SC430 Loose Power Steering Pulley

[Olderthanus]

My 4 month old to me SC430 lost power steering suddenly, with a clatter- but I limped 1 mile home.   

Turns out the nut on the power steering pulley was loose and it was spinning.   Tightened it back to 33 FP, and all is back to normal.

Is this a common occurrence?  There doesn't seem to be much other than the nut on the Power Steering pulley pump.  Or, should I just chalk it up to carelessness by the technician who replaced the timing belt 80 it so miles ago and quit worrying?

Thanks in advance. 

[RX400h]

I would say that it is the latter. An improperly torqued nut can certainly loosen over time.

[Olderthanus]

To close this loop, it wasn't just loose- but needed a new pulley- it had enough wobble that it wouldn't stay torqued- especially with AC on.  Made it only 29 miles before a repeat.  Don't know if the first "incident" was enough to add wear to the softer metal pulley- but a new one and new nut (and thread-locker was needed.)