If they're not making noise does it really matter how old they are?
>  Really?  A visual would be best but don't you think that it they were bad
> or getting bad, that you'd hear it sooner or later?  Reason I ask is I have
> a spare set (new) and wondering why I keep them.  Not like preemptively
> replacing hoses or a fuel pump after twenty years or fuel injector hoses
> after 10 years just to be safe.  I'm thinking they're either good and they
> haven't gone bad (won't likely for a while) or they're bad now and you'd
> know for sure.  Along the same audible hint you get when a CV is bad.
>
>  Thoughts?
>
> Thanks,
>
> TJ

No it dose not mater, don't change it if ain't broke.
You would know if they were are bad because they would wine.
You should clean / grease them once in a while.
This is on the 30,000 mile maintenance schedule and they could last
nearly forever if you do it.

Pull the rotor off.
The inner bearing is retained by the grease seal that has to be
removed to get bearing out.
The outer about falls out.
Clean and pack
Use new seal on inner bearing
Look here for entire procedure
http://volksweb.relitech.com/frntbrg.htm
Sell the ones you have and go out to dinner with a friend :-)