Help!!! Striped Thread On The Crankcase

Discussion in 'Technical Help' started by Simone17, Apr 10, 2023.

  1. Hello everyone!
    Something really bad happened. Months ago, while I was driving, the engine practically opened up with oil leakage, and I almost crashed. It's a Multistrada 2014, with about 35k km.

    After months of emails, the mechanic opened up the engine and found that the threads on the crankcase were damaged.
    The bike is basically ready for the trash bin because the estimate they gave me to fix it is more than buying a new one, unless I can prove that the previous work that the shop did is the cause of the damage they opened it up to replace the valves).

    The question here is not "Can I fix it" or "How can I fix it".
    Rather, "What could have caused this damage?"

    Is it realistic for me to claim that the previous work done by the shop caused it?
    I should add that the mechanics who did the work made one mistake after another for months, and they were both fired.

    Thanks in advance for your help!

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  2. This is really one for @nelly. Good luck!
     
  3. Very well, waiting for Nelly... :cool:
     
  4. That appears to be a barrel stud that has stripped the casing at the base.
    I would guess that that would not happen under normal usage and is likely due to overtightening the stud.
    If the shop removed the heads to “replace the valves” then it may have occurred at that time.
     
  5. Thank you very much for your answer.
     
  6. Might be a bit close to the edge for helicoil, wonder if a time sert would work?
     
  7. I
    I am not going to repair it. I just want to understand how this happened :bucktooth:
     
  8. Doubt there's enough meat left for any insert.

    Possibly grind away, fill with weld, re-drill and tap but it's a bit specialised and will require the cases spilt
     
  9. I believe that the OP just wants to know how it may have happened, not how to repair it.
     
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  10. Ah fair enough. Probably used a crowfoot spanner incorrectly on a torque wrench then.....
     
  11. not for O.P. then, but just out of interest, that crankcase pic does look as though there's a chance that an insert is in place already looking at the periphery break line and csk preparation. I had a hunt to try and confirm original arrangement but without luck.
     
  12. As mentioned, that hole is very close to the edge of the casting and if it does require welding and retappng or a helicoil insert, it's likely going to involve splitting the cases. I'm sure once Nelly sees the images he can advise but you could save yourself some money by removing the engine and all the ancilliaries yourself and take the engine to whoever ends up repairing it. It's not that daunting a job in reality and you seem adept at stripping things down, so as long as the quote is not beyond economical sense, I'd say it's worthwhile.
     
  13. One other thing, you said that they originally opened up the engine to replace the valves. Since this should not normally require the studs to be removed, I am assuming when they took the head off, the offending stud came loose as they removed the nuts and they subsequently overtorqued the stud when retightening it and stripped the threads or they overtorqued the head after they replaced the valves and thus damaged the threads on that stud. Hard to say which of the two caused the damage but the net result is the same. Even harder to prove unless you can ascertain if they were negligent.
     
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  14. It's almost impossible to say what caused it tbh. It's been apart twice now from what has been said. There doesn't look to be any pick up or damage on the thread of the stud. Maybe that's not the original stud???
    Only other thing that stood out is that in picture 4, the oil feed dowel looks to have the wrong o-ring fitted? That could have been the cause the oil leak?
    I doubt there's enough material to repair looking at it. Helicoil wouldn't be any good, but a Threadsert might. You'd need to get an opinion from a machine shop, but it'd be a tough repair.
     
  15. T
    hank you for your answer. I am posting in all forums I could find to hear as much feedback as possible. So far, it seems that there is no other way than a mistake from their side. Thank you very much.
     
  16. Thank you for your answer.
    So far most people I asked they agree that only their mistake could have caused this mistake. To be honest, other Ducati staff are certain that there is no other explanation than them making a mistake. But they claim it was overheating.
     
  17. Simone17

    I did something similar, although you don't seem to have much material to play with.
    May be this could give you some ideas.

    I have the bike running now and all seems OK, but need to see if it's OK long term, although I think the bigger diameter should be stronger than original size as long as ther is enough metal to hold it. I would say have a go, what you got to lose.

    https://www.ducatiforum.co.uk/threads/thread-inserts.30429/

    Cheers Gaz
     
  18. Fair enough, tightened by a Gorilla on bonus then...
     
    • Agree Agree x 1
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