Propshaft moves from side to side

[carl170]

Hi.

I am looking to buy a boat in my local boatyard. I have been out in her and she seems great. Just what I am looking for!

The boat has been taken out of the water this morning. The boat has an inboard diesel engine.

Everything seems fine apart from some play when I move the propellor. I can move it from side to side.

I know this is not good!. The owner has had a look and says something needs tightening and maybe a new bushing needs to be installed.

Is this as simple as it sounds? I don't really know much about inboards, prop shafts etc.

Thanks for any adviceanyone can offer.

Regards

Carl

 

[quimby]

Sounds like the Cutlass bearing has had its day! negotiate for cost of replacement.Degee of difficulty from easy to nightmare!

 

[KellysEye]

It needs the prop shaft pulled out and new bearings fitted, get a quote and knock it off the price. My guess, like all marine things, it won't be cheap. In a worst case scenario the prop shaft might be damaged.

 

[daveyw]

Google cutless bearing. To replace, remove prop. Disconnect shaft coupling at gear box. Remove coupling halve from shaft. Remove shaft from boat. Remove cutless bearing. Replace. Easy............apart from seized bolts, working upside down in engine bay............

 

[Pye_End]

Depends on how much movement there is, and what the installation is. You might be able to see the end of the cutless bearing to assess. There is no definitive guide to how much wear is acceptable, but more than a mm or so then either needs replacing or kept an eye on.

 

[garvellachs]

It needs the prop shaft pulled out and new bearings fitted, get a quote and knock it off the price. My guess, like all marine things, it won't be cheap. In a worst case scenario the prop shaft might be damaged.

Indeed, the shaft may well be worn under the bearing and require replacement too. Getting the shaft out of the gearbox coupling can be a pain too. But all boats require maintenance like this from time to time so it's not a deal breaker. You'll learn loads if you do it yourself.

 

[johnwest]

Don't forget to remove the shaft the rudder may need to be removed. The possible cause of a worn cutlass bearing is a miss aligned-engine, again not a major problem just a bit pernickety to adjust accuratley.

j

 

[Burnham Bob]

How much movement? If its the cutless bearing then you will be able to move it only within the wear of the bearing. If the boat has a transom hung rudder that you can take off from pintels the renewal job is easier. Get a quote from the boatyard on renewing the bearing and knock it off the price but do make sure its a firm quote.......you'd be amazed what they can discover that they "couldn't possible have anticipated but we had to do it and we only found out when........" you might be able to see if the shaft is worn by undoing the coupling and slipping the shaft down a little until it hits the rudder

post above says a misaligned engine could cause the problem but these bearings do wear out - even quicker in muddy water. using Occam's razor (look it up!) before you start worrying about the engine its most likely just to be a bearing at the end of its life

 

[alahol2]

It's not a given that the prop shaft has to be removed to replace the cutless bearing. I replaced mine by removing the bolts from the bearing holder, unscrewing it from the shaft log and sliding the whole thing off the prop shaft. Then relatively simple to replace the bearing.
Do we know that the shaft doesn't run through a 'P' bracket?

 

[Amulet]

All replies so far referring to the "cutlass bearing" are probably correct, but if it is an old-fashioned boat like mine it may well have a traditional packed stern gland with greaser, which may need repacking or replacing.

Same story, different bearing.

 

[boguing]

Hold on a minute, you're all assuming an older design.

What is the shaft arrangement? Does the shaft come out of the boat to the propellor or does it go through a bracket before the propellor?

 

[Neil_Y]

Firstly play or clearance of a shaft bearing is a factor of its size, larger shafts run larger clearances, so first thing is to find out the shaft size although on here I'll assume a shaft of between 25.40 - 38.10mm (1-1.5") as we're normally talking small boats especially if you can move the shaft by hand.

New clearance is going to be around 0.13-0.15mm, change the bearing when it gets close to 0.60mm, so not much, sounds like bearing is worn.

Changing the bearing isn't effected by the type of stern gland, but depending on the set up you may have more than one bearing and it's worth changing them all, as well as taking the shaft out to inspect it for wear. Bearings are made an accurate tolerance to a shaft diameter so you need that measured to 0.05mm accuracy.
Whatever type it's normal and usually easier to remove shaft, and then cut out, press out or use heat to remove the old bearings (depends on what is there)

If it's a stern tube it could have a white metal bearing but these can now be replaced directly with a new composite bearing so still quite straight forward, if the bearing is water fed and or lubricated it's probably going to be a rubber bearing (this is what people are referring to when they say cutless or cutlass) you can also use a water lubricated shaft bearing made from more modern materials developed for this application.

