sharing an experience

[darrsi]

[quote author=fazersharp link=topic=26267.msg316548#msg316548 date=1592550142]
Also a replacement new crush washer maybe will help ?

It just might  that said, he's saying the threads are stripped and there is load on the washer 40 odd Nm

No need really, it's only a bolt plugging a hole, there's no stress or load on it at all.
That's why i was saying it only needs nipping up.

No mate, the threads don't seal the washer does and there is load on it, by definition it's a washer, washer's spread load in this case 40 odd Nm forming the seal.  Also there're 2 types of sump bolt/plug washer you'll find, 1 is the crush type i.e. it requires an amount of crush (40 odd Nm) for it to from a mating/sealing surface and should be used only once, 2 flat type, which is soft steel, copper or aluminium, some older bikes had fibre, the flat type hardens in use, can be reused but should be anneled, but there's a limit.  Fibre is not used these days, especially where different metals are used ally sump, steel bolt or vice versa as the expand and contract at different rates, then leak.  Old Brit bikes and cars! 

Both crush/flat types will leak if over tighten i.e. nipping up, yes once may be, but if it's leaking at the correct torque the washer had it and/or the sump mating surface is damaged.  Reuse of the washer and nipping up is what causes this chaps problem in the fist place i.e. washer gets distorted, leaks, nip up, mating surfaces get damaged it leaks, nip it up threads stretch, less torque on the washer it leaks, nip it up threads strip :rolleyes

 
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Gonna have to agree to disagree with you there Gnasher. Nipping up works just fine on this particular bolt, as long as you're not heavy handed, which i'm not due to working with sensitive screws on film cameras at work.
It's blindingly obvious that the main cause of stripping the thread on the sump is caused by over tightening it, mostly because you can't get a socket on it (or normal torque wrench), and it's in a slightly awkward place which results in people wrenching hard on a ring spanner or even giving it a tap with a hammer too, which after a few times will take its toll on the sump thread and the hex head as well if not careful.


There's not too much science behind all this, it's just a hole in a bowl with a bolt in it stopping the oil from coming out.


I will agree that a crush washer in this particular case would not be a greatest idea at all due to the slightly extra force needed to crush it which would stress out dodgy threads even more.
Personally i would only ever use the flat washer type due to the mentioned sealing properties.


I'm guessing there is some sort of different version of a torque wrench that fits onto this bolt allowing things to be torqued properly but as you can imagine i would reckon that 99% or more of people won't have this gadget available in their tool box.


Maybe your version of nipping up is being heavy handed, but my version is not.