David of Essex
Well-Known Member
Question now is, how often should the coupling be unbolted and checked for alignment between the gearbox and prop shaft.
David
David
Heavy vibration
- Thread starter Wiggo
- Start date
Wiggo
Well-Known Member
Every time the boat sinks. Preferably about a week beforehand.
omega2
Well-Known Member
Pardon me if you have tried this, is there any play either up or down, side to side, if you give the prop a shaking? Ours looked OK until we shook them, we could "hear" the play, let alone feel it.
As you say the shine on yours looks like a "fouling" that has fallen off. Were it me I would replace the bearings if you have any sloppiness in the P bracket.
David of Essex
Well-Known Member
The reason for asking how often should you check the couplings be checked for alignment is because I don't know. My boat is 3 years old and never been checked. I was concerned if the alignment should be every 200-400-600 hours just asking.
I'am glad Wiggos problem was found before sinking.
David
I'am glad Wiggos problem was found before sinking.
David
omega2
Well-Known Member
If it aint broke don't fix it.
This will show how to adjust R&D couplings
http://www.randdmarine.com/downloads/RandD_Shaft.pdf
Last edited:
Wiggo
Well-Known Member
No play to be felt in the cutless bearings/P brackets, no, so once the coupling is undone, if they still feel OK we're leaving the cutless bearings alone.
Bilgediver
Well-Known Member
I was asked to look at a Sealine with similar problems some years ago after the marina suggested new props. The props were clearly visible on outdrives and fine... I suggested it could be an engine problem and we went out for a burl up and down he river on one engine at a time while I tested the cylinders....each engine had 3 non effective cylinders. A week later with a full set of serviced injectors the owner had a big smile and was puzzled how a raggie new about such things
Check he little things first before adding to my Volvo dividend. If props seem fine with no bumps or bit missing they are probably not the problem..
Wiggo
Well-Known Member
Now for the next part of the question.
Having found a collapsed engine mount, we will replace all four on that engine. Would the panel do all four on the other engine at the same time, or leave well alone?
Having found a collapsed engine mount, we will replace all four on that engine. Would the panel do all four on the other engine at the same time, or leave well alone?
Divemaster1
Well-Known Member
Is there any signs of material fatigue ?
... personally I am a great believer in "if it ain't broke, don't fix it...", but we don't have V...os onboard, so not sure how over engineered your fixings are....
... personally I am a great believer in "if it ain't broke, don't fix it...", but we don't have V...os onboard, so not sure how over engineered your fixings are....
hlb
RIP
Yes. Engine mounts were the pain of my life, until they were replaced and uprated.
Sinking focuses the mind.
Sinking focuses the mind.
JohnRob
Well-Known Member
Vibration
Cutlass bearing/s in my view the most likely.
When mine went, engineers did not detect at first.
Some F37s used in rivers reputed to get through cutlass bearings quickly. In sea mine 8th season and needed first replacement three-ish years ago.
Engineers will need to check carefully for wear but should be detectable if this is the fault.
Cutlass bearing/s in my view the most likely.
When mine went, engineers did not detect at first.
Some F37s used in rivers reputed to get through cutlass bearings quickly. In sea mine 8th season and needed first replacement three-ish years ago.
Engineers will need to check carefully for wear but should be detectable if this is the fault.
JohnRob
Well-Known Member
What a wally - I hadn't seen the rest of this thread....sorry!
hlb
RIP
In my case, I felt no vibration. Only that the port stern gland needed constant adjustment. Eventually it seemed to weap from behind the stern gland, I kept asking engineers to look at the problem for three years. Bear in mind, I was over 300 miles away from the boat..
DAKA
Well-Known Member
I would just replace the 4 and check the others.
Haydn makes a very valid point but I guess your mounts have done less than half the work of his, your stern gland has 1/2 the metal fatigue, you have had the boat since new and know the history of your staern gland, there is no way of knowing why Haydns failed without vibration but it could have had previous issues with bent shafts, broken bonding that weakened the gland or perhaps the 20 hour run in service wasnt done until Haydn got the boat ?
You have a spare engine anyway .
You will not sink at sea.
on one engine you should make 8-10knots
anything above 4 knots will suck water out of the broken stern gland, its only when you stop the water will pour in so you need a prommpt lift out.
Of course haydn could prove me and the laws of nature wrong here .
Haydn makes a very valid point but I guess your mounts have done less than half the work of his, your stern gland has 1/2 the metal fatigue, you have had the boat since new and know the history of your staern gland, there is no way of knowing why Haydns failed without vibration but it could have had previous issues with bent shafts, broken bonding that weakened the gland or perhaps the 20 hour run in service wasnt done until Haydn got the boat ?
You have a spare engine anyway .
You will not sink at sea.
on one engine you should make 8-10knots
anything above 4 knots will suck water out of the broken stern gland, its only when you stop the water will pour in so you need a prommpt lift out.
Of course haydn could prove me and the laws of nature wrong here .
Last edited:
iangrant
Well-Known Member
Yes
I think you know the answer is yes, if the engine is being lifted to do one busted mount then you may a well do the others,
As for the other engine, not sure about that 50/50 but then you'd be gutted if she had to come out again?
Ian
I think you know the answer is yes, if the engine is being lifted to do one busted mount then you may a well do the others,
As for the other engine, not sure about that 50/50 but then you'd be gutted if she had to come out again?
Ian
hlb
RIP
You will not sink at sea.
on one engine you should make 8-10knots
anything above 4 knots will suck water out of the broken stern gland, its only when you stop the water will pour in so you need a prommpt lift out.
Of course haydn could prove me and the laws of nature wrong here .
__________________
I understand exactly what you say. But I proved it dont work, slows it down a bit, but I was still going down.
Perhaps it depends on the size of hole.
on one engine you should make 8-10knots
anything above 4 knots will suck water out of the broken stern gland, its only when you stop the water will pour in so you need a prommpt lift out.
Of course haydn could prove me and the laws of nature wrong here .
__________________
I understand exactly what you say. But I proved it dont work, slows it down a bit, but I was still going down.
Perhaps it depends on the size of hole.
Hurricane
Well-Known Member
Put it another way.
How confident would you be going to sea if you didnt replace the other engine's mounts?
Wiggo
Well-Known Member
depends on why the other side failed, Mike. I'd like to leave well alone if I can.
hlb
RIP
Check that Volvo have not uprated yours, as they did with mine.
Wiggo
Well-Known Member
The engineer just rang. Problem solved. The outboard rear engine mount nut had worked loose, allowing the engine to drop and putting extra load on the shaft. That was enough, as described earlier, to cause the vibration. However, it had also put enough strain on the coupling to shear the head of one of the gearbox-coupling bolts.
They're just sourcing the coupling bolt now, and all should be back together very soon, at fairly minimal expense (no new engine mounts, cutless bearings, props or shafts needed). As an aside, I also managed to get her freshly antifouled, polished all the underwater gear and checked the anodes, so she's good to go!
Given the damage that could have been inflicted (a la Muckfarter sinking), it was a very lucky escape...
They're just sourcing the coupling bolt now, and all should be back together very soon, at fairly minimal expense (no new engine mounts, cutless bearings, props or shafts needed). As an aside, I also managed to get her freshly antifouled, polished all the underwater gear and checked the anodes, so she's good to go!
Given the damage that could have been inflicted (a la Muckfarter sinking), it was a very lucky escape...