Stern tube repair

[NB Victorianna]

Hi, has anyone had a stern tube repair recently and can give an idea of the cost to change the shaft and the tube has the boat I'm purchasing as slight play. The surveyor says they can be changed but it's obviously leaking as there is a bucket near the gland nut?

 

TIA

Edited April 6, 2016 by NB Victorianna

[bizzard]

Hi, has anyone had a stern tube repair recently and can give an idea of the cost to change the shaft and the tube has the boat I'm purchasing as slight play. The surveyor says they can be changed but it's obviously leaking as there is a bucket near the gland nut?

 

TIA

Very slight sideways play of the shaft in the tube is permissible. Is it leaking through lack of grease in the gland or needing adjustment to the gland or is it leaking from where the tube screws into the stern post collar or where the gland unit screws onto the tube? water can wire in or out via the threads at these points if they're loose at the thread and-or the thread sealant has broken down.

[Iain_S]

he price would depend a lot on what was worn.

Midland Swindlers list various bearings at prices ranging from £60 to £100, and around £100 for a prop shaft.

If the tube needs changing, the job becomes a bit more complicated, as often the tube mounting needs moved and re-welded to the hull. A major component in the cost of bearing/tube/shaft replacement is the dry docking.

 

On the other hand, slight play on the prop shaft is probably the rule, rather than the exception.

 

The bucket near the gland nut may indicate a tidy owner, who wants to keep his bilge dry, rather than a problem. Drips from the stern gland are normal. Some recommend that there should be a couple of drips per minute while running, while others swear that their gland doesn't drip at all.

[BWM]

If the surveyor has highlighted the problem its safer to assume that it will need replacement. I was quoted over a thousand pounds for this on my last boat.

[bizzard]

There is always slight running clearance of a few thou between shaft and tube bearing. If they were a perfect precision fit grease and water wouldn't be able to enter and lubricate them.

[Guest]

Also depends what the setup is. There are a lot of Vetus type about these days which are somewhat different than the "greaser" type. I had a bucket under the Vetus one in my boat last year as it was leaking badly.

[peterboat]

I had mine apart last year whilst in the dry dock when it was all cleaned up there was play present. when it was put back together and all greased up play gone! since then it drip when running one turn on greaser at night stops it

[Bee]

I think I would ask the surveyor for clarification. The tube is the (probably) steel pipe that is welded or bolted in place, this should not wear out. It probably has threaded ends on to which are fitted the outer bearing, this can wear, and the inner bronze bearing containing the gland packing. The shaft runs in the packing, not the metal, this wears but is cheap and easy to replace(!) The shaft is probably stainless and should not wear out although it can thin a bit where it runs in the packing. If you can shove it in or out a bit you might get it to run on nice new packing and an unworn bit of shaft. So - lots of variables and there are different systems but before you commit to expensive and probably unnecessary repairs ask the surveyor or someone with genuine experience to have a look.

[bizzard]

?

[Tiggs]

Hi, has anyone had a stern tube repair recently and can give an idea of the cost to change the shaft and the tube has the boat I'm purchasing as slight play. The surveyor says they can be changed but it's obviously leaking as there is a bucket near the gland nut?

 

TIA

 

I would expect slight play. You only need a new shaft and tube if you can't get the leak to stop (they all leak a bit, I mean stop when you moor up and grease the gland, there should be no overnight leakage) with a new gland.

 

We had to have one replaced on a 40+ years old boat and that's how long I would expect them to last (if engine / prop set-up is OK). It was done along with other work so I can't remember how much it cost. If it needs doing you should get it done with blacking etc to optimise dry dock costs.

I think I would ask the surveyor for clarification.

 

it can thin a bit where it runs in the packing. If you can shove it in or out a bit you might get it to run on nice new packing and an unworn bit of shaft.

 

Agree - check that the surveyor mean it need replacing or just new gland and tightening.

 

It might be possible to move it in or out a bit too - have seen this done as a quick fix.

[ditchcrawler]

I think I would ask the surveyor for clarification. The tube is the (probably) steel pipe that is welded or bolted in place, this should not wear out. It probably has threaded ends on to which are fitted the outer bearing, this can wear, and the inner bronze bearing containing the gland packing. The shaft runs in the packing, not the metal, this wears but is cheap and easy to replace(!) The shaft is probably stainless and should not wear out although it can thin a bit where it runs in the packing. If you can shove it in or out a bit you might get it to run on nice new packing and an unworn bit of shaft. So - lots of variables and there are different systems but before you commit to expensive and probably unnecessary repairs ask the surveyor or someone with genuine experience to have a look.

I have seen shafts of only a few years old with nice steps in them when the engine has been poorly aligned. I would suggest with labour and docking you are looking at the top side of £500 unless you can find someone who can lift the back end and do it without the docking fee.

[NB Victorianna]

Thanks everyone for the replies. I will confirm with the surveyor as to the probable causes, which has been suggested may just be a cheap fix or a more expensive repair and go forward with this to the seller.

[Claude]

I would either get the seller to sort out the repair to the satisfaction of the surveyor, or determine the "worst case" cost for you to get it done yourself (including dry docking) and make sure you knock this cost off whatever price has already been agreed with the seller.

[ditchcrawler]

I would either get the seller to sort out the repair to the satisfaction of the surveyor, or determine the "worst case" cost for you to get it done yourself (including dry docking) and make sure you knock this cost off whatever price has already been agreed with the seller.

Agree