vibration when accelerating... ideas what it is??

[boatlover]

Hey all,

Just wanted to pick fellow forumites brains.

Im about to get my boat lifted out of the water so want to do as many checks as possible.

2005 squad 58 , 950 hours.

One thing I noticed when maybe throttling forward from say 13 knots to 19 knots if you give it a bit of welly sometimes you hear a very hard shudder and vibration.

Can happen as well say you when you go astern hard...

I few people have said it could be the couplings around the shafts.

Any ideas?

On a separate note while she is out of the water anything else worthing checking apart from the usual anti fouling , anodes etc?

 

[aquatom]

I've had the same thing on one of the last sq 58 built. We had the boat lifted, checked prop, cutlass bearings and couplings. It turned out to be a gearbox fault. We have since had about 5 more with the same problem but only D12-800's, its always on the port side.

Have a very close look at the R&D couplings, when they were removed it was very clear that the holes in the nylon had worn oval and the bolts were nearly toutching.

Also check the bilges under the gearboxes for small pieces of black rubber. This comes from the drive rubbers between the flywheel and the gearbox.

Hope this helps.

 

[volvopaul]

D12s and squadrons seem to eat gearboxes i have heard about many, it must be that the gearbox is under specced for the hp, torque the d12 has.

There is also an issue with D9s running zf gearboxes especially in Broom 450s, I know of one boat thats had 2 boxes in a short space of hours, zf and volvo wont recognise there is an issue , its always on the forward clutch that burns out.

The d9 is only available with a twin disc box now out of interest, funny thing isnt it.

If the gearbox oil has gone black the clutches are slipping, id also check the shaft for distortion, cutlassbearings, prop and shaft , remove the prop and check the taper and key for movement, check the engine mounts, there have been recalls over them too, have an engineer in the engine bay to carry out the checks, if there is a problem the engine will move on its mounts more than normal, if its a shaft issue you will see all the vibration around the gearbox area.

 

[Latestarter1]

Wow this raises all manner of questions, are people accepting all this nonsense?

Failine using R&D couplings.........this is a solution looking for a problem.

Gearbox and damper failures...there are complex torsional compatability issues that people are just sweeping under the carpet. ZF would never supply or warrant a gearbox match which did not meet their rating criteria there are some deeper issues here. Engine and gearbox manufacturers know what the issues are, which is why when you drill down into the real small warranty print you come across 'Torsonal compatability excusions'.

#1 Engines do not turn at a constant speed when at a certain governor setting, rotation tends to slow down as flywheel approaches top dead centre on a cylinder and speed up after TDC not totally isochronous governing. I have a very accurate rotary shaft encoder which shows the tiny speed changes beautifully. The small changes in rotational speed do not trouble the engine, however the characteristic does make the gearbox real pissed. The gears complain bitterly by 'talking' to each other and modern gearboxes have light alloy casings which often transmit the chatter which is what people complain about, however issues can run far deeper. Oil can get hot or aerated if level not spot on and clutch packs fail.

I have lost count of the various gearbox drive plate designs that have come from Centa and Vulkan over the years to address certain engine/gearbox compatability issues with CAT, Cummins and Yanmar motors, if there is evidence of damping media such as rubber from the drive plate you have a torsional issue.

Sounds like Volvo and builders are not addressing root cause of the failures.

 

[jfm]

2005 squad 58 , 950 hours.

One thing I noticed when maybe throttling forward from say 13 knots to 19 knots if you give it a bit of welly sometimes you hear a very hard shudder and vibration.

Can happen as well say you when you go astern hard...

Is the vibration a new thing or has it always been there? (you have had the boat either since new or at least for many miles iirc). What's the history?

I had 2 Sq58s as you know, first was hull 74 (of 210) with D12 715s, and second was hull 201 with D12 800s, and neither had any problem like this in 800 and 300 hours respectively. Both had ZF boxes, obviously supplied with the engines as a complete package by Volvo

 

[Deleted User YDKXO]

With a vibration issue, the first thing to check for is a damaged prop or a failed cutless bearing before you start changing gearboxes. Damaged props have a habit of causing vibes at particular rpm ranges. Often you wont see the damage with the naked eye so get the props checked by a professional. With a cutless bearing, try moving the prop shaft from side to side and if you see or feel any play in the bearing, it needs changing

 

[volvopaul]

Wow this raises all manner of questions, are people accepting all this nonsense?

Failine using R&D couplings.........this is a solution looking for a problem.

Gearbox and damper failures...there are complex torsional compatability issues that people are just sweeping under the carpet. ZF would never supply or warrant a gearbox match which did not meet their rating criteria there are some deeper issues here. Engine and gearbox manufacturers know what the issues are, which is why when you drill down into the real small warranty print you come across 'Torsonal compatability excusions'.

