Wiggo's Annual Odyssey, Day 4

Wiggo

Wiggo

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OK, so last night we limped back on one engine again and this morning the nice man from BD Marine came round (top marks for service, BTW). We can't figure this out. Disconnect the shaft from the coupling and run the engine in gear: no vibration. Bolt up the couipling and do the same and the engine has 2" of lateral shake, so that's clearly a bent shaft, no?

No. Disconnect the shaft from the coupling and turn it with a dial gauge on it and it runs true. Do the same with the flange and there's no more than 0.2mm of runout. Similar or less runout on the gearbox output flange. Slide the tailshaft onto the coupling and again, 0.2mm of runout at most. Bolt it up, and the runout increases to over 1mm. Run the engine in gear with the tailshaft unbolted (just prop thrust holding it to the coupling) and there's no vibration. Bolt it up, even just one of the four bolts, and three quarters of a ton of engine and gearbox tries to climb out of the engine bay it shakes so badly (and that's just at tickover).

So we're lost. The next thing is to lift out again, draw the sahft and get it on the lathe to check it is straight over its entire length, and do the same with the flange coupler. We seem to have a bend in the shaft, though no idea of how or why, and we can't measure it in the boat.

Ideas welcome...
 
Last edited:
You said...

"Bolt it up, even just one of the four bolts, and three quarters of a ton of engine and gearbox tries to climb out of the engine bay it shakes so badly"

Have you tried it with all the bolts torked up properly?

This is a mystery how could the shaft be bent that much and not show up on the gauge?

Does it do it in reverse??


Ian
 
It could be, but they were fine before the relaunch, and we're pretty sure we didn't hit anything. Either way, the prop is coming off and will be checked for balance. We can't work out how we got to Poole with no dramas after a 2 1/2 hour run, then it all went Pete just off the Swashway...
 
For that sort of vibration at tickover to be caused by the prop would need a couple of blades missing.

My guess would be an out-of-shape shaft further down the shaft. Not sure why, though.
 
It all sounds to familiar. Ok my insurance paid out cos the survey said, I could have hit something. That might well have been the case, but there was no sign.

I now think that I had broken engine mounts for a while, which caused the stern glands to leak. When we sunk, the engine bent the prop shaft, which took the stern gland out and broke the coupling.

The same seems to be happening to you, except slower, because you had vibration, so stopped the engine.

As I said before. I think you need to start again, take the engine out and inspect mounts properly. Maybe then you need to check coupling, stern gland and shaft. You need to bottom this in one go, else you will be going round in continuous circles.
 
Wiggo's Woes

Wiggo, I can feel the pain for you as I'm having a similar issue at the moment.My boat is an F43 with tamd63s and ZF 220a gearboxes.
It transpires the boat had an (striking underwater object) issue prior to my purchase. Both props and 1 rudder were renewed.

After using the boat for only a couple of hours, without warning I lost propulsion on the port side. I immediately shut down the engine and on lifting the boards discovered that the R&D coupling had come apart and the shaft was disconnected from the output flange on the gearbox. The shaft had managed to connect with the gearbox oil pump, shearing it off in the process. The adaptor flange was also distorted in the process.

I had purchased the boat with a warranty so the repair was down to the seller. Apart from the lift out fees which seemingly I have to pay, the repair would be taken care of. Anyway the boat was lifted and after a while (I won't bore you with the delay story) all the parts were replaced and the boat was lifted back in. It turned out we still had some vibration on the port side, but not as severe as what you have experienced. I was then told the shaft is bent and it would need to be taken out and sent for straightening. The boat was lifted out the other day and the shaft was due to be taken out today.

After reading about your problems I am now wondering if my engine mounts are ok.

Obviously you and I are getting an education with both of our problems but it begs the question of "how competent are the engineers?" why can't they explore all the options during the first inspection and then act accordingly. In my case it looks like the seller is trying to do the bare minimum, who knows..

Anyway, I sincerely hope you get sorted out, I'll let you know my luck when I've something to report.
 
So

Wiggo said:
Nope, doesn't seem to vibrate anywhere near as much astern. And with all four bolts done up, it's awful. We can't work it out at all...
Click to expand...

If the shaft is straight, the engine mounts ok the gearbox and coupling in line.....

Just a thought, the engine runs OK when not under load?

It vibrates more in forward than reverse?

Looking at it another way; Is the engine itself OK, I mean is the engine causing the vibration when you load it up, is it running OK do you think? Seems odd that is just started doing it again all by itself. Would a timing fault making it run like a dog make if vibrate?

As already said, engine mounts?

This must be a living hell,


Ian
 
Sorry to hear about your continued problems and hope you are back to full speed soon.

I hope it turns out to be something petty like a stone trapped in the cutlass bearing but I fear it is far more serious and it is time to advise your insurers of a possible underwater impact.
They will appoint a surveyor and have expertise to establish what is going on.

Have you noticed any ATF fluid in the bilges ?
Its a light red oil easily mistaken for marine diesel.
Reason I ask is pessimistic and long so dont bother to read the rest if you havent seen any ATF and this could be just another Pete troll anyway :rolleyes:.

One possible cause in that you hit debris, your flexible coupling got damaged , when your flexible coupling failed the shaft ripped your gearbox off its mounts.

The gear box casing could have been cracked as this happened.
You will not see the crack at rest in a dark engine bay.
Once under load the crack opens up, and the gearbox becomes out of alignment and causing your vibrations.

I have a spare ZF63 a 2.5 : 1 , I could meet you in Portsmouth next Saturday 1300 hrs
you can try it if your shafts turn out to be straight.

If it solves the issues then you get your charter completed the following week.

Changing a gearbox isnt quick, the floor has to come out and the engine supported with a beam, this isnt a quick fix solution Im afraid and there will be 3-4 hours labour involved (more if you dont take the floor out ready).
If there is ATF in the bilges ,I wouldnt go out and buy a new gearbox for two reasons

they cost £3000 !
You could easily wreck another (including mine) as you cant be certain what damaged the first one yet .
 
The engine runs sweetly with the shaft uncoupled, and is vibration free ahead or astern. The P brackets are secure, as well.

The boat's being lifted a week today and the shaft pulled and checked for straightness. They will examin the engine mounts, and replace all of them if there is any suspicion about them. More next week...
 
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