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