#1 Engines do not turn at a constant speed when at a certain governor setting, rotation tends to slow down as flywheel approaches top dead centre on a cylinder and speed up after TDC however isochronous the governing. I have a very accurate rotary shaft encoder which shows the tiny speed changes beautifully. The small changes in rotational speed do not trouble the engine, however the characteristic does make the gearbox real pissed. The gears complain bitterly by 'talking' to each other and modern gearboxes have light alloy casings which often transmit the chatter which is what people complain about, however issues can run far deeper. Oil can get hot or aerated if level not spot on and clutch packs fail.

I have lost count of the various gearbox drive plate designs that have come from Centa and Vulkan over the years to address certain engine/gearbox compatability issues with CAT, Cummins and Yanmar motors, if there is evidence of damping media such as rubber from the drive plate you have a torsional issue.

Sounds like Volvo and builders are not addressing root cause of the failures.

Looking at the Broom boat issues id have thought there could have been a failure on the oil temp side, maybe the sea water output is not cold enough to cool the oil, or maybe its just plain too small, surely they would test oil temp in and out of the cooler, yet on most occasions the drive to the forward gear had more or less dissapeared, causing the oil to go jet black and smell overheated, as 30 grade is used maybe its properties are now far beyond the demands of a modern gearbox?

 

[boatlover]

Is the vibration a new thing or has it always been there? (you have had the boat either since new or at least for many miles iirc). What's the history?

I had 2 Sq58s as you know, first was hull 74 (of 210) with D12 715s, and second was hull 201 with D12 800s, and neither had any problem like this in 800 and 300 hours respectively. Both had ZF boxes, obviously supplied with the engines as a complete package by Volvo

Hi Jfm,

Well Ive had the boat from 350 hours. Engines are D12 715's.

In hind sight I think I've maybe noticed a 'slight' vibration possibly around 16 knots.

However this vibration is definitely a lot louder when you throttle hard.

When you increase gradually seems no problem.

The boat should be lifted next Tuesday 22nd March so we shall see

 

[jfm]

Hi Jfm,

Well Ive had the boat from 350 hours. Engines are D12 715's.

In hind sight I think I've maybe noticed a 'slight' vibration possibly around 16 knots.

However this vibration is definitely a lot louder when you throttle hard.

When you increase gradually seems no problem.

The boat should be lifted next Tuesday 22nd March so we shall see

You've had the boat 600hrs then, and driven to/from Eire/Med. You must know it quite well. I'm not clear from your post whether the vibration issue has been there all the time you've had the boat, or whether it's a new (and sudden) development. You use deliv skippers a bit; could one of them have accidentally dinged a prop, as per Deleted User's post? That would cause a sudden change from a smooth boat to a vibratey boat.

All that said, your "vibration is definitely a lot louder when you throttle hard. When you increase gradually seems no problem" suggests it is not a prop, and is instead a gearbox or engine issue.

Could do with loads more precise description of all the symptoms though!

Good luck with fixing it anyway

 

[boatlover]

You've had the boat 600hrs then, and driven to/from Eire/Med. You must know it quite well. I'm not clear from your post whether the vibration issue has been there all the time you've had the boat, or whether it's a new (and sudden) development. You use deliv skippers a bit; could one of them have accidentally dinged a prop, as per Deleted User's post? That would cause a sudden change from a smooth boat to a vibratey boat.

All that said, your "vibration is definitely a lot louder when you throttle hard. When you increase gradually seems no problem" suggests it is not a prop, and is instead a gearbox or engine issue.

Could do with loads more precise description of all the symptoms though!

Good luck with fixing it anyway

Thanks J - Yeah we are due for a lift out next Tuesday so all (will hopefully) be revealed then.

Quite a few people are guessing cutlass bearings.

We had some lovely sunny weather today - was putting the Bimini up

 

[Neil_Y]

I would also look at the shaft bearings first, when you apply thrust the shaft tries to flex between bearings, too much movement or collapse of water film due to too large a clearance and the shaft will run around the bearing.

It can also be carrier alignment resulting in a slighhtly uneven water film thickness which will encourage collapse of the water film under thrust. You can check this with feeler guages around shaft at rest the shaft should sit in the bottom leaving teh same clearance at the top and sides at both ends of teh bearing. Without taking things apart this is as far as you can go really.

Max clearances should be available from the bearing manufacturer.

It can also sometimes be the engines! we had a boat with large MTU's dropping a cylinder caused by a faulty injector which gave vibration at the same revs every time, it was only when diagnostics were plugged in whilst running that the problem was identified.

Good luck

 

[chrisgil]

Interested to see this thread. I am looking at sqadron 58 with vibration from port engine. Cutlass bearing had play and was diagnosed as prop issue. Props balanced, engineers said cutlass bearing within tolerance so not changed. Boat back in water, vibration still there! I heard rumours of gearbox issues and glad to have found this thread. Did you resolve the issue and/or establish why port side is main vibration culprit. I was about to get shafts checked and hadn't really thought gearbox would be a problem on a 200 hour, 3 year old boat! Would be glad to see any comments.

