Engine/ shaft alignement

[miket]

I just ruined a super trip through ignorance, and I have owned boats for some time, usually older ones.

Bought a ten year old cruiser by well respected builder with large engines, designed to cruise at 20/25 knots.

One careful owner from new, including service invoices.

When I have bought my previous boats (6 of them) I always get them checked by my friend/ engineer, but this time I didn't.

Cruised 1st day at 20+ knots, sun shining, sea calm and scotch winking gold. All was well with the world.
Arrived 3 hours later and went straight to the fuel pontoon. Manoeuvering on to pontoon..... no drive on port engine.

Tie up, and go to inspect reason. Flexible coupling bolts all sheared bar one that has ripped out a section of coupling, in the process bending itself at 90 degrees. Also notice that oil is flowing from back of gearbox. Reverse gear oil filter housing casting has broken. Later, when trying to join all together with a new coupling, discover top of shaft is bent.

2 possible causes:
Hit something.
Engine mounts sagged and alignment not checked.

1 is tough luck.
2 is avoidable. So periodically check your alignment!

 

[Deleted User YDKXO]

Not Volvo engines by any chance, Mike? Same thing happened to me in the middle of the Channel with a Princess 435 at 20kts. Suddenly lost drive from the s/b engine; on investigation I found all the bolts on the flex drive had sheared due to all four engine mounting bolts having failed allowing the engine to move backwards about 6". The real scary thing was that, when I inspected the port engine, 3 of the 4 bolts had sheared also and the engine was located only by 1 bolt. Needless to say, we limped back to the Solent extremely gingerly on the port engine.
I was told later that Volvo fitted very small diameter mounting bolts at the time and any corrosion weakened them considerably. The replacement mounting bolts for my engines were about twice the diameter so I guess I was'nt the only one who experienced this.
So the moral of the story is to check 'yer bolts

 

[miket]

TAMD61A's.

Engine mounts seem OK, as we had to loosen them all to move engine left a bit. Up and down adjustment OK also. Just seems the mounts had dropped a little.

Will check regularly!!

 

[byron]

Blimey MikeT, I had heard you had a problem but what you describe is scary. Modesty prevented you from telling all that you are VERY experienced. What do you think? Hit an object or the other? As regards the response from the other Mike. That just doubles my scare.

©2001

 

[miket]

Won't know until she's lifted, but if the undercarriage is bent downstairs, it can't be very bad.

Moral is to check this area very thoroughly, both when buying used and periodically during ownership.

Full marks to Broom's who got a new coupling to me in 24 hours. Also full marks to Nieupoort, marina staff and engineer.