my main thoughts are that it wasn't tightened really properly initially.
the torque value on that nut is way up there..
360 ft lbs, plus turn to the next cotter pin slot.

that nut squeases the two bearing races and the spacer against the
flange on the inner end of the stub axle.
It's hard to imagine that stub axle cracking ..or the inner races or the
spacer crumbling ...
I probably would take that whole thing apart and examine everything very
carefully. Like with a microscope.

I would make sure the nut threads and stub axle threads are in very good
shape too.
it's not  something that should happen at all, ever.
But if it ran loose ..
then things can wear.  It's the kind of thing where there should be no
relative movement at all..
those parts ...nut, stub axle, spacer, and inner parts of the two
bearings should be seriously bolted into one solid lump of metal, and no
parts ever move relative to each other the tiniest bit.

   if there's any looseness..and it runs that way ..it will likely cause
wear.
I can just seea few things pounded out from running with relative
movementbetween the parts.

  if 'total absolute safety' is the requirement..
I'd probably retire all those parts including the bearing housing even.
  or get the stub axle magnafuxed or x-rayed.., check the fit of the
bearings in the housing,
and put in new good german bearings.

I'd likely  just retire those parts ..
like it was a helicopter 'jesus nut' holding the main rotor on ..
  - after 10,000 flight hours you just retirethose parts, period.

scott
www.turbovans.com

On 11/13/2012 8:03 PM, John Goubeaux wrote:
> Howdy Folks,
>
> 90 2WD
>
> Has anyone seen a situation where a rear axle nut ( with cotter pin in
> place ) becomes loose ?  I had to tighten it down about a year ago after
> hearing what sounded like dragging  squeaking brake sounds from that
> side of the car. It appears to be loose again as I am hearing the same
> sounds when driving, so I am wondering if this is due to worn bearings ?
> Obviously the nut is not turning but what else could explain this ? The
> wheel , with car raised turns fine with no binding or what I would
> assume would be a shot bearing , I pulled the drum and the brakes are in
> order and not causing the noise nor is there a lot of play in the wheel
> when grabbing and rocking it so I am puzzled.
>
> Any ideas on this are appreciated.
>
> -john
>