 

[jfm]

Boatlover must have resolved it - he has 1400hrs on the boat now. I never had any issues with the 2x sq58s I owned, and this isn't a common problem on these boats. Good luck diagnosing and fixing it

 

[volvopaul]

Interested to see this thread. I am looking at sqadron 58 with vibration from port engine. Cutlass bearing had play and was diagnosed as prop issue. Props balanced, engineers said cutlass bearing within tolerance so not changed. Boat back in water, vibration still there! I heard rumours of gearbox issues and glad to have found this thread. Did you resolve the issue and/or establish why port side is main vibration culprit. I was about to get shafts checked and hadn't really thought gearbox would be a problem on a 200 hour, 3 year old boat! Would be glad to see any comments.

Hi, is this same sq58 at swanwick on with Essex boatyards? I had a call only yesterday from someone asking my advise on the same matter to a tee, eby had props done etc and put back in water trialled again to find its exactly the same.

I know some boats have had mounts changed and upgraded. Proper built boats from this builder should not have these kind of issues, in fact they should be pretty smooth on acceleration . Seemly previous posts on this thread.

 

[Latestarter1]

Hi, is this same sq58 at swanwick on with Essex boatyards? I had a call only yesterday from someone asking my advise on the same matter to a tee, eby had props done etc and put back in water trialled again to find its exactly the same.

I know some boats have had mounts changed and upgraded. Proper built boats from this builder should not have these kind of issues, in fact they should be pretty smooth on acceleration . Seemly previous posts on this thread.

Not sure what is going on here.........What is a Squadron 58 worth???

Screwing around with props, changing engine mountings, one legged men, ass kicking party all spring to mind. If this was a piece of industrial equipment there would be engineer on site in a trice with a Fluke 810 to sort the issue out!

This whole farce in an indictment of our marine industry.

Too much time spent looking at the problem rather than the cause.

 

[volvopaul]

Not sure what is going on here.........What is a Squadron 58 worth???

Screwing around with props, changing engine mountings, one legged men, ass kicking party all spring to mind. If this was a piece of industrial equipment there would be engineer on site in a trice with a Fluke 810 to sort the issue out!

This whole farce in an indictment of our marine industry.

Too much time spent looking at the problem rather than the cause.

Hi paul, I can't make any further comments about the swanwick boat other than while speaking to the buyer yesterday and hearing what he was telling me about the process and what was carried out I had my own thoughts over lunch after his call, I can't say any more other than I was asked if it was possible for me to accompany him on the sea trial tomorrow , which I may have time for. Ill see what experts turn up if I go, as he just received answers from there engineers like" they all do that it's a boat"

I know your amazed that dealers and builders treat people with 800k like that, but that's how it is! Pi55 poor I know.

 

[Latestarter1]

Hi paul, I can't make any further comments about the swanwick boat other than while speaking to the buyer yesterday and hearing what he was telling me about the process and what was carried out I had my own thoughts over lunch after his call, I can't say any more other than I was asked if it was possible for me to accompany him on the sea trial tomorrow , which I may have time for. Ill see what experts turn up if I go, as he just received answers from there engineers like" they all do that it's a boat"

I know your amazed that dealers and builders treat people with 800k like that, but that's how it is! Pi55 poor I know.

I used to charge £300 a day, builders do not charge much less. However it is a fact of life that people far more prepared to pay to simply change out tangeable items than a proper engineering exercise.

One vessel I was involved with had A brackets on the shafts........With four bladed propellers phasing with the brackets, mountings were replaced twice, transmission drive plates changed once, one engine was even swung. New three bladed propellers fixed the problem.

 

[volvopaul]

I used to charge £300 a day, builders do not charge much less. However it is a fact of life that people far more prepared to pay to simply change out tangeable items than a proper engineering exercise.

One vessel I was involved with had A brackets on the shafts........With four bladed propellers phasing with the brackets, mountings were replaced twice, transmission drive plates changed once, one engine was even swung. New three bladed propellers fixed the problem.

At 8 grand for the Luke 810 tester I can't imagine the nearest vp dealer of fairline having one in " the back of the van"

 

[sarabande]

serious question from a raggie...

Is it possible for cavitation to occur only at a very narrow rev band, and/or when under hi-torque loading ? Analogous to resonance when accelerating in a car.

 

[Latestarter1]

At 8 grand for the Luke 810 tester I can't imagine the nearest vp dealer of fairline having one in " the back of the van"

I have a Fluke, it is what comes with territory when you employ decent engineer.

Main dealer service tec's are not engineers.....................No point asking tec for report when it all goes horribly legal.

People always want to sort out problems on the back of a fag packet, certain you have people wanting to pick his brains for nowt!