installing new in my boat a couple of years ago I was advised to araldite dearing in as grub screws either corrode in place or have little effect

 

[Bodach na mara]

I contacted David Hardy at Trafalgar Yachts and he told me there are no grubscrews on these Westerly housings. The bearing is an interference fit in the housing, hence the need to saw them out of you do not have access to a suitable press.