U-joint diagnosis?

["T. S. White" <tswrace@pacbell.net>]

I have the drive shaft out of my TR3A and one of the bearing caps fell 
off.  The bearing surface of the shaft is "cloudy" in appearance.  I 
would expect it to be shiny.  Is this an indication that the u-joints 
should be changed?  Normally I change u-joints when they begin to clank 
in reverse.
-- 
        Best Regards,
        Tom