Cutlass bearing

[tcp]

I have a 40ft power boat (Fairline) and am trying to change my Port cutlass bearing. (leaving shaft in situ) I have removed the two lock pins and constructed a very sturdy push / puller but no matter how hard I try I cannot budge the bearing, not even with a bit of heat (propane). An observer told me that sometimes people will epoxy these bearings in place but he could not suggest how to check that this is what had happened or how to deal with it.

Any suggestions please.


Terry

[wingless]

Welcome to the forum.

When I change the cutlass bearings on my boat, I first remove the shafts, using seal protectors to prevent seal damage.

Once the set screws are removed from each side of the bearing strut, then LOTS of force is required to remove the old bearing.

After removal, I've found that the required drilled dimple creates a small burr, adding to the difficulty.

The installation is aided by freezing the replacement part, then installing to the final position as-quickly as-possible.

[bobnlesley]

Leaving the shaft in position definitely makes the task much harder, is there some specific reason that you can't take it out?

For whatever reason mine invariably tap in fairly easily but are a bugger to remove and are also only accessible from one end so I ensure the new one is always installed so that it projects 1/4" from the housing. That allows me to cut a 'slice' out of the bearing from the inside using either an electrical reciprocal-saw, or in the boondocks a heavy-duty hacksaw blade after which you can grab the projecting end with a mole wrench and easily twist/pull it out.
Re: The comment about 'burring' on the set-screw dimple, I measure, mark, drill and de-burr these prior to re-installation, matching marks on the housing allow it to be carefully tapped into the correct position and if you do cock-up you're no worse off as you can still drill post installation drill it, whilst praying that you don't damage the set-screw threads.

[tcp]

Many thanks Wingless and Bobnlesley

I cannot take the shaft out unless prepared to fork out £400 for a crane to lift me higher. which I am reluctant to do unless absolutely no other way.
I understand that there is no ridge or stop point in the Bronze housing so it can come out either way so I am going to attack it from the other end. I have concluded that I am going to have to apply a higher heat and greater force as it must be an unusually good interference fit. My main concern is that the previous owner did in fact epoxy it in.

[NYSail]

Did you remove the set screws?

[malbert73]

If PO epoxied it in, heat will solve that. But yes make sure all set screws are removed and then it’s just force

[tkeithlu]

If, god forbid, it is epoxied in, you might be able to confirm that by a close look at the junction between bearing and shaft log. Aside from seeing it at the end, a layer of epoxy would be visible between the two if you drill a shallow hole through the side of the shaft log, stopping just after the tip of the drill bit touches the bronze of the bearing, using a farely large diameter bit. There will be a differently colored layer between the metal of the log and the bronze of the bearing.

If it is glued in place, expansion heat from propane is not likely to be enough to free it. More likely, you would need to heat the shaft log until the glue decomposes. It hope you shaft log extends beyond the hull for the length of the bearing. That's a LOT of heat.

Pulling the bearing with the propeller shaft in place seems unlikely, given how resistant the bearing is to moving, and difficulty getting an adequate grip on it.

I managed to pull mine a few years ago by parking my truck behind the boat, such that the trailer hitch was on a line extending past the propeller, in line with the shaft. Then I used a come-along between the prop and the hitch to pull the shaft, and again to pull the bearing. I grabbed the top end of the bearing by tying a knot in a chain and running it down the shaft.

Maybe my experience will give you some ideas. I'm sorry that I can't come up with an idea that doesn't involve repositioning and pulling the shaft.

[wingless]

When my boat is setup in the yard, I need it blocked per ABYC TY-28, with cribbed blocking, as-shown in the image.





TY-28 states: "Stands should not be used as jacks to raise or lower the boat." and "Stands should be installed and adjusted by qualified, experienced, and authorized persons." Even with those restrictions, I have seen examples where multiple / extra sets of stands were used to pivot / arc / raise the boat attitude, pivoting on the forward cribbed blocking, so that the shafts could be removed where it had previously not been possible.

It is unlikely that any adhesive, such as epoxy, was used to secure the cutlass bearings. On mine, they are an interference fit, making the freezing prior to fast installation a great step.

Going forward is probably not a good option for removal.

A tool like this one would probably work w/ the shafts in-place.

[tkeithlu]

Wow, Wingless. A boat weighing thousands of pounds, and someone (you?) getting under it to loosen the supports and move the boat? That could permanently remove a person's third dimension. Should we give a new forum member such an idea? For 400 Pounds?

I remember getting under my boat as I was building it, and realizing that the welds in the cradle that supported the hull were the first welds I ever did....

[motion30]

I don't know how much space you need but perhaps you could dig a hole for the shifts to slide into

[wingless]

When my boat is properly blocked per ABYC TY-28 I have spent extended days working underneath on the myriad of projects.

My 24,000 lbs boat is not going anywhere when cribbed blocking is properly supporting the keel and side stands are properly preventing the boat from tipping.

When I observed instances of the boat attitude being changed (against the TY-28 recommendation) there was never anyone underneath the boat. This 10,000 lbs keel stand is my preference for under the garboard drain plug, permitting height adjustment for proper setting.

[a64pilot]

Originally Posted by motion30

I don't know how much space you need but perhaps you could dig a hole for the shifts to slide into

Or, can the shaft logs be removed and slid over the shafts, then taken to a machine shop to have the cutlass pressed out and new one pressed in?

[tcp]

Many thanks to you all for your comments and ideas, I have decided that a
combination of heat and a lot more brute force is my next logical step.
I am too old and fearful to try anything more ambitious such as jacking up etc
but thankyou anyway.
When I learn how to do it I will post photos.

I will post you all if I am successful with the heat and force.

[Steve Bean]

Penetrating oil - your choice of commercial products or 50/50 transmission oil/acetone, might help.

[wingless]

If using heat, first pack the parts with ice to get them as-cold as-possible.

Then, rapidly heat just the strut only, usage of MAPP gas works much better than propane, because it is hotter.

Immediately after heating remove the bearing, before the strut heat transfers to the bearing.

Note that is a point of no return step, because the heat will damage the bearing rubber and replacement will be required.