Just found a shredded bolt in my engine bay.

Rhylsailer99

Rhylsailer99

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Engine is a Bukh dv20 and the bolt was sat right next to the back right sided engine mount.
Will have to wait for the water to go as the boat is rolling so much :( in the east winds.
Must have sheared someehere as it has red paint on it.
 
Well I’m glad you found it before it got any worse. Is the remaining bit of bolt in the actual engine block?
 
Yes, I will have s look later when my boat sits on the mud. It is really rough at the moment.
I am guessing there is some left protruding out of the engine once I remove the bracket.
 
Rhylsailer99 said:
Yes, I will have s look later when my boat sits on the mud. It is really rough at the moment.
I am guessing there is some left protruding out of the engine once I remove the bracket.
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Glad I noticed it.I guess it would have been really bad if the other one snapped whilst motoring.
 
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The rear mounts are on the gearbox front casting so it's not such a difficult job to get some wedges under the engine, dismount the gearbox and take it ashore for treatment in the workshop. The mounts are also made of thick metal - maybe 10 mm - so with a bit of luck there will be a bit of stud poking out. There are two bolts for each mount- is the other one OK?
 
Not a perfect photo for diagnosis purposes but it looks very much like a fatigue fracture. The cause is looseness. A good reminder that it is worth checking bolt tightness from time to time.

Hope you can sort it without too much trouble.
 
neil_s said:
The rear mounts are on the gearbox front casting so it's not such a difficult job to get some wedges under the engine, dismount the gearbox and take it ashore for treatment in the workshop. The mounts are also made of thick metal - maybe 10 mm - so with a bit of luck there will be a bit of stud poking out. There are two bolts for each mount- is the other one OK?
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Yss the other one is ok. Is it ok to remove the bracket i.e. will the engne be ok supported by 3 mounts for a short time. There is access at the side through a locker that I can get inside.
 
I just put a socket on the one remaining bolt to find it moved with little effort. I would have expected them to be threadlocked in place.
vyv_cox said:
Not a perfect photo for diagnosis purposes but it looks very much like a fatigue fracture. The cause is looseness. A good reminder that it is worth checking bolt tightness from time to time.

Hope you can sort it without too much trouble
Click to expand...
 
neil_s said:
The rear mounts are on the gearbox front casting so it's not such a difficult job to get some wedges under the engine, dismount the gearbox and take it ashore for treatment in the workshop. The mounts are also made of thick metal - maybe 10 mm - so with a bit of luck there will be a bit of stud poking out. There are two bolts for each mount- is the other one OK?
Click to expand...
If you can take the gearbox home to fix - then you are a very lucky chap indeed. Best get a line for the lottery!
 
vyv_cox said:
Not a perfect photo for diagnosis purposes but it looks very much like a fatigue fracture. The cause is looseness. A good reminder that it is worth checking bolt tightness from time to time.

Hope you can sort it without too much trouble.
Click to expand...
 

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Minerva said:
If you can take the gearbox home to fix - then you are a very lucky chap indeed. Best get a line for the lottery!
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I think its going to be a left hand drill bit centre punch and some irwin screw extractors from Amazon. Then a lot of praying and crossing fingers.
 
1000011895.jpgI managed to get the snapped off part out with mole grips, but I could not turn the big bolt on the engine mount. I decieded to remove the mount and bracket by removing the 2bolts and they crumbled. Looks like I need to replace the mounts and get new coach screws. Not sure what is underneath the fiberglass engine bearers.
 
Rhylsailer99 said:
View attachment 206143I managed to get the snapped off part out with mole grips, but I could not turn the big bolt on the engine mount. I decieded to remove the mount and bracket by removing the 2bolts and they crumbled. Looks like I need to replace the mounts and get new coach screws. Not sure what is underneath the fiberglass engine bearers.
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I don't want to add to your concerns, but looking at your last photo, it really wouldn't surprise me if the earth continuity cable, going to the shaft seal was rotten, and 'about to' break, as well as (possibly) already having no continuity through being corroded. Perhaps worth a 'pull check'?
 
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