Rear hub nut backing off...

[Pupp]

Discovered rear o/s axle nut loose today while investigating a bearing noise... Correct stub on correct side, with right hand thread so should self tighten, so bit mystified. Retorqued and all feels OK but would like to know reason for it backing off. Ideas?

[spend]

Re-used Nyloc (past it's life expectancy)... Bearing collapsed/worn... Some prat cross threaded ~ gorilla'd ~ wrecked thread... (run a screw pitch gauge round to check) ???

[carsy]

Like you say. Left hand thread on near side and normal right hand thread on off side. It is supposed to stop exactly what has happened to you but for the life of me i cant see how it works in practice. Everytime i look at it and think it through to me they should be the other way round like a viscous fan coupling. Anyway i'l stop thinking about it as it makes my head hurt and just go with what Ford say.

If the nut has come loose pup i would renew with a new one.