In reply to IPPurewater:
> I'd check the nuts on wire too. I'd push the wire back up through the nut and check there isn't any hidden corrosion of the wire.
> I'm still using friends I have rethreaded with nylon tape. You can knot Dyneema with a triple fishermans knot. Make sure you leave an inch or so sticking out of the knot, each side after tightening it, if you do that.
> A friend of mine has drilled out the holes in his larger hexes to take slightly wider cord - 8mm I think.
Triple fisherman's will slip easily under load in Dyneema (at around 25-35% of line strength, or somewhere between 11 - 15kN). This means it could be the weakest link of the newly slung nut (a big modern nut is rated to 14kN, which means it's failure point is a fair bit higher than 14kN). So perhaps by reslinging with dyneema, you're reducing the strength of a big nut to that of a small nut. I have done some research into alternative knots for dyneema and found a few new knots that could work almost as good as a sewn joint (they break in dyneema rather than slipping), but more testing is needed before relying on them.
Better to stick a material with more predictable properties than dyneema.