hi,
if it was still very tight , perhaps it was just metal failure of the
pulley parts.
Foreign object comes to mind as a possibility.
Also ..how was the belt itself ?
and was there squealing happening much  ?

they are usually put on with an impact gun.
Guessing wildly I'd say 56 ft lbs.

if you want to take another alternator apart to get the rotating center
part out of it  to put in yours ..you 'could' do that without extreme
difficulty I'd think.

I have seen a lot of them with loose bearings, or worn housing where the
bearing sits.

scott
www.turbovans.com

>
> I did not use a torque wrench here but I had a breaker bar with an allen
> socket on the shaft and a large full length wrench on the nut, and applied
> "a lot" of torque.  Is the spec for this nut crazy large?  When I
> disassembled, everything was still fully tight, and the split washer was
> still completely and evenly compressed.
>
> Can the shaft on the alternator be swapped out easily?
>
>
>