It could easily add £200 I would think but the actual figure depends on many variables, that's the trouble with boat work!

 

[carl170]

Thanks everyone for your replies so far!

The boat is a Halcyon 23 from 1975. The engine is a Volvo MD1 (must be very old too!).

I think that Burnham Bob had one sometime.

The shaft comes out of the skeg, through a fitting that looks like a thick tube which bolts on to the skeg. (I am sure these is a technical name for this!).

After having a second look at it last night - it appears that the tube bit is loose and this is what is moving from side to side.

The seller didn't look too concerned and seems genuine enough about sorting it. I know he buys and sells boats on a regular basis and I have been told he really knows his stuff. The boat is seems OK and is within my price range (very low!).

I will report back - unless someone else can advise me futher.

Regards

Carl

 

[charles_reed]

Thanks everyone for your replies so far!

The boat is a Halcyon 23 from 1975. The engine is a Volvo MD1 (must be very old too!).

I think that Burnham Bob had one sometime.

The shaft comes out of the skeg, through a fitting that looks like a thick tube which bolts on to the skeg. (I am sure these is a technical name for this!).

After having a second look at it last night - it appears that the tube bit is loose and this is what is moving from side to side.

The seller didn't look too concerned and seems genuine enough about sorting it. I know he buys and sells boats on a regular basis and I have been told he really knows his stuff. The boat is seems OK and is within my price range (very low!).

I will report back - unless someone else can advise me futher.

Regards

Carl

For those with childhood hang-ups about swords it's a cutless bearing NOT a cutlass bearing.

Usually as they wear (and there should always be some play when out of the water) it's more apparent in the vertical - if there's much horizontal movement look elsewhere.

As reported the movement appears to be in the end of the stern-tube - from a simple tightening operation to a nightmare scenario of stripped threads or an unbonded stern-tube.

Needs some deeper investigation, involving 2 people, one inside on stomach with torch, one outside wiggling the thing.

None a deal-breaker, but the worst-case could be expensive.

 

[sarabande]

can I check please ?

You are buying a boat from the original owner, or someone who has taken the boat in part exchange, or who is selling it as a business perhaps as a broker ? And the boat has a potentially expensive (relative to the cost price) repair looming. And an old engine.



Am I alone in hearing a little warning bell ?



Have you had a proper survey, or even a visit from an independent third party who really does know about boats ?

 

[Melleman]

can I check please ?

You are buying a boat from the original owner, or someone who has taken the boat in part exchange, or who is selling it as a business perhaps as a broker ? And the boat has a potentially expensive (relative to the cost price) repair looming. And an old engine.



Am I alone in hearing a little warning bell ?



Have you had a proper survey, or even a visit from an independent third party who really does know about boats ?

+1
more investigation needed

 

[carl170]

can I check please ?

You are buying a boat from the original owner, or someone who has taken the boat in part exchange, or who is selling it as a business perhaps as a broker ? And the boat has a potentially expensive (relative to the cost price) repair looming. And an old engine.



Am I alone in hearing a little warning bell ?



Have you had a proper survey, or even a visit from an independent third party who really does know about boats ?

I have not had a survey due to the (relative) cost. Maybe this is my own stupidity?. He is asking a lot less than any other Halcyon 23's I have seen (1500-4000). I like the look of the boat and from the poke around I have had (the boat is down at my club and was on the water until yesterday) it really just needs cosmetic work, cleaning and tidying. I have probably spent about 5 hours on it, looking all over, armed with a copy of Don Caseys “Inspecting the aging sailboat”(!).

The Mast and sails are certainly serviceable and another member of the club said quite a bit of time and money had been spent on the engine over the last few months. I have been out a couple of times in it - Yesterday we were aboard for about an hour or so while the boat was lifted out. Bearing in mind and the engine started (electric start) no problem, and the boat was covered in frost and ice, I took this as a good sign!. I regularly see members of the club using outboards that look like they are from 70's and 80's so there must be some life left.

Do things like stern tubes become unbonded very often? Would the boat not sink?

I will get a couple of opinions from other guys down the club just for good measure. There are a few down there that have been building boats for 50+ years.

Thanks for all opinions – and keep it coming!

Regards

Carl