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Post by Deleted on Oct 18, 2020 16:24:24 GMT
Black magic. Actually I downloaded it from your dropbox post you now appear to have deleted. I'm all discombobulated now.... Anyway does it help? The sheared bolt is on the right hand side. I suppose a reasonable question would be "why did this bolt end up being sheared off? ETA it is actually a stud not a bolt but for the purpose of the above post it's ok to not worry too much about the difference. Point being it sheared off apparently. Not normal behaviour for one of these.
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Post by Telemachus on Oct 18, 2020 16:34:46 GMT
Yes surely you can deal with the pesky stud without having to remove the front plate completely. And to be honest, if you give it a good greasing I doubt the packing would be pushed out even if the plate was removed. You can try it anyway, before committing. Inadvisable to do 1/2 a job and then disappear for lunch etc, just in case... Well I only had the gland repacked last year so that should be ok. We were out last month on the Nene/Ouse and remember hitting something under water. I was doing a standard service yesterday and noticed that the right hand bolt had sheared off. In other words I wasnt tightening it. I spoke with RCR yesterday but the lady said bolts aren't covered due to wear and tear but I am going to try and speak to someone else tomorrow as in my mind, though it might be wishful thinking, I think it is covered as damage and I can't really have the engine turning as it may damage the shaft. Can’t really see from the photo but presumably the stud has sheared off flush with the hole? Or is there any stub protruding that you might be able to get mole grips etc onto. The stud probably isn’t particularly tight. As to getting onto it with a drill, yes that will be tight. You can get right-angle battery drills but by the time you’ve bought one it might be better to get a boatyard to do the job. Oh and you can also get left-hand drill bits, they can be quite good for gripping the stud and winding it out. Failing that a proper stud extractor.
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Post by jubjub on Oct 18, 2020 16:51:16 GMT
I'm all discombobulated now.... Anyway does it help? The sheared bolt is on the right hand side. I suppose a reasonable question would be "why did this bolt end up being sheared off? ETA it is actually a stud not a bolt but for the purpose of the above post it's ok to not worry too much about the difference. Point being it sheared off apparently. Not normal behaviour for one of these. I stand corrected it is a stud (brass replacement with two nuts £1.50 each Midland Chandler's) As I mentioned earlier we hit something, not sure what, but it was more than your usual log or whatever. I can only summise that it jolted the boat enough to affect the stern gland. I will take some close up photos tomorrow but the stuffing box is the same as this one from MC. It has 4 bolts so I don't think it is welded www.midlandchandlers.co.uk/products/stern-1-1-2-stuffing-box-complete-sg-048Unfortunately the stud is flush so I can't get any grips on it either. Thanks for all the help, advice, comments so far!!!
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Post by Deleted on Oct 18, 2020 17:41:43 GMT
I suppose a reasonable question would be "why did this bolt end up being sheared off? ETA it is actually a stud not a bolt but for the purpose of the above post it's ok to not worry too much about the difference. Point being it sheared off apparently. Not normal behaviour for one of these. I stand corrected it is a stud (brass replacement with two nuts £1.50 each Midland Chandler's) As I mentioned earlier we hit something, not sure what, but it was more than your usual log or whatever. I can only summise that it jolted the boat enough to affect the stern gland. I will take some close up photos tomorrow but the stuffing box is the same as this one from MC. It has 4 bolts so I don't think it is welded www.midlandchandlers.co.uk/products/stern-1-1-2-stuffing-box-complete-sg-048Unfortunately the stud is flush so I can't get any grips on it either. Thanks for all the help, advice, comments so far!!! Sorry for not reading it all. I would suggest that if you hit something with the prop hard enough to break one of the studs on the stuffing box (!) Then maybe it's worth getting boat out and seeing if there is any other damage. It seems to be a slightly improbable result of hitting something. Just wondering if at some time previously the nut may have been wound down too much and reached the (I'm not a materials scientist) limit thus weakening the stud. Too much twisting. As chubby checker would say. Yield point. That sort of thing.
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Post by TonyDunkley on Oct 18, 2020 19:11:15 GMT
I suppose a reasonable question would be "why did this bolt end up being sheared off? ETA it is actually a stud not a bolt but for the purpose of the above post it's ok to not worry too much about the difference. Point being it sheared off apparently. Not normal behaviour for one of these. I will take some close up photos tomorrow but the stuffing box is the same as this one from MC. It has 4 bolts so I don't think it is weldedwww.midlandchandlers.co.uk/products/stern-1-1-2-stuffing-box-complete-sg-048The stuffing box won't be welded in place, . . it's the internally threaded steel boss that the outer end of the threaded (at both ends) sterntube screws into that you need to check is welded where it passes through the hull plating. An alternative type of fitment has a bolted in flanged boss instead of being welded in place. It certainly appears in the photo to be a welded in job - there is what looks like some lumps of 'birdshit' welding just where the hull plating touches the steel boss - but before disturbing anything, it's best to be absolutely sure it's not lumps of sealant that's squeezed out, . . which would indicate that a bolt-on tube/outer bearing boss had been used by whoever installed the sterngear.
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Post by Deleted on Oct 18, 2020 19:24:17 GMT
there is what looks like some lumps of 'birdshit' welding just where the hull plating touches the steel boss - . While this may be a valid observation it does not seem to me to be relevant to the question. It is a welded-in stern tube boss. The quality of the welding for this item is not part of the discussion. What is part of the discussion is the port side (right hand in the picture) stud which for some reason has sheared off. I'm not convinced it is a brass stud although the OP did say it was brass I suspect it may be a steel stud with a brass nut. I'm just interested in how this stud ended up sheared off. Something wrong. Or as naughtyfox would put it Sum ting Wong. Dis ting bwokken Why? A little birdie tells me it was wound down too tight and busted. Normally this bit don't get moved by prop fouling. No packing? We not do summit if you have no packing.
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Post by naughtyfox on Oct 18, 2020 19:41:41 GMT
there is what looks like some lumps of 'birdshit' welding just where the hull plating touches the steel boss - . Or as naughtyfox would put it It would be interesting to know how it broke, and to have better photos of it close up. One suggestion from me would be to remove the moveable plate, cut the old stud clean off and weld a new stud on. As long as it matches up with the hole in the moveable plate, all is OK. It's not like there's much pressure in that area, all the moveable plate does is squeeze the (fibre) rings in a bit. Squish, squish, and a bit of tightening up when you feel like it. I'm sure our resident mechanic Gazza will be pleased to hear I know our nuts down there are 17mm. I don't know why I retain this information in my head with all the bus timetables. Might save a few seconds one day. Here's a pic I found from t'Net:
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Post by naughtyfox on Oct 18, 2020 19:47:49 GMT
Another photo of one of them:
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Post by TonyDunkley on Oct 18, 2020 20:13:52 GMT
there is what looks like some lumps of 'birdshit' welding just where the hull plating touches the steel boss - . While this may be a valid observation it does not seem to me to be relevant to the question. It is a welded-in stern tube boss. The quality of the welding for this item is not part of the discussion. What is part of the discussion is the port side (right hand in the picture) stud which for some reason has sheared off. I'm not convinced it is a brass stud although the OP did say it was brass I suspect it may be a steel stud with a brass nut. I'm just interested in how this stud ended up sheared off. Why? A little birdie tells me it was wound down too tight and busted. Normally this bit don't get moved by prop fouling. No packing? We not do summit if you have no packing. I haven't said that the quality of any welding is anything to do with the basic problem of the sheared stud. What I want Jubjub to check is that those lumpy blobs really are weld, and not lumps of sealant that's squeezed out whilst a bolt-on tube/outer bearing boss was being installed. If the sterntube boss is a bolt-on job, it's probable or at least possible that the bang that bust the packing follower stud might have also weakened or broken any bolts or setscrews in a bolt-on sterntube boss, . . which would make it into a slip or dock job ! If whatever the prop hit was sufficiently solid or heavy enough to put a high enough radial shock loading on that very short, and therefore very stiff, tailshaft, the shaft could well have managed enough momentary lateral displacement within the range of movement of the resilient gearbox output coupling with enough force to shear the follower stud, . . especially if the stud had already been weakened by overtightening, or if the follower was sitting cock-eyed in the stuffing box bore due to the follower nuts being tightened unevenly.
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Post by Deleted on Oct 18, 2020 20:22:56 GMT
Fair enough.
either that or it is a welded in stern tube boss.
The problem here is that someone at some point had excessive leakage and thought that the solution was to tighten up the nut until the leakage stopped. Which it didn't. I'm sure I can see some deformation.
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Post by TonyDunkley on Oct 18, 2020 20:31:11 GMT
Fair enough. It is a welded in stern tube boss. Yes, I think so too, . . but I'm not going tell Jubjub to go ahead and sort this out with the boat still in the water if there's even the remotest possibility of it having a bolt-on sterntube boss which may well now be held in place by damaged or weakened bolts.
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Post by Deleted on Oct 18, 2020 20:33:21 GMT
I did edit my previous post to take account of it But I still think it's someone who had wound the nut down too tight when the packing was nackered.
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Post by jubjub on Nov 2, 2020 10:29:20 GMT
UPDATE. Sorry about delay in responding. Covid struck my family Sister in hospital and unfortunately her husband who also had Covid died of a massive brain haemorrhage whilst being treated.
Anyway solved the problem with a tiny left handed drill bit and one of those 'get out' screw bits. Rebolted loosely. Running fine no major leaks just a couple of drips every now and then.Will test it more when we can go back and take her out. Thanks for all the help and advice.
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Post by JohnV on Nov 2, 2020 12:55:25 GMT
I was always told if there wasn't an occasional drip while underway ..... it was too tight
I'm sorry to hear of your familly troubles ..... these are not good times
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Post by jubjub on Nov 2, 2020 13:10:20 GMT
I was always told if there wasn't an occasional drip while underway ..... it was too tight
I'm sorry to hear of your familly troubles ..... these are not good times
Thanks
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